ALBERT

Notes: Matlab scripts that apply the Bence & Albee (1968) matrix correction algorithm to X-ray intensity data collected as element maps on a Cameca SX-50 microprobe are used to produce two-dimensional maps of oxide weight percent and cation proportions for SiO2, Al2O3, FeO, MnO, MgO, CaO, Na2O and K2O. Once generated, large data sets of mapped oxide weight percent values or cation numbers that retain spatial information can be used petrologically. The technique is used to evaluate the compositional range of barroisitic amphibole in an eclogite from New Caledonia, to examine aspects of equilibration during the partial hydration of the eclogite facies mineral assemblage.

Notes: The exceptional andalusite–kyanite–andalusite sequence occurs in Al-rich graphitic slates in a narrow pelite belt on the hangingwall of a ductile normal fault in NW Variscan Iberia. Early chiastolite is replaced by Ky–Ms–Pg aggregates, which are overgrown by pleochroic andalusite near granites intruded along the fault. Slates plot in AKFM above the chloritoid-chlorite tie-line. Their P–T grids are modelled with Thermocalc v2.7 and the 1998 databases in the NaKFMASH and KFMASH systems. The univariant reaction Ctd + And/Ky = St + Chl + Qtz + H2O ends at progressively lower pressure as F/FM increases and A/AFM decreases, shrinking the assemblage Cld–Ky–Chl, and opening a chlorite-free Cld–Ky trivariant field on the low temperature reaction side. This modelling matches the observed absence of chlorite in high F/FM rocks, which is restricted to low pressure in the andalusite stability field.The P–T path deduced from modelling shows a first prograde event in the andalusite field followed by retrogression into the kyanite field, most likely coupled with a slight pressure increase. The final prograde evolution into the andalusite field can be explained by two different prograde paths. Granite intrusion caused the first prograde part of the path with andalusite growth. The subsequent thermal relaxation, together with aH2O decrease, generated the retrograde andalusite–kyanite transformation, plus chlorite consumption and chloritoid growth. This transformation could have been related to folding in the beginning, and aided later by downthrowing due to normal faulting. Heat supplied by syntectonic granite intrusion explains the isobaric part of the path in the late stages of evolution, causing the prograde andalusite growth after the assemblage St–Ky–Chl. Near postectonic granites, a prograde path with pressure decrease originated the assemblage St–And–Chl.

Notes: Sm–Nd garnet-whole rock geochronology, phase equilibria, and thermobarometry results from Garnet Ledge, south-eastern Alaska, provide the first precisely constrained P–T–t path for garnet zone contact metamorphism. Garnet cores from two crystals and associated whole rocks yield a four point isochron age for initial garnet growth of 89.9 ± 3.6 Ma. Garnet rims and matrix minerals from the same samples yield a five point isochron age for final garnet growth of 89 ± 1 Ma. Six size fractions of zircon from the adjacent pluton yield a concordant U–Pb age of 91.6 ± 0.5 Ma. The garnet core and rim, and zircon ages are compatible with single-stage garnet growth during and/or after pluton emplacement. All garnet core–whole rock and garnet rim-matrix data from the two samples constrain garnet growth duration to ≤5.5 my. A garnet mid-point and the associated matrix from one of the two garnet crystals yield an age of 90.0 ± 1.0 Ma. This mid-point result is logically younger than the 90.7 ± 5.6 Ma core–whole rock age and older than the 88.4 ± 2.5 Ma rim-matrix age for this sample. A MnNaCaKFMASH phase diagram (P–T pseudosection) and the garnet core composition are used to predict that cores of garnet crystals grew at 610 ± 20 °C and 5 ± 1 kbar. This exceeds the temperature of the garnet-in reaction by c. 50 °C and is compatible with overstepping of the garnet growth reaction during contact metamorphism. Intersection of three reactions involving garnet-biotite-sillimanite-plagioclase-quartz calculated by THERMOCALC in average P–T mode, and exchange thermobarometry were used to estimate peak metamorphic conditions of 678 ± 58 °C at 6.1 ± 0.9 kbar and 685 ± 50 °C at 6.3 ± 1 kbar, respectively. Integration of pressure, temperature, and age estimates yields a pressure-temperature-time path compatible with near isobaric garnet growth over an interval of c. 70 °C and c. 2.3 my.

Notes: Metapelites and intercalated metapegmatites of the Saualpe crystalline basement, which forms part of the Austroalpine nappe complex in the Eastern Alps, display a polyphase tectonometamorphic history. Here, we focus on the evolution that these rocks underwent prior to Cretaceous (eo-Alpine) high-pressure metamorphism and related penetrative deformation. Geothermobarometry on coarse-grained porphyroclastic parageneses (garnet–biotite–muscovite–plagioclase–sillimanite–quartz), which occur as relics in kyanite–garnet, two-mica gneiss, yielded 600 °C/0.4 GPa. Results from a corundum-bearing lithology suggest that higher temperatures may have been reached in very restricted areas. The matrix of these rocks displays intense recrystallization during a pressure-dominated metamorphic overprint. Microstructures and mineral chemistry indicate that this low-pressure metamorphism was the first significant metamorphic imprint in these rocks. Mineral relics in all metapelitic rock types reflect low-pressure conditions for this interkinematic crystallization phase.The distribution, macroscopic and microscopic observations and the mineralogical composition of intercalated metapegmatites point to regionally elevated temperature conditions during their emplacement. Therefore, pegmatite formation is correlated with mineral formation in metapelites. Sm–Nd-dating of magmatic garnet from the pegmatite gneiss yielded 249 ± 3 Ma, which is interpreted to represent the age of pegmatite-emplacement and low-pressure metamorphism in the metapelites. Since the pegmatites are overprinted by mylonitisation and high-pressure metamorphism, this Permo–Triassic age also sets an upper age-limit to the eclogite facies metamorphic event, which affected considerable parts of the Saualpe crystalline basement.

Notes: A sequence of psammitic and pelitic metasedimentary rocks from the Mopunga Range region of the Arunta Inlier, central Australia, preserves evidence for unusually low pressure (c. 3 kbar), regional-scale, upper amphibolite and granulite facies metamorphism and partial melting. Upper amphibolite facies metapelites of the Cackleberry Metamorphics are characterised by cordierite-andalusite-K-feldspar assemblages and cordierite-bearing leucosomes with biotite-andalusite selvages, reflecting P–T conditions of c. 3 kbar and c. 650–680 °C. Late development of a sillimanite fabric is interpreted to reflect either an anticlockwise P–T evolution, or a later independent higher-P thermal event. Coexistence of andalusite with sillimanite in these rocks appears to reflect the sluggish kinematics of the Al2SiO5 polymorphic inversion. In the Deep Bore Metamorphics, 20 km to the east, dehydration melting reactions in granulite facies metapelites have produced migmatites with quartz-absent sillimanite-spinel-cordierite melanosomes, whilst in semipelitic migmatites, discontinuous leucosomes enclose cordierite-spinel intergrowths. Metapsammitic rocks are not migmatised, and contain garnet–orthopyroxene–cordierite–biotite–quartz assemblages. Reaction textures in the Deep Bore Metamorphics are consistent with a near-isobaric heating-cooling path, with peak metamorphism occurring at 2.6–4.0 kbar and c. 750–800 °C. SHRIMP U–Pb dating of metamorphic zircon rims in a cordierite-orthopyroxene migmatite from the Deep Bore Metamorphics yielded an age of 1730 ± 7 Ma, whilst detrital zircon cores define a homogeneous population at 1805 ± 7 Ma. The 1730 Ma age is interpreted to reflect the timing of high-T, low-P metamorphism, synchronous with the regional Late Strangways Event, whereas the 1805 Ma age provides a maximum age of deposition for the sedimentary precursor. The Mopunga Range region forms part of a more extensive low-pressure metamorphic terrane in which lateral temperature gradients are likely to have been induced by localised advection of heat by granitic and mafic intrusions. The near-isobaric Palaeoproterozoic P–T–t evolution of the Mopunga Range region is consistent with a relatively transient thermal event, due to advective processes that occurred synchronous with the regional Late Strangways tectonothermal event.

Notes: The Pinos terrane (Isle of Pines, W Cuba) is a coherent metamorphic complex that probably represents a portion of the continental margin of the Yucatan Block during the Mesozoic. Within the framework of other metamorphic terranes in the Greater Antilles, the Pinos terrane is characterized by the occurrence of high-grade kyanite-, sillimanite- and andalusite-bearing metapelites and migmatites. Assessment and modelling of phase relations in these high grade rocks indicate that they reached a peak temperature of c. 750 °C at 11–12 kbar, and then underwent strong decompression to c. 3 kbar at c. 600 °C. Decompression was contemporaneous with the main synmetamorphic deformation in the area (D2), and was accompanied by segregation of trondhjemitic partial melts formed by wet melting of metapelites. Metamorphism terminated in the Uppermost Cretaceous (68 ± 2 Ma; 40Ar/39Ar dates on biotite and muscovite). The P–T–t-deformation relations of the high-grade rocks suggest that crustal thickening (during collision of this portion of the Yucatan margin with the Great Volcanic Arc of the Caribbean?) was followed by decompression interpreted to reflect exhumation by extension, possibly related to the initial development of the Yucatan Basin in the uppermost Cretaceous.

Notes: Phengite occurring along with carpholite±lawsonite and/or chloritoid in HP–LT domains shows not only variable Si–(Mg+Fe) contents, but also variable interlayer contents (IC). To determine whether these chemical variations are coherently related to variation in P–T conditions on a regional scale, c. 100 rock samples were sampled in metapelites metamorphosed at conditions varying from 350 °C, 8 to 12 kbar to 450–500 °C, 18 to 20 kbar (Schistes Lustrés complex, franco-italian Western Alps). Based on microstructural and habit criteria, four types of phengite were differentiated that are related either to the rock mineralogy (carpholite vs chloritoid bearing samples) or correspond to various generations of phengite occurring in the same rock sample or thin section. Microprobe analyses reveal that each type of phengite is characterized by a specific composition and that phengite associated with carpholite has a lower interlayer content than phengite associated with chloritoid. The successive generations of retrograde phengite overgrowing carpholite point to a large decrease of interlayer content (c. 0.9–0.7 pfu) and (Fe+Mg) content (c. 0.25–0 pfu) with decreasing P–T conditions. This change is best accounted for by a gradual increase of the pyrophyllite component. In contrast, phengite from higher-temperature, chloritoid-bearing rock samples shows an almost constant interlayer content (c. 0.9–0.95 pfu) but a larger decrease of (Fe+Mg) content (c. 0.6–0.1 pfu). Hence, (1) the composition of the different phengite generations occurring (metastably) in the same rock sample may be used to retrieve points in P–T loops and (2) the pyrophyllitic substitution in phengite is large at low-temperature conditions and cannot be ignored. Thermobarometric estimates based on the Si-content alone will therefore result in pressure over-estimates. We propose a tentative location of the phengite Si and IC isopleths in P–T space which could allow a direct determination of the P–T conditions in carpholite-bearing rocks. Especially in some carpholite-bearing rocks, new thermodynamic models accounting for tschermak and pyrophyllitic substitution are also required prior to making reliable thermobarometric estimates in HP-LT metapelites.

Notes: High-MgAl rocks occur as xenoliths (up to 2 m in diameter) in mafic granulites at a newly discovered locality near Anakapalle. Following an early phase of deformation, ultrahigh-temperature (UHT) metamorphism and near-isothermal decompression, the rocks were intruded in a lit-par-lit manner by felsic melts (charnockite), which caused local-scale metasomatism. A subsequent deformation produced isoclinal folds and the distinct gneissic foliation of the charnockite still at granulite facies conditions.The sequence of multiphase reaction textures in the high-MgAl xenoliths reflects the changes of physico-chemical conditions during the polyphase evolution of the terrane; UHT metamorphism (stage 1, 〉 1000°C, c. 10 kbar) is documented by relics of extremely coarse grained domains with the assemblage orthopyroxene (opx)1 + garnet (grt)1 + sapphirine (spr)1 + spinel (spl)1 + rutile (rt). A subsequent phase of near-isothermal decompression in the order of 1–2 kbar (stage 2) resulted in extensive replacement of grt1 and opx1 megacrysts by lamellar (opx2 + spr2) symplectites. The intrusion of felsic melt (stage 3) led to the development of a narrow metasomatic black wall reaction zone (bt + sil + plg3 + opx2,3 + rt) at the immediate contact of the xenoliths and in melt infiltration zones to the partial replacement of (opx2 + spr2) symplectites by biotite and sillimanite and/or plg3, mainly at the expense of orthopyroxene, with concomitant coarsening of the intergrowth texture. The subsequent deformation (stage 4) further modified the symplectite textures through polygonization, recrystallization and grain-size coarsening. The deformation was followed by a period of cooling and decompression (stage 5, c. 800°C, 4–7 kbar) as indicated by local growth of late garnet (grt5) at the expense of (opx + spr + plg) domains at static conditions.Recently published isotope data suggest that the multistage evolution of the high-MgAl granulites at Anakapalle followed a discontinuous P–T trajectory that may be related to heating of the crust through magmatic accretion culminating in deep-crustal UHT metamorphism at 1.4 Ga (stage 1), fast uplift of the UHT granulites into mid-crustal levels as a consequence of extensional tectonics (stage 2), emplacement of felsic magmas in the Grenvillian (at c. 1 Ga, stage 3) resulting in reheating of the crust to high–T conditions followed by a phase of compressional tectonics (stage 4) and a period of cooling to the stable geotherm (stage 5) still in the Grenvillian.

Notes: The Flatraket Complex, a granulite facies low strain enclave within the Western Gneiss Region, provides an excellent example of metastability of plagioclase-bearing assemblages under eclogite facies conditions. Coesite eclogites are found 〈200 m structurally above and 〈1 km below the Flatraket Complex, and are separated from it by amphibolite facies gneisses related to pervasive late-orogenic deformation and overprinting. Granulites within the Flatraket Complex equilibrated at 9–11 kbar, 700–800°C. These predate eclogite facies metamorphism and were preserved metastably in dry undeformed zones under eclogite facies conditions. Approximately 5% of the complex was transformed to eclogite in zones of fluid infiltration and deformation, which were focused along lithological contacts in the margin of the complex. Eclogitisation proceeded by domainal re-equilibration and disequilibrium breakdown of plagioclase by predominantly hydration reactions. Both hydration and anhydrous plagioclase breakdown reactions were kinetically linked to input of fluid. More pervasive hydration of the complex occurred during exhumation, with fluid infiltration linked to dehydration of external gneisses. Eclogite facies shear zones within the complex equilibrated at 20–23 kbar, 650–800°C, consistent with the lack of coesite and with the equilibration conditions of external HP eclogites. If the complex experienced pressures equivalent to those of nearby coesite eclogites (〉 28 kbar), unprecedented metastability of plagioclase and quartz is implied. Alternatively, a tectonic break exists between the Flatraket Complex and UHP eclogites, supporting the concept of a tectonic boundary to the UHP zone of the Western Gneiss Region. The distribution of eclogite and amphibolite facies metamorphic overprints demonstrates that the reactivity of the crust during deep burial and exhumation is strongly controlled by fluid availability, and is a function of the protolith.

Notes: One of the currently popular theories on magma ascent is that it mainly occurs by propagating hydrofractures (dykes) and that magma viscosity is the primary rate-controlling factor. This theory is based on mathematical models for single hydrofractures under idealised conditions. We simulated magma ascent with air ascending through gelatine and observed that the air ascended in batches, following paths made by their predecessors. Multiple batches accumulate at obstacles along the path. Although magma viscosity may control ascent rate during movement, obstacles ultimately control the size and average ascent velocity of ascending batches. We propose that step-wise movement of magma batches is the mechanism of primary accumulation and ascent from the partially molten source rock of a magma to its first emplacement site and therefore the main ascent mechanism for granitic magmas. ‘Classical’ dyking is the mechanism for secondary ascent from a magma chamber.

Notes: Generally, P–T pseudosections for reduced compositional systems, such as K2O–FeO–MgO–Al2O3–SiO2–H2O, Na2O–K2O–FeO–MgO–Al2O3–SiO2–H2O and MnO–K2O–FeO–MgO–Al2O3–SiO2–H2O, are well suited for inferring detailed P–T paths, comparing mineral assemblages observed in natural rocks with those calculated. Examples are provided by P–T paths inferred for four metapelitic samples from a 1 m2 wide outcrop of the Herbert Mountains in the Shackleton Range, Antarctica. The method works well if the bulk composition used is reconstituted from average mineral modes and mineral compositions (AMC) or when X-ray fluorescence (XRF) data are corrected for Al2O3 and FeO. A plagioclase correction is suitable for Al2O3. Correction for FeO is dependent on additional microscopic observations, e.g. the kind and amount of opaque minerals. In some cases, all iron can be treated as FeOtot, whereas in others a magnetite or hematite correction yields much better results. Comparison between calculated and observed mineral modes and mineral compositions shows that the AMC bulk composition is best suited to the interpretation of rock textures using P–T pseudosections, whereas corrected XRF data yield good results only when the investigated sample has few opaque minerals. The results indicate that metapelitic rocks from the Herbert Mountains of the Northern Shackleton Range underwent a prograde P–T evolution from about 600 °C/5.5 kbar to 660 °C/7 kbar, followed by nearly adiabatic cooling to about 600 °C at 4.5 kbar.

Notes: A major problem with the current use of porphyroblast–matrix microstructural relationships to infer orogenic histories, such as multiple orthogonal orogenic events, is that other evidence for these events is typically lacking. For example, a comparison of regional relationships and local structures formed in and adjacent to porphyroblasts present in contact aureoles in the Foothills Terrane, Sierra Nevada, California, shows that: (1) except in shear zones, contact aureoles and local zones along lithological contacts, the Foothills Terrane has a single regional cleavage, although locally formed by multiple processes; (2) the regional cleavage and locally developed porphyroblast inclusion trails have variable orientations, and neither dataset supports the formation of dominantly subhorizontal and subvertical cleavages in this orogen; (3) structural and metamorphic heterogeneities occur at all scales and can markedly affect inclusion trail patterns in porphyroblasts; (4) complex porphyroblast growth features and internal inclusion trail patterns can form in porphyroblasts that grow during short time intervals in contact aureoles, indicating that local complexity in porphyroblasts does not imply regional complexity. Because of these conclusions, multiple datasets, rather than data acquired only from porphyroblasts, should be considered when attempting to understand the evolution of orogens. Furthermore, using microstructural information preserved only in porphyroblasts to infer orogenic processes and plate motions is generally unjustified.

Notes: An extensive humite-bearing marble horizon within a supracrustal sequence at Ambasamudram, southern India, was studied using petrological and stable isotopic techniques to define its metamorphic history and fluid characteristics. At peak metamorphic temperatures of 775±73°C, based on calcite-graphite carbon isotope thermometry, the mineral assemblages suggest layer-by-layer control of fluid compositions. Clinohumite + calcite-bearing assemblages suggest XCO2 〈 0.4 (at 700°C and 5 kbar), calcite + forsterite + K-feldspar-bearing assemblages suggest XCO2〉0.9 (at 790°C); and local wollastonite + scapolite + grossular-bearing zones formed at XCO2 of c. 0.3. Retrograde reaction textures such as scapolite + quartz symplectites after feldspar and calcite and replacement of dolomite + diopside or tremolite+dolomite after calcite+forsterite or calcite+clinohumite are indicative of retrogression under high XCO2 conditions. Calcite preserves late Proterozoic carbon and oxygen isotopic signatures and the marble lacks evidence for extensive retrograde fluid infiltration, while during prograde metamorphism the possible infiltration of aqueous fluids did not produce significant isotopic resetting. Isotopic zonation of calcite and graphite grains was likely produced by localized CO2 fluid infiltration during retrogression. Contrary to the widespread occurrence of humite-marbles related to retrograde aqueous fluid infiltration, the Ambasamudram humite-marbles record a prograde-to-peak metamorphic humite formation and retrogression under conditions of low XH2O.

Notes: The Central Anatolian Crystalline Complex (CACC) is a microcontinent in the Alpine–Himalayan belt. It has previously been considered as a coherent structural entity, but, although the entire CACC is comprised of similar rocks (primarily metasedimentary rocks and granitoids), it consists of at least four tectonic blocks characterized by different P–T–t paths. These blocks are the Kırşehir (north-west), Akdağ (north-east), Niğde (south) and Aksaray (west) massifs. The northern massifs experienced thrusting and folding during collision and were slowly exhumed by erosion; metamorphic rocks are characterized by clockwise P–T paths at moderate P–T and local low-P–high-T (LP–HT) overprinting in the highest grade rocks. Apatite fission track ages are Eocene to Oligocene (47–32 Ma). The Aksaray block represents the hot, shallow mid-crust of a Late Cretaceous–early Tertiary arc. It is dominated by intrusions; rare metapelitic rocks record low-P (〈 4 kbar) regional metamorphism overprinted by LP–HT contact metamorphism. Apatite fission track ages are 50–45 Ma. The Niğde massif is different from the other CACC blocks because it evolved as a core complex in a wrench-dominated setting. It is characterized by clockwise P–T paths at moderate P–T followed by widespread LP–HT metamorphism. Apatite fission track ages are Miocene (12–9 Ma), significantly younger than those in the northern massifs. Niğde rocks resided in the mid-crust at a time when the rest of the CACC was at or near the Earth's surface. Variations in P–T–t and tectonic histories — especially timing of exhumation — between the northern and southern CACC reflect the difference between head-on collision vs. mid-crustal wrenching.

Notes: Granulite facies rocks from the northernmost Harts Range Complex (Arunta Inlier, central Australia) have previously been interpreted as recording a single clockwise cycle of presumed Palaeoproterozoic metamorphism (800–875 °C and 〉9–10 kbar) and subsequent decompression in a kilometre-scale, E-W striking zone of noncoaxial, high-grade (c. 700–735 °C and 5.8–6.4 kbar) deformation. However, new SHRIMP U-Pb age determinations of zircon, monazite and titanite from partially melted metabasites and metapelites indicate that granulite facies metamorphism occurred not in the Proterozoic, but in the Ordovician (c. 470 Ma).The youngest metamorphic zircon overgrowths from two metabasites (probably meta-volcaniclastics) yield 206Pb/238U ages of 478±4 Ma and 471±7 Ma, whereas those from two metapelites yield ages of 463±5 Ma and 461±4 Ma. Monazite from the two metapelites gave ages equal within error to those from metamorphic zircon rims in the same rock (457±5 Ma and 462±5 Ma, respectively). Zircon, and possibly monazite ages are interpreted as dating precipitation of these minerals from crystallizing melt within leucosomes. In contrast, titanite from the two metabasites yield 206Pb/238U ages that are much younger (411±5 Ma & 417±7 Ma, respectively) than those of coexisting zircon, which might indicate that the terrane cooled slowly following final melt crystallization. One metabasite has a second titanite population with an age of 384±7 Ma, which reflects titanite growth and/or recrystallization during the 400–300 Ma Alice Springs Orogeny. The c. 380 Ma titanite age is indistinguishable from the age of magmatic zircon from a small, late and weakly deformed plug of biotite granite that intruded the granulites at 387±4 Ma. These data suggest that the northern Harts Range has been subject to at least two periods of reworking (475–460 Ma & 400–300 Ma) during the Palaeozoic.Detrital zircon from the metapelites and metabasites, and inherited zircon from the granite, yield similar ranges of Proterozoic ages, with distinct age clusters at c. 1300–1000 and c. 650 Ma. These data imply that the deposition ages of the protoliths to the Harts Range Complex are late Neoproterozoic or early Palaeozoic, not Palaeoproterozoic as previously assumed.

Notes: Seven eclogite facies samples from lithologically different units which structurally underlie the Semail ophiolite were dated by the 40Ar/39Ar and Rb–Sr methods. Despite extensive efforts, phengite dated by the 40Ar/39Ar method yielded saddle, hump or irregularly shaped spectra with uninterpretable isochrons. The total gas ages for the phengite ranged from 136 to 85 Ma. Clinopyroxene–phengite, epidote–phengite and whole-rock–phengite Rb–Sr isochrons for the same samples yielded ages of 78 ± 2 Ma. We therefore conclude that the eclogite facies rocks cooled through 500 °C at c. 78 ± 2 Ma, and that the 40Ar/39Ar dates can only constrain maximum ages due to the occurrence of excess Ar inhomogeneously distributed in different sites.Our new results lead us to conclude that high-pressure metamorphism of the Oman margin took place in the Late Cretaceous, contemporaneous with ophiolite emplacement. Previously published structural and petrological data lead us to suggest that this metamorphism resulted from intracontinental subduction and crustal thickening along a NE-dipping zone. Choking of this subduction zone followed by ductile thinning of a crustal mass wedged between deeply subducted continental material and overthrust shelf and slope units facilitated the exhumation of the eclogite facies rocks from depths of c. 50 km to 10–15 km within c. 10 Ma, and led to their juxtaposition against overlying lower grade rocks. Final exhumation of all high-pressure rocks was driven primarily by erosion and assisted by normal faulting in the upper plate.

Notes: Recreational and other human activities degrade coral reefs worldwide to a point where efficient restoration techniques are needed. Here we tested several strategies for gardening denuded reefs. The gardening concept consists of in situ or ex situ mariculture of coral recruits, followed by their transplantation into degraded reef sites. In situ nurseries were established in Eilat's (Northern Red Sea) shallow waters, sheltering three types of coral materials taken from the branching species Stylophora pistillata (small colonies, branch fragments, and spat) that were monitored for up to two years. Pruning more than 10% of donor colonies' branches increased mortality, and surviving colonies displayed reduced reproductive activity. Maricultured isolated branches, however, exceeded donor colony life span and reproductive activity and added 0.5–45% skeletal mass per year. Forty-four percent of the small colonies survived after 1.5-year mariculture, revealing average yearly growth of 75 ± 32%. Three months ex situ maintenance of coral spat (sexual recruits) prior to the in situ nursery phase increased survivorship. Within the next 1.5 years, they developed into colonies of 3–4 cm diameter. Nursery periods of 2 years, 4–5 years, and more than〉 5 years have been estimated for small colonies, spat, and isolated branches, respectively. These and other results, including the possible use of nubbins (minute fragments the size of a single or few polyps), are discussed, revealing benefits and drawbacks for each material. In situ coral mariculture is an improved practice to the common but potentially harmful protocol of direct coral transplantation. It is suggested that reef gardening may be used as a key management tool in conservation and restoration of denuded reef areas. The gardening concept may be applicable for coral reefs worldwide through site-specific considerations and the use of different local coral species.

Notes: Efforts to restore ponderosa pine ecosystems to open, park-like conditions that predominated prior to European-American settlement result in altered stand structure and increased landscape heterogeneity, potentially altering habitat suitability for invertebrates and other forest organisms. We examined the responses of two butterfly species, Colias eurytheme and Neophasia menapia, to microclimatic changes at structural edges created by experimental restoration treatments in northern Arizona. We monitored microclimate, including air temperature, light intensity, and vapor pressure deficit (VPD), on several mornings during butterfly releases. We placed adult butterflies at east- and west-facing edges approximately one half-hour before dawn to determine their behavioral response to microclimatic differences between east- and west-facing edges. After sunrise, all three microclimatic variables were higher at east-facing edges, and the difference in microclimate between the two edge orientations increased through early morning. For both species, butterflies placed at east-facing edges flew earlier than butterflies at west-facing edges. Colias eurytheme, an open-habitat species, tended to move toward the treated forest during initial flight, while movements of Neophasia menapia, a forest-dwelling species, did not differ from random flight. Our results indicate that butterflies respond to microclimatic factors associated with restoration treatments, while responses to structural changes in habitat vary among species, based on habitat and food plant preferences. These changes in forest structure and microclimate may affect the distribution of many mobile invertebrates in forested landscapes undergoing restoration treatments.

Notes: An accumulated body of theory and empirical evidence suggests that habitat selection by animals is a scale-dependent, hierarchical process. Hierarchy theory predicts that habitat suitability is influenced by the interaction of factors at multiple spatial scales from the microsite to the landscape and that higher-order factors impose constraints at lower levels. For instance, large-scale factors such as landscape context may make a site unsuitable for a species even if the vegetation structure and composition are appropriate. In addition, the spatial arrangement of habitat elements at all scales must be considered when planning restoration efforts. For example, the presence of snags does not ensure that the site will be suitable for snag-dependent species. The size, age, and spacing of snags and their juxtaposition to other habitat elements must also be considered. Finally, all habitats are dynamic, and therefore the ecological processes that contribute to those dynamics must be maintained or suitable substitutes included in the recovery plan. When considering restoring habitat for wildlife, we recommend that managers: (1) identify the wildlife species they want to target for restoration efforts, (2) consider the size and landscape context of the restoration site and whether it is appropriate for the target species, (3) identify the habitat elements that are necessary for the target species, (4) develop a strategy for restoring those elements and the ecological processes that maintain them, and (5) implement a long-term monitoring program to gauge the success of the restoration efforts.

Notes: Caretta caretta (loggerhead sea turtle) nesting activity was recorded daily during three seasons prior to and two seasons immediately following a beach nourishment (replenishment) project in Palm Beach County, Florida. Surveys were done at the nourished beach (Jupiter/Carlin) and at two natural beaches (Juno and Tequesta). The size of the nourishment effect on nesting activity was estimated using Before-After-Control-Impact Paired Series (BACIPS) models. Nesting declined by 4.4 to 5.4 nests km−1 day−1 on the nourished beach compared to the two natural beaches in the first season after nourishment. At the same time, false crawls (FC, non-nesting crawls) increased by 5.0 to 5.6 FC km−1 day−1 on the nourished beach. In the second season following nourishment, nesting was reduced by 0.5 to 1.6 nests km−1 day−1 on the nourished beach compared to the two natural beaches. The increase in false crawl frequency in the second season following nourishment was 0.7 to 0.9 FC km−1 day−1.These results suggest that beach nourishment significantly decreased loggerhead sea turtle nesting during the first season following the project. However, the size of the effect, in terms of nesting frequency and false crawl frequency, was much reduced by the second season following nourishment.

Notes: We studied the role of genetic variability of donor beds in establishing transplantation criteria for the Mediterranean seagrass Posidonia oceanica. Horizontal rhizomes, collected from three geographically distinct populations, were transplanted into a common bed at a highly human-impacted locality. The transplantation site was located near one of the donor populations. After three years, the shoots collected in the population adjacent to the transplanting site showed the lowest growth performance. Genetic variability, assessed through the analysis of hypervariable microsatellite regions, and growth performance followed a similar trend. The shoots growing and branching at the highest rate were those collected from populations with the highest heterozygosity values, despite greater geographic distance. No genetic differences were found between the transplanted shoots and shoots from donor meadows, as expected due to the low rate of sexual reproduction in P. oceanica and the short time that had passed since the transplants. The problem of affecting the local gene pool by the introduction of foreign genotypes could arise, but introduction of new alleles could balance the degradation of genetic variability caused by human impact. In general our study suggests that the genetic variability of source material is an important aspect to consider in the development of seagrass restoration strategies.

Notes: The present investigation was part of a fen restoration project, which deals with the rehabilitation of a deeply drained peat land used for intensive agriculture for more than 200 years. Consequently, the conditions for restoration are unfavorable. The hay of well-developed fen meadows from nature reserves in the region appeared to contain enough viable seeds to act as a source for the development of target communities when spread out on bare peat after topsoil removal. Repeated vegetation analysis showed that a combination of topsoil removal and hay transfer resulted in the establishment of new populations in the target area for 70% of the species of the donor area. Germination conditions of fen species were investigated to determine the optimal combination for stimulating germination rates. Most fen species were found to be dormant, and it was shown that dormancy could be broken with fluctuating light and temperature cycles and stratification pre-treatment.

Notes: The objective of this study was to identify soil nutrient availability conditions that would allow the establishment of key species of the Molinia caerulea-Cirsium dissectum fen meadow. The restoration site was a species-poor agriculturally improved pasture that had received no inorganic fertilizer for greater than 13 years. Treatments designed to reduce site fertility included: cutting and removal of herbage, cultivation, fallowing and topsoil removal. Straw and/or lignitic-clay were incorporated as soil amendment treatments. Cirsio-Molinietum species were either sown or planted as seedlings on treated plots. Neither soil nitrogen nor potassium availability, per se, appeared to limit the establishment of Cirsio-Molinietum species, whereas enhanced phosphorus availability did. Removal of the top 15–20 cm of soil reduced the total soil phosphorus amount by about 85 percent and depleted plant P availability. Nutrient-poor and relatively calcium-enriched soil exposed by topsoil removal allowed the development of a community with affinities to the Cirsio-Molinietum typical fen meadow. Redundancy analysis indicated the existence of marked vegetational gradients within the topsoil removal treatments that were influenced by the straw and the lignitic-clay amendments. The way in which these two amendments influenced edaphic conditions were unclear. Where the topsoil was not removed the vegetation became dominated by a few competitive species and although many of the planted Cirsio-Molinietum species were still present after four years, they were found only in trace amounts. Removal of most of the soil organic matter was a practical success in that it created suitable edaphic conditions for all the planted Cirsio-Molinietum species to remain well established.

Notes: Grazing at low stocking rates has become a common management practice in nature restoration projects in the Netherlands. However, detailed knowledge of grazing impact is often poor, in particular for invertebrates. This study addressed the impact of extensive grazing on butterflies. Butterflies are critical indicators of habitat quality for many plant and animal species. We compared monitoring data from 1992 to 1996 for calcareous coastal dune areas in the Netherlands with different management: 11 grazed areas, 7 ungrazed areas and 4 areas managed by annual cutting. Grazing typically concerned year-round grazing by cattle and/or ponies, at low stocking rates (0.05–0.26 head ha−1 yr−1). Butterfly abundance was related to species composition and structure of the vegetation. Changes in butterfly abundance were positive in grazed and ungrazed areas compared to cut areas. Species richness was not affected by management, but individual species differed in their response. Species from open grassland benefited most from grazing, particularly Issoria lathonia (Queen of Spain Fritillary) and Lycaena phlaeas (Small Copper). No clear negative effects of grazing were observed, but species occurrence was not always positively related to the environmental characteristics associated with grazing. In the long run, even lower stocking rates might prove more beneficial to the butterfly community as a whole. Four of the more frequently observed species, I. lathonia, Hipparchia semele (Grayling), Pyrgus malvae (Grizzled Skipper) and Aricia agestis (Brown Argus), are listed as threatened to susceptible in the Netherlands. All were apparently favored by grazing. It is concluded that extensive grazing has good potential to enhance butterfly diversity in restoration projects.

Notes: A number of experimental freshwater wetlands (150 m long × 75 m wide) with different ages since they were abandoned as rice fields, were used to analyze the prospects of multipurpose wetland restoration for such degraded areas. Nitrogen and phosphorus removal rate of the wetlands were determined monthly during the flooding season to estimate their efficiency as filters to remove nutrients from agricultural sewage. The number of wetland birds was recorded regularly to identify their habitat preferences. Both the temporal dynamics and changes in the spatial pattern of land use cover during the last 20 years were determined from aerial photographs and field analysis. All the wetlands appeared to be very efficient in the removal of nitrogen and phosphorus exported from rice fields. Usually 50–98% of the nitrogen and less than 50% of the soluble phosphorus were removed by the wetlands at any stage of restoration. Wetland birds preferred wetlands with intermediate plant cover for resting and sleeping activities better than rice fields and either very open wetlands or very dense ones with tall vegetation. Apart from the improvement in water quality and the restoration of natural habitats, restoration of wetland belts around lagoons will increase spatial heterogeneity and diversity of the landscape.

Notes: This paper is based on research of the restoration of species-rich calcareous grasslands in The Netherlands, over the last 30 years. Chalk grassland is a semi-natural vegetation with a high density of species at a small scale. This type of vegetation was once widespread in Western Europe as common grazing land, mainly for flocks of sheep for which the main function was dung production. In some regions of Central Europe, these grasslands were also used for hay production. The dung was used to maintain arable field production at a reasonable level. In the chalk district in the southernmost part of The Netherlands some 25 sites of this vegetation, varying in area from 0.05–4.5 ha, are still present. Chalk grassland completely lost its significance for modern agricultural production after the wide application of artificial fertilizer following World War II. This grassland has a high conservation value both for plants and animal species, of which a large number of species are exclusively restricted to this biotope. When conservation activities started at a large scale in the early 1960s, three different types of restoration activities could be distinguished: (1) restoration of fertilized sites; (2) restoration of abandoned grasslands; and (3) recreation of chalk grassland on former arable fields. The main aim of the restoration attempt is to create and/or improve sustainable conditions for both plant and animal species characteristic of the chalk grassland ecosystem. In the process of restoration, several phases of different activities can be distinguished: (1) pre-restoration phase, during which information of the land use history is collected and, based on these data, clear restoration goals are established; (2) initial restoration phase, during which effects of former, non-conservational land use has to be undone in order to stimulate germination and establishment of target species originating from soil seed bank and species pool; (3) consolidation phase, including the introduction and continuation of a regular management system for sustainable conservation; and (4) long-term conservation strategy, including measures to prevent disturbance from the outside and genetic erosion and extinction of locally endangered plant populations.

Notes: We tested whether the intensity of hardwood midstory reduction causes commensurate improvements of herbaceous groundcover in fire-suppressed Pinus palustris (longleaf pine) sandhills. Using a complete randomized block design, we compared the effects of three hardwood reduction techniques (spring burning, application of the ULW® form of the herbicide hexazinone, chainsaw felling/girdling) and a no-treatment control on plant species richness, and on life form and common species densities at Eglin Air Force Base, Florida, U.S.A., from 1995 to 1998. ULW® and felling/girdling plots were burned for fuel reduction two years after initial treatment application. We also sampled the same variables in frequently-burned reference sandhills to establish targets for restoration. Spring burns achieved partial topkill of oaks (17.6–41.1% from 1995 to 1998) compared to reductions of 69.1–94% accomplished by ULW® and of 93.2–67.8% by felling/girdling treatments. We predicted that plant species richness and densities of herbaceous groundcover life forms would increase according to the percent hardwood reductions. Predictions were not supported by treatment effects for species richness because positive responses to fire best explained increases in plant richness, whereas ULW® effects accounted for the largest initial decreases. Legumes, non-legume forbs, and graminoids did not respond to treatments as predicted by the hypothesis. Again, positive responses to fire dominated the results, which was supported by greater herbaceous densities observed in reference plots. Overall, we found that the least effective and least expensive hardwood midstory reduction method, fire, resulted in the greatest groundcover improvements as measured by species richness and herbaceous groundcover plant densities.

Notes: We determined the effects of shade, burial by sand, simulated herbivory, and fertilizers on the survival and growth of artificially planted population of Cirsium pitcheri—an endangered plant species of the sand dunes along Lake Huron. Sand burial experiments showed that greenhouse grown plants should optimally be transplanted into areas receiving 5 cm of sand deposition: burial at this depth maximized emergence, survivorship, and below-ground biomass. Under field conditions, simulated herbivory of up to 50% of the plant height produced a slight increase in biomass after one year of growth. Field observations showed that when white-tailed deer removed more than 50% of the transplant's leaf tissue, the plant died. The application of a 20:20:20 (N:P:K) water-soluble fertilizer produced a significant increase in the dry leaf biomass, total leaf area, and total dry biomass relative to control plants. We also tested for the presence or absence of a persistent seed bank. Few seeds were recovered from soil samples collected from Pinery Provincial Park and Providence Bay. However, C. pitcheri has the ability to form a persistent seed bank under field conditions but only at soil depths of 〈inlineGraphic alt="geqslant R: gt-or-equal, slanted" extraInfo="nonStandardEntity" href="urn:x-wiley:10612971:REC90006:ges" location="ges.gif"/〉15 cm. Cirsium pitcheri seeds are able to germinate and seedlings can emerge from a burial depth of up to 6 cm. Thus, seeds planted in open, sunny areas will probably maximize emergence, growth, and survivorship of seedlings. Populations of C. pitcheri can be restored by planting seeds at shallow depths, transplanting greenhouse-grown plants, applying water soluble fertilizers, and protecting plants from herbivores.

Notes: Historically, oak woodlands of northern California have been subject to intensive tree and brush removal efforts to improve land for livestock grazing. As a result of this tree removal, these watersheds are susceptible to soil erosion and stream degradation. Therefore, planting woody vegetation is often required to restore watershed function. Prior to such actions, a thorough understanding of natural vegetation regeneration patterns is essential. The physical and biological attributes of natural vegetation regeneration in a cleared watershed were characterized using remote sensing, a Geographic Information System, and field surveys. A 79-ha watershed at the University of California's Hopland Research and Extension Center was examined because the clearing of vegetation was part of a well-documented experiment in the early 1960s, providing essential baseline data. The results of this study reveal that significantly more oak regeneration, consisting mostly of evergreen oaks, occurred on moister and steeper northerly slopes. Deciduous oaks, located primarily on drier and less steep southerly slopes, have not regenerated. Hardwood regeneration was associated with Josephine, Los Gatos, and Maymen soils. The distribution of hardwood regeneration is clustered, suggesting that the presence of other trees may promote regeneration. These results also suggest that without active restoration efforts such as tree planting and seedling protection, southerly slopes will most likely remain barren and erosion will continue, while northerly slopes and riparian areas will recover under the current land management practices. Despite some woody plant regeneration, the once densely forested watershed is now predominantly grassland, emphasizing the need to minimize clearing of California oak woodlands.

Notes: The current study demonstrated that Themeda australis (R. Br.) Stapf (kangaroo grass), a major understory component of the original grassy Box woodlands in the Central Tablelands of New South Wales, was suitable for use in large-scale mine rehabilitation. The results of the trial were applied in the mine rehabilitation program. Due to extensive clearing of the woodlands and the introduction of exotic flora and fauna for agriculture, only small remnants of the original flora remain. The final land use of the gold mine is a conservation area free from agricultural pressure. Local native species adapted to the soil conditions and variable climate are highly desirable for the control of soil erosion following mining. Germination and establishment of T. australis on oxidized overburden were examined over 53 weeks. Seed-bearing mulch was used as both the seeding material and an organic additive to the overburden. The effects of five factors were investigated: time since soil preparation, position within small contour banks, location of contour on experimental slopes, additional water, and rate of seed/mulch application. Direct seeding using the lowest rate of mulch application resulted in the establishment of more T. australis seedlings on new contours than on 15-month-old contours. The provision of additional water increased germination and establishment in both old and new contours, but was not essential. Seedling densities were greatest in the middle positions of contour banks up to week seven, but were destroyed during a heavy storm. At the close of the experiment, seedling densities were greater in the top and bottom positions of contours. Although significant slope × rate and age × slope interactions occurred, SNK tests did not reveal any consistent interpretable results.

Notes: Antitaxial non-deforming strain fringes from Lourdes, France, show complex quartz, calcite and chlorite fibre patterns that grew around pyrite in a slate during non-coaxial progressive deformation. Development of these fringes was modelled using a computer program ‘Fringe Growth 2.0’ which can simulate incremental growth of crystal fibres around core-objects of variable shape. It uses object-centre paths as input, which are obtained from fibre patterns in thin section. The numerical experiments produced fibre patterns that show complex intergrowth of displacement-controlled, face-controlled and intermediate fibres similar to those in the natural examples. The direction of displacement-controlled growth is only dependent on the relative movement between core-object and fringe, so that core-object rotation with respect to the fringe influences the fibre patterns and produces characteristic asymmetric fibre curvature. Object-centre paths should be used for kinematic analysis of strain fringes instead of single fibres since these paths represent the fringe as a whole. The length along the path can be interpreted in terms of finite strain and path curvature in terms of rigid body rotation of fringes with respect to an external reference frame.

Notes: A sharp line delimitating the distribution of tourmaline (termed as a ‘tourmaline-out isograd’) is defined in the migmatite zone of the Ryoke metamorphic belt, Japan. The trend of the tourmaline-out isograd closely matches that of the isograds formed through the regional metamorphism, suggesting that it represents the breakdown front of tourmaline during regional metamorphism. This is confirmed by the presence of the reaction textures of tourmaline to sillimanite and cordierite near the tourmaline-out isograd. The breakdown of tourmaline would release boron into associated melts or fluids and be an important factor in controlling the behaviour of boron in tourmaline-bearing high-temperature metamorphic rocks.Near the tourmaline-out isograd, large tourmaline crystals occur in the centre of interboudin partitions containing leucosome. In the melanosome of the intervening matrix, reaction textures involving tourmaline are locally observed. These observations imply that tourmaline breakdown is related to a melting reaction and that the boron in the leucosome is derived from the breakdown of tourmaline in the melanosome during prograde metamorphism.Boron released by tourmaline breakdown lowers both the solidus temperature of the rock and the viscosity of any associated melt. Considering that the tourmaline-out isograd lies close to the schist–migmatite boundary, these effects might have enhanced melt generation and segregation in the migmatite zone of the Ryoke belt.The evidence for the breakdown of tourmaline and the almost complete absence of any borosilicates throughout the migmatite zone suggest that boron was effectively removed from this region by the movement of melt and/or fluid. This implies that the tourmaline-out isograd can reflect a significant amount of mass transfer in the anatectic zones.

Notes: A sequence of prograde isograds is recognized within the Dalradian Inzie Head gneisses where pelitic compositions have undergone variable degrees of partial melting via incongruent melting reactions consuming biotite. Three leucosome types are identified. At the lowest grades, granitic leucosomes containing porphyroblasts of cordierite (CRD-melt) are abundant. At intermediate grades, CRD-melt mingles with garnetiferous leucosomes (GT-melt). At the highest grades, CRD-melt coexists with orthopyroxene-bearing leucosomes (OPX-melt), while garnet is conspicuously absent. The prograde metamorphic field gradient is constrained to pressures of 2–3 kbar below the CRD-melt isograd, and no greater than 4.5 kbar at the highest grade around Inzie Head.A petrogenetic grid, calculated using thermocalc, is presented for the K2O–FeO–MgO–Al2O3–SiO2–H2O (KFMASH) system for the phases orthopyroxene, garnet, cordierite, biotite, sillimanite, H2O and melt with quartz and K-feldspar in excess. For the implied field gradient, the reaction sequence predicted by the grid is consistent with the successive prograde development of each leucosome type. Compatibility diagrams suggest that, as anatexis proceeded, bulk compositions may have been displaced towards higher MgO content by the removal of (relatively) ferroan granitic leucosome. An isobaric (P = 4 kbar) T–aH2O diagram shows that premigmatization fluids must have been water-rich (aH2O 〉 0.85) and suggests that, following the formation of small volumes of CRD-melt, the system became fluid-absent and melting reactions buffered aH2O to lower values as temperatures rose. GT- and OPX-melt formed by fluid-absent melting reactions, but a maximum of 7–11% CRD-melt fraction can be generated under fluid-absent conditions, much less than the large volumes observed in the field. There is strong evidence that the CRD-melt leucosomes could not have been derived by buoyantly aided upwards migration from levels beneath the migmatites. Their formation therefore required a significant influx of H2O-rich fluid, but in a quantity insufficient to have exhausted the buffering capacity of the solid assemblage plus melt. Fluid : rock ratios cannot have exceeded 1 : 30. The fluid was channelled through a regionally extensive shear zone network following melt-induced failure. Such an influx of fluid at such depths has obvious consequences for localized crustal magma production and possibly for cordierite-bearing granitoids in general.

Notes: The South Karakorum margin, east of the Himalayan syntaxis, consist of an E–W elongated zone of young (10–3 Ma) high-grade metamorphic rocks (M2) and related migmatitic domes. This late tectono-metamorphic event post-dates the Palaeogene (55–37 Ma) phase of thickening of the belt featured by NW–SE structures and associated M1 amphibolite facies metamorphism (0.7 GPa, 700 °C). This M2 metamorphism is characterised by low-pressure, high-temperature conditions coeval with migmatite formation in response to a thermal increase of c. 150 °C compared to M1, culminating at a temperature of c. 770 °C and a pressure of 0.5–0.6 GPa. Rapid exhumation of migmatitic domes, at a rate of 5 mm yr−1, was accommodated by vertical extrusion, in the core of E–W crustal-scale folds. These crustal-scale folds formed in response to N–S syn-collisional shortening and were enhanced by thermal weakening of the migmatised continental crust.M2 metamorphism is spatially and temporarily associated with granitoids showing a mantle affinity, firmly suggesting that this could be the advective heat source for the granite and syenite generation and the subsequent migmatisation of the mid-crustal level. Such relationships between a mantle-related magmatism and a high-temperature metamorphism in a convergent shortening context are suggestive of the breakoff of the subducted Indian slab since 20 Ma.

Notes: High-P/low-T metamorphic rocks of the Hammondvale metamorphic suite (HMS) are exposed in an area of 10 km2 on the NW margin of the Caledonian (Avalon) terrane in southern New Brunswick, Canada. The HMS is in faulted contact on the SE with c. 560–550 Ma volcanic and sedimentary rocks and co-magmatic plutonic units of the Caledonian terrane. The HMS consists of albite- and garnet-porphyroblastic mica schist, with minor marble, calc-silicate rocks and quartzite. Pressure and temperature estimates from metamorphic assemblages in the mica schist and calc-silicate rocks using TWQ indicate that peak pressure conditions were 12.4 kbar at 430 °C. Peak temperature conditions were 580 °C at 9.0 kbar. 40Ar/39Ar muscovite ages from three samples range up to 618–615 Ma, a minimum age for high-P/low-T metamorphism in this unit. These ages indicate that the HMS is related to the c. 625–600 Ma subduction-generated volcanic and plutonic units exposed to the SE in the Caledonian terrane. The ages are also similar to those obtained from detrital muscovite in a Neoproterozoic-Cambrian sedimentary sequence in the Caledonian terrane, suggesting that the HMS was exposed by latest Neoproterozoic time and supplied detritus to the sedimentary units. The HMS is interpreted to represent a fragment of an accretionary complex, similar to the Sanbagawa Belt in Japan. It confirms the presence of a major cryptic suture between the Avalon terrane sensu stricto and the now-adjacent Brookville terrane.

Notes: The Sanddal mafic-ultramafic complex (SMUK) is a cluster of variably eclogitised mafic and ultramafic bodies that comprise the westernmost known eclogite facies locality in the North-East Greenland eclogite province (NEGEP). Although there are no true eclogites in the SMUK, we interpret three distinct textural types of plagioclase replacement to record sequential stages in adjustment of SMUK olivine gabbro-norites to eclogite facies conditions. The earliest stage, in which plagioclase was replaced by omphacite/spinel symplectite before nucleation of garnet (Type 1A & 1B) has not previously been described. Documentation of this texture provides clear evidence that, at least in some cases, garnet nucleation is delayed relative to nucleation of omphacite and is a rate-limiting step for eclogitisation. Type 1C domains were produced by scattered nucleation of garnet in the same sample. In Type 2 domains, plagioclase was replaced by a layered corona with an outer layer of garnet, an inner layer of omphacite and an interior of inclusion-rich plagioclase. In Type 3 domains, the omphacite layer was overgrown by the garnet rim, and omphacite is preserved only as inclusions in garnet. In more coarse grained leucogabbros, recrystallization was more complete, plagioclase replacement textures were less localised, and could not be divided into distinct stages. Plagioclase replacement in SMUK samples was not isochemical, and required diffusion of at least Mg and Fe from replacement of mafic phases in the surroundings. Strong compositional gradients in garnet reflect disequilibrium and were controlled by the different diffusion rates of Mg/Fe and Ca, different local chemical environments, and progress of the plagioclase breakdown reaction. The presence of small amounts of hydrous minerals (amphibole, phlogopite and clinozoisite) in local equilibrium in plagioclase domains of most SMUK samples indicates that a small amount of H2O was present during high pressure metamorphism.

Notes: Kyanite and staurolite occur in the Tananao Metamorphic Complex as submicron inclusions in almandine-rich garnet from a metamorphosed palaeosol weathering horizon, near Hoping, eastern Taiwan. Quartz, rutile/brookite and zircon are also found as associated submicron inclusions in garnet. Employing the reaction ilmenite+kyanite+quartz=almandine+rutile, and the breakdown of staurolite and quartz as thermobarometers, these submicron-scale minerals formed at 〉8.3–8.8 kbar and 〈 660–690 °C. This P–T estimate is different from that (i.e. 5–7 kbar and 530–550 °C) derived from matrix minerals, which include almandine-rich garnet, muscovite, chlorite, chloritoid, plagioclase, quartz and ilmenite. These results suggest that submicron inclusions in garnet-like materials may record portions of the otherwise undocumented prograde path or provide information about previous metamorphic events and thus yield new insights into orogenic belts.

Notes: A hydrothermally metamorphosed/altered greenstone complex capped by bedded cherts exposed in the North Pole, Pilbara Carton, Western Australia, is interpreted as an accretionary complex. It is distinctive in being characterised by both duplex structure and an oceanic crust stratigraphy. This complex is shown to represent an Archaean upper oceanic crust with a mid-ocean ridge hydrothermal metamorphism that increases in grade stratigraphically downward. Three mineral zones have been defined; Zone A of the zeolite facies, the prehnite-pumpellyite facies or the lower-greenschist facies at high-XCO2 condition, Zone B of the greenschist facies, and Zone C of the greenschist/amphibolite transition facies. In Zone A metabasites, Ca-Al silicates including Ca-zeolites, prehnite and pumpellyite are absent and epidote/clinozoisite is extremely rare. Instead, abundant carbonates are present with chlorite suggesting high-XCO2 composition in the fluid. On the other hand, in Zones B and C metabasites, where Ca-amphibole + epidote/clinozoisite + chlorite + Ca-Na plagioclase are the dominant assemblages, carbonate is not identified. The metamorphic conditions boundary of Zones B/C were estimated to be about 350 °C at a pressure of 〈0.5 kbar.Fluid compositions coexisting with Archaean greenstones at the transition between Zones B and C were estimated by thermodynamic calculation in the CaFMASCH system (T = 350–370 °C, P = 150–1000 bar) at XCO2 of 0.012–0.140, such values are higher than present-day vent fluids collected near mid-ocean ridges with low-XCO2 values, up to 0.005. The Archaean seawater depth at the mid-ocean ridge was estimated to be 1600 m at XCO2 = 0.06 using a depth-to-boiling point curve for a fluid. The carbonation due to high-XCO2 hydrothermal fluids occurred near the ridge-axis before or was coincident with ridge metamorphism.

Notes: Metapelitic rocks from the Marble Hall Fragment, enclosed in the granites of the magmatic Bushveld Complex, record a two-stage, low-pressure, high-temperature metamorphism. An early paragenesis containing chiastolitic andalusite, cordierite, biotite and quartz ± garnet crystallized in most rocks and equilibrated at 550–600 °C, 0.2 GPa. It was transformed during the second, peak event into various parageneses that commonly coexist within a single thin section. These include garnet–cordierite–biotite–K-feldspar–quartz, sillimanite–cordierite–K-feldspar–quartz and spectacular quartz-undersaturated cordierite–spinel symplectites replacing the chiastolite porphyroblasts.Based on a detailed phase diagram analysis, we argue that these parageneses result from rapid heating at an approximately constant pressure to temperatures of more than about 720 °C. At these temperatures, the internally buffered activity of water was reduced by incipient water-saturated partial melting, while only minor quantities of melt were produced. Subsequent dry conditions inhibited large-scale equilibration and, together with local inhomogeneities in mineral distribution, led to the development of contrasting parageneses and symplectite textures. No signs of widespread fluid-absent melting of biotite were found, and so the temperature probably did not exceed 760 °C. The peak metamorphic event is attributed to the emplacement of the hot Nebo granite, whereas the early metamorphism was probably caused by the intrusion of one of the phases of the Rustenburg Layered Suite.We infer the conditions of development of the cordierite–spinel intergrowths and we show that, although symplectites are commonly associated with retrograde processes (cooling and/or decompression), they can record a prograde metamorphic evolution. Furthermore, our contribution emphasizes the importance of the concept of reduced equilibration volume for the understanding and interpretation of some particular textures and parageneses in common rocks.

Notes: Two types of garnet porphyroblast occur in the Schneeberg Complex of the Italian Alps. Type 1 porphyroblasts form ellipsoidal pods with a centre consisting of unstrained quartz, decussate mica and small garnet grains, and a margin containing large garnet grains. Orientation contrast imaging using the scanning electron microscope shows that the larger marginal garnet grains comprise a number of orientation subdomains. Individual garnet grains without subdomains are small (〈 50 µm), faceted and idioblastic, and have simple zoning profiles with Ca-rich cores and Ca-poor rims. Subdomains of larger garnet grains are similar in size to the individual, small garnet grains. Type 2 porphyroblasts comprise only ellipsoidal garnet, with small subdomains in the centre and larger subdomains at the margin. Each subdomain has its own Ca high, Ca dropping towards subdomain boundaries. Garnet grains, with or without subdomains, all have the same Ca-poor composition at rims in contact with other minerals. The compositional zonation patterns are best explained by simultaneous, multiple nucleation, followed by growth and amalgamation of individual garnet grains. The range of individual garnet and garnet subdomain sizes can be explained by a faster growth rate at the porphyroblast margin than in the centre. The difference between Type 1 and Type 2 porphyroblasts is probably related to the growth rate differential across the porphyroblast.Electron backscatter diffraction shows that small, individual garnet grains are randomly oriented. Large marginal garnet grains and subdomain-bearing garnet grains have a strong preferred orientation, clustering around a single garnet orientation. Misorientations across subdomain boundaries are small and misorientation axes are randomly oriented with respect to crystallographic orientations. The only explanation that fits the observational data is that individual garnet grains rotated towards coincident orientations once they came into contact with each other. This process was driven by the reduction of subdomain boundary energy associated with misorientation loss. Rotation of garnet grains was accommodated by diffusion in the subdomain boundary and diffusional creep and rigid body rotation of other minerals (quartz and mica) around the garnet. An analytical model, in which the kinetics of garnet rotation are controlled by the rheology of surrounding quartz, suggests that, at the conditions of metamorphism, the rotation required to give a strong preferred orientation can occur on a similar time-scale to that of porphyroblast growth.

Notes: The late Mesozoic and Cenozoic metamorphic evolution of the western North American continental margin is recorded in a belt of homogeneous metapelitic rocks, the Kluane metamorphic assemblage (KMA), in the northern Coast Belt of Yukon Territory. A record of Late Cretaceous medium-pressure and -temperature (c. 7 kbar, 500 °C) metamorphism, M1, is preserved in Ca-rich garnet and Na-rich plagioclase cores in rocks that were little affected by later events. M1 was synchronous with mylonitization and is attributed to accretion of the KMA to the ancient continental margin. Isothermal decompression during rapid uplift was followed by early Eocene emplacement of the Ruby Range Batholith (RRB), part of a magmatic arc produced by subduction of the Kula plate. The intrusion of the RRB led to a contact metamorphic overprint, M2, producing a 5–6 km wide aureole in which the grade ranges from subgarnet zone to garnet–cordierite–K-feldspar zone. Pressure and temperature estimates for M2, calculated from mineral equilibria, are 3.5–4.5 kbar and 530–720 °C, generally consistent with the stability limits of the observed mineral assemblages. Comparison of mineral assemblages and P–T conditions in the KMA with those in the Mclaren Glacier metamorphic belt in Alaska does not support the correlation of the two metamorphic sequences. This weakens the hypothesis proposing 400 km of dextral slip along the Denali fault zone.

Notes: Primary multiphase brine fluid inclusions in omphacite and garnet from low- to medium-temperature eclogites have been analysed for Cl, Br, I, F, Li and SO4. Halogen contents and ratios provide information about trapped lower crustal fluids, even though the major element (Na, K, Ca) contents of inclusion fluids have been modified by fluid–mineral interactions and (step-) daughter-crystal formation after trapping. Halogens in the inclusion fluids were analysed with crush–leach techniques. Cl/Br and Cl/I mass ratios of eclogite fluids are in the range 31–395 and 5000–33 000, respectively. Most fluids have a Cl/Br ratio lower than modern seawater and a Cl/I ratio one order of magnitude lower than modern seawater. Fluids with the lowest Cl/Br and highest Cl/I ratios come from an eclogite that formed by hydration of granulite facies rocks, and may indicate that Br and I are fractionated into hydrous minerals. Reconstructions indicate that the inclusion fluids originally contained 500–4000 ppm Br, 1–14 ppm I and 33–438 ppm Li. Electron microprobe analyses of eclogite facies amphibole, biotite, phengite and apatite indicate that F and Cl fractionate most strongly between phengite (F/Cl mass ratio of 1469 ± 1048) and fluid (F/Cl mass ratio of 0.008), and the least between amphibole and fluid. The chemical evolution of Cl and Br in pore fluids during hydration reactions is in many ways analogous to Cl and Br in seawater during evaporation: the Cl/Br ratio remains constant until the aH2O value is sufficiently lowered for Cl to be removed from solution by incorporation into hydrous minerals.

Notes: A thermodynamic model for haplogranitic melts in the system Na2O–CaO–K2O–Al2O3–SiO2–H2O (NCKASH) is extended by the addition of FeO and MgO, with the data for the additional end-members of the liquid incorporated in the Holland & Powell (1998) internally consistent thermodynamic dataset. The resulting dataset, with the software thermocalc, is then used to calculate melting relationships for metapelitic rock compositions. The main forms for this are P–T and T–X pseudosections calculated for particular rock compositions and composition ranges. The relationships in these full-system pseudosections are controlled by the low-variance equilibria in subsystems of NCKFMASH. In particular, the solidus relationships are controlled by the solidus relationships in NKASH, and the ferromagnesian mineral relationships are controlled by those in KFMASH. However, calculations in NCKFMASH allow the relationships between the common metapelitic minerals and silicate melt to be determined. In particular, the production of silicate melt and melt loss from such rocks allow observations to be made about the processes involved in producing granulite facies rocks, particularly relating to open-system behaviour of rocks under high-grade conditions.

Notes: Soil microfungi were studied in the Sokolov (Czech Republic) post-mining dumps afforested with Alnus glutinosa and in the Lusatian (Germany) post-mining dumps afforested with Pinus sylvestris or P. nigra. Microfungi were isolated using the soil dilution plate method. Soil microfungi communities of two chronosequences were compared by species composition, frequency of species occurrence, and colony forming units of fungi (CFU-counts). Differences in species occurrence were determined. More species of entomopathogenic microfungi were found from the Sokolov post-mining area in comparison with the Cottbus post-mining area. Absidia glauca, A. cylindrospora, Penicillium glabrum, and P. janthinellum were the most frequently isolated species from the Cottbus post-mining area, while A. glauca, Geomyces pannorum, and Trichoderma koningii predominated at the Sokolov post-mining area.

Notes: Successive development of millipede and terrestrial isopod assemblages in colliery spoil heaps in the Sokolov region (northwest Bohemia, Czech Republic) was studied during the years 1993–1998. Younger colliery spoil heaps were characterized by a lower number and low density of millipede species. The millipedes Polydesmus inconstans, Polydesmus testaceus, and Craspedosoma rawlinsii represented the main pioneer species. Alder afforestation proved to be more suitable for the recolonization of millipede populations, especially for the predominant Julus scandinavius. Terrestrial isopods colonized all parts of the heaps, including the youngest open plots. The most frequent isopod, Trachelipus rathkii, is a colonizing species with an apparently high adaptability to different environmental conditions. The isolated character of the extensive heap areas, together with existing extreme soil conditions, resulted in slow recolonization and a successional development of stable populations of these animals. However, the relatively high densities of millipede and isopod assemblages in suitable alder afforestation can represent further potential sources for colonization of other open-heap areas.

Notes: Earthworm communities were studied at six heap sites representing a chronosequence of Alnus glutinosa (black alder) stands (age 3–62 years) and compared with those on an unameliorated heap and in an alder stand (60 years old) on natural soil. Spoil heaps in the open-cast coal mining area near Sokolov (northwestern Bohemia) were mainly reclaimed using afforestation. No earthworms were found on the virgin heap. Young plots were colonized by euryecious epigeic earthworms (i.e., those living above soil surface), but higher proportions of endogeic species (i.e., soil dwellers), did not appear until after more than 30 years of succession. The density and biomass of earthworms increased from the youngest stand (67 individuals/m2; 5 g/m2) to the older ones (e.g., 407 ind/m2; 13 g/m2 in the 23-year-old stand). However, both parameters were low in the oldest stand (35 ind/m2; 3 g/m2), but this may have been the result of extensive soil disturbance. Earthworm populations were often higher in reclaimed sites than in the control alder stand (150 ind/m2; 7 g/m2). However, the community structures were different, with the control being dominated by the litter-feeding species, Dendrobaena vejdovskyi.

Notes: The goal of the present study was to assess a soil seed bank as an input seed source for revegetating lead/zinc (Pb/Zn) mine tailings. The seed bank source was abandoned farmland, whose top 10-cm layer of topsoil contained 6,850 ± 377 seeds/m2 from 41 species. The seeds in the soil were principally distributed in the upper 0–2 cm, which held 75.8% of total seeds and 92.7% of species composition. The top 2-cm layer of topsoil may be sufficient to serve the purpose of providing a seed source for revegetation on derelict lands, including mined lands. Four different thicknesses of topsoil (1, 2, 4, and 8 cm, redistributed from the total 0–10-cm layer from the farmland) were field-tested on the Pb/Zn mine tailings. There was no significant difference in seedling density among the 4 thickness treatments. Many seeds in the treatments with more than 1-cm of topsoil were unable to emerge from the deeper layer. Seedlings in plots with topsoil of 1-, 2- and 4-cm failed to establish within 1 year due to the extremely high acidity (pH 2.39 to 2.76). A shallow layer of topsoil cannot neutralize the sulfuric acid generated from oxidation of pyrites in the tailings. For establishment of seedlings on metalliferous lands, an insulating layer such as subsoil, building rubble, or domestic refuse is necessary before covering with valuable topsoil. The woody legume Leucaena leucocephala grown on the tailings with a topsoil cover of 8-cm was the most dominant species. Lead was accumulated in root, branch, stem bark, and xylem, which accounted for more than 80% of the total metal concentration in the plant. This portion of Pb will reside in the plant for a long period, while the smaller portion of Pb in the leaf (about 15%) could be returned to the environment as litter during growth. Woody plants may have an advantage in metal-phyto-remediation over herbaceous plants.

Notes: This study, conducted in the Santa Cruz Mountains of California, provides data on the abundance and diversity of litter spiders and other arthropods in three redwood forest conditions: old growth, second growth, and tree farm. Litter spiders are linked to and reflect habitat structure and prey abundance and can act as indicators for redwood forest restoration and monitoring. There were significant declines in spider and other arthropod diversity and abundance with increased logging and decreased herb cover. The absolute and relative increase in nocturnal spiders and detritivores in unlogged sites suggests that guild structures of spiders and other arthropods can indicate forest recovery from logging disturbance. Furthermore, selectively harvested stands do not retain old-growth levels of litter arthropod diversity or abundance. This study identifies potential indicator redwood litter spiders that show higher abundances in old-growth areas, Zelotes sp. (Gnaphosidae), Xysticus sp. (Thomisidae), and Ceratinops inflata (Linyphiidae) and a possible old-growth specialist, Phrurotimpus sp. (Liocranidae). These findings strengthen the case for including soil arthropods in redwood forest monitoring and assessment and for the preservation of undisturbed forest areas.

Notes: Restoration of ponderosa pine ecosystems results in altered stand structure, potentially affecting microclimatic conditions and habitat quality for forest organisms. This research focuses on microclimatic changes resulting from forest and landscape structural alterations caused by restoration treatments in southwestern ponderosa pine forests. Three microclimate variables—light intensity, air temperature, and vapor pressure deficit (VPD)—were monitored over two field seasons. Differences in microclimate between the treated forest and the surrounding untreated forest were measured, and microclimatic gradients across the structural edge between these two forest types were quantified. Restoration treatments increased sunlight penetration to the forest floor but did not significantly impact ambient air temperature or VPD. Mean values for air temperature and VPD did not differ significantly between treatments, although temperature and vapor pressure deficit did exhibit a trend in the morning; both variables were higher at the structural edge and in the treated forest during morning hours. Significant edge gradients were detected for air temperature and VPD in the morning and evening, increasing from the structural edge into the untreated forest. Our results show that microclimatic effects of these restoration treatments are generally modest, but the changes are more prominent at specific locations and during certain times of day. Because even modest changes in microclimate have the potential to impact a range of key ecological processes, microclimatic effects should be considered when forest restoration treatments at the landscape scale are being planned and implemented.

Notes: To restore habitat is to restore the functional aspects of a place where one or more species are intended to live. However, habitat restored with the right structural elements can still fail to support the species due to insufficient space and spatial contiguity (e.g., movement corridors) with nearby habitat. The spatial extent of habitat determines its capacity to support various demographic units, such as a breeding pair of individuals, a true population, or a metapopulation. In scatter-plots of published density estimates and their corresponding study area sizes, I found consistent patterns that appeared to represent spatial scale domains, in which subpopulations, populations, and multiple populations exist for each species. These spatial scale domains can help guide habitat restoration by indicating the minimum area needed to support a population. The effectiveness of restored habitat, considered alone or in combination with existing habitat, should be judged by the habitat's capacity to sustain a functioning population, which includes the population's membership in a metapopulation. Additionally, the evidence increasingly demonstrates that habitat must include sufficient space for the population(s) to periodically relocate as resources are depleted locally. The spatial extent of proposed habitat restoration can now be linked to the likely demographic unit of the species that can be supported there. I provide two examples of proposed habitat conservation and their likely effectiveness based on their spatial areas.

Notes: Humans fragment landscapes to the detriment of wildlife. We review why fragmentation is detrimental to wildlife (especially birds), review the effects of urbanization on birds inhabiting nearby native habitats, suggest how restoration ecologists can minimize these effects, and discuss future research needs. We emphasize the importance of individual fitness to determining community composition. This means that reproduction, survivorship, and dispersal (not simply community composition) must be maintained, restored, and monitored. We suggest that the severity of the effects of fragmentation are determined by (1) the natural disturbance regime, (2) the similarity of the anthropogenic matrix to the natural matrix, and (3) the persistence of the anthropogenic change. As a result, urbanization is likely to produce greater effects of fragmentation than either agriculture or timber harvest. Restoration ecologists, land managers, and urban planners can help maintain native birds in fragmented landscapes by a combination of short- and long-term actions designed to restore ecological function (not just shape and structure) to fragments, including: (1) maintaining native vegetation, deadwood, and other nesting structures in the fragment, (2) managing the landscape surrounding the fragment (matrix), not just the fragment, (3) making the matrix more like the native habitat fragments, (4) increasing the foliage height diversity within fragments, (5) designing buffers that reduce penetration of undesirable agents from the matrix, (6) recognizing that human activity is not compatible with interior conditions, (7) actively managing mammal populations in fragments, (8) discouraging open lawn on public and private property, (9) providing statutory recognition of the value of complexes of small wetlands, (10) integrating urban parks into the native habitat system, (11) anticipating urbanization and seeking creative ways to increase native habitat and manage it collectively, (12) reducing the growing effects of urbanization on once remote natural areas, (13) realizing that fragments may be best suited to conserve only a few species, (14) developing monitoring programs that measure fitness, and (15) developing a new educational paradigm.

Notes: The talus slope adjacent to the Niagara River at Niagara Falls (Ontario, Canada) has been severely disturbed over the course of the past century as the area has been increasingly developed for tourism. In addition the lower talus slope is disturbed by periodic ice scour, most recently one year prior to this study. Historical evidence suggests that the original vegetation was similar to that currently found on talus slopes of the Niagara Escarpment, which could, therefore, be used as a reference system and restoration target. The current community structure and physical environment were sampled in 75 randomly placed 1-×-1–m quadrats. A total of 137 species were found, of which 62%were aliens. ANOVA showed that species richness, woody debris cover, litter cover, soil depth, and photosynthetically active radiation changed along a gradient perpendicular to the river. Three different sections of the study area whose last severe disturbance dated back 100, 30, and 4 years, respectively, were similar in their physical environment but were significantly different in species richness. Ordinations of species frequencies showed that light levels and distance from the river were the principal gradients controlling the vegetation structure. The species composition of the section last disturbed 100 years ago was different from that of the more recently disturbed sections. Ordination and cluster analysis of the pooled data showed large differences between the Niagara Falls site and reference escarpment talus slopes. Natural escarpment vegetation was much more homogeneous and had more species and fewer aliens. By comparing reference talus with sections of the study area at Niagara Falls that were last disturbed at different times, we conclude that the trajectory of natural succession at Niagara Falls is leading to an alternative state, an urban forest dominated by aliens, and that active restoration will be required to return the talus to its original state.

Notes: Centaurea maculosa (Lam.) (spotted knapweed) reduces wildlife and livestock habitat biodiversity and increases erosion. Nutrient availability to plants may be used to accelerate succession away from spotted knapweed. Early-successional plant communities often have high nutrient availability, whereas late-successional communities are often found on lower nutrient soils. We hypothesized that removal of nutrients would change the competitive advantage from spotted knapweed to Pseudoroegneria spicatum (bluebunch wheatgrass) (late seral). In two addition series matrices, background densities of Secale cereale (annual rye) and Elymus elimoides (bottlebrush squirreltail) (3,000 seeds/m2) were used to remove nutrients from the soil. In another set of addition series matrices, nitrogen (33 kg/ha) or phosphorus (33 kg/ha) were added to the soil. Nutrient analysis of soil and vegetation indicated that annual rye and bottlebrush squirreltail reduced nutrient availability in soils. In another matrix, neither a background density nor nutrients were added. Data were fit into Watkinson's curvilinear model to determine the competitive relationship between bluebunch wheatgrass and spotted knapweed. This allowed comparison of the equivalence ratios (C) generated from each addition series. The C parameters are the per-plant equivalent of bluebunch wheatgrass or spotted knapweed and can be interpreted as the ratio of intra-to-interspecific competition. The C parameters are also the equivalence ratio of the number of spotted knapweed it takes to have equivalent effect on bluebunch wheatgrass or the number of bluebunch wheatgrass having the equivalent effect on spotted knapweed. Without nutrient manipulation, spotted knapweed was more competitive than bluebunch wheatgrass. The C for bluebunch wheatgrass was 0.17, indicating that 0.17 knapweed plants were competitively equivalent to one wheatgrass. Annual rye changed the competitive balance in favor of bluebunch wheatgrass (C = 9.9). Addition of nitrogen, phosphorus, or the mid-seral species did not change the competitive relationship between the two species. This preliminary study suggests that succession from spotted knapweed to late-seral bluebunch wheatgrass community may be accelerated by altering resource availability.

Notes: The effects of sod cutting were studied in a dune area on the Dutch Wadden Sea Island of Texel. Sod cutting was carried out in a range of different dune slacks in order to restore dune slack vegetation with many endangered Red List species. Sod cutting removed approximately 96% of the soil seed bank. Species abundant in the seed bank, notably Juncacea, also had a high frequency in the vegetation that established during the first year after the restoration measures. Many other species not registered in the seed bank or in the former vegetation also appeared. Species richness in the monitored plots exceeded that of uncut reference plots after a few years. Colonization rates were higher than extinction rates in most plots, indicating that a stable state has not been reached after 5 years. Differences in species richness between slacks appeared to be related to the occurrence of source areas nearby and availability of dispersal agents, such as flooding and animals.

Notes: After almost 40 years of experience in wetland restoration in Central Europe in which vegetation changes have been monitored by means of permanent plots or vegetation maps, some light can be shed on the intrinsic dynamics of such ecosystems, showing the limits of restoration and constraints in its manipulation. Sometimes such constraints in the restoration process can be identified, mostly being constraints in nutrient availability or in the water regime, but unexpected changes can also be the result of intrinsic species fluctuations or invasive species. Unexpected vegetation developments are sometimes undesired, can be very persistent and may indicate that environmental conditions are not suitable for target communities. Unexpected developments also illustrate the limits in restoration ecology. Very often the restoration process simply proceeds along successional pathways we did not anticipate. Theories about such alternative pathways can be explored using prediction models, such as cellular automata, which can handle the results of biomonitoring very efficiently. Biomonitoring during 40 years, however, has also shown that a certain amount of unpredictability has to be taken for granted, both in natural wetlands and in areas under restoration.

Notes: Valuation of nature is an important aspect of nature conservation and restoration. Understanding valuation in a broad sense may contribute to conservation strategies since it may lead to better support from society. In this article we propose a model of valuation with respect to conservation and restoration of nature. According to the model, valuation of nature can be characterized by a “valuation approach,” consisting of ecological, ethical and aesthetic perspectives. Such an approach includes scientific and normative aspects and leads to a particular claim of conservation. In this paper we discuss different perspectives, and accordingly, we sketch three main types of these valuation approaches. Political and policy issues with respect to nature conservation and restoration are considered in terms of this model.

Notes: Phragmites australis (common reed) has expanded in many wetland habitats. Its ability to exclude other plant species has led to both control and eradication programs. This study examined two control methods—herbicide application or a herbicide-burning combination—for their efficacy and ability to restore plant biodiversity in non-tidal wetlands. Two Phragmites-dominated sites received the herbicide glyphosate. One of these sites was burned following herbicide application. Plant and soil macroinvertebrate abundance and diversity were evaluated pre-treatment and every year for four years post-treatment using belt transects. The growth of Phragmites propagules—seeds, rhizomes, and rooted shoots—was examined in the greenhouse and under bare, burned, or vegetated soil conditions. Both control programs greatly reduced Phragmites abundance and increased plant biodiversity. Plant re-growth was quicker on the herbicide-burn site, with presumably a more rapid return to wetland function. Re-growth at both sites depended upon a pre-existing, diverse soil seed bank. There were no directed changes in soil macroinvertebrate abundance or diversity and they appeared unaffected by changes in the plant community. Phragmites seeds survived only on bare soils, while buried rhizomes survived under all soil conditions. This suggests natural seeding of disturbed soils and inadvertent human planting of rhizomes as likely avenues for Phragmites colonization. Herbicide control, with or without burning, can reduce Phragmites abundance and increase plant biodiversity temporarily. These changes do not necessarily lead to a more diverse animal community. Moreover, unless Phragmites is eradicated and further human disturbance is prohibited, it will likely eventually re-establish dominance.

Notes: Quarrying for granite in Hong Kong, mainly for construction aggregates, has left huge and unsightly scars on the landscape. Recent government policy demands rehabilitation of the disturbed lands and restoration of the landscape adopting the ecological approach. At an active quarry, a method was tested for controlled restoration: blasting of the vertical rocky production faces to pile up the debris and to form artificial slopes that mimic those of the environs in a landform replication approach. On the scree blast piles, a soil cap of fine-earth materials with organic amendments was installed to grow mainly tropical leguminous trees. The restoration trial largely failed, with extensive death or poor performance of most plants. The inability of the soil and the site to support vegetation was investigated. The main physical problems are shallow solum, large cavities in the bouldery substrate, high stone content, excessively coarse texture, compaction, and limited available-moisture storage. The main chemical problems are the lack of nitrogen and phosphorus related to the meager organic-matter content, low cation exchange capacity, and base saturation. Suggestions are made to ameliorate habitat conditions for plant growth in a comprehensive ecosystem-reconstitution package that encompasses the landform, hydrology, microclimate, soil, and plant assemblage. Recommendations are given on the application of organic amendments to establish and maintain soil structure, restore decomposition regime, and raise nutrient and moisture storage capacities for a modified approach that could overcome the site difficulties.

Notes: Restoration projects are often developed with little consideration for understanding their effects on wildlife. We contend, however, that monitoring treatment effects on wildlife should be an integral component of the design and execution of any management activity, including restoration. Thus, we provide a conceptual framework for the design and implementation of monitoring studies to understand the effects of restoration on wildlife. Our underlying premise is that effective monitoring hinges on an appropriate study design for unbiased and precise estimates of the response variables. We advocate using measures of population dynamics for response variables given that they provide the most direct measures of wildlife status and trends. The species to be monitored should be those constituting an assemblage of umbrella species that represent the range of spatial and functional requirements of wildlife in a restored ecological system. Selection of umbrella species should be based on strong empirical evidence that justifies their usage. We also advocate that monitoring be designed as true experiments or quasi-experiments rather than as observational studies to allow for stronger inferences regarding the effects of restoration on wildlife. Our primary message is that if monitoring is to be done, it must be scientifically based.

Notes: The suitability of 24 native species for restoration above the timberline in Switzerland was assessed with demographic monitoring of their populations after transplanting. The plots were laid out in 1985–1986 and 1995–1996 on machine-graded ski runs using a total of 8,603 transplants of native grasses, legumes and forbs. Establishment conditions were improved with biodegradable wood-fiber mats and a small addition of garden soil. Transplant survival rates were generally good after 12 years. The regeneration of mixed stands was clearly recognizable because some transplants successfully reproduced by seed, and colonizers immigrated from the adjacent natural vegetation and neighboring restoration plots. Comparative studies of reproductive parameters in transplants and their donor population revealed that differences in seed production may become nonsignificant within a short time span. These fitness features have important diagnostic value for assessing restoration success and provide information on the performance of the same or closely related genotypes in their natural populations and in the restoration site. The plants studied showed species-specific traits in establishment after transplanting. Most species can be recommended for restoration in the alpine vegetation belt. The risk of restoration failure can be considerably reduced by using species with different life-history characteristics. From an ecological point of view, this method is a valid alternative to commercial revegetation using seed mixtures of non-native species and large amounts of fertilizers.

Notes: In the Netherlands, the characteristic flora of shallow softwater lakes has declined rapidly as a consequence of eutrophication, alkalization and acidification. The sediment of most lakes has become nutrient rich and anaerobic. We expected that, if a vital seed bank was still present, restoration of the original water quality and sediment conditions would lead to the return of softwater macrophytes. The restoration of 15 degraded, shallow, softwater lakes in the Netherlands was monitored from 1983 to 1998. In eutrophied as well as in acidified lakes, removal of accumulated organic matter from the sediment and shores was followed by rapid recolonization of softwater macrophytes present in the seedbank. After isolation from alkaline water and subsequent mud removal, this recovery was also observed in alkalized lakes. Further development of softwater vegetation correlated strongly with the water quality. When renewed eutrophication was successfully prevented, softwater macrophytes could expand. However, in acidified lakes, Juncus bulbosus and Sphagnum species became dominant after restoration. Liming of an acidified lake was followed by re-acidification within 3 years. Recolonization by softwater macrophytes was inhibited by high turbidity of the water column and spreading of large helophytes on the shore. As an alternative, controlled inlet of alkaline, nutrient-poor groundwater was studied in a few lakes. The pH of those lakes increased, the carbon and nitrogen availability decreased and softwater macrophytes returned. Successful restoration has contributed considerably to maintaining biodiversity in softwater lakes in the Netherlands.

Notes: Successional pathways in native forest, planted 15–33 years ago on reconstructed surfaces to restore aesthetic values destroyed by hydro-electric dam construction at Aratiatia, central North Island, New Zealand, were compared with those on similar surfaces left unplanted. Only native species were planted. Classification identified three canopy communities and several ground layer communities with significant inter-stratum relationships: Pittosporum tenuifolium-Sophora tetraptera short forest with ground layers dominated by litter; P. tenuifolium-Kunzea ericoides short forest over adventive grasses on planted sites; and adventive Cytisus scoparius shrubland over grasses on unplanted sites. Planted communities mirror young secondary forests on intact substrates in the district, but have lower density and similar or higher basal area than such forests elsewhere. Established seedlings of seven planted canopy trees, mostly early successional bird-dispersed species, are reasonably widespread in floristically rich Pittosporum-Sophora forest. Seedlings of only two species are widespread in floristically poor Pittosporum-Kunzea forest, and none on unplanted sites. This first large-scale attempt at ecological restoration in New Zealand, by mass planting of new surfaces with early successional native woody species, has created aesthetically-pleasing stands of indigenous forest on sites which would otherwise remain in relatively stable adventive shrubland communities for the foreseeable future. Only continued monitoring will show whether further management is necessary and whether natural processes are operating at a level sufficient to ensure that artificially initiated successions will continue along more or less natural pathways.

Notes: A detailed analysis of chemical zoning in two garnet crystals from Harpswell Neck, Maine, forms the basis of an interpretation of garnet nucleation and growth mechanisms. Garnet apparently nucleates initially on crenulations of mica and chlorite and quickly overgrows the entire crenulation, giving rise to complex two-dimensional zoning patterns depending on the orientation of the thin section cut. Contours of Ca zoning cross those of Mn, Fe and Mg, indicating a lack of equilibrium among these major garnet constituents. Zoning of Fe, Mg and Mn is interpreted to reflect equilibrium with the rock matrix, whereas Ca zoning is interpreted to be controlled by diffusive transport between the matrix and the growing crystal.Image analysis reveals that the growth of garnet is more rapid along triple-grain intersections than along double-grain boundaries. Moreover, different minerals are replaced by garnet at different rates. The relative rate of replacement by garnet along double-grain boundaries is ordered as muscovite 〉 chlorite 〉 plagioclase 〉 quartz. Flux calculations reveal that replacement is limited by diffusion of Si along double-grain boundaries to or from the local reaction site. It is concluded that multiple diffusive pathways control the bulk replacement of the rock matrix by garnet, with Si and Al transport being rate limiting in these samples.

Notes: Due to the retrograde cation exchange problems experienced by conventional geothermobarometers above their closure temperatures, petrogenetic grids are a potentially powerful alternative to unravelling the P–T evolution of ultrahigh-T granulite terranes. A new qualitative KFMASH (K2O–FeO–MgO–Al2O3–SiO2–H2O) petrogenetic grid for Mg–Al rich metapelites containing K-feldspar, sillimanite and quartzofeldspathic melt that successfully accounts for the majority of assemblages composed of variations of sapphirine, spinel, garnet, orthopyroxene, cordierite, biotite and quartz is developed. Univariant reactions are predicted utilizing a newly derived ‘melt projection’ and these reactions are entirely consistent with algebraically calculated reaction coefficients obtained using a set of standard phase compositions. Based upon observations of commonly associated mineral assemblages in natural lithologies the [Spr, Spl], [Qtz, Spl], [Bt, Spl], [Opx, Spr], [Opx, Qtz] and [Bt, Opx] invariant points are assumed to be stable, whilst the [Grt, Spr], [Grt, Qtz], [Spr, Qtz] and [Crd, Qtz] are assumed to be metastable. Biotite-bearing assemblages are confined to the lowest temperatures, and sapphirine + quartz to the highest temperatures. Orthopyroxene + sillimanite ± quartz assemblages are confined to the highest pressures, whilst spinel-bearing assemblages are stabilized by lower pressures. The alternative choice of invariant point stability leads to significant differences between this grid and previously proposed topologies. Spinel cannot be stable along with the orthopyroxene and sillimanite assemblage as previously proposed. Further, more subtle differences in topology result from the treatment of H2O in the chemographic projection used to deduce univariant reactions, and projecting from a water-bearing quartzofeldspathic melt does not yield the same reaction coefficients as projection from H2O. The new grid allows reinterpretation of previously proposed evolutionary P–T paths for Mg–Al rich granulites from the Napier Complex and Rauer Group, East Antarctica, and In Ouzzal, Algeria.

Notes: Sm–Nd (garnet), U–Pb (monazite) and Rb–Sr (biotite) ages from a composite migmatite sample (Damara orogen, Namibia) constrain the time of high-grade regional metamorphism and the duration of regional metamorphic events. Sm–Nd garnet whole-rock ages for a strongly restitic melanosome and an adjacent intrusive leucosome yield ages of 534±5, 528±11 and 539±8 Ma. These results provide substantial evidence for pre-500 Ma Pan-African regional metamorphism and melting for this segment of the orogen. Other parts of the migmatite yield younger Sm–Nd ages of 488±9 Ma for melanosome and 496±10, 492±5 and 511±16 Ma for the corresponding leucosomes. Garnet from one xenolith from the leucosomes yields an age of 497±2 Ma. Major element compostions of garnet are different in terms of absolute abundances of pyrope and spessartine components, but the flat shape of the elemental patterns suggests late-stage retrograde equilibration. Rare earth element compositions of the garnet from the different layers are similar except for garnet from the intrusive leucosome suggesting that they grew in different environments. Monazite from the leucosomes is reversely discordant and records 207Pb/235U ages between 536 and 529 Ma, indicating that this monazite represents incorporated residual material from the first melting event. Monazite from the mesosome MES 2 and the melanosome MEL 3 gives 207Pb/235U ages of 523 and 526 Ma, and 529 and 531 Ma, respectively, which probably indicates another thermal event. Previously published 207Pb/235U monazite data give ages between 525 and 521 Ma for composite migmatites, and 521 and 518 Ma for monazite from neosomes. Monazite from granitic to granodioritic veins indicates another thermal event at 507–505 Ma. These ages are also recorded in 207Pb/235U monazite data of 508 Ma from the metasediment MET 1 from the migmatite and also in the Sm–Nd garnet ages obtained in this study. Taken together, these ages indicate that high-grade metamorphism started at c. 535 Ma (or earlier) and was followed by thermal events at c. 520 Ma and c. 505 Ma. The latter event is probably connected with the intrusion of a large igneous body (Donkerhoek granite) for which so far only imprecise Rb–Sr whole-rock data of 520±15 Ma are available. Rb–Sr biotite ages from the different layers of the migmatite are 488, 469 and 473 Ma. These different ages indicate late-stage disturbance of the Rb–Sr isotopic system on the sub-sample scale. Nevertheless, these ages are close to the youngest Sm–Nd garnet ages, indicating rapid cooling rates between 13 and 20°C Ma−1 and fast uplift of this segment of the crust. Similar Sm–Nd garnet and U–Pb monazite ages suggest that the closure temperatures for both isotopic systems are not very different in this case and are probably similar or higher than the previously estimated peak metamorphic temperatures of 730±30°C. The preservation of restitic monazite in leucosomes indicates that dissolution of monazite in felsic water-undersaturated peraluminous melts can be sluggish. This study shows that geochronological data from migmatites can record polymetamorphic episodes in high-grade terranes that often contain cryptic evidence for the nature and timing of early metamorphic events.

Notes: A combined study of major and trace elements, fluid inclusions and oxygen isotopes has been carried out on garnet pyroxenite from the Raobazhai complex in the North Dabie Terrane (NDT). Well-preserved compositional zoning with Na decreasing and Ca and Mg increasing from the core to rim of pyroxene in the garnet pyroxenite indicates eclogite facies metamorphism at the peak metamorphic stage and subsequent granulite facies metamorphism during uplift. A P–T path with substantial heating (from c. 750 to 900 °C) after the maximum pressure reveals a different uplift history compared with most other eclogites in the South Dabie Terrane (SDT). Fluid inclusion data can be correlated with the metamorphic grade: the fluid regime during the peak metamorphism (eclogite facies) was dominated by N2-bearing NaCl-rich solutions, whereas it changed into CO2-dominated fluids during the granulite facies retrograde metamorphism. At a late retrograde metamorphic stage, probably after amphibolite facies metamorphism, some external low-salinity fluids were involved. In situ UV-laser oxygen isotope analysis was undertaken on a 7 mm garnet, and impure pyroxene, amphibole and plagioclase. The nearly homogeneous oxygen isotopic composition (δ18OVSMOW = c. 6.7‰) in the garnet porphyroblast indicates closed fluid system conditions during garnet growth. However, isotopic fractionations between retrograde phases (amphibole and plagioclase) and garnet show an oxygen isotopic disequilibrium, indicating retrograde fluid–rock interactions. Unusual MORB-like rare earth element (REE) patterns for whole rock of the garnet pyroxenite contrast with most ultra-high-pressure (UHP) eclogites in the Dabie-Sulu area. However, the age-corrected initial εNd(t) is − 2.9, which indicates that the protolith of the garnet pyroxenite was derived from an enriched mantle rather than from a MORB source. Combined with the present data of oxygen isotopic compositions and the characteristic N2 content in the fluid inclusions, we suggest that the protolith of the garnet pyroxenite from Raobazhai formed in an enriched mantle fragment, which has been exposed to the surface prior to the Triassic metamorphism.

Notes: Fluid inclusions in coesite-bearing eclogites and jadeite quartzite at Shuanghe in Dabie Shan, East-central China, have preserved remnants of early, prograde and/or peak metamorphic fluids, reset during post-UHP (ultrahigh-pressure) metamorphic uplift. Inclusions occur in several minerals (e.g. omphacite & epidote), notably as isolated, primary inclusions in quartz included in various host minerals. Two major fluid types have been identified: non-polar fluid species (N2 or CO2) and aqueous, the latter is by far the most predominant. Aqueous fluids cover a wide range of salinity, from halite-bearing brines to low salinity fluids. For non-polar fluids, few N2 inclusions occur in undeformed eclogite, whereas a number of CO2-rich inclusions have been found in microshear zones of eclogite or jadeite quartzite in close proximity to marble occurrences.The primary character of N2 and high-salinity aqueous inclusions indicates that they are remnants from UHP metamorphic fluids and for some there is the distinct possibility that they are ultimately derived from pre-metamorphic fluids. This conclusion is supported by the preservation, in some samples, of microdomains containing synchronous inclusions of variable salinities, which tend to relate to the chemical composition of the host crystal. Carbonic fluids may be derived from neighbouring rocks, notably marble and carbonate-bearing metasediments, during post-metamorphic uplift. During post-UHP exhumation, a limited decrease of the fluid density has occurred, with formation of new sets of fluid inclusions. Fluid movements, however, remained exceedingly limited, at the scale of the enclosing crystal.

Notes: Granulite facies gabbroic and dioritic gneisses in the Pembroke Valley, Milford Sound, New Zealand, are cut by vertical and planar garnet reaction zones in rectilinear patterns. In gabbroic gneiss, narrow dykes of anorthositic leucosome are surrounded by fine-grained garnet granulite that replaced the host two-pyroxene hornblende granulite at conditions of 750 °C and 14 kbar. Major and trace element whole-rock geochemical data indicate that recrystallization was mostly isochemical. The anorthositic veins cut contacts between gabbroic gneiss and dioritic gneiss, but change in morphology at the contacts, from the anorthositic vein surrounded by a garnet granulite reaction zone in the gabbroic gneiss, to zones with a septum of coarse-grained garnet surrounded by anorthositic leucosome in the dioritic gneiss. The dioritic gneiss also contains isolated garnet grains enclosed by leucosome, and short planar trains of garnet grains linked by leucosome. Partial melting of the dioritic gneiss, mostly controlled by hornblende breakdown at water-undersaturated conditions, is inferred to have generated the leucosomes. The form of the leucosomes is consistent with melt segregation and transport aided by fracture propagation; limited retrogression suggests considerable melt escape. Dyking and melt escape from the dioritic gneiss are inferred to have propagated fractures into the gabbroic gneiss. The migrating melt scavenged water from the surrounding gabbroic gneiss and induced the limited replacement by garnet granulite.

Notes: This paper examines the spatial statistics of matrix minerals and complex patterned cordierite porphyroblasts in the low-pressure, high-temperature (low P/T) Tsukuba metamorphic rocks from central Japan, using a density correlation function. The cordierite-producing reaction is sillimanite + biotite + quartz = K-feldspar + cordierite + water. The density correlation function shows that quartz is distributed randomly. However, the density correlation functions of biotite, plagioclase and K-feldspar show that their spatial distributions are clearly affected by the formation of cordierite porphyroblasts. These observations suggest that cordierite growth occurred through a selective growth mechanism: quartz adjacent to cordierite has a tendency to prevent the growth of cordierite, whereas other matrix minerals adjacent to cordierite have a tendency to enhance the growth of cordierite. The density correlation functions of complex patterned cordierite porphyroblasts show power-law behaviour. A selective growth mechanism alone cannot explain the origin of the power-law behaviour. Comparison of the morphology and fractal dimension of cordierite with two-dimensional sections from a three-dimensional diffusion-limited aggregation (DLA) suggests that the formation of cordierite porphyroblasts can be modelled as a DLA process. DLA is the simple statistical model for the universal fractal pattern developed in a macroscopic diffusion field. Diffusion-controlled growth interacting with a random field is essential to the formation of a DLA-like pattern. The selective growth mechanism will provide a random noise for the growth of cordierite due to random distribution of quartz. Therefore, a selective growth mechanism coupled with diffusion-controlled growth is proposed to explain the power-law behaviour of the density correlation function of complex patterned cordierite. The results in this paper suggest that not only the growth kinetics but also the spatial distribution of matrix minerals affect the progress of the metamorphic reaction and pattern formation of metamorphic rocks.

Notes: Alpine metamorphism, related to the development of a metamorphic core complex during Cretaceous orogenic events, has been recognized in the Veporic unit, Western Carpathians (Slovakia). Three metamorphic zones have been distinguished in the metapelites: 1, chloritoid + chlorite + garnet; 2, garnet + staurolite + chlorite; 3, staurolite + biotite + kyanite. The isograds separating the metamorphic zones have been modelled by discontinuous reactions in the system K2O–FeO–MgO–Al2O3–SiO2–H2O (KFMASH). The isograds are roughly parallel to the north-east-dipping foliation related to extensional updoming along low-angle normal faults. Thermobarometric data document increasing P–T conditions from c. 500 °C and 7–8 kbar to c. 620 °C and 9–10 kbar, reflecting a coherent metamorphic field gradient from greenschist to middle amphibolite facies. 40Ar/39Ar data obtained by high spatial resolution in situ ultraviolet (UV) laser ablation of white micas from the rock slabs constrain the timing of cooling and exhumation in the Late Cretaceous. Mean dates are between 77 and 72 Ma; however, individual white mica grains record a range of apparent 40Ar/39Ar ages indicating that cooling below the blocking temperature for argon diffusion was not instantaneous. The reconstructed metamorphic P–T–t path is ‘clockwise’, reflecting post-burial decompression and cooling during a single Alpine orogenic cycle. The presented data suggest that the Veporic unit evolved as a metamorphic core complex during the Cretaceous growth of the Western Carpathian orogenic wedge. Metamorphism was related to collisional crustal shortening and stacking, following closure of the Meliata Ocean. Exhumation was accomplished by synorogenic (orogen-parallel) extension and unroofing in an overall compressive regime.

Notes: In cold-temperate ecosystems of the upper Great Lakes Region, evergreen conifer-dominated forests were once common. As a result of past management practices, early-successional deciduous forests now dominate the landscape. Embedded in this matrix are stands of shade-tolerant conifers, including Thuja occidentalis. For the past several decades, large-scale T. occidentalis regeneration in remnant T. occidentalis and adjacent Betula papyrifera forests has not occurred. Using a combination of restoration experiments and field surveys at three study sites on the Lake Superior Highlands, Minnesota, U.S.A., we examined safe sites for T. occidentalis regeneration under both Thuja and Betula canopy types. This study focused on the colonization and establishment phases of regeneration, differentiating among safe-site components for T. occidentalis. Seedbed type determined colonization success, with higher rates on conifer logs than on B. papyrifera logs, mounds, or pits. Mortality rates for seedlings on natural decayed wood seedbeds were higher under Thuja canopy than under Betula canopy, but the reverse was true for seedlings on manipulated seedbeds, suggesting that seedbed type was more important than the dominant canopy type. Growth rates for seedlings on moved log segments were greater under the Betula than the Thuja canopy type, but seedlings on natural decayed wood seedbeds did not exhibit this difference. Results indicated that T. occidentalis regeneration was more limited in Betula forest by seedbed availability, while in Thuja forest canopy conditions were more limiting.

Notes: FIRESUM, an ecological process model incorporating surface fire disturbance, was modified for use in southwestern ponderosa pine ecosystems. The model was used to determine changes in forest structure over time and then applied to simulate changes in aboveground biomass and nitrogen storage since exclusion of the natural frequent fire regime in an unharvested Arizona forest. Dendroecological reconstruction of forest structure in 1876, prior to Euro-American settlement, was used to initialize the model; projections were validated with forest measurements in 1992. Biomass allocations shifted from herbaceous plants to trees, and nitrogen was increasingly retained in living and dead tree biomass over the 116-year period (1876–1992). Forest conditions in 1992 were substantially degraded compared to reference presettlement conditions: old-growth trees were dying at accelerated rates, herbaceous production was reduced nearly 90%, and the entire stand was highly susceptible to high-intensity wildfire. Following an experiment initiated in 1993 to test ecological restoration treatments, future changes were modeled for the next century. Future forest structure remained within the natural presettlement range of variability under the full restoration treatment, in which forest biomass structure was thinned to emulate presettlement conditions and repeated low-intensity fire was reintroduced. Simulation of the control treatment indicated continuation of exceptionally high tree density, probably culminating in stand-replacing ecosystem change through high-intensity wildfire or tree mortality from pathogens. Intermediate results were observed in the partial restoration treatment (tree thinning only); the open forest structure and high herbaceous productivity found immediately after treatment were gradually degraded as dense tree cover reestablished in the absence of fire. Modeling results support comprehensive restorative management as a long-term approach to conservation of key indigenous ecosystem characteristics.

Notes: Algal communities were investigated in two contrasting chronosequences established on reclaimed spoils in the west Bohemian brown coal mining district near Sokolov (Czech Republic) and in the Lusatian lignite mining district near Cottbus (Germany). The Sokolov chronosequence was characterized by tertiary cypric clay substrate, afforestation with Alnus glutinosa (L.) Gaertn., and high pH of deposited spoil material, Cottbus chronosequence by tertiary carboniferous and pyritic sand of extremely low pH ameliorated by fly ash, and afforestation with Pinus sylvestris L. and P. nigra Arnold. A total of 122 species of algae was found in both areas. Although the same species number (80) was identified from Sokolov and Cottbus, both proportion of individual algal groups and species composition were different. Green algae prevailed in both areas, but in Sokolov cyanobacteria and diatoms were also quite diverse, and in younger sites they were also abundant. Total abundance of algae ranged mostly between 104–107 cells/g dry soil, and was one order higher in Cottbus than in Sokolov. Species number was high in young sites, decreased with increasing age, and was the lowest in control forests. In Sokolov, the highest abundance was recorded in the youngest alder plantation. In Cottbus, sludge and compost fertilization used in the youngest pine plantations resulted in rapid formation of visible algal crusts dominated by Klebsormidium crenulatum (Kütz) Lokhorst.

Notes: This article compares reclaimed soils in the Rhineland lignite mining area, Germany (RA) and in the north Bohemian brown coal basin, Czech Republic (NBB). Because of highly significant differences of physical and chemical characteristics (RA was characterized by lower content of sand, clay, soil organic carbon, and total nitrogen) between both analyzed areas, the content of microbial biomass carbon (CMB) differs significantly (p 〈 0.01): RA: 241.17 ± 96.50 μg C/g dry soil; NBB: 424.42 ± 136.23 μg C/g. Extracellular microbial carbon (CEX) was also significantly higher in RA than NBB. The measured CMB values from both mining areas were verified using two empirical mathematical models. Because our former model (used for evaluation of NBB) did not fit soils with low organic carbon content (0.10–0.80%), a new model was proposed. For evaluation of RA reclaimed sites the measured, model-predicted, and calculated values were used. The best site in RA was Dürwiss Deponie (site 18 near Eschweiler), reclaimed in 1965 and characterized by good soil physical parameters (sand 4%, silt 77%, and clay 19%). In NBB undisturbed soils were the best, together with the site of Úžín (site 2 near Ústí and Labem), reclaimed in 1964, where high-quality reclamation management resulted in high biological activity. According to biological criteria, the best management practice in NBB was use of high-quality loam overlaying montmorillonite clayey subsoil. In RA direct reclamation of high-quality loess with low content of sand also gave good results.

Notes: High soil pH has been highlighted as a constraint to the restoration of heathland on ex-arable land. Previous studies at the Minsmere Reserve of the Royal Society for the Protection of Birds (RSPB) in England have shown that it is possible to acidify ex-arable soils using elemental sulfur and bracken litter, although sulfur (S) is more effective. Current recommendations suggest that 4 tS/ha need to be applied to reduce soil pH below pH 4, control vigorous ruderal species, and create conditions suitable for Calluna vulgaris (heather) establishment. However, S is relatively expensive, and as bracken litter is moderately abundant within the reserve, it made economic sense to evaluate the potential for mixing S with bracken to see if adequate pH reductions could be achieved at lower S rates. Accordingly an experiment was designed to test the effects of combining S (0–8 t S/ha) and bracken litter (0–10 cm depth layers) on (1) soil pH, (2) cover of ruderal species, and (3) the developing plant community. Significant interactions were detected, especially in the period immediately after application. Where bracken litter was applied the soil pH fell immediately; in contrast, S took at least six months to start reducing pH. Where mixtures were applied there was a synergistic effect, which produced a lower pH than the S or bracken litter applied alone. These effects were most marked at low S application rates, between 0.5–4 t S/ha. The effects of the bracken litter addition also reduced the growth of ruderal species in the period immediately after application, probably through a combination of acidification and physical smothering. There is, therefore, a clear potential to acidify ex-arable soils using combinations of S and bracken litter in schemes designed to restore Calluna heathland.

Notes: The hypothesis that habitat restoration will provide for community reestablishment and the creation of habitat heterogeneity was examined with regards to the herpetofauna of longleaf pine sandhills in northwest Florida. The herpetofaunal response to restoration was examined in fire-suppressed, hardwood-dominated areas treated with (1) spring fire; (2) felling or girdling; or (3) a granular form of the herbicide hexazinone. No-treatment controls were also included. Felling or girdling and herbicide plots were burned for fuel reduction two dormant seasons after initial treatment application. Additionally, data were collected in frequently burned reference sandhills to establish the target condition or restoration goal. Vegetation variables and herpetofaunal capture rates were compared among control and treatment areas. Two similarity indices were utilized to compare treatments and controls with reference sites, to examine restoration success. Restoration treatment effects were observed through reduced hardwood densities. Litter composition varied among control and treatment plots, with leaf litter being highest in areas lacking recent fire. Capture rates of some herpetofaunal species varied significantly among treatment plots. In 1997 similarity indices showed that spring-burned and felling or girdling plots were more similar to the reference sandhills than the other plots. Treated plots were not significantly different from controls in 1998, a year of a severe drought.

Notes: There are two reasons for strategic planning in passive wildlife restoration: first, to maximize the potential for colonization of restoration sites in challenged landscapes, and second, to maximize the contribution of each restoration project to regional, management area, ecosystem, or target species goals. Landscape configuration and the demographic/dispersal characteristics of target species can govern the level of wildlife response to habitat restoration projects. This is particularly true for fragmented habitats in rapidly suburbanizing areas, where the widely held notion that wildlife can colonize any restored habitat is challenged by barriers to dispersal. Because habitat restoration is a passive means of restoring wildlife populations, equal weight needs to be given to the context (likelihood of site colonization by target species) as well as the content (habitat) of restoration projects. Defining spatial patterns of demography, dispersion, and dispersal allows restorationists to place projects where they can have the greatest impact on the threats and sensitivities of target species, and the greatest contribution to the persistence and/or recovery of populations. Further, it provides a means of evaluating the relative potential worth of different restoration sites. If passive wildlife restoration is to be successful, the constraints to colonization need to be interpreted with regional goals of ecosystem and species management in mind.

Notes: Restoration of bottomland hardwood forests is the subject of considerable interest in the southern United States, but restoration success is elusive. Techniques for establishing bottomland tree species are well developed, yet problems have occurred in operational programs. Current plans for restoration on public and private land suggest that as many as 200,000 hectares could be restored in the Lower Mississippi Alluvial Valley alone. The ideal of ecological restoration is to reestablish a completely functioning ecosystem. Although some argue that afforestation is incomplete restoration, it is a necessary and costly first step but not an easy task. The 1992 Wetlands Reserve Program in Mississippi, which failed on 90% of the area, illustrates the difficulty of broadly applying our knowledge of afforestation. In our view, the focus for ecological restoration should be to restore functions, rather than specifying some ambiguous natural state based on reference stands or pre-settlement forest conditions. We view restoration as one element in a continuum model of sustainable forest management, allowing us to prescribe restoration goals that incorporate landowner objectives. Enforcing the discipline of explicit objectives, with restoration expectations described in terms of predicted values of functions, causal mechanisms and temporal response trajectories, will hasten the development of meaningful criteria for restoration success. We present our observations about current efforts to restore bottomland hardwoods as nine myths, or statements of dubious origin, and at best partial truth.

Notes: Restoration ecology plays an important role in nature conservation policy in Europe today. It establishes the scientific basis for restoring ecosystems altered or destroyed by man to a more “natural” state. The goals of restoration ecology can generally be described in terms of increased biodiversity, enhanced water retention capacity, avoidance of soil erosion, etc. In practice, however, a discrepancy exists between the high ideals of restoration goals and reality, where one often encounters limiting factors. These limiting factors can include the conflict between different restoration goals, the unpredictability of restoration goals owing to long-term effects and stochastic events, the insufficient social acceptance of landscape changes during restoration processes, and the use of restoration processes themselves (e.g., undisturbed succession, certain management measures like impoverishment of fertilized areas) as restoration goals in place of a certain resource quality (such as species composition, population sizes, water quality). Two examples from southern Germany show that restoration goals in European cultural landscapes can only be implemented successfully when they are integrated into the respective land use systems.

Notes: The extent of human-induced change and damage to Earth's ecosystems renders ecosystem repair an essential part of our future survival strategy, and this demands that restoration ecology provide effective conceptual and practical tools for this task. We argue that restoration ecology has to be an integral component of land management in today's world, and to be broadly applicable, has to have a clearly articulated conceptual basis. This needs to recognize that most ecosystems are dynamic and hence restoration goals cannot be based on static attributes. Setting clear and achievable goals is essential, and these should focus on the desired characteristics for the system in the future, rather than in relation to what these were in the past. Goal setting requires that there is a clear understanding of the restoration options available (and the relative costs of different options). The concept of restoration thresholds suggests that options are determined by the current state of the system in relation to biotic and abiotic thresholds. A further important task is the development of effective and easily measured success criteria. Many parameters could be considered for inclusion in restoration success criteria, but these are often ambiguous or hard to measure. Success criteria need to relate clearly back to specific restoration goals. If restoration ecology is to be successfully practiced as part of humanity's response to continued ecosystem change and degradation, restoration ecologists need to rise to the challenges of meshing science, practice and policy. Restoration ecology is likely to be one of the most important fields of the coming century.

Notes: Prairie restoration is not complete without the establishment of both grasses and forbs. However, if desirable forbs and grasses are seeded simultaneously, control of broadleaf weeds is problematic. If possible, a two-step process of introducing forbs after establishing grasses would allow use of broadleaf-specific herbicides at the critical early stages of grass growth. We conducted experiments to investigate methods for introducing forbs into previously restored native perennial grasslands on rural roadsides in the Sacramento Valley of California. In one experiment, we studied the effects of background vegetation (established perennial grasses or tilled ground) on seven native forb species planted from seed. In a second experiment, we evaluated the effects of background vegetation (existing perennial grasses or tilled ground) and container size (36 ml or 105 ml) with excavation technique (excavation by core removal [core] or by creating an impression [dibble]) on the growth of transplants of the native perennial forbs Asclepias fascicularis and Sisyrinchium bellum. The presence of established perennial grasses reduced the growth of seeded forbs, but did not affect transplants, indicating the vulnerability of seedling forbs to interference. When compared to control plots that had been tilled in the autumn, weed canopy cover was significantly lower in the presence of perennial grasses if seeded with forbs, but not in the presence of perennial grasses alone. Both transplanted species grew better in the large container/core treatment than the small container/dibble treatment; however, existing grasses eliminated these positive effects. Asclepias fascicularis performed better when grown in large containers than in small containers, but its growth was not affected by excavation method; S. bellum performed better when planted with the core method than the dibble method of excavation, but container size made no difference. We attribute differences in the responses of the species to interactions between phenological differences and expansive clay soils that naturally de-compact upon drying.

Notes: Invasion by woody alien plants, construction, and mining operations are among the major disturbances degrading vegetation in the Cape Floristic Kingdom, South Africa. The aim of this study was to assess whether native fynbos shrubland vegetation could be restored following dense alien invasion and disturbance by mining. An area supporting dense alien trees was cleared and topsoil was stripped and stockpiled to simulate mining disturbance. A field trial investigated the effects of topsoil depth, seed mix application, and fertilizer on native species recruitment and vegetation development over a three-year period. Soil-stored seed banks contributed 60% of the species recruited, indicating that areas invaded for three decades have good restoration potential. The addition of a fynbos seed mix, which included serotinous overstory species, improved both the richness and structural composition of the vegetation. Most species sown in untopsoiled plots established, but survival and growth was low compared to topsoil plots. Poor growth in combination with a lack of soil seed bank species, indicate that restoring a diverse and functional cover of indigenous vegetation on subsoil is not possible in the short-term. Soil amelioration is required to improve rooting conditions and initiate ecosystem processes. Shallow and deep topsoil treatments yielded high plant density, richness, and projected canopy cover, but canopy cover was higher in deep topsoil plots throughout the trial. Fertilizer addition increased canopy cover in untopsoiled and shallow topsoil plots via an increase in alien annual species. Fertilizer addition ultimately may lead to increased native vegetation cover in untopsoiled areas, but as it increased proteoid mortality on deep topsoil plots, it is not recommended for sites where topsoil is available. A species-rich and structurally representative fynbos community may be restored on topsoiled areas provided that the native disturbance regime is simulated and seeds of major structural guilds not present in the soil seed bank are included in the seed mix.

Notes: An experimental analysis of soil water retention was conducted on three substrates (an abandoned road, an overburden pile, and a heap leach) created by gold mining activities in the Mojave Desert in southeastern California. We mixed each substrate with straw, and the overburden pile and heap leach with growth medium, then applied surface rock mulch to half the plots in an attempt to increase soil water-holding capacity for revegetation efforts. For each of the six treatments (controls included) we monitored soil water with time domain reflectometry following both a simulation of a rainfall event and a natural rainfall that occurred immediately following the simulation. Both the simulation and the rainfall increased soil water between 3 and 8%, depending on the substrate. Water retention patterns in the two-week periods following each water addition were similar between the simulation and rainfall, and among all substrate types as values returned to background (pre-water) conditions. The abandoned road substrate had higher background water content (16.5%) than the overburden pile (6%) and heap leach (5%). The road also had three times higher organic matter and five times higher soil nitrogen than the other two sites. Soil water retention was improved on the overburden pile by the addition of just surface rock mulch or of straw-plus-rock mulch. On the heap leach, increases were found with rock mulch only or with growth medium-plus-rock mulch. Rock mulches did not improve soil water retention and straw additions decreased soil water on the abandoned road. Judicious use of soil amendments can improve soil water conditions and improve revegetation efforts on disturbed lands in desert environments.

Notes: Models of fluid/rock interaction in and adjacent to the Alpine Fault in the Hokitika area, South Island, New Zealand, were investigated using hydrogen and other stable isotope studies, together with field and petrographic observations. All analysed samples from the study area have similar whole-rock δD values (δDWR = −56 to −30‰, average = −45‰, n = 20), irrespective of rock type, degree of chloritization, location along the fault, or across-strike distance from the fault in the garnet zone. The green, chlorite-rich fault rocks, which probably formed from Australian Plate precursors, record nearly isothermal fluid/rock interaction with a schist-derived metamorphic fluid at high temperatures near 450–500°C (δD of water in equilibrium with the green fault rocks (δDH2O, green) ≈ −18‰; δD of water in equilibrium with the greyschists and greyschist-derived mylonites (δDH2O, grey) ≈ −19‰ at 500°C; δDH2O, green ≈ −17‰; δDH2O, grey ≈ −14‰ at 450°C). There is no indication of an influx of a meteoric or mantle-derived fluid in the Alpine Fault Zone in the study area. The Alpine Fault Zone at the surface shows little evidence of late-stage retrogression or veining, which might be attributed to down-temperature fluid flow. It is probable that prograde metamorphism in the root zone of the Southern Alps releases metamorphic fluids that at some region rise vertically rather than following the trace of the Alpine Fault up to the surface, owing to the combined effects of the fault, the disturbed isotherms under the Southern Alps, and the brittle–ductile transition. Such fluids could mix with meteoric fluids to deposit quartz-rich, possibly gold-bearing veins in the region c. 5–10 km back from the fault trace. These results and interpretations are consistent with interpretations of magnetotelluric data obtained in the South Island GeopHysical Transects (SIGHT) programme.

Notes: Metagranodiorite samples from the Brossasco-Isasca Unit, Dora-Maira Massif, western Alps, show pseudomorphous and coronitic textures where igneous minerals were partially replaced by ultra-high pressure (UHP) metamorphic assemblages. The original magmatic paragenesis consisted of quartz, plagioclase, K-feldspar, biotite and minor phases. During UHP metamorphism, the plagioclase (site P) was replaced by zoisite, jadeite, quartz, K-feldspar and kyanite, and coronitic reactions developed between biotite and adjacent minerals. At the original igneous biotite–quartz contact (site A), a single corona of poorly zoned garnet is developed, whereas at the biotite–K-feldspar (site B) and biotite–plagioclase (site C) contacts, composite coronas are formed. Integration of results from petrographic observations, calculations of mineral stoichiometry and thermodynamic calculations of mineral stability has allowed the determination of the metamorphic reactions involved and the estimation of the metamorphic conditions, which reached as high as 24 kbar and 650 °C. Accurate microanalysis by energy-dispersive spectroscopy (EDS) and statistical analysis of the data allowed us to identify, for the first time in a natural Na-pyroxene of metagranitoid rocks, the end-member Ca-Eskola.