ALBERT

Notes: Andalusite porphyroblasts are totally pseudomorphosed by margarite–paragonite aggregates in aluminous pelites containing the peak mineral assemblage andalusite, chlorite, chloritoid, margarite, paragonite, quartz ± garnet, in a NW Iberia contact area. Equilibria at low P–T are investigated using new KFMASH and (mainly) MnCNKFMASH grids constructed with Thermocalc 3.21. P–T and T–X pseudosections with phase modal volume isopleths are constructed for compositions relatively richer and poorer in andalusite to model the assemblages in an andalusite-bearing rock that contains a thin andalusite-rich band (ARB) during retrogression. Their compositions, prior to retrogression, are used in the modelling, and have been retrieved by restoring the pseudomorph-forming elements into the current-depleted matrix, except for Al2O3 which is assumed to be immobile. Compositional differences between the thin band and the rest of the rock have not resulted in differences in andalusite porphyroblast retrogression. The absence of chloritoid resorbtion implies either a pressure increase at constant reacting-system composition, or that its composition changed during retrogression at constant pressure, by becoming enriched in the progressively replaced andalusite porphyroblasts. T–X pseudosections at 1 kbar model this latter process using as end-members in X, first, the restored original rock and ARB compositions, and, then the same process, taking into account the change in composition of both as retrogression proceeded. The MnNCKFMASH pseudosections of rocks with different Al contents facilitate making further deductions on the rock-composition control of the resulting assemblages upon retrogression. Andalusite eventually disappears in relatively Al-poor rocks, resulting, as in this study, in a rock formed by chloritoid–chlorite as the only FM minerals, plus margarite–paragonite pseudomorphs of andalusite. In rocks richer in Al, chlorite would progressively disappear and a kyanite/andalusite–chloritoid assemblage would eventually be stable at retrograde conditions. The Al-silicate, stable during retrogression in Al-rich rocks, indicates pressure conditions and hence the tectonic context under which retrogression took place.

Notes: In statistically optimised P–T estimation, the contributions to overall uncertainty from different sources are represented by ellipses. One source, for a diffusion-controlled reaction at non-equilibrium, is diffusion modelling of the reaction texture. This modelling is used to estimate ratios, Q, between free-energy differences, ΔG, of reactions among mineral end-members, to replace the equilibrium condition ΔG = 0. The associated uncertainty is compared with those already inherent in the equilibrium case (from end-member data, activity models and mineral compositions). A compact matrix formulation is introduced for activity coefficients, and their partial derivatives governing error propagation. The non-equilibrium example studied is a corona reaction with the assemblage Grt–Opx–Cpx–Pl–Qtz. Two garnet compositions are used, from opposite sides of the corona. In one of them, affected by post-reaction Fe, Mg exchange with pyroxene, the problem of reconstructing the original composition is overcome by direct use of ratios between chemical-potential differences, given by the diffusion modelling. The number of geothermobarometers in the optimisation is limited by near-degeneracies. Their weightings are affected by strong correlations among Q ratios. Uncertainty from diffusion modelling is not large in comparison with other sources. Overall precision is limited mainly by uncertainties in activity models. Hypothetical equilibrium P–T are also estimated for both garnet compositions. By this approach, departure from equilibrium can be measured, with statistical uncertainties. For the example, the result for difference from equilibrium pressure is 1.2 ± 0.7 kbar.

Notes: This paper characterizes the metamorphic thermal structure of the Higo Metamorphic Complex (HMC) and presents the results of a numerical simulation of a geotherm with melt migration and solidification. Reconstruction of the geological and metamorphic structure shows that the HMC initially had a simple thermal structure where metamorphic temperatures and pressures increased towards apparent lower structural levels. Subsequently, this initial thermal structure has been collapsed by E–W and NNE–SSW trending high-angle faults. Pressure and temperature conditions using the analysis of mineral assemblages and thermobarometry define a metamorphic field P–T array that may be divided into two segments: the array at apparent higher structural levels has a low-dP/dT slope, whereas that at apparent lower structural levels has a high-dP/dT slope. This composite array cannot be explained by heat conduction in subsolidus rocks alone. Migmatite is exposed pervasively at apparent lower structural levels, but large syn-metamorphic plutons are absent at the levels exposed in the HMC. Transport and solidification of melt within migmatite is a potential mechanism to generate the composite array. Thermal modelling of a geotherm with melt migration and solidification shows that the composite thermal structure may be formed by a change of the dominant heat transfer from an advective regime to a conduction regime with decreasing depth. The model also predicts that strata beneath the crossing point will consist of high-grade solid metamorphic rocks and solidified melt products, such as migmatite. This prediction is consistent with the observation that migmatite was associated with the very high-dP/dT slope. The melt migration model is able to generate the very high-dP/dT segment due to the high rate of heat transfer by advection.

Notes: This study analyses the mineralogical and chemical transformations associated with an Alpine shear zone in polymetamorphic metapelites from the Monte Rosa nappe in the upper Val Loranco (N-Italy). In the shear zone, the pre-Alpine assemblage plagioclase + biotite + kyanite is replaced by the assemblage garnet + phengite + paragonite at eclogite facies conditions of about 650 °C at 12.5 kbar. Outside the shear zone, only minute progress of the same metamorphic reaction was attained during the Alpine metamorphic overprint and the pre-Alpine mineral assemblage is largely preserved. Textures of incomplete reaction, such as garnet rims at former grain contacts between pre-existing plagioclase and biotite, are preserved in the country rocks of the shear zone. Reaction textures and phase relations indicate that the Alpine metamorphic overprint occurred under largely anhydrous conditions in low strain domains. In contrast, the mineralogical changes and phase equilibrium diagrams indicate water saturation within the Alpine shear zones. Shear zone formation occurred at approximately constant volume but was associated with substantial gains in silica and losses in aluminium and potassium. Changes in mineral modes associated with chemical alteration and progressive deformation indicate that plagioclase, biotite and kyanite were not only consumed in the course of the garnet-and phengite-producing reactions, but were also dissolved ‘congruently’ during shear zone formation. A large fraction of the silica liberated by plagioclase, biotite and kyanite dissolution was immediately re-precipitated to form quartz, but the dissolved aluminium- and potassium-bearing species appear to have been stable in solution and were removed via the pore fluid. The reaction causes the localization of deformation by producing fine-grained white mica, which forms a mechanically weak aggregate.

Notes: Low-pressure crystal-liquid equilibria in pelitic compositions are important in the formation of low-pressure, high-temperature migmatites and in the crystallization of peraluminous leucogranites and S-type granites and their volcanic equivalents. This paper provides data from vapour-present melting of cordierite-bearing pelitic assemblages and augments published data from vapour-present and vapour-absent melting of peraluminous compositions, much of which is at higher pressures. Starting material for the experiments was a pelitic rock from Morton Pass, Wyoming, with the major assemblage quartz-K feldspar-biotite-cordierite, approximately in the system KFMASH. A greater range in starting materials was obtained by addition of quartz and sillimanite to aliquots of this rock. Sixty-one experiments were carried out in cold-seal apparatus at pressures of 1–3.5 kbar (particularly 2 kbar) and temperatures from 700 to 840 °C, with and without the addition of water. In the vapour-present liquidus relations at 2 kbar near the beginning of melting, the sequence of reactions with increasing temperature is: Qtz + Kfs + Crd + Sil + Spl + V = L; Qtz + Kfs + Crd + Spl + Ilm + V = Bt + L; and Qtz + Bt + V = Crd + Opx + Ilm + L. Vapour-absent melting starts at about 800 °C with a reaction of the form Qtz + Bt = Kfs + Crd + Opx + Ilm + L. Between approximately 1–3 kbar the congruent melting reaction is biotite-absent, and biotite is produced by incongruent melting, in contrast to higher-pressure equilibria. Low pressure melts from pelitic compositions are dominated by Qtz-Kfs-Crd. Glasses at 820–840 °C have calculated modes of approximately Qtz42Kfs46Crd12. Granites or granitic leucosomes with more than 10–15% cordierite should be suspected of containing residual cordierite. The low-pressure glasses are quite similar to the higher-pressure glasses from the literature. However, XMg increases from about 0.1–0.3 with increasing pressure from 1 to 10 kbar, and the low-temperature low-pressure glasses are the most Fe-rich of all the experimental glasses from pelitic compositions.

Notes: Quartz-rich veins in metapelitic schists of the Sanandaj-Sirjan belt, Hamadan region, Iran, commonly contain two Al2SiO5 polymorphs, and, more rarely, three coexisting Al2SiO5 polymorphs. In most andalusite and sillimanite schists, the types of polymorphs in veins correlate with Al2SiO5 polymorph(s) in the host rocks, although vein polymorphs are texturally and compositionally distinct from those in adjacent host rocks; e.g. vein andalusite is enriched in Fe2O3 relative to host rock andalusite. Low-grade rocks contain andalusite + quartz veins, medium-grade rocks contain andalusite + sillimanite + quartz ± plagioclase veins, and high-grade rocks contain sillimanite + quartz + plagioclase veins/leucosomes. Although most andalusite and sillimanite-bearing veins occur in host rocks that also contain Al2SiO5, kyanite-quartz veins crosscut rocks that lack Al2SiO5 (e.g. staurolite schist, granite). A quartz vein containing andalusite + kyanite + sillimanite + staurolite + muscovite occurs in andalusite–sillimanite host rocks. Textural relationships in this vein indicate the crystallization sequence andalusite to kyanite to sillimanite. This crystallization sequence conflicts with the observation that kyanite-quartz veins post-date andalusite–sillimanite veins and at least one intrusive phase of a granite that produced a low-pressure–high-temperature contact aureole; these relationships imply a sequence of andalusite to sillimanite to kyanite. Varying crystallization sequences for rocks in a largely coherent metamorphic belt can be explained by P–T paths of different rocks passing near (slightly above, slightly below) the Al2SiO5 triple point, and by overprinting of multiple metamorphic events in a terrane that evolved from a continental arc to a collisional orogen.

Notes: Zircon fission track dating and track length analysis in the high-grade part of the Asemigawa region of the Sanbagawa belt demonstrates a simple cooling history passing through the partial annealing zone at 63.2 ± 5.8 (2 σ) Ma. Combining this age with previous results of phengite and amphibole K–Ar and 40Ar/39Ar dating gives a cooling rate of between 6 and 13 °C Myr−1, which can be converted to a maximum exhumation rate of 0.7 mm year−1 using the known shape of the P–T path. This is an order of magnitude lower than the early part of the exhumation history. In contrast, zircon fission track analyses in the low-grade Oboke region show that this area has undergone a complex thermal history probably related to post-orogenic secondary reheating younger than c. 30 Ma. This event may correlate with the widespread igneous activity in south-west Japan around 15 Ma. The age of subduction-related metamorphism in the Oboke area is probably considerably older than the generally accepted range of 77–70 Ma.

Notes: Garnet-bearing ultramafic rocks including clinopyroxenite, wehrlite and websterite locally crop out in the Higashi-akaishi peridotite of the Besshi region in the Cretaceous Sanbagawa metamorphic belt. These rock types occur within dunite as lenses, boudins or layers with a thickness ranging from a few centimetres to 1 metre. The wide and systematic variation of bulk-rock composition and the overall layered structure imply that the ultramafic complex originated as a cumulate sequence. Garnet and other major silicates contain rare inclusions of edenitic amphibole, chlorite and magnetite, implying equilibrium at relatively low P–T conditions during prograde metamorphism. Orthopyroxene coexisting with garnet shows bell-shaped Al zoning with a continuous decrease of Al from the core towards the rim, consistent with rims recording peak metamorphic conditions. Estimated P–T conditions using core and rim compositions of orthopyroxene are 1.5–2.4 GPa/700–800 °C and 2.9–3.8 GPa/700–810 °C, respectively, implying a high P/T gradient (〉 3.1 GPa/100 °C) during prograde metamorphism. The presence of relatively low P–T conditions at an early stage of metamorphism and the steep P/T gradient together trace a concave upwards P–T path that shows increasing P/T with higher T, similar to P–T paths reported from other UHP metamorphic terranes. These results suggest either (1) down dragging of hydrated mantle cumulate parallel to the slab–wedge interface in the subduction zone by mechanical coupling with the subducting slab or (2) ocean floor metamorphism and/or serpentinization at early stage of subduction of oceanic lithosphere and ensuing HP–UHP prograde metamorphism.

Notes: During emplacement and cooling, the layered mafic–ultramafic Kettara intrusion (Jebilet, Morocco) underwent coeval effects of deformation and pervasive fluid infiltration at the scale of the intrusion. In the zones not affected by deformation, primary minerals (olivine, plagioclase, clinopyroxene) were partially or totally altered into Ca-amphibole, Mg-chlorite and CaAl-silicates. In the zones of active deformation (centimetre-scale shear zones), focused fluid flow transformed the metacumulates (peridotites and leucogabbros) into ultramylonites where insoluble primary minerals (ilmenite, spinel and apatite) persist in a Ca-amphibole-rich matrix. Mass-balance calculations indicate that shearing was accompanied by up to 200% volume gain; the ultramylonites being enriched in Si, Ca, Mg, and Fe, and depleted in Na and K. The gains in Ca and Mg and losses in Na and K are consistent with fluid flow in the direction of increasing temperature.When the intrusion had cooled to temperatures prevailing in the country rock (lower greenschist facies), deformation was still active along the shear zones. Intense intragranular fracturing in the shear zone walls and subsequent fluid infiltration allowed shear zones to thicken to metre-scale shear zones with time. The inner parts of the shear zones were transformed into chlorite-rich ultramylonites. In the shear zone walls, muscovite crystallized at the expense of Ca–Al silicates, while calcite and quartz were deposited in ‘en echelon’ veins. Mass-balance calculations indicate that formation of the chlorite-rich shear zones was accompanied by up to 60% volume loss near the centre of the shear zones; the ultramylonites being enriched in Fe and depleted in Si, Ca, Mg, Na and K while the shear zones walls are enriched in K and depleted in Ca and Si. The alteration observed in, and adjacent to the chlorite shear zones is consistent with an upward migrating regional fluid which flows laterally into the shear zone walls. Isotopic (Sr, O) signatures inferred for the fluid indicate it was deeply equilibrated with host lithologies.

Notes: As the best preserved high- and ultrahigh-pressure (HP and UHP) metamorphic terrane in the Qinling-Dabieshan-Sulu orogen, western Dabieshan is divided into six lithotectonic units along a traverse across the orogen, i.e. from north to south, the Nanwan, Balifan, Huwan, Xinxian, Hong'an and Mulanshan units. In this terrane five eclogite-bearing zones (I–V) are developed. The garnet and clinopyroxene in eclogites from these zones exhibit chemical zoning, suggesting that the rims record general peak temperature and pressure. Thermobarometric study indicates that the peak P–T conditions of eclogite are 550–570°C and 21 kbar for Zone I, 470–500°C and 14–17 kbar for Zone II, 620–670°C and 26–29 kbar for Zone III, 530–560°C and 20–22 kbar for Zone IV, and 490–510°C and 19–20 kbar for Zone V. The symmetrical thermobaric pattern, in conjunction with structural and geochronological data, demonstrates that the Huwan and Hong'an units belong to the same HP slice overlying the UHP slice. This pattern, together with the Mulanshan LT/HP blueschist–greenschist belt in the south, roughly constitutes a ‘normal’ metamorphic zonation. However, clear metamorphic gaps occur between different slices. It is inferred that the LT/HP, HP and UHP slices were broken up from the downgoing slab during subduction and reached different depths along different geothermal gradients. The successive subduction of underlying slices leads to a nearly concomitant uplift of overlying slices, whereas exhumation of the deepest UHP slice was effected by underthrusting of the lower crust of the Yangtze craton.

Notes: The Zermatt-Saas serpentinite complex is an integral member of the Penninic ophiolites of the Central Alps and represents the mantle part of the oceanic lithosphere of the Tethys. Metamorphic textures of the serpentinite preserve the complex mineralogical evolution from primary abyssal peridotite through ocean-floor hydration, subduction-related high-pressure overprint, meso-Alpine greenschist facies metamorphism, and late-stage hydrothermal alteration. The early ocean floor hydration of the spinel harzburgites is still visible in relic pseudomorphic bastite and locally preserved mesh textures. The primary serpentine minerals were completely replaced by antigorite. The stable assemblage in subduction-related mylonitic serpentinites is antigorite–olivine–magnetite ± diopside. The mid-Tertiary greenschist facies overprint is characterized by minor antigorite recrystallization. Textural and mineral composition data of this study prove that the hydrated mineral assemblages remained stable during high-pressure metamorphism of up to 2.5 GPa and 650 °C. The Zermatt-Saas serpentinites thus provide a well documented example for the lack of dehydration of a mantle fragment during subduction to 75 km depth.

Notes: The reintroduction of Sphagnum fragments has been found to be a promising method for restoring mire vegetation in a cutaway peatland. Although it is known that moisture controls Sphagnum photosynthesis, information concerning the sensitivity of carbon dynamics on water-level variation is still scarce. In a 4-year field experiment, we studied the carbon dynamics of reintroduced Sphagnum angustifolium material in a restored (rewetted) cutaway peatland. Cutaway peatland restored by Sphagnum reintroduction showed high sensitivity to variation in water level. Water level controlled both photosynthesis and respiration. Gross photosynthesis (PG) had a unimodal response to water-level variation with optimum level at −12 cm. The range of water level for high PG (above 60% of the maximum light-saturated PG) was between 22 and 1 cm below soil surface. Water level had a dual effect on total respiration. When the water level was below soil surface, peat respiration increased rapidly along the lowering water level until the respiration rate started to slow down at approximately −30 cm. Contrary to peat respiration, the response of Sphagnum respiration to water-level variation resembled that of photosynthesis with an optimum at −12 cm. In optimal conditions, Sphagnum reintroduction turned the cutaway site from carbon source to a sink of 23 g C/m2 per season (mid-May to the end of September). In dry conditions, lowered photosynthesis together with the higher peat respiration led to a net loss of 56 g C/m2. Although the water level above the optimum amplitude restricted CO2 fixation, a decrease in peat respiration led to a positive CO2 balance of 9 g C/m2.

Notes: Restoration status of forest rehabilitation areas can be assessed by comparing their ecosystem characteristics with those of a reference system, most often what is considered the natural climax vegetation. However, comprehensive measurements needed for a traditional vegetation description are often hard or impractical in complex (sub)tropical ecosystems. Therefore, an alternative approach is the identification of simple indicators of ecosystem integrity. The use of such indicators can speed up the availability of resource inventories and thus contribute to the accelerated implementation of successful rehabilitation practices. Thermal buffer capacity (TBC) of ecosystems has been previously proposed as an overall indicator of ecosystem integrity. In this article, sequential surface-temperature measurements are proposed as a method for TBC assessment of different land-use types. Surface temperatures of seven land units in central Tigray (northern Ethiopia), each with a uniform land-use type (degraded and bushy grazing land, enriched and non-enriched rehabilitation area, and forest), were measured with a hand-held infrared thermometer in the rainy and the dry season. Surface-temperature models were derived by means of quadratic regression. Cross-correlation functions were calculated for all possible pairs of land-unit time-series data. Instantaneous heat-up rates, average TBC, and accumulated heat load were calculated. Repeated-measures analysis of variance was used to test the effect of aspect and protection status on TBC. Kruskal–Wallis one-way analysis of variance by ranks for small samples was used to test the significance of differences in heat-up rates and heat load among land-use groups. Time lags between land-unit surface temperatures are caused by differences in aspect rather than land-use type. Protection status and aspect have a significant effect on the average TBC. Results clearly demonstrate a differentiation between protected (low heat-up rate) and non-protected areas (high heat-up rate). Overall ranking suggests that the remnant forest has the highest TBC of all surveyed land-use types, followed by the enriched protected area. Results of this study show that TBC quickly responds to area closure and can therefore be used to monitor the development of protected areas. It is strongly recommended that a detailed monitoring strategy for protected areas on the basis of this technology be devised, validated, and finally transferred to the local communities.

Notes: An ecological functional assessment (EFA) was used on 10 southwest Costa Rica sites representing a chronosequence of formerly pastured lands to undisturbed tropical wet forest. Ecological functional assessment is a tool designed to assess wetland functions in the United States that was adapted to upland forests. Models to indicate characteristic soil hydrologic features and soil structure and aboveground spatial structure of habitat were used to examine the degree to which selected sites within the chronosequence approach the undisturbed condition of the natural forest. An index of the functional model for the maintenance of characteristic soil hydrologic features (such as infiltration, bulk density, etc.) showed that the 20-year-old secondary forest was at approximately 60% of the condition of the undisturbed sites, whereas active pasture was evaluated at approximately 20% of the reference undisturbed forest; 4- and 10-year-old sites were intermediate. The spatial structure of habitat model showed that 20-year-old secondary forest was approximately 50% of reference forest, whereas active pasture was approximately 10% of the condition of undisturbed forest; 4-year-old sites were evaluated at approximately 20% and 10-year-old sites at approximately 60% of the reference state. Overall the functional assessment process indicated that degraded tropical wet forest sites have recovered almost 60% of their functional qualities 10 years following pasture abandonment. These results indicate that EFA can be a useful technique for monitoring restoration programs in the tropics.

Notes: We evaluated changes in ecosystem function in semiarid Stipa tenacissima L. steppes along a degradation gradient in southeast Spain. We used soil surface indicators to obtain surrogates of ecosystem function (resistance to erosion, infiltration, and nutrient cycling) and related these values to the main abiotic and biotic characteristics of the experimental sites. When ranked in an ordered sequence, the trajectory of these indicators showed abrupt changes, providing empirical evidence of discontinuities in ecosystem function along the degradation gradient evaluated. Surrogates of resistance to erosion showed nonlinear relationships with variables defining the spatial structure of patches, the area covered by sprouting shrubs, and species richness. The latter two variables were significantly related to surrogates of nutrient cycling and infiltration. Our results suggest that sprouting shrubs are playing a key role in improving ecosystem function and composition in degraded S. tenacissima steppes. The implications of our results for the optimization of restoration procedures in semiarid degraded steppes are discussed.

Notes: Restoration of salt marsh ecosystems is an important concern in the eastern United States to mitigate damage caused by industrial development. Little attention has been directed to the mycorrhizal influence on plantings of salt marsh species to stabilize estuarine sediments and establish cover. In our study, seedlings of two salt marsh grasses, Spartina alterniflora and Spartina cynosuroides, were grown in soil with a commercial, mixed species inoculum of arbuscular mycorrhizal fungi. Plants were grown in experimental “ebb and flow” boxes, simulating three levels of tidal inundation, to which two levels of applied phosphorus (P) and two levels of salinity were imposed. After 2.5 months, S. alterniflora was poorly colonized by arbuscular mycorrhizae, developing only fungal hyphae and no arbuscules, but S. cynosuroides became moderately colonized. Mycorrhizal inoculation marginally improved growth and P and nitrogen (N) content of both plant species at low levels of P supply but significantly increased tillering in both plant species. This factor could be beneficial in enhancing ground cover during restoration procedures. Greater P availability increased the mycorrhizal status of S. cynosuroides and improved P nutrition of both plant species, despite a reduction in the root-to-shoot ratio. Increasing salinity reduced mycorrhizal colonization of S. alterniflora but not of S. cynosuroides. Growth and nutrient content of S. alterniflora was improved at higher levels of salinity, but only increased nutrient content in S. cynosuroides. Increased duration of tidal inundation decreased plant growth in both species, but tissue P and N concentrations were highest with the longest time of inundation in both species.

Notes: As monitoring plans for the restoration of Pinus ponderosa forests in the southwestern United States evolve toward examining multifactor ecosystem responses to ecological restoration, designing efficient sampling procedures for understory vegetation will become increasingly important. The objective of this study was to compare understory composition and diversity among thin/burn and control treatments in a P. ponderosa restoration, while simultaneously examining the effects of sampling design and multivariate analyses on which conclusions were based. Using multi-response permutation procedures (MRPP), we tested the null hypothesis of no difference in understory species composition among treatments using different data matrices (e.g., frequency and cover) for two different sampling methods. Treatment differences were subtle and were detected by an intensive 50, 1-m2 subplot sampling method for all data matrices but were not detected by a less intensive point-intercept sampling method for any matrix. Sampling methods examined in this study controlled results of multivariate analyses more than the data matrices used to summarize data generated by a sampling method. We partitioned data into plant life form and native/exotic species categories for MRPP, and this partitioning isolated plant groups most responsible for treatment differences. We also examined the effects of number of 1-m2 subplots sampled on mean-species-richness/m2 estimates and found that estimates based on 10 subplots and based on 50 subplots were highly correlated (r = 0.99). Species–area curves indicated that the 50, 1-m2 subplot sampling method detected the common species of sites but failed to detect the majority of rare species. Additional sampling-design studies are needed to develop single sampling designs that produce multifactor data on plant composition, diversity, and spatial patterns amenable to multivariate analyses as part of monitoring plans of vegetation responses to ecological restoration.

Notes: The relative abundances of Chenopodiaceae shrubs are different from the seed composition in the original seed mix when sown on mine waste material in semiarid regions of Western Australia. Experiments were therefore undertaken to determine what species interactions are responsible for shifts in relative abundance after seeding. The growth parameters of five members of the Chenopodiaceae were used to determine intra- and interspecific density-dependent interactions. Dominant and subordinant species were paired and grown in pots at differing densities. The growth parameters measured were height, root, and shoot biomass. Of the five species chosen for this study, Maireana georgei (golden bluebush) and Enchylaena tomentosa (ruby saltbush) do not establish well on mine site areas. These were sensitive to density in monoculture, as well as in the presence of both Atriplex bunburyana (silver saltbush) and Atriplex codonocarpa (flat-topped saltbush). Although Maireana brevifolia (small leaf bluebush) does establish successfully on mine sites when sown, it showed the same negative reaction when grown in monoculture and in a two-species mixture. Atriplex bunburyana and A. codonocarpa, in contrast, are dominant species and reacted differently when grown with increasing numbers of the target species (M. georgei, M. brevifolia, and E. tomentosa). Atriplex bunburyana did not exhibit any decreases in growth when grown in competition with up to four plants of the target species. However, A. codonocarpa did react adversely to the presence of the target species. It is thought that the resulting plant community organization reflects the original seed mixture, which is usually sown at a high density. Yet, this study has shown that the differing intra- and interspecific density responses of these chenopod species provide an indication of the resulting community organization. To maximize diversity and to prevent dominance by highly competitive species, such as A. bunburyana, it is important to take density-dependent effects into account during the restoration planning stage.

Notes: Plant species richness in rural landscapes of northern Europe has been positively influenced by traditional management for millennia. Owing to abandonment of these practices, the number of species-rich semi-natural grasslands has decreased, and remaining habitats suffer from deterioration, fragmentation, and plant species decline. To prevent further extinctions, restoration efforts have increased during the last decades, by reintroducing grazing in former semi-natural grasslands. To assess the ecological factors that might influence the outcome of such restorations, we made a survey of semi-natural grasslands in Sweden that have been restored during the last decade. We investigated how plant species richness, species density, species composition, and abundance of 10 species that are indicators of grazing are affected by (1) the size of the restored site, (2) the time between abandonment of grazing and restoration, (3) the time elapsed since restoration, and (4) the abundance of trees and shrubs at the restored site. Only two factors, abundance of trees and shrubs and time since restoration, were positively associated with total species richness and species density per meter square at restored sites. Variation in species composition among restored sites was not related to any of the investigated factors. Species composition was relatively similar among sites, except in mesic/wet grasslands. The investigated factors had small effects on the abundance of the grazing-indicator species. Only Campanula rotundifolia responded to restoration with increasing abundance and may thus be a suitable indicator of improved habitat quality. In conclusion, positive effects on species richness may appear relatively soon after restoration, but rare, short-lived species are still absent. Therefore, remnant populations in surrounding areas may be important in fully recreating former species richness and composition.

Notes: Ground and pelletized Wollastonite (Wo; CaSiO3) was added to a 50-m reach of an anthropogenically acidified stream within the Hubbard Brook Experimental Forest, New Hampshire, to evaluate its buffering and restoration potential. The Wo was highly effective in raising the pH, acid-neutralizing capacity (ANC), dissolved inorganic carbon (DIC), and Ca2+ concentrations of the stream water, but during the short duration of the experiment had no discernable effect on the stream biota. After initial, spike-like fluctuations in pH and concentrations of ANC, DIC, and Ca2+, the relatively slow dissolution rates of the Wo dampened extreme concentrations and contributed to relatively long-lasting (4 months) amelioration of streamwater acidity. Changes in concentrations of Ca2+, dissolved Si, ANC, and DIC were inversely related to streamflow. After several high, stream-discharge events, concentrations quickly and consistently returned to pre-event conditions.

Notes: The potential of Cephalophyllum inaequale was investigated for use in initiating ecosystem restoration in degraded landscapes of Namaqualand, South Africa. Cephalophyllum inaequale, a perennial shrub, is a member of the succulent Mesembryanthemaceae family, typical of the Succulent Karoo Biome and in particular of the Namaqualand area. A bioclimatic envelope was modeled to establish the area in which this species might feasibly be used. The regional bioclimatic potential for C. inaequale proved to be extensive, covering approximately 17,500 km2. An examination of the functional role of C. inaequale showed it to facilitate early seedling survival in this community. A nearest-neighbor study found no evidence of interspecific competition between C. inaequale and its dominant co-occurring species, possibly due to vertical stratification of rooting structures. Cephalophyllum inaequale significantly reduced wind speed and soil erosion. Experiments to test the feasibility of propagating, reintroducing, and establishing this species showed that it easily germinates from seed, and transplanted cuttings have a high survival rate. This study demonstrates that C. inaequale has potential for use in initiating the restoration of degraded lands in South Africa.

Notes: The cloud forests of Mexico have been degraded and severely fragmented, and urgently require restoration. However, progress with restoration has been constrained by a lack of information concerning the seedling ecology of native tree species. An experiment was therefore conducted to assess the influence of different environmental factors on the seedling survival and growth of four native tree species (Fagus grandifolia var. mexicana, Carpinus caroliniana, Symplocos coccinea, and Quercus acutifolia). The seedlings were established on three sites, in two contrasting environments: inside forest fragments and on adjacent agricultural land. Highly significant differences were recorded in seedling survival and growth among sites, environments, species, and interactions between these factors. Highest survival was recorded for Quercus, which uniquely among the four species displayed the same survival percentage inside and outside the forest. Survival of the other species was higher inside the forest. In contrast, growth rates of all four species were higher outside the forest. The most important cause of mortality outside the forest was desiccation, although significant seedling predation was also observed on two sites. Results indicate that all four species can be established successfully both within forest fragments and in neighboring agricultural areas, emphasizing the scope for forest restoration. However, the interactions observed between species, sites, and environments highlight the importance of accurate species–site matching if optimum rates of growth and survival are to be obtained. Quercus spp. have great potential for establishment on agricultural sites.

Notes: The mature oak (Quercus liaotungensis Koidz) forests in the Dongling mountains of northern China have become degraded in recent years because regeneration has been limited. To determine whether or not seedling establishment of the oak is seed limited, microsite limited, or predator limited and to determine whether seedling establishment is affected by ground cover, we conducted field experiments during a mast year and investigated the fate of seeds and the soil seed bank dynamics of the oak. A large acorn crop (128.8 acorns/m2) was observed in the study period, and the peak density of acorns on the forest floor reached 46.5 acorns/m2, suggesting that tree recruitment was not seed limited. Acorns in the soil seed bank were mainly lost through decay (principally after fungal attack), consumption in situ, and removal by animals. Predation (including consumption in situ and removal) accounted for 86.4% of acorn loss and was therefore likely to have been the most important factor influencing seed dynamics. More than 70% of acorns were found to have germinated, but no established seedling was observed on the forest floor. Using cages to exclude predators, it was estimated that 87% of acorns germinated and 49% became established as seedlings, indicating that the acorns on the forest floor could emerge and grow in the absence of predators. We conclude that the regeneration of the tree population is limited by predators rather than by the availability of microsites. The presence of ground cover increased the germination rate and increased the chance of seed survival in the early stage of the experiment, but at the end of the investigation, no established seedling was found in the quadrats both with and without ground cover, possibly because of high density of animal predators. On the basis of these results, we suggest that selective tree felling will increase the coverage of the herbaceous layer, which can further decrease the population density of the rodents, and thereby improve the regeneration of oak trees.

Notes: Reach-scale stream restorations are becoming a common approach to repair degraded streams, but the effectiveness of these projects is rarely evaluated or reported. We surveyed governmental, private, and nonprofit organizations in the state of Indiana to determine the frequency and nature of reach-scale stream restorations in this midwestern U.S. state. For 10 attempted restorations in Indiana, questionnaires and on-site assessments were used to better evaluate current designs for restoring stream ecosystems. At each restoration site, habitat and water quality were evaluated in restored and unrestored reaches. Our surveys identified commonalities across all restorations, including the type of restoration, project goals, structures installed, and level of monitoring conducted. In general, most restorations were described as stream-relocation projects that combined riparian and in-stream enhancements. Fewer than half of the restorations conducted pre- or post-restoration monitoring, and most monitoring involved evaluations of riparian vegetation rather than aquatic variables. On-site assessments revealed that restored reaches had significantly lower stream widths and greater depths than did upstream unrestored reaches, but riparian canopy cover often was lower in restored than in unrestored reaches. This study provides basic information on midwestern restoration strategies, which is needed to identify strengths and weaknesses in current practices and to better inform future stream restorations.

Notes: Abstract We examined the 7-year effects of three restoration treatments on leaf physiology and insect-resistance characteristics of pre-settlement age ponderosa pines (Pinus ponderosa Dougl. ex Laws.) at the Gus Pearson Natural Area (GPNA) in northern Arizona. Restoration treatments were: (1) thinned in 1993 to approximate pre-Euro-American settlement stand structure, (2) thinned plus prescribed burned in 1994 and 1998, and (3) untreated control. Tree physiological and insect-resistance characteristics were measured in year 2000, 7 years after thinning, using the same procedures as an earlier study performed in 1996. Consistent with the 1996 results, pre-dawn water potential in 2000 was consistently lower in the control than both thinned treatments. Both thinned treatments continued to have increased foliar nitrogen concentration in leaves 7 years after treatment. However lower leaf nitrogen concentration in the thinned and burned compared with the thinned treatment suggests lower nitrogen availability to trees in repeatedly burned plots. Analysis of leaf gas exchange characteristics and carbon isotope content (δ13C) suggests continued stimulation of photosynthesis by both thinning treatments. Differences among treatments in resin volume, a measure of bark beetle resistance, depended on season of measurement. Trees in both thinning treatments continued to have increased leaf toughness, a measure of resistance to insect folivores. Our results show that many beneficial effects of restoration treatments on carbon, water, and nitrogen relations and insect-resistance characteristics of pre-settlement ponderosa pines continue to be expressed 7 years after treatment at the GPNA.

Notes: Establishment of native plant populations on disturbed roadsides was investigated at Bryce Canyon National Park (BCNP) in relation to several revegetation and seedbed preparation techniques. In 1994, the BCNP Rim Road (2,683–2,770 m elevation) was reconstructed resulting in a 23.8-ha roadside disturbance. Revegetation comparisons included the influence of fertilizer on plant establishment and development, the success of indigenous versus commercial seed, seedling response to microsites, methods of erosion control, and shrub transplant growth and survival. Plant density, cover, and biomass were measured 1, 2, and 4 years after revegetation implementation (1995–1998). Seeded native grass cover and density were the highest on plots fertilized with nitrogen and phosphorus, but by the fourth growing season, differences between fertilized and unfertilized plots were minimal. Fertilizers may facilitate more rapid establishment of seeded grasses following disturbance, increasing soil cover and soil stability on steep and unstable slopes. However the benefit of increased soil nutrients favored few of the desired species resulting in lower species richness over time compared to unfertilized sites. Elymus trachycaulus (slender wheatgrass) plants raised from indigenous seed had higher density and cover than those from a commercial seed source 2 and 4 years after sowing. Indigenous materials may exhibit slow establishment immediately following seeding, but they will likely persist during extreme climatic conditions such as cold temperatures and relatively short growing seasons. Seeded grasses established better near stones and logs than on adjacent open microsites, suggesting that a roughened seedbed created before seeding can significantly enhance plant establishment. After two growing seasons, total grass cover between various erosion-control treatments was similar indicating that a variety of erosion reduction techniques can be utilized to reduce erosion. Finally shrub transplants showed minimal differential response to fertilizers, water-absorbing gels, and soil type. Simply planting and watering transplants was sufficient for the greatest plant survival and growth.

Notes: We compared four types of 30-year-old forest stands growing on spoil of opencast oil shale mines in Estonia. The stand types were: (1) natural stands formed by spontaneous succession, and plantations of (2) Pinus sylvestris (Scots pine), (3) Betula pendula (silver birch), and (4) Alnus glutinosa (European black alder). In all stands we measured properties of the tree layer (species richness, stand density, and volume of growing stock), understory (density and species richness of shrubs and tree saplings), and ground vegetation (aboveground biomass, species richness, and species diversity). The tree layer was most diverse though sparse in the natural stands. Understory species richness per 100-m2 plot was highest in the natural stand, but total stand richness was equal in the natural and alder stands, which were higher than the birch and pine stands. The understory sapling density was lower than 50 saplings/100 m2 in the plantations, while it varied between 50 and 180 saplings/100 m2 in the natural stands. Growing stock volume was the least in natural stands and greatest in birch stands. The aboveground biomass of ground vegetation was highest in alder stands and lowest in the pine stands. We can conclude that spontaneous succession promotes establishment of diverse vegetation. In plantations the establishment of diverse ground vegetation depends on planted tree species.

Notes: This study examined factors affecting germination, survival, and growth of the grass trees Xanthorrhoea gracilis and X. preissii on newly rehabilitated bauxite mine pits in the jarrah forest of southwestern Australia. Grazing by kangaroos (Macropus fuliginosus) was the major factor in reducing survival and growth of both species during the first 2 years. Provision of artificial grazing protection increased survival and growth (plant mass) of both species by 3-fold. Grazing by native vertebrates has not previously been identified as affecting mine restoration in Western Australia. Initial germination rates from sown seeds of X. preissii at eight replicate sites ranged from 25 to 64% with a mean of 42%. Corresponding figures for X. gracilis were 5–42% with a mean of 17%. Germination of X. gracilis was greater on heavier, moister soils, but X. preissii germinated better on sandier soils. High levels of initial germination did not ensure high survival. Plants of both species grew bigger and survived better on the lighter, sandy soils. Xanthorrhoea seedlings located in the depressions created by the ripping process grew larger than seedlings on the slopes of the riplines. The presence of plants of other species did not have a significant effect on survival. However, these plants facilitated the growth of both species when artificial grazing protection was unavailable. Plants of other species reduced the growth rates of Xanthorrhoea seedlings where artificial grazing protection was provided. Artificial shade by itself had no significant effect on growth of either species. In rehabilitated bauxite mines in the jarrah forest, the provision of grazing protection is recommended to ensure successful establishment and early survival of Xanthorrhoea spp.

Notes: To assess the potential for enhancing an existing stand of native perennial grasses on a California Coast Range Grassland site, we experimentally manipulated the seasonal timing and presence of grazing for 3 years (1994 through 1996) and of autumn burning for 2 years (1994 and 1995) and measured species cover for 6 years (1993 through 1998). We subjected the species matrix to classification (TWINSPAN) and ordination (CCA) and tested the ordination site scores as well as diversity indices with linear mixed effects models. Four distinct plant community groups emerged from the classification. Two of these were dominated by annual grasses and two by perennial grasses. No treatment effects were observed on diversity. For composition, temporal and spatial random effects were important mixed effects model parameters, as was the fixed effect covariate, pre-treatment CCA site score, indicating the importance of random environmental variation and initial starting conditions. Incorporation of these random effects and initial condition terms made for more powerful tests of the fixed effects, grazing season, and burning. We found no significant burning effects. Grazing removal imparted a shift in plant community from more annual-dominated toward more perennial-dominated vegetation. Individual perennial grass species responded differently according to genus and species. Nassella spp. increased gradually over time regardless of grazing treatment. Nassella pulchra (purple needlegrass) increase was greatest under spring grazing and N. lepida (foothill needlegrass) was greatest with grazing removal. Danthonia californica (California oatgrass) had little response over time under seasonal grazing treatments, but increased with grazing removal. Under relatively mesic weather conditions it appears that grazing removal from Coast Range Grasslands with existing native perennial grass populations can increase their cover. However if N. pulchra is the sole existing population, spring season-restricted grazing should be equally effective at enhancing cover of the native grass species.

Notes: A combination of air-photo interpretation, field data, and Geographic Information System (GIS) analysis was used to map riparian areas that are likely to provide wood and shade to small- and medium-sized streams and where, conversely, restoration might be most beneficial. The analysis encompassed all salmonid-bearing waters of the Nooksack River basin, in northwest Washington State, plus small tributaries that were thought to contribute wood or effective shading. The size and composition of each riparian stand was examined to determine whether trees were large enough to contribute logs that would form pools in the adjacent channel, with pool-forming size of wood a function of channel width. Riparian stands were classified according to whether they passed this pool-forming test. Model results were an exact match to actual conditions in 69% of field-verified stands. A large proportion (74%) of the stands failing the test in reaches of anadromous fish use were in agricultural areas. Passing stands typically had high shade levels, because both stream shade and effective large woody debris size are a function of the size of the trees relative to the size of the stream. The GIS layer of passing and failing riparian stands can be combined with layers depicting property ownership, threatened fish distribution, and other information to objectively prioritize riparian restoration locations and strategies.

Notes: The benefits of wetlands are now widely appreciated. Less widely known is that historically many wetlands were drained to help control malaria and other deadly diseases. This essay's general theme is that there are pros and cons to restoration or creation of wetlands. The specific theme is that mosquitoes pose practical and theoretical problems. In particular, abundant mosquitoes should not be regarded as an after-the-fact surprising side effect but rather, abundant mosquitoes should be viewed as a primary and foreseeable effect of providing habitat suitable for them. Yet our funding mechanisms and educational institutions often fail properly to address the reality that restoring or creating wetlands has a downside.

Notes: The recruitment of native seedlings is often reduced in areas where the invasive Amur honeysuckle (Lonicera maackii) is abundant. To address this recruitment problem, we evaluated the effectiveness of L. maackii eradication methods and restoration efforts using seedlings of six native tree species planted within eradication and unmanipulated (control) plots. Two eradication methods using glyphosate herbicide were evaluated: cut and paint and stem injection with an EZ-Ject lance. Lonicera maackii density and biomass as well as microenvironmental characteristics were measured to study their effects on seedling growth and survivorship. Mean biomass of Amur honeysuckle was 361 ± 69 kg/ha, and density was 21,380 ± 3,171 plants/ha. Both eradication treatments were effective in killing L. maackii (≥ 94%). The injection treatment was most effective on large L. maackii individuals (〉1.5 cm diameter), was 43% faster to apply than cutting and painting and less fatiguing for the operator, decreased operator exposure to herbicide, and minimized impact to nontarget vegetation. Deer browse tree protectors were used on half of the seedlings, but did not affect survivorship or growth. After 3 years, survival of native seedlings was significantly less where L. maackii was left intact (32 ± 3%) compared with the eradication plots (p 〈 0.002). Seedling survival was significantly different between cut (51 ± 3%) and injected (45 ± 3%) plots. Species had different final percent survival and rates of mortality. Species survival differed greatly by species (in descending order): Fraxinus pennsylvanica 〉 Quercus muehlenbergii ≥ Prunus serotina≥ Juglans nigra 〉 Cercis canadensis 〉 Cornus florida. Survivorship and growth of native seedlings was affected by a severe first-year drought and by site location. One site exhibited greater spring soil moisture, pH, percent open canopy, and had greater survivorship relative to the other site (55 ± 2 vs. 30 ± 2%). Overall, both L. maackii eradication methods were successful, but restorationists should be aware of the potential for differential survivorship of native seedlings depending on species identity and microenvironmental conditions.

Notes: Several eastern states are considering the restoration of free-ranging elk populations via translocation from western populations. Optimal habitat immediately surrounding release sites has been found to enhance elk reintroduction success in western states. Little information exists, however, to aid eastern managers in identifying release sites with the highest chance of restoration success. We monitored the movements of 415 translocated elk released at three sites in southeastern Kentucky to identify landscape characteristics that enhance release-site fidelity. The distance elk moved after release differed among sites (F2,322 = 4.63, p = 0.01), age classes (F2,322 = 4.37, p = 0.01), and time intervals (F2,322 = 40.74, p 〈 0.001). At 6 and 12 months post-release, adults (15.81 ± 17.32 and 16.38 ± 20.29) and yearlings (13.91 ± 16.44 and 14.61 ± 21.11) moved farther than calves (8.06 ± 14.03 and 9.37 ± 14.40). The release site with the highest fidelity was privately owned, 15% open, and had the highest amount of edge compared with the other release sites. The two remaining sites contained large amounts of expansive openland or forest cover with lower amounts of edge. Additionally, both sites were publicly owned and experienced a higher degree of human-generated disturbance compared with the site to which elk were most faithful. When selecting release sites, managers should avoid areas dominated by a single cover type with little interspersion of other habitats. Rather, areas with high levels of open-forest edge (approximately 5.0 km/km2) and limited-human disturbance will likely enhance release-site fidelity and promote restoration success.

Notes: Limestone quarries are spread over the Mediterranean Basin and have a strong environmental impact on the landscape, causing vegetation losses and soil losses. A reclamation project was conducted in a limestone quarry, situated in Arrábida Natural Park (southwest Portugal), that is dominated by mediterranean vegetation. Revegetation was conducted using three evergreen sclerophyllous shrub species (Ceratonia siliqua, Olea europaea, and Pistacia lentiscus), and new techniques were assayed to improve plant water status and nutrient status during the first phases after plantation. A water-holding polymer (gel), fertilizer, and mycorrhiza inoculum were applied in a factorial experiment in a randomized complete block design. The success of these techniques was evaluated during 1.5 years, through monitoring of growth and ecophysiology of plants. Plant survival was high, the lowest values (95%) being recorded in C. siliqua. There were species-specific responses to the treatments applied. Ceratonia siliqua showed the highest growth rates and was the only species with growth stimulated by fertilizer application. However, the application of fertilizer induced changes in leaf characteristics of the other two species, increasing chlorophyll and nitrogen contents. Mycorrhiza inoculum had no effect on plant response. The addition of the water-holding polymer induced higher midday plant water potentials in C. siliqua, O. europaea, and P. lentiscus, but in the latter two species the simultaneous addition of gel and fertilizer induced the lowest water potentials. The addition of fertilizer and gel is recommended in future revegetation programs but not the combination of both when revegetating with O. europaea and P. lentiscus. The results of this experiment indicate that the use of these mediterranean species, adapted to nutrient and water stress, can circumvent harsh conditions of the quarry.

Notes: Structural attributes of the C4, perennial bunchgrass Schizachyrium scoparium in restored prairies may be affected by the time since restoration. One hundred plants each in 8-, 17-, and 23-year-old restored prairies and a native Texas Blackland prairie were assessed for the presence/absence and diameter of a hollow crown (i.e., dead center portion), degree of fragmentation, plant height, and tiller density. Structural attributes of S. scoparium plants were generally (1) different between recent (8 years) and older (17 and 23 years) restored prairies (2) similar between the 17- and 23-year-old restored prairies, and (3) more similar between the 8- and 17-year restored prairies and the native, remnant prairie than between the 23-year restored prairie and the native prairie. Plants were shorter in restored prairies, regardless of time since restoration, than in the native prairie. Mean basal area of plants was 80–163% greater in the 17- and 23-year restored prairies compared with the native and 8-year restored prairies. Percentage of hollow crowns and fragmentation was smallest in the 8-year restored prairie, largest in the 17- and 23-year restored prairies, and intermediate in the native prairie. Tiller density exhibited inverse second-order polynomial decreases with increasing plant basal area for all prairies. In contrast to tiller density, diameter of hollow crowns increased logarithmically with increasing plant basal area. Structural attributes of S. scoparium in restored prairies changed predictably with age, despite growing in different communities.

Notes: There is growing interest in the addition of carbon (C) as sucrose or sawdust to the soil as a tool to reduce plant-available nitrogen (N) and alter competitive interactions among species. The hypothesis that C addition changes N availability and thereby changes competitive dynamics between natives and exotics was tested in a California grassland that had experienced N enrichment. Sawdust (1.2 kg/m) was added to plots containing various combinations of three native perennial bunchgrasses, exotic perennial grasses, and exotic annual grasses. Sawdust addition resulted in higher microbial biomass N, lower rates of net N mineralization and net nitrification, and higher concentrations of extractable soil ammonium in the soil. In the first year sawdust addition decreased the degree to which exotic annuals competitively suppressed the seedlings of Nassella pulchra and, to a lesser extent, Festuca rubra, both native grasses. However there was no evidence of reduced growth of exotic grasses in sawdust-amended plots. Sawdust addition did not influence interactions between the natives and exotic perennial grasses. In the second year, however, sawdust addition did not affect the interactions between the natives and either group of exotic grasses. In fact, the native perennial grasses that survived the first year of competition with annual grasses significantly reduced the aboveground productivity of annual grasses even without sawdust addition. These results suggest that the addition of sawdust as a tool in the restoration of native species in our system provided no significant benefit to natives over a 2-year period.

Notes: Concepts and models from complex systems theory are introduced to help expand the approaches to quantify restoration success in ecology. Main points are illustrated using case studies. These include (1) recovery and restoration trajectories may be complex (nonlinear, unpredictable, and leading to multiple attractors), and thus knowledge of well-known model trajectories from complex systems theory may be useful; (2) modeling may be inevitable, as complete and long-term observation of recovery pathways are rarely possible; (3) holistic views (e.g., community level as opposed to population-level) may be necessary to understand governing processes in restoration and recovery.

Notes: Recent efforts to clear invasive plants from the fynbos of South Africa forces managers to think about how N2-fixing invasives have altered ecosystem processes and the implications of these changes for community development. This study investigated the changes in nitrogen (N) cycling regimes in fynbos with the invasion of Acacia saligna, the effects of clear-cutting acacia stands on soil microclimate and N cycling, and how altered N resources affected the growth of a weedy grass species. Litterfall, litter quality, soil nutrient pools, and ion exchange resin (IER)-available soil N were measured in uninvaded fynbos, intact acacia, and cleared acacia stands. In addition, a bioassay experiment was used to ascertain whether the changes in soil nutrient availability associated with acacia would enhance the success of a weedy grass species. Acacia plots had greater amounts of litterfall, which had higher concentrations of N. This led to larger quantities of organic matter, total N, and IER-available N in the soil. Clearing acacia stands caused changes in soil moisture and temperature, but did not result in differences in IER-available N. The alteration of N availability by acacias was shown to increase growth rates of the weedy grass Ehrharta calycina, suggesting that secondary invasions by nitrophilous weedy species may occur after clearing N2-fixing alien species in the fynbos. It is suggested that managers use controlled burns, the addition of mulch, and the addition of fynbos seed after clearing to lower the levels of available N in the soil and initiate the return of native vegetation.

Notes: Ponderosa pine forest restoration consists of thinning trees and reintroducing prescribed fire to reduce unnaturally high tree densities and fuel loads to restore ecosystem structure and function. A current issue in ponderosa pine restoration is what to do with the large quantity of slash that is created from thinning dense forest stands. Slash piling burning is currently the preferred method of slash removal because it allows land managers to burn large quantities of slash in a more controlled environment in comparison with broadcast burning slash. However burning slash piles is known to have adverse effects such as soil sterilization and exotic species establishment. This study investigated the effects of slash pile burning on soil biotic and chemical variables and early herbaceous succession on burned slash pile areas. Slash piles were created following tree thinning in two adjacent approximately 20-ha ponderosa pine (Pinus ponderosa) restoration treatments in the Coconino National Forest near Flagstaff, Arizona. We selected 30 burned slash pile areas and sampled across a gradient of the burned piles for arbuscular mycorrhizal (AM) propagule densities, the soil seed bank, and soil chemical properties. In addition, we established five 1-m2 plots in each burned pile to quantify the effect of living soil (AM inoculum) and seeding amendments on early herbaceous succession in burned slash pile areas. The five treatments consisted of a control (no treatment), living soil (AM inoculum) amendment, sterilized soil (no AM inoculum) amendment, seed amendment, and a seed/soil (AM inoculum) amendment. Slash pile burning nearly eliminated populations of viable seeds and AM propagules and altered soil chemical properties. Amending scars with native seeds increased the cover of native forbs and grasses. Furthermore adding both seed and living soil more than doubled total native plant cover and decreased ruderal and exotic plant cover. These results indicate that seed/soil amendments that increase native forbs and grasses may enhance the rate of succession in burned slash pile areas by allowing these species to outcompete exotic and ruderal species also establishing at the site through natural regeneration.

Notes: Quantitative P–T path determination in metamorphic rocks is commonly based on the variation in composition of growth-zoned garnet. However, some component of growth zoning in garnet is necessarily the result of an effective bulk composition change within the rock that has been generated by crystal fractionation of components into the core of garnet. Therefore, any quantitative calculation of the P–T regime of garnet growth should be completed using an accurate assessment of the composition of the chemical system from which garnet is growing. Consequently, a method for calculating the extent of crystal fractionation that provides a means of estimating the composition of the unfractionated rock at any stage during garnet growth is developed. The method presented here applies a Rayleigh fractionation model based on measured Mn content of garnet to generate composition v. modal proportion curves for garnet, and uses those curves to estimate the vectors of crystal fractionation. The technique is tested by calculating the precision of the equilibrium between three garnet compositional variables within the chemical system determined to be appropriate for each of a series of microprobe analyses from garnet. Application of the fractionation calculations in conjunction with the P–T estimates based on intersecting compositional isopleths provides a means of calculating P–T conditions of garnet growth that is based on individual point-analyses on a garnet grain. Such spatially precise and easily obtainable P–T data allow for detailed parallel studies of the microstructural, the P–T, and the chemical evolution of metamorphosed pelites. This method provides a means of studying the dynamics of orogenic systems at a resolution that was previously unattainable.

Notes: Field, petrographic, microstructural and isotopic studies of mylonitic gneisses and associated pegmatites along the Hope Valley shear zone in southern Rhode Island indicate that late Palaeozoic deformation (c. 275 Ma) in this zone occurred at very high temperatures (〉650 °C). High-energy cuspate/lobate phase boundary microstructures, a predominance of equant to sub-equant grains with low internal lattice strain, and mixed phase distributions indicate that diffusion creep was an important and possibly predominant deformation mechanism. Field and petrographic evidence are consistent with the presence of an intergranular melt phase during deformation, some of which collected into syntectonic pegmatites. Rb/Sr isotopic analyses of tightly sampled pegmatites and wall rocks confirm that the pegmatites were derived as partial melts of the immediately adjacent, isotopically heterogeneous mylonitic gneisses. The presence of syntectonic interstitial melts is inferred to have permitted a switch from dislocation creep to melt-enhanced diffusion creep as the dominant mechanism in these relatively coarse-grained mylonitic gneisses (200–500 µm syn-deformational grain size). A switch to diffusion creep would lead to significant weakening, and may explain why the Hope Valley shear zone evolved into a major regional tectonic boundary. This work identifies conditions under which diffusion creep operates in naturally deformed granitic rocks and illuminates the deformation processes involved in the development of a tectonic boundary between two distinct Late Proterozoic (Avalonian) basement terranes.

Notes: The Pouébo and Diahot terranes of NE New Caledonia mostly comprise eclogite to blueschist facies metabasite and metasedimentary rocks that experienced c. 40 Ma metamorphism. This Eocene high-P event has been linked with the SW-directed obduction of the New Caledonian Ophiolite, an extensive ultramafic nappe that dominates outcrop in the south of the island. In the north, ultramafic lithologies are found only as sheets or discrete lenticular masses interleaved with, but separated from, the eclogites and blueschists by foliated talc–chlorite–serpentine–carbonate-bearing rocks. The base of the largest and best-preserved ultramafic body at Yambé is marked by a distinctive (2 m thick) layer of high-P mylonite that preserves evidence for early blueschist facies conditions (S1) as inclusions in eclogite facies minerals. Textural evidence preserved in olivine-bearing serpentinites and their bounding mafic mylonites suggest that the ultramafic bodies were emplaced within the structurally highest levels of the high-P terrane as serpentinite tectonites sourced from hydrated mantle, formerly in the hangingwall of the Eocene subduction zone. Serpentinite emplacement accompanied burial of the NE New Caledonian margin at T〈500 °C and P〈16 kbar. The ultramafic fragments were buried to depths of 50–60 km in the subduction zone, where olivine was stable and coarse-grained garnet–omphacite-rich assemblages developed in low strain domains within enclosing mylonites. Host metabasic and metasedimentary rocks from the structurally highest portions of the high-P belt have a prograde record identical to that of the ultramafic tectonites. The early emplacement and similar P–T history of host rocks and ultramafic masses suggest that NE New Caledonia preserves a fossil slab/mantle–wedge boundary reactivated during exhumation.

Notes: In the Vizianagaram area (E 83°29.442′; N 18°5.418′) of the Eastern Ghats Belt, India, a suite of graphite-bearing calc-silicate granulites, veined by syenitic rocks, developed wollastonite-rich veins at 6–7 kbar and 〉 850 °C. During subsequent near-isobaric cooling wollastonite was replaced by calcite + quartz and a graphic intergrowth of fluorite + quartz ± clinopyroxene. Titanite with variable Al and F contents is present throughout the rock. Combining the compositional variation of titanite and recent experimental data, it is demonstrated that the mineral assemblage, the composition of coexisting fluids and the mobility of Al exert a far greater control on the composition of titanite than pressure, temperature or the whole rock composition. Thermodynamically computed isothermal–isobaric logfO2– logfCO2 and logfF2– logfO2 grids in the systems Ca–Fe–Si–O–F (CISOF; calcite-free) and Ca–Fe–Si–O–F–C–H (CISOFV; calcite-present) demonstrate the influence of bulk rock and fluid compositions on the stability of the fluorite-bearing assemblages in diverse geological environments and resolve the problem of the stability of titanite in fayalite + fluorite-bearing rocks in the Adirondacks. The mineralogy of the studied rocks and the topological constraints tightly fix the logfO2, logfF2 and logfCO2 at −15.8, −30.6 and 4.1, respectively, at 6.5 kbar and c. 730 °C. Because of the similarity in the P–T conditions, the compositions of pore fluids in the fluorite-bearing assemblages of the Adirondacks and the Eastern Ghats Belt have been compared.

Notes: Recent losses and fragmentation of tallgrass prairie habitat to agriculture and urban development have led to corresponding declines in diversity and abundance of plants and birds associated with such habitat. Mowing and burning are alternative management strategies for restoring and rejuvenating prairies in fragmented landscapes, but their specific, comparative effects are the subjects of ongoing evaluation. We compared the responses of plant and bird communities on four sets of mowed, burned, and untreated sites of small (3–10 ha), fragmented tallgrass prairies at the DeSoto National Wildlife Refuge (DNWR), Iowa, U.S.A., during May–July in 1998 and 1999. Species richness and diversity of plants, resident grassland birds, and communities of birds associated with grassland edges (edge species) were independent of treatment. Although not affecting species richness and diversity in plant communities, mowed sites ranked lower in total plant coverage and total forb coverage than burned sites or untreated sites. In contrast, untreated sites had more coverage by shrubs, suggesting that mowing and burning did retard shrub encroachment. Overall, abundance and diversity of plants and birds were generally insensitive to management strategies. Small, fragmented sites of rare habitat may not respond in the short term to management treatments and may not be capable of supporting highly diverse communities, no matter how intensively manipulated. It is more probable that diversity of native prairie communities can be enhanced and restored only through long-term efforts, acquisition of large land units capable of supporting stable populations, and deliberate reintroduction of species of high conservation value.

Notes: Forest openings, also known as glades, arise through a variety of mechanisms including disturbance (fire and blow downs) and local variation in soil or bedrock geology. They are common in many forest types and are often dominated by locally rare herbaceous species. Prescribed burning is increasingly used as a management approach for maintaining glades although little is known about the effects of fire on these habitats. Of particular concern is the potential for nutrient loss during and after fire because glades are often characterized by nutrient-poor soils. We quantitated nutrient losses through combustion and leaching for glade and adjacent forest habitats subjected to a prescribed burn. Our findings suggest that spring burns do not result in appreciable loss of nutrient capital from glades in comparison with those observed in the surrounding forest. Fire resulted in a substantial loss of litter mass (37%) in the forest but no measurable loss in the glade. Nitrogen losses through combustion were significant in the forest and were equivalent to 4.5 years of atmospheric inputs. Fire significantly increased soil nitrate pools in forest but not in glade plots. No detectable increases in nitrogen, phosphorus, or base cation leaching were observed in either forest or glade habitats within 4 months after the burn. These findings suggest that plant and microbial nutrient uptake rapidly reestablish control over leaching losses when burns are conducted at the start of the growing season. Biotic retention minimizes fire impacts on nutrient loss from the ecosystem.

Notes: Since the early 1990s, restoration techniques have been developed for milled and cutover peatlands in eastern Canada. These techniques are based on the active reintroduction of peatland plant diaspores, blocking drainage, and the use of straw mulch to improve surface conditions. This study examines the effectiveness of using shallow (20 cm deep) basins of various widths to improve the success of current peatland restoration techniques. It comprises three different experiments, each spanning three or four growing seasons and combining both small-scale manual and large-scale mechanized plant reintroductions. Cover data recorded in two of the experiments were regressed against a series of environmental factors to determine how Sphagnum establishment success was related to abiotic variables such as moisture, water ponding, surface roughness, and mulch cover. Results of these experiments demonstrate that shallow basins were generally effective at promoting Sphagnum establishment and that this effect extends beyond the positive impact that basins have on hydrological conditions. Basins of various widths were equally successful. Soil-moisture content (linear positive effect) and duration and severity of flooding events (quadratic effect) were shown to be determinant of plant recovery. Other factors such as the density of straw cover (positive effect) and surface roughness (negative effect) were also instrumental in explaining local variation in Sphagnum cover. Plant cover after three and four growing seasons averaged 20–25% in mechanical reintroductions and 40–60% in manual reintroductions, demonstrating the overall effectiveness of the restoration techniques used.

Notes: The moth Cactoblastis cactorum (Berg), the poster child of weed biological control in Australia, has recently invaded the United States and threatens native cacti. Concern is greatest for the endangered semaphore cactus, Opuntia corallicola, of which only two known populations exist in the wild. We made three separate outplantings of O. corallicola, designed to bolster the number of extant cacti and to test the effectiveness of three different treatments to protect the cacti from Cactoblastis. In one outplanting, we tested the associational susceptibility hypothesis and found that cacti planted more than 20 m away from the common prickly pear cactus, Opuntia stricta, which act as a reservoir of Cactoblastis, were just as frequently attacked and killed by Cactoblastis as cacti planted within 5 m. In addition, Cactoblastis attack was greater in the shade than in the sun. In the second outplanting, we minimized the attack from Cactoblastis by using protective cages planted at least 500 m from O. stricta in areas not inhabited by cacti. Cages attracted the attention of local animals, which destroyed the cages and trampled the cacti inside to death. Crown rot caused high mortality in this outplanting. In the third outplanting, again conducted at least 500 m away from O. stricta, fertilization did not reduce crown rot mortality. We suggest that increasing populations of O. corallicola in Florida, by means of outplantings, will remain a challenge because of death from Cactoblastis when planted in areas where cacti normally grow and because of death from crown rot in areas where they do not. Because Cactoblastis is moving rapidly northward and westward and has already reached Charleston, South Carolina, rare cacti in the rest of the U.S. Southeast may be in danger. Eventually, many cactus species in the U.S. South, Southwest, and Mexico will likely be threatened by this moth.

Notes: Some of the most species-rich areas and highest concentrations of threatened and endangered species in the southeastern United States are found in wet savanna and flatwood longleaf pine (Pinus palustris Mill.) communities. Where intensive forestry practices have eliminated much of the natural understory of the longleaf ecosystem, the potential for reestablishment through a seed bank may present a valuable restoration opportunity. Longleaf pine sites converted to loblolly pine plantations and non-disturbed longleaf sites on the Coastal Plain of North Carolina were examined for seed bank presence and diversity. Conducting vegetation surveys and examining the seed bank using the seedling emergence technique allowed for verification of the seed bank presence, as well as evaluation of the quality of the seed bank on disturbed longleaf pine sites. Forty-three species and over 1,000 individuals germinated, and the seed banks of both the disturbed and non-disturbed stand types contained species not noted in the vegetation survey. Although many of these species were considered weedy and typical of disturbance, numerous taxa were indicative of stable longleaf pine communities. This study confirms both the presence and quality of seed banks in highly disturbed former longleaf pine sites, suggesting that the seed bank may be an important tool in restoration efforts.

Notes: Ant communities have been widely used as indicators of minesite rehabilitation in Australia and are beginning to play a similar role in other parts of the world. Here we examine ant communities on rehabilitated ash dams associated with a coal-fired power station on the highveld of South Africa, to improve our understanding of ecosystem development on these substrates. Ants were sampled using pitfall traps at 11 ash-dam sites, ranging from unrehabilitated to 9-year-old rehabilitated sites, as well as two adjacent natural grassland sites. Sampling was conducted on 12 occasions from March 1997 to January 1999. Forty-nine ant species from 19 genera were recorded during the study. Site species richness was positively correlated with rehabilitation age, ranging from 10 to 25 at ash-dam sites, compared with 28 and 34 at the two natural grassland sites. There was a humped relationship between total ant abundance and rehabilitation age, with abundance peaking after 5–7 years at levels far higher than those at natural sites. Ordination analysis showed clear separation between ash-dam and natural sites along the first axis. The unrehabilitated ash-dam site was also separated from rehabilitated sites along the first axis. Sites of different rehabilitation age were separated along the second axis. Individual ant species showed clear successional patterns across the rehabilitation gradient. Although there was a clear successional trend for the development of ant communities on rehabilitated ash dams, this trend was not toward natural grassland. The lack of convergence toward ant communities of natural grasslands reflects the markedly different substrate and plant composition on ash dams and supports the widely held view that restoration of natural grassland communities is not a realistic goal of ash-dam rehabilitation. However, the development of species-rich ant communities, containing at least some late-successional species, indicates the potential for rehabilitated ash dams to support diverse and complex ecosystems.

Notes: The restoration of inland salt-affected plant communities, including saltflat mixed prairie and playa lakes wetlands, has received little attention despite the importance of these communities for critical wildlife habitat. The salt-affected communities of Cheyenne Bottoms, located in central Kansas, are a crucial stopover site for migratory waterfowl and shorebirds. In 1998, The Nature Conservancy attempted to restore native plant communities to grazed and former cropland at Cheyenne Bottoms by reestablishing sheet flow across these disturbed areas. We collected vegetation cover data along permanent transects established in rangeland, former cropland, and in a shallow basin 3 years (1996–1998) before the hydrological changes and continued to collect vegetation data for 3 years (1999–2001) after the hydrological changes. Vegetation composition changes in response to the restored hydrology were subtle, but the average wetland index along the transects in the basin and the rangeland significantly declined. Significant decreases occurred in the cover of perennials and graminoids in both spring and fall species assemblages of the rangeland area. Changes in the former cropped areas were mixed, indicating the difficulty of restoring these disturbed plant communities to native plant assemblages within a few years.

Notes: Little information exists about the establishment of native longleaf pine flatwoods species for use in restoration efforts and as buffers around natural areas in the southeastern United States. Composition of groundcover in these systems is dominated by perennial graminoid species. Vegetation in current buffers is generally non-native turfgrass that can escape into natural areas, often reducing establishment and survival of native species. Where management objectives involve actively restoring native groundcover or reducing the probability of invasion by these non-native turfgrasses, identification of native species and restoration methods is needed. We investigated seed germination and establishment of four species native to longleaf pine flatwoods in central Florida and one species native to the adjacent wetland communities. Paspalum setaceum, Panicum anceps, Eustachys petraea, and Eragrostis refracta were directly seeded, and P. distichum was planted as sprigs into three former P. notatum pastures. Irrigation, fertilization, weed control, and mowing treatments were assessed in terms of cover development of the sown species. Paspalum distichum developed the highest percent cover—over 80% in wet areas after 1 year. Mowing had mixed impacts depending on the species, and fertilization never significantly increased cover. Directly seeded species developed sparse cover (0–40%), probably as a result of drought conditions. However, E. petraea and E. refracta appeared more promising for use on rights-of-way when using high sowing rates. A second experiment conducted on a roadside included these two species and sprigged P. distichum. Both E. petraea and P. distichum developed more than 45% cover on the roadside. Establishment of these natives from seed or sprigs was significantly enhanced when site preparation effectively reduced the seedbank of other species present in the soil.

Notes: Relatively intense burning has been suggested as a possible alternative to the restoration of pre-European settlement forest conditions and fire regime in mixed conifer forests, in contrast to thinning of trees and light prescribed burning. In 1993 a management-ignited fire in a dense, never-harvested forest in Grand Canyon National Park escaped prescription and burned with greater intensity and severity than anticipated. We sampled the burned site and an adjacent unburned site (270 ha each) 6 years after the fire to assess burn effects on tree structure (species composition, size and age distributions, regeneration, and snags), forest floor fuels, and coarse woody debris. Tree structure before fire-regime disruption (1879 CE) was reconstructed with dendroecological techniques. By 6 years after burn the fire reduced average tree density (331 trees/ha) and basal area (28.5 m2/ha) to levels similar to pre-European reference conditions (approximately 246 trees/ha and 28.5 m2/ha). Mortality was concentrated in fire-susceptible species, especially white fir, restoring dominance by fire-resistant ponderosa pine. Forest floor fuels were reduced, and regeneration by aspen and understory plants was vigorous. Densities of large snags and logs were high. However the fire also killed a high proportion of old-growth trees, especially aspen. Burning created more spatial variability in forest structure than was present before fire-regime disruption by killing many trees in some areas of the site but few in other areas. The intentional use of severe burning would be challenging to managers because of the increased risk of escaped fires, but the ecological outcome of this particular wildfire was not inconsistent with ecological restoration goals for this ecosystem type.

Notes: The effects of sewage sludge, used to improve fertility of replaced soil, on vegetation were studied in limestone quarry restoration. Plant community growing in the first stages after sludge application was surveyed in six quarries of NE Spain. Areas with a mixture of sewage sludge and residual soil were compared to areas where the application consisted only of residual soil (a mixture of previous top soil and mine spoils). Sewage sludge was hypothesized to increase total biomass and cover, modifying species composition and delaying the early successional recover of the community. The results showed that both biomass and plant cover increased because of sewage sludge addition. The floristic composition was dominated by ruderal species that did not show any dependence on sewage sludge application. Convergence on similarity between sludge and control plots was not detected along a 5-year period. Although species richness was significantly lower in sludge plots, diversity and equitability indexes did not show differences between treatments. The results did not show differences in the proportion of non-native species. The proportion of legumes was lower in sludge plots. These results show that the plant communities resulting from the addition of sewage sludge to the soil used in limestone quarry restoration have more biomass and cover, but less number of species, and they do not show a clear trend to converge to those areas restored only with non-amended soil.

Notes: The long-term effects (20–45 years) of reclamation treatments on plant succession are examined at two localities in Iceland that were fertilized and seeded from 1954 to 1979 with perennial grasses or annual grasses, or left untreated. The areas that underwent reclamation treatments had significantly higher total plant cover (7–100%) than the untreated control plots (〈5%), and floristic composition was usually significantly different between treated and untreated plots. Dwarf-shrubs (Calluna vulgaris and Empetrum nigrum), bryophytes, biological soil crust, grasses, and shrubs characterized the vegetation in the treated plots, but low-growing herbs that have negligible effects on the environment, such as Cardaminopsis petraea and Minuartia rubella, and grasses characterized the control plots. The seeded grass species had declined (〈10%, the perennials) or disappeared (the annuals) but acted as nurse species that facilitated the colonization of native plants. It seems that by seeding, some factors that limit plant colonization were overcome. Soil nutrients, vegetation cover, litter, and biological soil crust were greater in the treated areas than the control plots. This may have enhanced colonization through an increase in soil stability and fertility, increased availability of safe microsites, increased moisture, and the capture of wind-blown seeds. This study demonstrates the importance of looking at the long-term effects of reclamation treatments to understand their impact on vegetation succession.

Notes: In semiarid Mediterranean areas, the widespread environmental impact caused by the construction of motorways, railways, and pipelines has created an increasing need for effective restoration. We examined the influence of slope characteristics on vegetation and water erosion on 71 motorway slopes in a semiarid Mediterranean region. Specifically, we studied the effect of slope angle, type (roadfill vs. roadcut) and aspect (north vs. south) on soil properties, vegetation cover, species richness, floristic composition, and water-caused erosion. Temporal dynamics of soil water content was monitored and related to the soil water potential in order to explain possible differences in vegetation cover between slope types. The main factors influencing vegetation on motorway slopes were the angle, type, and aspect of the slope. Vegetation was almost completely lacking on roadcuts with slopes greater than 45°. On gentler slopes, vegetation cover was 44–78% on roadfills but did not reach 10% on roadcuts, regardless of aspect. The main soil properties affected by the slope type and aspect were the organic matter content, soil available P, and water content. Rill erosion, gully erosion, and mass movement were all significantly higher on roadcuts than roadfills. A total of 308 spontaneous colonizers and seeded species were recorded. The type and aspect of the slope also controlled species composition. The short duration of available water in the soil with respect to soil water potential proved to be a limiting factor to plant colonization on roadcuts and south-facing slopes as well as the low soil fertility in the case of roadcuts. Our results underscore the difficulty of revegetating slopes with angles greater than 45°, where the probability of seeds moving downhill is high. Future efforts should focus on increasing the surface roughness or building terraces at regular intervals in order to reduce slope angle to less than 45° and favor seed trapping and germination. On gentler slopes, adjusting of seed mixes according to dominant species associated with each slope type and aspect should improve considerably the success of roadside revegetation.

Notes: Induced mycorrhization of sweet birch (Betula lenta L.) by Pisolithus tinctorius (Pers.) Coker & Couch, as influenced by substrate fertility, was evaluated for its effects on seedling growth and physiology. Following a brief period in seed flats, seedlings were transplanted to mine spoil where they resided for 30 months, and three nutrition regimes were imposed throughout the study by application of differing nutrient solution concentrations. High fertility suppressed mycorrhizal formation by P. tinctorius but promoted that of other mycobionts. Pisolithus mycorrhization induced substantial aboveground and belowground growth as indicated by dimensions and mass for the former and mass and length for the latter but favoring root over shoot growth overall. Furthermore, these mycorrhizae were frequently able to compensate for the growth stimulation of higher nutrient additions. Measurements of xylem pressure potential and soil water potential indicated that water uptake was enhanced by P. tinctorius during simulated drought episodes of two durations and in subsequent recovery periods. Inoculated seedlings had higher foliar concentrations of critical nutrients, especially N, and lower concentrations of potentially phytotoxic metallic elements, particularly Mn, than uninoculated seedlings, although the latter response was absent in high fertility. Spoil analyses clearly revealed the influence of the nutrition regimes but also the effects of seedling uptake on substrate chemistry, and reinforced the findings of the foliar analysis concerning suppression of metal uptake by P. tinctorius. Collectively, these results suggest that P. tinctorius can provide sweet birch an array of physiological benefits that will permit this tree species to flourish on harsh substrates such as surface mine spoils without heavy application of chemical fertilizers.

Notes: The surfgrass Phyllospadix torreyi is an abundant seagrass found on rocky exposed shores of the Pacific coast of North America. In southern California surfgrass populations are adversely affected by a range of natural events and anthropogenic activities. Few attempts have been made to develop restoration methods for surfgrass, and none have investigated the efficacy of using different life stages. We evaluated several techniques for restoration in intertidal and subtidal habitats using: (1) laboratory-reared seedlings transplanted to the field (2) sprigs (short lengths of rhizome containing a few shoots) transplanted from undisturbed populations, and (3) plugs (a cohesive clump of shoots and rhizomes) transplanted from undisturbed populations. We calculated the net change in the aerial coverage of surfgrass after 6 months, taking into account the recovery or additional losses from the donor population, and amount of effort involved in transplanting. Transplanted seedlings survived poorly and had minimal rhizome growth at both the intertidal and the subtidal sites, yet the individuals that did survive showed a 275% increase in leaf number. Survivorship of transplanted plugs was high in both habitats; however, physical disturbances to the donor populations exacerbated damage sustained at the time of collecting, yielding a substantial net loss in surfgrass. Sprigs transplanted to the subtidal had higher survivorship (71 versus 48%) and a greater increase in the aerial coverage of rhizome (86 versus 42%) than those transplanted to the intertidal. Of the three techniques, transplanted sprigs had the greatest overall increase in aerial coverage per unit effort, suggesting that this method may be the most effective approach for restoring P. torreyi.

Notes: Few ecosystem restoration studies evaluate whether arthropods are important components of ecosystem recovery. We tested the hypothesis that ponderosa pine restoration treatments would increase adult butterfly species richness and abundance as a direct result of increased understory diversity and abundance. To examine mechanisms that potentially affect adult butterfly distribution, we quantified host plant frequency, nectar plant abundance, and insolation (light intensity) in restoration treatment and control forests. This study is unique, because this is the first invertebrate monitoring in ponderosa pine forest restoration treatments in the U.S. Southwest and also because these treatments are the first replicated ponderosa pine restoration treatments at a landscape scale. Three patterns emerged: (1) butterfly species richness and abundance were 2 and 3 times greater, respectively, in restoration treatment units than in paired control forests 1 year after treatment, and 1.5 and 3.5 times greater, respectively, 2 years after treatment, ordination of control and treatment sampling units using butterfly assemblages showed significant separation of control and restoration treatment units after restoration treatment; (2) host plant and nectar plant species richness showed little difference between treated and control forests even 2 years after treatment; and (3) insolation (light intensity) was significantly greater in treated forests after restoration. We suggest that changes in the butterfly assemblage may occur due to light intensity effects before plant community changes occur or can be detected. Butterfly assemblage differences will have additional cascading effects on the ecosystem as prey for higher trophic levels and through plant interactions including herbivory and pollination.

Notes: Dunes, which account for 13% of the Ille et Vilaine north Brittany coast, France, were degraded by high tourist pressure, and they were restored from 1988 onward. Ten years after commencing work an assessment of the restoration was made on three dunes: Les Chevrets, L'Anse Du Guesclin, and Le Verger. Annual monitoring of the vegetation and dune morphology provided an opportunity to study the restoration process. The dune front, which is similar to a reference pioneer dune, lies in front of the mobile dune. The highest part of the dune is an advanced stage of mobile dune. The restoration of the fixed rear dune was accomplished neither in terms of vegetation composition nor in terms of species richness. The vegetation parameter study allows differentiation between the dune front, the dune summit, and the rear dune. The variation in species richness and floristic composition from one zone to another can be explained by abiotic factors such as salinity and the accretion of sand. The restoration was satisfactory in terms of the geomorphology. Marram grass is a good tool for restoring the topography, but it will take a very long time to restore the conservation value of the dune.

Notes: In California's Mediterranean type grasslands, native perennial grasses such as Nassella pulchra are surrounded by introduced annual species and these annuals are thought to have displaced natives through much of their range. Amongst other invaders, two grasses Lolium multiflorum and Bromus hordeaceus, commonly dominate portions of the grassland with potential for N. pulchra restoration. We hypothesized that competitor species differences and small-scale gaps (150 cm2) could be important determinants of N. pulchra survival and performance on these sites. Lolium multiflorum and B. hordeaceus were planted in 20 cm diameter circular plots at a constant rate of 1 seed per cm2 surrounding newly transplanted N. pulchra plants. Nassella pulchra showed no significant effect of the species of competitor or from the distribution of the competitors. Both interspersion of patches of bare ground and separation of competitors into patches did not increase N. pulchra pre-dawn water potential, basal area change, number of seeds produced, or average weight of seeds. The presence of L. multiflorum was associated with a decrease in N. pulchra survival compared with plots with only B. hordeaceus. Plants with increases in basal area of less than 0.75 cm2 during the growing season had 74% mortality compared with no mortality in plants with more growth. However, initial N. pulchra plant size was not a good predictor of mortality. Limiting competition from annuals may increase survival of N. pulchra plantings, but 60% of the plants survived for at least 1 year, despite being transplanted into soil containing substantial annual grass seed.

Notes: Plants that have evolved to survive on metal-rich soils—metallophytes—have key values that must drive research of their unique properties and ultimately their conservation. The ability of metallophytes to tolerate extreme metal concentrations commends them for revegetation of mines and metal-contaminated sites. Metallophytes can also be exploited in environmental technologies, for example, phytostabilization, phytoremediation, and phytomining. Actions towards conserving metallophyte species are imperative, as metallophytes are increasingly under threat of extinction from mining activity. Although many hundreds of papers describe both the biology and applications of metallophytes, few have investigated the urgent need to conserve these unique species. This paper identifies the current state of metallophyte research, and advocates future research needs for the conservation of metallophyte biodiversity and the sustainable uses of metallophyte species in restoration, rehabilitation, contaminated site remediation, and other nascent phytotechnologies. Six fundamental questions are addressed: (1) Is enough known about the global status of metallophytes to ensure their conservation? (2) Are metallophytes threatened by the activities of the minerals industry, and can their potential for the restoration or rehabilitation of mined and disturbed land be realized? (3) What problems exist in gaining prior informed consent to access metallophyte genetic resources and how can the benefits arising from their uses be equitably shared? (4) What potential do metallophytes offer as a resource base for phytotechnologies? (5) Can genetic modification be used to “design” metallophytes to use in the remediation of contaminated land? (6) Does the prospect of using metallophytes in site remediation and restoration raise ethical issues?

Notes: Historical landscape reconstructions provide baseline information for evaluating current land management regimes and restoration potentials. We assessed the historical landscape composition and structure of the state of Wisconsin (U.S.A.). This knowledge forms a basis for delineation of potential spatial distribution of forest species and landscape structures before major human-induced changes, quantification of the spatial extent and intensity of change in habitats and landscapes, and identification of target areas for ecological restoration (e.g., threatened ecosystems). Methods included two conceptually and methodologically different vegetation classifications. The classifications rely on the original U.S. Public Land Office Surveys conducted during the nineteenth century to sell land to Euro-American settlers. The subjective classification method we examined was R. W. Finley's “Original Vegetation of Wisconsin.” This classification accounts for qualitative information such as early land surveyors' descriptions of ecosystems (e.g., distinctions into wet and dry prairies). However, the classification is hard to reproduce because some criteria are not strictly hierarchical or exclusive. Numerical cluster analysis was used as an objective classification method. This method offers reproducible, quantitative results and full hierarchical distinction between the classes. Qualitative information, however, is not accounted for in the objective numerical approach and may thus be viewed as less complete when representing local landscape details. Both classifications represent major vegetation characteristics consisting of a complex mosaic of forests (coniferous, mixed coniferous–deciduous, deciduous, and swamps), savannas (oak and pine), and prairies. The objective classification indicates that savannas cover two times more (40%) and prairies six times less area (2%) compared with the subjective classification (savanna, 20%; prairie, 12%). We address the applications of these classifications to current and potential restoration projects, including eastern hemlock (Tsuga canadensis), wetland/riparian, savanna, and prairie ecosystems.

Notes: Within the Albany–Fraser Orogen of southwestern Australia, the Coramup Gneiss is a NE–SW trending zone of high-strain rocks that preserves a detailed record of orogenesis related to Mesoproterozoic convergence of the West Australian and Mawson cratons. New structural, metamorphic and U–Pb SHRIMP zircon age data establish that the Coramup Gneiss underwent high-grade tectonism during both Stage I (c. 1290 Ma) and Stage II (c. 1170 Ma) of the Albany–Fraser Orogeny. Stage I commenced with c. 1300 Ma high-T, low-P M1a metamorphism during extension, and the formation of small-scale ptygmatic folds within a subhorizontal S1a gneissosity. High-P M1b metamorphism at c. 1290 Ma was accompanied by the transposition and shearing of S1a into a composite, shallow SE-dipping S1b foliation, and the development of tight recumbent F1b folds with S1-parallel axial surfaces and asymmetries indicating NW-directed thrusting. The preservation of a similar P–T–time record in the Fraser Complex (NE of the Coramup Gneiss) is consistent with large-scale, NW-directed Stage I thrusting of the Mawson Craton margin over the south-eastern edge of the West Australian Craton. Stage II tectonism in the western Coramup Gneiss involved high-T, low-P M2a metamorphism and the formation of subvertical SE-dipping D2 shear zones, shallow SW-plunging L2 mineral stretching lineations, and NW-verging F2 folds with S2-parallel axial surfaces. A synkinematic pegmatite dyke emplaced into a D2 shear zone yielded a U–Pb SHRIMP zircon age of 1168 ± 12 Ma. Kinematic indicators suggest a combination of pure shear flattening perpendicular to S2, and dextral simple shear. However, contemporaneous structures elsewhere in the Albany–Fraser Orogen are consistent with continued NW–SE convergence at craton-scale during Stage II, and oblique compression in the Coramup Gneiss is attributed to the arcuate geometry of the orogen-scale deformation front.

Notes: Quartz–garnet oxygen isotope thermometry of quartz-rich metasedimentary rocks from the southern Adirondack Highlands (Grenville Province, New York) yields metamorphic temperatures of 700–800 °C, consistent with granulite facies mineral assemblages. Samples from the Irving Pond quartzite record Δ18O(Qtz–Grt) = 2.68 ± 0.21‰ (1 s.d., n = 15), corresponding to peak metamorphic conditions of 734 ± 38 °C. This agrees well with the estimates from garnet–biotite exchange thermometry. Similar temperature estimates are obtained from Swede Pond (682 ± 47 °C, n = 3) and King's Station (c. 700 °C). The Whitehall area records higher temperatures (798 ± 25 °C, n = 3). All of these temperatures are higher than previous regional temperature estimates. The c. 800 °C temperatures near Whitehall are consistent with preservation of pre-granulite contact temperatures adjacent to anorthosite. The preservation of peak metamorphic temperatures in garnet of all sizes is consistent with slow oxygen diffusion in garnet, and closure temperatures of at least 730 °C. Peak metamorphic fractionations are preserved in rocks with varying quartz:feldspar ratios, indicating that the modal percentage of feldspar does not affect retrograde oxygen exchange in these rocks. The lack of this correlation suggests slow rates of oxygen diffusion in quartz and feldspar, consistent with the results of anhydrous oxygen diffusion experiments.

Notes: The Albany–Fraser Orogen in southwestern Australia preserves an important thermo-tectonic record of Australo-Antarctic cratonic assembly during the Mesoproterozoic. New petrologic and thermobarometric data from the Coramup Gneiss (a 10 km wide zone of high strain rocks within the NE-trending eastern Albany–Fraser Orogen) indicate at least two high-grade metamorphic events during 1345–1140 Ma convergence and amalgamation of the West Australian and Mawson cratons. The first event (M1) involved c. 1300 Ma granulite facies metamorphism of the Coramup Gneiss (M1a: 800–850 °C, 5–7 kbar), followed by burial and recrystallization under high-P conditions (M1b: 800–850 °C, c. 10 kbar) prior to high-T decompression (M1c: 700–800 °C, 7–8 kbar) and the 1290–1280 Ma emplacement of Recherche Granite sills. The second event (M2) entailed high-T, low-P metamorphism within dextral D2 shear zones (M2a: 750–800 °C, 5–6 kbar), followed by fluid-present amphibolite facies M2b retrogression. Subsequent sinistral D3 mylonites and pseudotachylites are considered contemporaneous with similar structures in the adjacent Nornalup Complex that postdate the c. 1140 Ma Esperance Granite. Our petrological and thermobarometric data permit two end-member P–T-time relationships between M1 and M2: (1) a single post-M1b event involving continuous M1b–M1c–M2a–M2b cooling and decompression, and (2) a two-stage post-M1b evolution involving M1c metamorphism during the waning stages of an event unrelated causally or temporally to subsequent M2a metamorphism and D2 deformation. In a companion paper, new structural and U–Pb SHRIMP zircon data are presented to support a two-stage P–T evolution for the Coramup Gneiss, with M1 and M2, respectively, reflecting thermo-tectonic activity during Stage I (1345–1260 Ma) and Stage II (1215–1140 Ma) of the Albany–Fraser Orogeny.

Notes: The western Fiordland Orthogneiss (WFO) is an extensive composite metagabbroic to dioritic arc batholith that was emplaced at c. 20–25 km crustal depth into Palaeozoic and Mesozoic gneiss during collision and accretion of the arc with the Mesozoic Pacific Gondwana margin. Sensitive high-resolution ion microprobe U–Pb zircon data from central and northern Fiordland indicate that WFO plutons were emplaced throughout the early Cretaceous (123.6 ± 3.0, 121.8 ± 1.7, 120.0 ± 2.6 and 115.6 ± 2.4 Ma). Emplacement of the WFO synchronous with regional deformation and collisional-style orogenesis is illustrated by (i) coeval ages of a post-D1 dyke (123.6 ± 3.0 Ma) and its host pluton (121.8 ± 1.7 Ma) at Mt Daniel and (ii) coeval ages of pluton emplacement and metamorphism/deformation of proximal paragneiss in George and Doubtful Sounds. The coincidence emplacement and metamorphic ages indicate that the WFO was regionally significant as a heat source for amphibolite to granulite facies metamorphism. The age spectra of detrital zircon populations were characterized for four paragneiss samples. A paragneiss from Doubtful Sound shows a similar age spectrum to other central Fiordland and Westland paragneiss and SE Australian Ordovician sedimentary rocks, with age peaks at 600–500 and 1100–900 Ma, a smaller peak at c. 1400 Ma, and a minor Archean component. Similarly, one sample of the George Sound paragneiss has a significant Palaeozoic to Archean age spectrum, however zircon populations from the George Sound paragneiss are dominated by Permo-Triassic components and thus are markedly different from any of those previously studied in Fiordland.

Notes: Metamorphic zircon from coesite-bearing eclogites in the Dabie Mountains encloses high-P phases, and may have formed at the peak of ultrahigh-pressure (UHP) metamorphism. Morphologically, the metamorphic zircon typically occurs as small, multi-faceted, near-spherical grains with homogeneous internal structure and weak backscattered electron (BSE) luminescence. Geochemically, it is characterized by extremely high and relatively constant contents of hafnium (Hf) and very low contents of Y, U and Th, reflecting the contraction of the zircon lattice under the UHP conditions. High contents of Hf may be characteristic of zircon formed during UHP metamorphism, which has important consequences for interpretation of geochronological results. We propose that the metamorphic zircon extremely enriched in Hf may be used to date the peak of UHP metamorphism that produced the coesite-bearing eclogites in the Dabie Mountains, and potentially in other UHP terranes.

Notes: Inclusion – porphyroblast and porphyroblast – porphyroblast relationships show that abundant albite in mica schists in the Caledonides of the SW Scottish Highlands are part of the Barrovian metamorphic assemblage. Growth early in the D2 deformational phase of porphyroblast cores followed the growth of Mn-rich garnet but preceded the growth of porphyroblasts of the index mineral almandine. Two sets of inclusion trails in the albite correspond to the regionally expressed S1 and S2. Straight trails of muscovite, chlorite, quartz, epidote and the earliest growth of biotite make up S1. Crenulated trails express deformation of S1 early in D2 with muscovite, chlorite, biotite, quartz, epidote and the Mn-rich garnet associated with the development of S2 crenulation cleavage. The geometries of these trails uniquely record early stages of D2 deformational history. An 0−3 growth is related to the temporal coincidence of the formation of S1–S2 crenulation cleavage hinges as favourable sites for nucleation and the release of large amounts of water from prograde reactions during tectonothermal reconstitution of first cycle immature sediments with a volcanic component. The main characteristics of the regionally expressed D2 schistosity were developed during the major grain coarsening that followed both albite and almandine porphyroblast growth. Essentially inclusion-free An 4−19 rims grew on the inclusion-containing cores in the almandine zone in the later stages of schistosity growth and unoriented porphyroblasts of muscovite, biotite and chlorite indicate that mineral growth extended from the later stages of D2 to post-D2. Previous interpretations of the albite porphyroblast growth having been during D4 to post-D4 contemporaneous with retrogression are inconsistent with the microstructural evidence.

Notes: Thermobarometry suggests that ultrahigh-pressure (UHP) to high-pressure (HP) rocks across the Western Gneiss Region ponded at the Moho following as much as 100 km of exhumation through the mantle and before exhumation to the upper crust. Eclogite across the c. 22 000 km2 study area records minimum pressures of c. 8–18 kbar and temperatures of c. 650–780 °C. One orthopyroxene eclogite yields an UHP of c. 28.5 kbar, and evidence of former coesite has been found c. 50 km farther east than previously known. Despite this widespread evidence of UHP to HP, thermobarometry of metapelite and garnet amphibolite samples reveals a surprisingly uniform ‘supra-Barrovian’ amphibolite-facies overprint at c. 11 kbar and c. 650–750 °C across the entire area. Chemical zoning analysis suggests that garnet in these samples grew during heating and decompression, presumably during the amphibolite-facies event. These data indicate that the Norwegian UHP/HP province was exhumed from mantle depths of c. 150 km to lower crustal depths, where it stalled and underwent a profound high-temperature overprint. The ubiquity of late-stage supra-Barrovian metamorphic overprints suggests that large-scale, collisional UHP terranes routinely stall at the continental Moho where diminishing body forces are exceeded by boundary forces. Significant portions of the middle or lower crust worldwide may be formed from UHP terranes that were arrested at the Moho and never underwent their final stage of exhumation.

Notes: Mineral textures, coupled with thermodynamic modelling in the MnO–Na2O–CaO–K2O–FeO–MgO–Al2O3–SiO2–H2O (MnNCKFMASH) model system, of mid-amphibolite facies metapelites from the Georgetown Inlier, northeast Australia, point to the recording of two separate and unrelated metamorphic events. The first occurred contemporaneously with Palaeo- to Mesoproterozoic orogenesis and involved heating and burial to temperatures and pressures of approximately 600–650 °C and 6.0–7.0 kbar. Textural evidence for the up-temperature (and pressure) prograde part of this path is inferred from the inclusion of garnet in biotite and staurolite. The second metamorphic event resulted in a low-pressure thermal overprint that is equated with the advective addition of heat to the terrane via the emplacement of the Forsayth Batholith (c. 1550 Ma). This event is inferred from subsequent growth of andalusite and randomly orientated fibrolitic sillimanite after garnet, biotite and staurolite. This two stage metamorphic evolution, when coupled with a number of other distinct geological characteristics, suggests that the Georgetown Inlier is dissimilar to the other Australian Palaeoproterozoic terranes with which it is commonly correlated.

Notes: The Qinglongshan eclogites in the Southern Sulu ultrahigh pressure metamorphic (UHPM) terrane show very different retrograded textures from their counterparts in the Northern Sulu terrane, implying a different thermal history. Scanning electron and optical microscope observations indicate that the peak assemblage of the Qinglongshan eclogite is anhydrous, composed of Grt + OmpI + Rt + (Ky + coesite). These primary minerals were replaced by second and third stage minerals, resulting in symplectite pseudomorphs or coronas. The following relationships are inferred: OmpI → OmpII + Ab + Fe-oxide symplectite (type I) and Rt → Rt + Ilm intergrowth; and, Ky → Pg, OmpII (+Pl) → Amp (+Pl) symplectite (type II), and Grt → Prg (+Fe-oxide). Mineral chemistry and mass-balance demonstrate that the pseudomorphed textures were developed by metasomatism involving dissolution and precipitation intensified by fluids along grain boundaries. The formation of symplectite type I produced Fe, Mg and Na but consumed Ca and Si. The Mg and Fe diffused to garnet where exchange of (Mg, Fe) with Ca of the garnet resulted in compositional zonation with decreased Ca towards the edge of garnet grains where Ca was consumed during symplectite formation. The replacement of kyanite by paragonite consumed the extra Na. In the later stage, fluid infiltration partially transformed symplectite type I to type II, and narrow rims of pargasite resorbed garnet from their boundaries. Mass balance suggests that the transformation and resorption would have been coupled during fluid infiltration. In the latest stage, epidote and quartz were precipitated at very late stage as a result of fluid activity along microfractures. Tentative P–T conditions based on mineral reactions and thermocalc software suggest that the retrograded eclogite did not record the granulite facies retrograde evolution characteristic of eclogites from the Northern Sulu terrane. The difference in retrograde evolution between the Southern and Northern Sulu eclogites suggests a different exhumation history.

Notes: Spinel–cordierite symplectites partially replacing andalusite occur in metapelitic rocks within the cores of several country rock diapirs that have ascended into the upper levels of layered mafic/ultramafic rocks in the Bushveld Complex. We investigate the petrogenesis of these symplectites in one of these diapirs, the Phepane dome. Petrographic evidence indicates that at conditions immediately below the solidus the rocks were characterized by a cordierite-, biotite- and K-feldspar-rich matrix and 5–10 mm long andalusite porphyroblasts surrounded by biotite-rich fringes. Phase relations in the MnNCKFMASHT model system constrain the near-solidus prograde path to around 3 kbar and imply that andalusite persisted metastably into the sillimanite + melt field, where the fringing relationship between biotite and andalusite provided spatially restricted equilibrium domains with silica-deficient effective bulk compositions that focused suprasolidus reaction. MnNCKFMASHT pseudosections that model these compositional domains suggest that volatile phase-absent melting reactions consuming andalusite and biotite initially produced a moat of cordierite surrounding andalusite; reaction progressed until all quartz was consumed. Spinel is predicted to grow with cordierite at around 720 °C. Formation of the aluminous solid products was strongly controlled by the receding edge of andalusite grains, with symplectites forming at the andalusite-cordierite moat interface. Decompression due to melt-assisted diapiric rise of the floor rocks into the overlying mafic/ultramafic rocks occurred close to the thermal peak. Re-crossing of the solidus at P = 1.5–2 kbar, T 〉 700 °C resulted in preservation of the symplectites. Two features of the silica-deficient domains inhibited resorption of spinel. First, the cordierite moat armoured the symplectites from reaction with crystallizing melt in the outer part of the pseudomorphs. Second, an up-T step in the solidus at low-P, which may be in excess of 100 °C higher than the quartz-saturated solidus, resulted in high-T crystallization of melt on decompression. Even in metapelitic rocks where melt is retained, preservation of spinel is favoured by decompression.