ALBERT

Notes: Abstract Three experiments were undertaken to investigate the influence of seed mixture on the establishment of a target grassland community on a site with high available phosphorus. In the first experiment autumn- and spring-sown commercial seed mixtures were compared with seed harvested from a nature reserve with respect to their ability to produce an inundation grassland community similar to that described by the British National Vegetation Classification (NVC) as Agrostis stolonifera–Alopecurus geniculatus grassland (MG13). In the second experiment the composition and sowing rate of a commercial seed mixture were altered to investigate whether these factors were significant in the establishment of a sward similar to MG13. Similarly, in the third experiment the composition of a commercial seed mixture designed to achieve an alternative community, Cynosurus cristatus–Caltha palustris grassland (NVC code MG8), was sown. The vegetation resulting from each of these treatments was monitored with permanent quadrats for a 3-year period, and the hydrological regime of each quadrat location was modeled and quantified. The results showed that seed mixture, timing of sowing, and seeding rate had an initial effect on the vegetation that established. However, by the third year of monitoring there were no significant differences between these treatments, and hydrological regime had become the most important factor in determining the distribution of species. The vegetation was less diverse than predicted from germination tests and decreased in diversity over the monitoring period. It is suggested that this may be a result of the hydrological regime being unsuitable for several of the sown species or due to the extremely high available phosphorus concentration in the soil. This study highlights the need to understand the soil and hydrological conditions of a site before choosing a target community and designing a seed mixture.

Notes: Abstract Introduced perennial grasses are one of the greatest constraints to prairie restoration. Herbicides suppress but do not eliminate introduced grasses, so we explored the interaction of herbicide with two additional controls: heavy clipping (to simulate grazing) and competition from native species. A 50-year-old stand of the introduced perennial grass Agropyron cristatum (crested wheatgrass) in the northern Great Plains was seeded with native grasses and treated with herbicide annually for 7 years in a factorial experiment. Clipping was applied as a subplot treatment in the final 3 years. Both herbicide and clipping significantly reduced the cover of A. cristatum, but clipping produced an immediate and consistent decrease, whereas herbicide control varied among years. The cover of A. cristatum decreased significantly with increasing cover of a seeded native grass, Bouteloua gracilis (blue grama), suggesting that both top-down (i.e., grazing) and bottom-up (i.e., resource competition) strategies can contribute to A. cristatum control. No treatment had any effect on the seed bank of A. cristatum. Even in the most effective control treatments, A. cristatum persisted at low amounts (approximately 5% cover) throughout the experiment. The cover of B. gracilis increased significantly with seed addition and herbicide, and, after 7 years, was similar to that in undisturbed prairie. The total cover of native species increased significantly with clipping and herbicide, and species richness was significantly higher in plots receiving herbicide. Clipping season had no effect on any variable. In summary, no method extirpated A. cristatum, but clipping reduced its cover by 90% and doubled the cover of native species. Extirpation might not be a realistic goal, but relatively simple management allowed coexistence of native species.

Notes: Abstract The reduction and fragmentation of forest habitats is expected to have profound effects on plant species diversity as a consequence of the decreased area and increased isolation of the remnant patches. To stop the ongoing process of forest fragmentation, much attention has been given recently to the restoration of forest habitat. The present study investigates restoration possibilities of recently established patches with respect to their geographical isolation. Because seed dispersal events over 100 m are considered to be of long distance, a threshold value of 100 m between recent and old woodland was chosen to define isolation. Total species richness, individual patch species richness, frequency distributions in species occurrences, and patch occupancy patterns of individual species were significantly different among isolated and nonisolated stands. In the short term no high species richness is to be expected in isolated stands. Establishing new forests adjacent to existing woodland ensures higher survival probabilities of existing populations. In the long term, however, the importance of long-distance seed dispersal should not be underestimated because most species showed occasional long-distance seed dispersal. A clear distinction should be made between populations colonizing adjacent patches and patches isolated from old woodland. The colonization of isolated stands may have important effects on the dynamics and diversity of forest networks, and more attention should be directed toward the genetic traits and viability of founding populations in isolated stands.

Notes: Abstract The effects of the earthworm Pontoscolex corethrurus (Muller) on the rate of mineralization of cattle dung-amended iron (Fe2+) ore mine wastes and its preference for partially decomposed leaf litter with contrasting chemical composition were studied in pot trials. The growth and survival rates of earthworms showed significant positive correlations with percent of organic matter. During 96 days of exposure, the earthworms significantly increased exchangeable Ca2+, Mg2+, PO43− and NH4-N. Iron ore mine wastes amended with 5–10% organic matter supported earthworm fauna better than mine wastes amended with 0–3% organic matter. The leaf litter preference shown by the earthworm was, in descending order, Phyllanthus reticulatus, Tamarindus indica, Anacardium occidentale, Casuarina equisetifolia, Acacia auriculiformis, and Eucalyptus camaldulensis. A significant positive correlation was observed between the survival and growth rates of earthworms and the nutrient contents of partially decomposed leaf litter. The first three plant species were significantly richer in nutrients, mainly organic carbon, calcium, phosphorus, and nitrogen, than the other two plant species. Acacia auriculiformis and E. camaldulensis litter were preferred less because of their high lignin and polyphenolic compounds, despite being rich in other macronutrients like nitrogen and phosphorus. It is concluded that the introduction of P. corethrurus to cattle dung-amended (5–10%) iron ore mine wastes or revegetation of the sites with P. reticulatus, T. indica, and A. occidentale plant species should be attempted before earthworm introduction. The litter from these species acts as a source of food for earthworms, thereby hastening the process of restoration of abandoned iron ore mines of Goa, India.

Notes: Abstract River and stream rehabilitation projects are increasing in number, but the success or failure of these projects has rarely been evaluated, and the extent to which buffers can restore riparian and stream function and species composition is not well understood. In New Zealand the widespread conversion of forest to agricultural land has caused degradation of streams and riparian ecosystems. We assessed nine riparian buffer zone schemes in North Island, New Zealand that had been fenced and planted (age range from 2 to 24 years) and compared them with unbuffered control reaches upstream or nearby. Macroinvertebrate community composition was our prime indicator of water and habitat quality and ecological functioning, but we also assessed a range of physical and water quality variables within the stream and in the riparian zone. Generally, streams within buffer zones showed rapid improvements in visual water clarity and channel stability, but nutrient and fecal contamination responses were variable. Significant changes in macroinvertebrate communities toward “clean water” or native forest communities did not occur at most of the study sites. Improvement in invertebrate communities appeared to be most strongly linked to decreases in water temperature, suggesting that restoration of in-stream communities would only be achieved after canopy closure, with long buffer lengths, and protection of headwater tributaries. Expectations of riparian restoration efforts should be tempered by (1) time scales and (2) spatial arrangement of planted reaches, either within a catchment or with consideration of their proximity to source areas of recolonists.

Notes: Abstract One of the greatest challenges for ecologists this century will be restoring forests on degraded tropical lands. This restoration will require understanding complex processes that shape successional pathways, including interactions between trees and other plants. Shrub species often quickly invade disturbed tropical lands, yet little is known about whether they facilitate or inhibit subsequent tree recruitment and growth. We examined how shrubs and other vegetation (e.g., vines, grasses, herbs) affect tree recruitment, survival, and growth during the first 6 years of forest succession in Kibale National Park, Uganda. The study was undertaken in two recently logged exotic softwood plantations. We studied the successional trajectories in two recently logged areas that varied in their initial densities of trees and shrubs. Analyses suggested tree seedling presence and density were not strongly related to shrub density or height during succession. Tree sapling presence and density were positively significantly related to shrub density and height. We found little response in the tree community to experimental shrub removal, and although removal of all nontree vegetation temporarily enhanced tree growth, the effect disappeared after 2 years. Some early-successional trees benefited from reduced competition, whereas some mid-successional trees benefited from the presence of other vegetation. Some specific tree species responded strongly to vegetation removal. We interpret our findings in light of designing manipulations promoting forest restoration for biodiversity conservation and conclude with four tentative guidelines: (1) manage at the species level, not the community level; (2) increase facilitation for seedlings, reduce competition for saplings; (3) be cautious of assumptions about plant interactions; and (4) be adaptable and creative with new strategies when manipulations fail.

Notes: Abstract Soil chemical properties and soil mesofauna composition were assessed at a forest site in northern Austria, where 20 years earlier an amelioration treatment had been performed. The site had been treated with limestone, a high P slag, and ammonium nitrate to replace the poorly growing pine (Pinus sylvestris) forest with a Norway spruce (Picea abies) stand. This treatment was at that time a common means for the amelioration of nutrient-poor forest soils with recalcitrant forest floor layers. After treatment, a dense cover of a nitrophilic stinging nettle (Urtica dioica) developed. Most likely, the site had been over-fertilized, and inadvertently, an experiment with extreme N enrichment had been conducted. The abundance of collembolans increased, and dominance structure shifted from Isotomiella minor, Lipothrix lubbocki, and Isotoma notabilis at fertilizer treatment to Friesea mirabilis, Isotomiella minor, and Sphaeridia pumilis in the control, but the abundance of soil mesofauna generally decreased in the fertilizer treatment. Fertilization reduced the mass of the litter layer from 7.6 to 2.4 kg/m2. The total carbon pool in the soil was reduced due to reduction of the litter layer. However, the content of soil organic matter in the upper mineral soil was significantly increased. A part of the applied and mineralized nitrogen had been lost from the soil, but N retention in the upper mineral soil was still considerable. Soil pH and the base saturation were sustainably increased. Carbon losses upon mineralization of the litter layer were not offset by the increase in C content of the mineral soil. Presently, the C pool in the soil of the fertilized treatment is lower than in the control. However, the overall nutrient enrichment of the soil may facilitate C sequestration in the fertilized site in the future.

Notes: Abstract Poor growth of Quercus robur L. (oak) trees has been reported on mine sites where overburden and subsoil have been used in the reinstatement of surface layers. This stunting has been attributed to a lack of macronutrients and to an adverse soil environment for root growth and mycorrhizal development. Growth, mineral nutrition, and ectomycorrhizal colonization of Q. robur seedlings were studied in an experiment carried out under controlled growing conditions in which mine spoil material was enriched with a leaf litter mulch. Enrichment of mine spoil material was found to produce a significant increase in growth and foliar N concentrations of oak seedlings. Inoculation with three taxa of ectomycorrhizal fungi did not benefit seedlings when mine spoil was the only substrate, possibly due to the poor physical properties of the unamended spoil and lack of nutrients. Inoculation with two taxa, Laccaria laccata and Hebeloma crustuliniforme, isolated from 3-year-old trees produced a significant stimulation of growth in the organically enriched treatment, which was believed to be due to greater uptake of mineralized N. However, Cortinarius anomalus isolated from fruit bodies associated with a 15-year-old tree did not increase biomass. The presence of organic matter was found to result in a significant stimulation of mycorrhizal infection by both inoculum and contaminant mycobionts. Recommendations are made for improving the establishment and growth of oak seedlings on reinstated sites.

Notes: Abstract Prairie restoration at the northern edge of the Great Plains can be frustrated by previously established non-native perennial grasses. We compared the emergence of a widely introduced grass, Agropyron cristatum, and a common native grass, Bouteloua gracilis, in a 4-year-old field experiment in which the Agropyron-dominated vegetation had either been left intact or treated annually with herbicide. This was done at two levels of water supply, reflecting conditions expected in wet and dry years, to examine the effects of among-year variability in precipitation. Water addition significantly increased the emergence of both surface-sown and buried (1 cm deep) seeds. Herbicide treatment of neighbors did not increase the emergence of experimentally added seeds. Emergence was much greater for buried (80%) than surface-sown seeds (20%). Significantly more Bouteloua than Agropyron germinated from experimentally buried seeds. Whereas only a single seedling of Bouteloua emerged from the existing seed bank, the mean density of Agropyron seedlings emerging from the seed bank was 930/m2 (range, 0 to 6,455/m2). Surprisingly, the emergence of Agropyron from the seed bank was not decreased by 4 years of herbicide treatment, possibly because herbicide may release Agropyron from intraspecific competition and allow increased seed production to compensate for decreased plant abundance. In summary, we found few differences between Agropyron and Bouteloua in spring and summer emergence at high or low water availability. The persistence of Agropyron stands despite repeated herbicide application may be partly due to increased seed production.

Notes: Abstract The effect of increasing planting unit size and stabilizing sediment was examined for two seagrass planting methods at Carnac Island, Western Australia in 1993. The staple method (sprigs) was used to transplant Amphibolis griffithii (J. M. Black) den Hartog and the plug method was used to transplant A. griffithii and Posidonia sinuosa Cambridge and Kuo. Transplant size was varied by increasing the number of rhizomes incorporated into a staple and increasing the diameter of plugs. Planting units were transplanted into bare sand, back into the original donor seagrass bed, or into a meadow of Heterozostera tasmanica, which is an important colonizing species. Sprigs of A. griffithii were extracted from a monospecific meadow; tied into bundles of 1, 2, 5, and 10 rhizomes; and planted into unvegetated areas. Half the units were surrounded by plastic mesh and the remainder were unmeshed. All treatments were lost within 99 days after transplanting, and although larger bundles survived better than smaller ones, no significant differences could be attributed to the effects of mesh or sprig size. Plugs of P. sinuosa and A. griffithii were extracted from monospecific meadows using polyvinyl chloride pipe of three diameters, 5, 10, and 15 cm, and planted into unvegetated areas nearby. Half the units were surrounded by plastic mesh and the remainder were unmeshed. Posidonia sinuosa plugs were also placed within a meadow of H. tasmanica (Martens ex Aschers.) den Hartog. Only 60% of A. griffithii plug sizes survived 350 days after transplanting back into the donor bed; however, survival of transplants at unvegetated areas varied considerably, and analysis of variance indicated a significant two-way interaction between treatment and plug size. Transplants survived better when meshed (90% survived) and survival improved with increasing plug size. Posidonia sinuosa transplants survived poorly (no plugs survived beyond 220 days in bare or meshed treatments) regardless of size. Survival of 10- and 15-cm plugs was markedly better than the 5-cm plugs in vegetated areas, including the H. tasmanica meadow. The use of large seagrass plugs may be appropriate for transplantation in high-energy wave environments.

Notes: Abstract Dominance-diversity curves have been previously constructed for a range of ecosystems around the world to illustrate the dominance of particular species and show how their relative abundances compare between communities separated in time or space. We investigate the usefulness of dominance-diversity curves in rehabilitated areas to compare the floristic composition and abundance of “undisturbed” areas with disturbed areas, using bauxite mining rehabilitation in Western Australia as an example. Rehabilitated pits (11–13 years old) subjected to prescribed fire in autumn and spring were compared with unburned rehabilitated areas and the native jarrah (Eucalyptus marginata) forest. Dominance diversity curves were constructed by ranking the log of the species density values from highest to lowest. Species were categorized according to a variety of functional responses: life form (trees, shrubs, subshrubs, and annuals), fire response syndrome (seeder or resprouter), nitrogen fixing capability, and origin (native or adventive). Exponential functions showed extremely good fits for all sites (r2 = 0.939–0.995). Dominance diversity graphs showed that after burning of rehabilitated areas, sites exhibited a more similar dominance-diversity curve than before burning. This was emphasized in a classification (UPGMA) of the regression equations from the dominance-diversity curves that showed that sites burned in spring were more similar to the native forest than sites burned in autumn. There was no significant segregation of the nitrogen-fixing and species origin categories, although the life form and fire response groupings showed significant segregation along the dominance-diversity curve. Resprouters tended to be over-represented in the lower quartiles and under-represented in the upper quartiles of post-burn sites. It is suggested that using dominance-diversity curves in the monitoring of rehabilitated areas may be a useful approach because it provides an easily interpretable visual representation of both species richness and abundance relationships and may be further utilized to emphasize categories of plants that are over- or under-represented in rehabilitated areas. This will assist in the post-rehabilitation management of these sites.

Notes: Abstract The wave-exposed nature of much of the southwestern Australian coastline considerably reduces the protective influence of seagrasses, and sediment movement appears to be relatively unaffected by their presence. Present seagrass restoration efforts focus on the deployment of large mechanically transplanted “sods” of seagrass as a means of combating the negative effects of water motion on transplant survival. The aim of this study was to investigate the combined role of wave energy and transplant spacing on sediment movement and transplant survival to provide guidance for seagrass transplantation in areas of high wave energy. One hundred sixty sods (0.25 m2) of seagrass were mechanically extracted from a mixed meadow consisting of Amphibolis griffithii (Cymodoceaceae) and Posidonia coriacea (Posidoniaceae) and planted in a high wave energy site with the treatments configured as three replicates of 16 sods placed in 4 × 4–meter squares at distances of 0.5, 1.0, and 2.0 meters apart. An additional 16 single sods were planted randomly throughout the site. Monitoring was conducted at two monthly intervals and consisted of counting the number of sods surviving and measuring the shoot density of seagrass species within each surviving sod. Sediment height was monitored using a series of sediment plates and an electronic sediment level sensor. Sod spacing had no significant effect upon transplant survival, which remained above 90% for 4 months after transplantation and then declined with the onset of winter (June to August). After 14 months individual sod survival was between 9% and 40%. Initial shoot densities were 200 to 500 shoots/m2 and declined to less than 50 shoots/m2. Sediment fluctuations up to 35 cm were noted, occasionally taking place over a matter of hours, and storms during winter caused significantly increased sediment movement. This probably curtailed rhizome extension and prevented the expansion of the transplants. This study indicates that the ability of seagrasses to influence sediment would appear to vary with the prevailing hydrodynamic regime and that a reappraisal of the notion that all seagrass communities trap sediment is necessary.

Notes: Abstract Logging, fire suppression, and urbanization have all contributed to the serious decline and fragmentation of Pinus palustris (longleaf pine) ecosystems in the southeastern United States. Effective management of the remaining patches of these pyrogenic communities must incorporate periodic low-intensity fires, even where they are located on private lands in populated urban and suburban areas. To explore the effects of fire and its potential use for restoration and management of small fragments surrounded by suburban development, we conducted growing season prescribed fires in remnant longleaf pine sandhill patches in the suburbs of Gainesville, Florida. Density and composition of hardwoods were surveyed pre-burn and 1 and 9 months post-burn. Woody stem density decreased in the burn plots, predominantly in the smaller size classes. Flowering responses of forbs and small shrubs were surveyed six times post-burn for 1 year. Overall, the burns did not yield greater densities of flowering stems, but burn patches had higher species richness and diversity than control patches. In addition, there were consistently greater numbers of “showy flowered” sandhill species in flower in burn patches relative to controls. The results of this research demonstrate that prescribed fire can be used for restoration and management of small remnants of longleaf pine sandhill in suburban neighborhoods. It is also clear that although a single prescribed burn can be effective, it will take more than one burn to attain desired restoration goals in degraded longleaf remnants.

Notes: Abstract Efficient and accurate vegetation sampling techniques are essential for the assessment of wetland restoration success. Remotely acquired data, used extensively in many locations, have not been widely used to monitor restored wetlands. We compared three different vegetation sampling techniques to determine the accuracy associated with each method when used to determine species composition and cover in restored Pacific coast wetlands dominated by Salicornia virginica (perennial pickleweed). Two ground-based techniques, using quadrat and line intercept sampling, and a remote sensing technique, using low altitude, high resolution, color and color infrared photographs, were applied to estimate cover in three small restoration sites. The remote technique provided an accurate and efficient means of sampling vegetation cover, but individual species could not be identified, precluding estimates of species density and distribution. Aerial photography was determined to be an effective tool for vegetation monitoring of simple (i.e., single-species) habitat types or when species identities are not important (e.g., when vegetation is developing on a new restoration site). The efficiency associated with these vegetation sampling techniques was dependent on the scale of the assessment, with aerial photography more efficient than ground-based sampling methods for assessing large areas. However, the inability of aerial photography to identify individual species, especially mixed-species stands common in southern California salt marshes, limits its usefulness for monitoring restoration success. A combination of aerial photography and ground-based methods may be the most effective means of monitoring the success of large wetland restoration projects.

Notes: Abstract Possible constraints on the passive recovery of bare areas in the Karoo, a semiarid region in South Africa, include inadequate supply of seed, availability of suitable microsites for plant establishment, altered soil properties, and the truncation of key soil biotic processes. Here we investigate the possibility of initiating the restoration of bare areas by soil surface treatments with gypsum (CaSO4) and/or organic mulch. We also apply an exogenous seed source to test the hypothesis that seed availability limits autogenic recovery. Both gypsum and mulch improved rain water infiltration, gypsum more so than mulch, and both treatments resulted in significantly higher numbers of reseeded seedlings compared with controls. Gypsum also improved the survival of the cohorts of seedlings of the larger seeded Tripteris sinuata. Tripteris showed the highest number of seedlings (maximum count of 150 seedlings/1,000 viable seeds sown) and surviving plants of the three reseeded species, which included two small-seeded species, Ruschia spinosa and Chaetobromus dregeanus. Throughout the study period significantly higher plant volumes of naturally seeded annuals and perennials were recorded in the gypsum and/or mulch treatments compared with the controls. Germination and emergence of reseeded and naturally seeded plants appears to be determined by the availability of cool season (autumn to spring ) soil moisture, whereas follow-up rainfall during this time is important for plant survival. Mulching of bare areas in the Succulent Karoo has the potential to re-create vegetated areas that will further capture and conserve water, soil, and nutrients. Gypsum also showed positive results but might not be a cost-effective option because of transport costs to these remote arid areas.

Notes: Abstract Spring burning of sedge-grass meadows in the Slave River Lowlands (SRL), Northwest Territories, Canada was applied between 1992 and 1998 to reduce shrub encroachment and enhance Bison bison (bison) habitat, although the impact of fire on preferred bison forage was unknown before management. In the summer of 1998 we conducted a study in the Hook Lake area of the SRL to test the effect of burn frequency (unburned, burned once, or burned three times since 1992) on herbaceous plant community composition and Salix spp. L. (willow) shrub vigor. Plant species abundance, litter biomass, soil pH, and depth of the organic soil horizon were measured in 300 1-m2 quadrats nested within 30 1,000-m2 plots in both burned and unburned dry meadows. To test the relationship between frequency and willow vigor, all willow shrubs within the plots were assigned a vigor score from I (dead) to IV (flourishing). The spring burns appear to have reduced willow vigor; however, shrub survival remained high (76%) on the most frequently burned meadows. Ordination plots resulting from canonical correspondence analysis suggest that multiple spring burns influenced plant community composition in dry meadow areas and that less palatable bison forage species (e.g., Carex aenea Fern. and Juncus balticus L.) were correlated with a regime of three spring burns. Our results suggest that frequent spring fires in the Hook Lake area have only a small negative effect on willow cover but may reduce the abundance of primary bison forage plants compared with less frequently burned meadows.

Notes: Abstract Although there is no one correct technique for sampling vegetation, the sampling design chosen may greatly influence the conclusions researchers can draw from restoration treatments. Considerations when designing vegetation sampling protocol include determining what sampling attributes to measure, the size and shape of the sampling plot, the number of replicates and their location within the study area, and the frequency of sampling. We installed 20 point-intercept transects (50-m long), 8 belt transects (10 × 50 m), 10 adapted Daubenmire transects (four 0.5 × 2-m plots), and 4 modified-Whittaker plots (20 × 50 m with smaller nested plots) in treatment and control units to measure understory herbaceous response in a forest restoration experiment that tested different treatments. Point-intercept transects on average recorded at least twice as much plant cover as did adapted Daubenmire transects and modified-Whittaker plots taken at the same location for all control and treatment units. Point-intercept transects and adapted Daubenmire plots on average captured fewer rare and exotic species in the control and treatment units in comparison with the belt transects and modified-Whittaker plots. Modified-Whittaker plots captured the highest species richness in all units. Early successional understory response to restoration treatments was likely masked by the response of the herbaceous community to yearly climatic variation (dry vs. wet years). Species richness and abundance were higher in wet years than dry years for all control and treatment units. Our results illustrate that sampling techniques can greatly influence perceptions of understory plant trajectories and therefore the interpretation of whether restoration goals have been achieved. In addition, our results suggest that restoration monitoring needs to be conducted for a sufficient length of time so that restoration treatment responses can be detected.

Notes: Abstract A comparison of a composted organic amendment, a controlled-release fertilizer, and induced mycorrhizal inoculation as affecting the establishment and nutrition of bareroot Jeffrey pine (Pinus jeffreyi Grev. & Balf.) was conducted on a Sierra Nevada surface mine. The soil amendments were applied at outplanting to the backfill of augered planting holes, with a low rate of 8 g and a high rate of 16 g per seedling for the fertilizer, Gromax 21-6-2 + Minors, whereas a single rate of 2.0 L was used for organic matter. Colonization by Pisolithus tinctorius (Pers.) Coker & Couch was induced by coating the root systems with basidiospores suspended in a gel carrier. The organic amendment especially, but also mycorrhizal inoculation, caused substantial seedling mortality, whereas survival was unaffected by controlled-release fertilization. Gromax applied at the high rate produced a 74% increase in shoot volume after three growing seasons, whereas the organic amendment reduced volume by 28%. Growth was unaffected by mycorrhizal treatment. The growth response to the 16-g Gromax application probably reflected enhanced N, P, and K nutrition and decreased concentrations of potentially toxic metallic elements, including Mn and Al among others, as revealed through foliar analysis. Because they were accompanied by growth reduction, nutritional responses to the organic amendment, which involved both macronutrients and trace elements, were of little consequence. Impaired water relations may account for the poor response to this amendment. Likewise, nutritional responses to mycorrhizal inoculation produced no discernible benefit in terms of seedling performance. An inoculation procedure that failed to induce substantially greater P. tinctorius colonization in inoculated than uninoculated seedlings, and that may have also impaired water relations, likely explains this result. Overall, these findings indicate that further research is needed before either the organic amendment or the mycorrhizal inoculation procedure used here can be used in forest restoration efforts on dry sites.

Notes: Abstract We compared the floristic composition and structure of restoration areas of eucalypt woodland with untreated pasture (control) and remnant vegetation (reference) in western Sydney. The restored areas comprised over 1,000 ha of abandoned pasture, which had been treated to reduce weeds and planted with seedlings of 26 native plant species raised from seed obtained locally from remnant vegetation. Plantings were carried out 0–9 years ago. Floristic composition was measured in quadrats using frequency scores and cover abundance. As far as possible treatments and restoration ages were replicated across sites. Ordination and analyses of similarity failed to distinguish the composition of restored vegetation from that of untreated pasture, which were both significantly different from that of remnant vegetation. There was a weak compositional trend with age of restored vegetation, but this was not in the direction of increasing resemblance to remnant vegetation. There was some evidence for convergence in structural features of restored with remnant vegetation, but this was at least partly attributed to plant growth. Subject to constraints imposed by the sampling design, environmental factors, and spatial variation were discounted as explanations for the results. The results therefore suggest either failure of restoration treatments or a restoration trajectory that is too slow to detect within 10 years of establishment. Our conclusions agree with those of similar studies in other ecosystems and support: (1) the need to monitor restoration projects against ecological criteria with rigorous sampling designs and analytical methods, (2) further development of restoration methods, and (3) regulatory approaches that seek to prevent damage to ecosystems rather than those predicated on replacing losses with reconstructed ecosystems.

Notes: Abstract Landslides result in the loss of vertical vegetative structure, soil nutrients, and the soil seed bank. These losses impede timely recovery of tropical forest communities. In this study we added bird perches to six Puerto Rican landslides with three types of surfaces (bare, climbing fern, grass) in an effort to facilitate inputs of forest seeds through bird dispersal and to accelerate plant succession. Numbers of bird-dispersed forest seeds were significantly higher in plots beneath introduced perches than in control plots. Perches did not increase forest seedling densities compared with control plots. Seven different species of birds were observed on introduced perches. Because 99% of the seed inputs to controls and perch plots in the six landslides were wind-dispersed seeds (mostly graminoids), perches can improve landslide restoration if woody plants establish and shade out the dominant graminoid and climbing fern ground cover. Although increasing seed inputs from forest species is a critical step in accelerating revegetation of landslides, we suggest that supplemental restoration techniques be applied in addition to bird perches to promote forest recovery.

Notes: Abstract The effects of seasonal drought, belowground competition, and low soil fertility on the survival and growth over 2 years of four native tree species planted on a degraded hillside grassland in Hong Kong were studied in a field transplant experiment using three-way analysis of variance. The tree species were Schima superba (Theaceae), Castanopsis fissa (Fagaceae), Schefflera heptaphylla (Araliaceae), and Sapium discolor (Euphorbiaceae), and the treatments were dry season irrigation, herbicide, and fertilizer. Each species responded differently to the treatments. Sapium had a very low survival rate as a result of wind damage at the exposed study site. All three treatments significantly reduced the survival rate of Castanopsis seedlings, whereas herbicide reduced it for Sapium but increased it for Schefflera. The significant effects on seedling growth were all positive, except for a strong negative effect of herbicide on Castanopsis growth. Overall, the results suggest that all three factors—seasonal drought, belowground competition, and low soil nutrients—can significantly impair seedling growth on a degraded hillside site in Hong Kong but that their relative importance differs among species. The growth benefits of the three treatments were largest and most consistent for Schima, which as a mature forest dominant would be expected to be particularly sensitive to the environmental conditions on degraded open sites. This study highlights the fact that more systematic planting trials are needed to identify suitable native tree species for cost-effective reforestation on degraded hillsides in Hong Kong and South China.

Notes: Abstract Prescribed fire is often used to restore grassland systems to presettlement conditions; however, fire also has the potential to facilitate the invasion of exotic plants. Managers of wildlands and nature reserves must decide whether and how to apply prescribed burning to the best advantage in the face of this dilemma. Herbicide is also used to control exotic plants, but interactions between fire and herbicides have not been well studied. Potentilla recta is an exotic plant invading Dancing Prairie Preserve in northwest Montana. We used a complete factorial design with all combinations of spring burn, fall burn, no burn, picloram herbicide, and no herbicide to determine the effects of fire, season of burn, and their interaction with herbicide on the recruitment and population growth of P. recta over a 5-year period. Recruitment of P. recta was higher in burn plots compared with controls the first year after the fire, but this did not lead to significant population growth in subsequent years, possibly due to drier than normal conditions that occurred most years of the study. Effect of season of burn was variable among years but was higher in fall compared with spring burn plots across all years. Herbicide effectively eliminated P. recta from sample plots for 3–5 years. By the end of the study density of P. recta was greater in herbicide plots that were burned than those that were not. Results suggest that prescribed fire will enhance germination of P. recta, but this will not always lead to increased population growth. Prescribed fire may reduce the long-term efficacy of herbicide applied to control P. recta and will be most beneficial at Dancing Prairie when conducted in the spring rather than the fall. Results of prescribed fire on exotic plant invasions in semiarid environments will be difficult to predict because they are strongly dependent on stochastic climatic events.

Notes: Abstract Boating activities are an increasing source of physical damage to coral reefs worldwide. The damage caused by ship groundings can be significant and may result in a shift in reef structure and function. In this study we evaluate the status of two restoration projects established in 1995, 6 years after two freighters, the M/V Maitland and the M/V Elpis, ran aground on reefs of the Florida Keys National Marine Sanctuary. Our approach includes field monitoring in support of simulation model development to assess the effectiveness of the restoration efforts. A population model was developed for the coral Porites astreoides to project the convergence rates of coral abundance and population size structure between the restored and surrounding reference habitats. Coral communities are developing rapidly on the restoration structures. Species richness and abundance of the dominant coral, P. astreoides, were nearly indistinguishable between the restoration structures and reference habitats after only 6 years. However, although abundance and size structure of P. astreoides populations are rapidly approaching those of the reference habitats (a convergence in size structure within 10 years was simulated), maximum coral size will take twice as long to converge for this species. The sensitivity of the model to maximum recruitment rates highlights the importance of recruitment on the recovery rates of restored habitats, suggesting that special attention should be afforded to provide coral recruits with appropriate recruitment substrate at the time of restoration. Finally, the rates of convergence and, hence, the level of success of a restoration effort were shown to be influenced not only by the recruitment and survivorship rates of corals on the restoration structures but by the characteristics of the reference population as well. Accordingly, reference populations ought to be considered a “moving target” against which restoration success has to be measured dynamically. The simple, cost-effective, monitoring–modeling approach presented here can provide the necessary tools to assess the current status of a restoration effort and to project the time required for coral populations to resemble those found on undamaged reference habitats

Notes: Abstract Uniola paniculata (sea oats) rhizomes uprooted by hurricanes and deposited as wrack could be salvaged and replanted in dune restoration. To test this unexplored technique, percent tiller emergence was observed for 4 years from U. paniculata rhizomes replanted after submersion in seawater; air exposure of 0, 1, 3, 5, 7, and 11 days; freshwater rinse; and reburial in pots (watered) or on the beach (with or without supplemental water). In addition, U. paniculata rhizomes uprooted by Hurricane Georges were experimentally planted, and effects of soil salinity and moisture on emergence were tested in the greenhouse. Tiller emergence declined with increasing length of air exposure and decreasing size of rhizome. Tiller survival was enhanced by rainfall, rinsing with salt or fresh water during exposure and immediately after planting or supplemental beach watering. Although emergence was not reduced by soil salinity of 1,800 μS/cm, emergence was reduced by soil salinity of 5,800 μS/cm. Across the 4 years of the study tiller emergence from treated rhizomes varied considerably. U. paniculata rhizomes lost bud viability after 3–5 days of beach exposure, unless fresh water from rainfall, wet burlap storage, or watering was applied within 3 days. Bud viability was extended through 11 days when supplied with water. Thus, reburial within 3–11 days after a storm is a viable restoration technique.

Notes: Abstract Annual grasslands in California are often managed with seasonal grazing and prescribed burning on the assumption that such practices have long-term benefits for native species. Mature native perennial bunchgrasses, particularly Nassella pulchra (purple needlegrass), are often the focal species, although very little is known about responses at different life history stages. Thus, important questions remain about long-term population dynamics of both mature plants and seedling recruitment. In plots receiving repeated grazing and burning events over 7 years, mortality of mature plants was threefold higher on mounds than on intermounds and likely reflected increased competition intensity associated with increased resource availability in deeper soil. Burning and grazing treatments had strong positive effects on basal area of mature N. pulchra. However, plants in grazed plots that were not burned contained considerable standing dead biomass. Topographic location strongly influenced growth as intermound plants grew relatively more than mound plants, but the effects on growth of burning and grazing did not vary with topographic location. In mapped plots N. pulchra recruitment was very low, and overall density dropped an average of 31%. However, a significant time-by-burning effect indicated that survival was significantly higher in burned plots. After 7 years of repeated treatments, effects of burning and grazing management on mature N. pulchra were positive but not for all phenological stages. Understanding long-term influence of management on bunchgrass populations may not be easy to determine because short-term results may not reflect long-term responses and some life cycle dynamics may be observed only over very long periods.

Notes: Abstract Cades Cove, Great Smoky Mountains National Park, U.S.A. was historically cleared largely for pastoral purposes; it is now comprised of recently abandoned pastures dominated by non-native pasture species. To investigate the potential for reducing non-native species relative to native species, park managers initiated an experiment in 1995 that included mowing, herbicide application, planting of seed, and burning of replicate 20 × 50–m plots at each of two sites within Cades Cove. Between 1995 and 2001 we evaluated the response of the plant community (i.e., species-specific cover and frequency, biomass, diversity) to this suite of treatments and compared it with unmanipulated control plots at each site. Four years after treatment initiation abundance measures of Plantago lanceolata, Setaria geniculata, and Trifolium spp. averaged one-third lower in treated than control plots. Frequency of Festuca pratensis was lower in treated than in control plots for 2 years, but after 4 years its frequency, cover, and biomass did not differ between treated and control plots. By 2000 the cover of Sorghastrum nutans in treated plots increased to 23–47%, depending on the site. Total biomass and diversity increased in treated plots. The dominance of Lespedeza cuneata at one site apparently reduced planting success, biomass production, and diversity and evenness. Post-treatment lags in response for several species, coupled with interannual variation in response to environmental conditions, suggest that evaluations of treatment success would differ greatly depending on when the evaluation was conducted.

Notes: Abstract We compared nekton and benthos densities and community compositions in a natural mixed seagrass bed dominated by Halodule wrightii (shoalgrass) with those found in three shoalgrass transplant sites and adjoining sand habitats in western Galveston Bay, Texas, U.S.A. Quantitative drop traps and cores were used to compare communities up to seven times over 36 months post-transplant where transplant beds survived. Total densities of fishes, decapods, annelids, benthic crustaceans, and most dominant species were significantly higher in natural seagrass than in transplanted shoalgrass or sand habitats during most sampling periods. On occasion, fish and decapod densities were significantly higher in transplanted shoalgrass than in adjoining sand habitats. No consistent faunal differences were found among transplant sites before two of three sites failed. Taxonomic comparison of community compositions indicated that nekton and benthos communities in natural seagrass beds were usually distinct from those in transplanted beds or sand habitats, which were similar. We conclude that reestablishing a shoalgrass bed that resembles a natural seagrass bed and its faunal communities in the Galveston Bay system will take longer than 3 years, provided that transplants persist.

Notes: Abstract Restoration of degraded natural vegetation in parks is often complicated by the need to maintain public access. We tested whether the natural canopy species, Thuja occidentalis, can be restored to degraded cliff edges in Bruce Peninsula National Park, Ontario, Canada without reductions in visitor numbers. Eighty 10-year-old and 80 4-year-old container-grown saplings and 1,400 seeds were planted and monitored for 4 years. Eight treatments were applied that tested for effects of planting site (distance from cliff edge and pathways) and supportive measures (soil, water, cages, or signs) on survival, growth, and damage. No trees became successfully established from seed. Younger trees showed faster initial establishment and growth, but 4-year survival was the same for both age groups (39%). Supplemental soil improved the health of planted trees, and both soil and water slightly improved their survival. Cages did not affect survival and growth but decreased damage to 4-year-old trees and increased it for 10-year-olds. Signs had no effect on any measured variable. Trees planted away from the cliff edge and from pathways had the greatest establishment success, 4-year survival, and general health. Relative visitor density, as estimated from spot counts of visitors, had the largest effect on restoration success; the results suggest a threshold of visitor density above which restoration may be impossible. Planting location, especially with respect to shade, was also important. The planting of 4-year-old trees without supportive measures is suggested as the most cost-effective restoration technique at this site. The results indicate that restoration of open woodland habitats is possible without total visitor exclusion but that some restrictions on visitor numbers or activities are necessary.

Notes: We model firms as competing for socially responsible consumers by linking the provision of a public good (environmentally friendly or socially responsible activities) to sales of their private goods. In many cases, too little of the public good is provided, but under certain conditions, competition leads to excessive provision. Further, there is generally a trade-off between more efficient provision of the private and the public good. Our results indicate that the level of private provision of the public good varies inversely with the competitiveness of the private-good market and that the types of public goods provided are biased toward those for which consumers have high participation value.

Notes: Abstract Ecological restoration enjoys widespread use as a technique to mitigate for environmental damage. Success of a restoration project often is evaluated on the basis of plant cover only. Recovery of a native arthropod fauna is also important to achieve conservation goals. I sampled arthropod communities by pitfall trapping in undisturbed, disturbed, and restored coastal sage scrub habitats in southern California. I evaluated arthropod community composition, diversity, and abundance using summary statistics, cluster analysis, and detrended correspondence analysis (DCA) and investigated influence of vegetation on arthropod communities with multiple regression analysis. Arthropod diversity at undisturbed and disturbed sites was greater than at sites that were 5 and 15 years following restoration ( p 〈 0.05). Number of arthropod species was not significantly different among undisturbed, disturbed, and restored sites, and two restoration sites had significantly more individuals than other sites. Vegetation at disturbed and undisturbed sites differed significantly; older restorations did not differ significantly from undisturbed sites in diversity, percent cover, or structural complexity. In multiple regression models, arthropod species richness and diversity was negatively related to vegetation height but positively related to structural complexity at intermediate heights. Exotic arthropod species were negatively associated with overall arthropod diversity, with abundance of the earwig Forficula auricularia best predicting diversity at comparison (not restored) sites (r2 = 0.29), and abundance of the spider Dysdera crocata and the ant Linepithema humile predicting diversity at all sites combined (r2 = 0.48). Native scavengers were less abundant at restored sites than all other sites and, with a notable exception, native predators were less abundant as well. DCA of all species separated restored sites from all other sites on the first axis, which was highly correlated with arthropod diversity and exotic arthropod species abundance. Lower taxonomic levels showed similar but weaker patterns, with example families not discriminating between site histories. Vegetation characteristics did not differ significantly between the newly restored site and disturbed sites, or between mature restoration sites and undisturbed sites. In contrast, arthropod communities at all restored sites were, as a group, significantly different from both disturbed and undisturbed sites. As found in other studies of other restoration sites, arthropod communities are less diverse and have altered guild structure. If restoration is to be successful as compensatory mitigation, restoration success standards must be expanded to include arthropods.

Notes: Abstract The Pacific islands off southern California, U.S.A. and Baja California, Mexico hold potential for the conservation and restoration of California Mediterranean coastal ecosystems. However, the presence of exotic herbivores and invasive plants pose threats to these systems. Here, we use introduced herbivore removal as a large-scale experimental manipulation to examine the importance of top-down and bottom-up processes to a large-scale restoration effort. Using a paired approach on the Todos Santos Islands, Mexico we removed herbivores from one island, while they temporarily remained on an adjacent and similar island. We augmented this experiment with smaller scale herbivore exclosures on the control island. At both scales we failed to detect an herbivore effect on the plant community; rather plant community dynamics appeared to be dominated by El Niño related precipitation and exotic annuals. A parallel experiment on the San Benito Islands, Mexico revealed a different dynamic: Top-down effects on the plant community by exotic herbivores were evident. Differences in the response from the plant communities to both exotic herbivore presence and removal between these two island groups, along with Santa Barbara Island, U.S.A., where restoration has been on-going, raise important questions in ecosystem restoration. The history of anthropogenic disturbance, exotic plant abundance, and aridity play roles in postherbivore removal recovery. Although island conservation practitioners have honed the ability to remove exotic mammals from islands, development of invasive plant removal techniques is needed to fully capitalize on the conservation potential of California island ecosystems.

Notes: Abstract Restoration practitioners have long been faced with a dichotomous choice of native versus introduced plant material confounded by a general lack of consensus concerning what constitutes being native. The “restoration gene pool” concept assigns plant materials to one of four restoration gene pools (primary to quaternary) in order of declining genetic correspondence to the target population. Adaptation is decoupled from genetic identity because they often do not correspond, particularly if ecosystem function of the disturbed site has been altered. Because use of plant material with highest genetic identity, that is, the primary restoration gene pool, may not be ultimately successful, material of higher order pools may be substituted. This decision can be made individually for each plant species in the restored plant community in the scientific context that ecosystem management demands. The restoration gene pool concept provides a place for cultivars of native species and noninvasive introduced plant material when use of native-site material is not feasible. The use of metapopulation polycrosses or composites and multiple-origin polycrosses or composites is encouraged as appropriate. The restoration gene pool concept can be implemented as a hierarchical decision-support tool within the larger context of planning seedings.

Notes: Abstract Willamette Valley upland prairie in western Oregon, U.S.A. has been severely degraded and fragmented in the past 150 years after European settlement, resulting in vast population reductions of endemic species. Icaricia icarioides fenderi (Fender's blue butterfly) and Lupinus sulphureus ssp. kincaidii (Kincaid's lupine) are federally listed as Endangered and Threatened Species, respectively. Both are Willamette Valley upland prairie endemics, and Kincaid's lupine is the primary host plant for the Fender's blue butterfly. Attempts to grow Kincaid's lupine have been partially successful in a greenhouse situation; however, propagating plants from field-sown seed can be tenuous and plant establishment is unpredictable. Kincaid's lupine seeds were planted in the fall 1997 at two different upland prairie sites, and the cohort was followed through the summer 2000. Based on cohort tables the most vulnerable life stages to mortality are the germinant stage and the first growing year. Mechanical scarification of Kincaid's lupine seeds yielded no significant differences in survivorship, maternal function, plant size, and the percentage of seeds germinated compared with unscarified seeds. Differential seed source performance detected at one planting site suggests that underlying differences in population genetics may affect Kincaid's lupine vigor, fitness, and establishment. Future restoration projects for Kincaid's lupine should focus on upland prairie sites with naturally occurring lupine populations because local ecological conditions are favorable for lupine establishment. Moreover, the addition of new individuals to small Kincaid's lupine colonies will buffer against the effects of inbreeding depression and increase the site carrying capacity for Fender's blue butterfly.

Notes: Abstract Rapid establishment by aggressive plants such as Phalaris arundinacea (reed canarygrass) often interferes with sedge meadow establishment in restored prairie pothole wetlands in the mid-continental United States. Introducing a cover crop during community establishment might suppress P. arundinacea invasion in restored prairie potholes by reducing resource availability. We evaluated two potential cover crops, Echinochloa crusgalli (barnyardgrass) and Polygonum lapathifolium (nodding smartweed), for suppressing P. arundinacea invasion in an experimental wetland using replacement series competition experiments. Further, we assessed the effects of E. crusgalli and P. lapathifolium on sedge meadow establishment by sowing Carex hystericina, a common wetland sedge, as a third species at a constant density in the replacement experiments. Echinochloa crusgalli, compared with no cover crop, reduced P. arundinacea biomass by more than 1,000 g/m2 (65%) after two growing seasons. Polygonum lapathifolium did not affect P. arundinacea biomass. Dense E. crusgalli canopies in the first year and thick E. crusgalli thatch in the second year substantially reduced light availability for P. arundinacea establishment. Echinochloa crusgalli also reduced C. hystericina biomass by more than 1,800 g/m2 (99%) after two growing seasons. Carex hystericina biomass was similar in plots sown with E. crusgalli to P. arundinacea monocultures. Neither E. crusgalli nor P. lapathifolium is likely to improve sedge meadow restoration success. These trends were not sensitive to initial sowing density or elevation above water level. Without methods to suppress P. arundinacea invasions, sedge meadow restorations may often fail. Thorough site preparation to remove P. arundinacea propagule sources before restoration is essential.

Notes: Abstract Interest in restoring native ecosystems is resulting in conversion of marginal agricultural lands to bottomland hardwood-dominated forests in the midwestern and midsouthern United States. Growing stock for these efforts typically consists of planted oak (Quercus spp.) and volunteer vegetation. Reports of mixed reforestation success and the lack of post-establishment tree growth data prompted this evaluation of vegetation characteristics of 5- to 7-year-old operational restorations in the Lower Cache River Watershed in southernmost Illinois, U.S.A. Fraxinus pennsylvanica (green ash), Acer negundo (box-elder), and Liquidambar styraciflua (sweetgum) together comprised 77% of all tree stems observed. Full stocking of overstory tree species can be expected to produce a closed canopy stand within 160 m of a forested edge, due primarily to the abundance of rapidly growing volunteer-origin trees. Planted oaks contributed minimally to total tree stocking but were present in sufficient numbers to eventually improve wildlife habitat, and therefore satisfied restoration objectives. Oak height was 23% greater when in the presence of a non-oak tree species. Herbaceous cover was dominated by Solidago gigantea (late goldenrod) and Juncus spp. (rushes). Solidago gigantea was associated with poor growth and low density of non-oak stems, whereas Juncus dudleyi (Dudley's rush) was associated with taller non-oak stems. These results suggest that the presence of volunteer-origin trees is crucial for the creation of full stand stocking that will result in rapid development of a closed canopy forest. Improved success of future reforestation efforts will require more intensive methods to establish adequate stocking beyond 160 m of a forest edge. Methods described here could be adapted for agricultural field to forest restorations in other regions to predict critical distances from volunteer seed sources within which supplemental planting would be unnecessary to meet tree stocking objectives.

Notes: Abstract The decline and range reduction of sage grouse populations are primarily due to permanent loss and degradation of sagebrush–grassland habitat. Several studies have shown that sage grouse productivity may be limited by the availability of certain preferred highly nutritious forb species that have also declined within sagebrush ecosystems of the Intermountain West, U.S.A. The purpose of this study was to determine the suitability of three species of forbs for revegetation projects where improving sage grouse habitat is a goal. Species suitability was determined by evaluating the emergence, survival, and reproduction of Crepis modocensis, C. occidentalis, and Astragalus purshii in response to method of establishment (seeding or transplanting), site preparation treatment (burned or unburned), and microsite (mound or interspace) in an Artemisia tridentata ssp. wyomingensis vegetation association in south central Oregon. For seeded plants A. purshii had the lowest emergence (8%) of all three species. Both seeded Crepis species had similar overall emergence (38%). Significantly more Crepis seedlings emerged from shrub mounds in unburned areas (50%) than in any other fire-by-microsite treatment (33 to 36%). Approximately 10% more Crepis seedlings survived in mounds compared with interspaces. Nearly twice as many emerging Crepis seedlings survived in the burned areas as opposed to unburned areas (p 〈 0.01). This resulted in more plant establishment in burned mounds despite higher emergence in unburned mounds. Astragalus purshii seedlings also survived better in burned areas (p = 0.06) but had no differential response to microsite. Fire enhanced survival of both Crepis and A. purshii transplants (p = 0.08 and p = 0.001). We believe additional research is needed to improve A. purshii emergence before it will become an effective plant for restoring sage grouse habitat. Conversely, we conclude that these Crepis species provide a viable revegetation option for improving sage grouse habitat in south central Oregon.

Notes: Abstract Vegetation samples from either spontaneously revegetated or technically reclaimed spoil heaps of different ages in one of the largest active brown coal mining districts in Europe were analyzed and compared. The spoil heaps are located in the northwestern part of the Czech Republic and represent ages between 0 and 45 years. Ordination analysis (detrended correspondence analysis) showed that vegetation on technically reclaimed spoil heaps developed in a different way than that on spontaneously revegetated ones. The latter exhibited much higher species diversity in the oldest stages with the number of species doubled that of technically reclaimed sites. The oldest stages were also more advanced along an expected successional gradient as indicated by the ordination. Accelerating the vegetation development by technical reclamation was only of temporal character, whereas spontaneous succession proceeded further over the longer time scale. Spontaneous succession is advocated as an inexpensive and easy alternative to technical reclamation, because it leads to a more natural and rich vegetation cover. Unfortunately, technical reclamation is still the only approach considered in the present reclamation activities for this region.

Notes: Abstract Fauna serve a key role in many forest ecological processes. Despite this, few studies have considered long-term faunal recolonization after mining and rehabilitation of forest ecosystems. In the jarrah forest of southwestern Australia, permanent fauna monitoring sites have been established in bauxite mined areas rehabilitated in 1990 and in a range of representative unmined forest control sites. At each site mammals, birds, reptiles, and ants were surveyed in 1992, 1995, and 1998. The aims of the monitoring were to develop a better understanding of faunal recolonization trends, to produce recommendations for promoting fauna return, and to consider which techniques and fauna groups are best suited for monitoring recolonization. The results showed that successional trends varied between fauna groups. Generalist foraging mammals recolonized rapidly, whereas small predators took longer. Feral mice were initially abundant and then declined. Birds gradually recolonized, and after 8 years bird communities were very similar to those in unmined forest sites. Reptile species took longer, and after 8 years numbers of species remained lower than in unmined forests. Species richness and diversity of ants in 8-year-old rehabilitation were comparable with those of unmined forest in some rehabilitated sites but were lower in others. The composition of ant communities was still different from that of unmined sites. Ant species that only use disturbed forest declined rapidly in abundance as rehabilitation aged. The results suggest that although the rates of faunal recolonization will vary, with time most or all mammal, bird, reptile, and ant species should inhabit rehabilitated bauxite mines. The densities of many are likely to be similar to those in unmined forest, but for others it is too early to know whether this will be the case. Techniques for promoting fauna return are discussed. This study demonstrates that no single fauna group is suitable for use as an overall “indicator” of faunal recolonization; different fauna species and groups reflect different aspects of faunal succession.

Notes: Abstract Endozoochory has proven to be a highly effective mechanism in the dispersal of viable seeds in Mediterranean grasslands. We studied the effect of cattle dung application on species richness, particularly on the reintroduction of species lost after abandonment. Sown and control plots were monitored for 3 years after dung sowing. We found a significant increase in small-scale richness, which may be attributed to the treatment, with the inclusion of species detected in the dung and in the grazed pasture. The differences in richness and floristic composition diminished over time. This experiment proves the potential utility of this treatment for the restoration of species richness in abandoned pastures, although supplementary steps are necessary, including further sowing and/or shrub cutting in subsequent years.

Notes: Abstract Natural accumulation of wind-borne sediments within or around the canopies of plants plays an important role in the ecological and evolutionary dynamics of many coastal and desert ecosystems. The formation of such phytogenic mounds (nebkhas) creates patches that can strongly influence the spatial distribution of plant and soil resources. In land restoration of arid and semiarid environments it is important to study the potential role of such biological patchiness that may provide sites for coexistence of species with different life and growth forms. Our main objective was to test whether the nebkhas of a leguminous shrub, Retama raetam (white broom), promote restoration of herbaceous vegetation and soil in the degraded rangelands of northern Sinai. Vegetation and microclimatic and edaphic characteristics within the nebkhas, as well as within internebkha spaces, were compared for ungrazed and grazed sites. Abundance and richness of herbaceous plants were positively related to nebkha area, which explained more of the variance of abundance and richness in the grazed site than in the ungrazed one. Protection from grazing, especially on nebkhas, was associated with an increase in abundance and richness of herbaceous plants, improved soil microclimate, and increased soil fine particles and nutrient concentrations. The results suggest that management (in casu protection from grazing) of nebkhas of woody perennial shrubs changes rangeland conditions and improves the resource regulatory processes. Furthermore, nebkhas of unpalatable plants have the potential to preserve plant diversity in overgrazed plant communities, because they are effective in capturing and retaining water, soil materials, and propagules within and from nearby areas, resources that would otherwise be lost.

Notes: Abstract Sustained-release fertilizer and two kinds of mulch treatments were tested to determine their effects on survival and growth of planted Chamaecyparis thyoides (Atlantic white cedar) on a sandy extremely nutrient-deficient site. Height, basal trunk diameter, dry weight, and concentrations of nitrogen (N), phosphorus (P), and potassium (K) were measured for each treatment. After two growing seasons, survival was very high in untreated controls (mean, 86%) and was not significantly increased by any treatment (significance was assessed at p = 0.05 throughout this work). Stem height and cross-sectional area doubled in unamended plots during the course of the study. Fresh mulch alone caused no additional increase in growth, compared with unamended plots. Decomposed mulch caused a slight but significant increase. Sustained-release fertilizer caused significant increases in height (threefold) and dry weight (approximately sixfold). Combined treatment with fertilizer and mulch gave significantly greater growth responses than did other treatments, increasing heights 4- to 5-fold, trunk cross-sectional areas 4-fold, and dry weights 11- to 21-fold over no-treatment controls. Tissue concentrations of N and P correlated with growth trends, with combinations of mulch and timed-release fertilizer providing the highest values. Though statistically different, the two mulch treatments were similar in their effects on tissue nutrient concentrations. When combined with fertilizer, undecomposed mulch stimulated increases in height and dry weight significantly more than did decomposed mulch. Thus, establishment of C. thyoides on low-nutrient sandy soils is improved by combined soil amendment with sustained-release nutrients and organic mulch.

Notes: Abstract Many grassland restoration projects on former arable land face problems because early successional grassland species establish vigorously and persistently but late successional grassland species fail to establish. Differences in establishment characteristics of early and late successional species might provide an explanation for the failure of many late successional species to colonize grasslands on ex-arable land. I examined whether early and late successional species had different establishment rates in the initial years of a grassland succession, whether a specific establishment stage (seedling emergence, mortality or growth) could be identified as the key process controlling establishment, and what management would enhance the establishment of late successional grassland species. Seeds of three early and three late successional species were sown separately in ex-arable plots with bare soil, 1-year-old vegetation, and 2-year-old vegetation. Emergence, mortality, and seedling growth were monitored for 1 year. Early successional species established successfully in the bare soil plots but failed to establish in plots with 1- and 2-year-old vegetation. Late successional species showed either lower establishment rates in the younger succession stages or decreased establishment with succession that nevertheless resulted in significant establishment in the oldest plots. Seedling emergence proved to be the key factor determining the establishment pattern of early and late successional species. In absolute numbers, emergence of late successional species was, however, similar or higher than that of early successional species, even in the earliest succession stage. The poor establishment of late successional species on former arable land could therefore not be explained solely by differences in establishment characteristics between early and late successional grassland species. Competitive processes between early and late successional species later in the life cycle probably play an important role. The results do point out that establishment of late successional species can be promoted by creating vegetative cover from the start of the restoration effort.

Notes: We analyze the interactions between internal and external control mechanisms in a framework in which the board selects the CEO and then decides whether to retain or dismiss him after observing a signal regarding his ability. The novel aspect of our paper is that we consider both the hiring and the firing of the CEO by the board. The type of board is defined by its ability to select a good CEO, so that the quality of the CEO depends on the type of board. Then, the dismissal-retention decision provides information not only on the quality of the CEO but also on the board's type. We show that the board's behavior depends on the pressure from the takeover market and on whether its type is publicly known. When the pressure from the takeover market is high and the type of board is private information, the board prefers not to dismiss the manager even if it has received a very low signal regarding his quality. Hence, our model endogenously derives a collusion between board and CEO in which the board does not fire a bad CEO. This behavior emerges as an attempt to hide the board's inability to accomplish the first task, CEO selection, by distorting the second task, the CEO retention-dismissal decision.

Notes: This paper estimates the importance of indirect network effects in the US video cassette recorder (VCR) market between 1978 and 1986. Estimation reveals the significant role of networks in the format competition between VHS and Beta. The paper also finds that if Sony, the system sponsor of Beta, had aggressively introduced its VCRs at the early stage of competition, Beta would likely have dominated the market in 1985; instead, the format disappeared in 1989. Finally, the paper measures consumer welfare for the value of network effects in VCRs, and assesses the consumer welfare effect of standardization.

Notes: We consider a repeated interaction between a manufacturing firm and a subcontractor. The relationship between the two parties is characterized (1) by moral hazard, and (2) by the fact that they do not have perfect knowledge about the base cost level of the project, which is carried out by a subcontractor (the parties only have identical a priori beliefs). We consider a two-period model where the players can update their estimate of the base cost level according to incoming information. Exit relationships, where the firm signs one-period contracts with different subcontractors, are compared with voice relationships, where both partners commit to a two-period interaction and (due to information sharing and face-to-face communication between the partners) additional information about the base cost level is generated. It is shown that in such a dynamic framework with common uncertainty the quality of the additional information plays a crucial role in determining the characteristics of the optimal relationship: voice-based strategies governed by long-term contracts are preferable if the precision of the additional information about the base cost level is high. If the precision of the additional signal is low, exit strategies with frequent changes of the subcontractors are optimal for the manufacturer.

Notes: We examine a model of locational choice in commercial media markets. Commercial media (stations) compete for audiences with their choice of programming variety in order to attract advertising revenues from advertisers. These advertisers (producers) compete in a differentiated product market and rely on advertising to inform consumers about their product. We use the model to show that media have incentives to minimize the extent of differentiation between them. This incentive is an implication of the assumed role of advertising as information and as an ultimate nuisance to the audience. When stations minimally differentiate their programming offerings, producers choose lower levels of advertising. Consequently, lower levels of product information are available to consumers, permitting producers to gain higher margins on product sales. As a result, stations can negotiate higher payments for advertising space.

Notes: This paper applies spatial econometrics to hamburger price data to assess the degree of substitutability of products and locations of spatially dispersed franchised chains. First, while intrachain price variation exists, I find that hamburger prices at neighboring outlets of different chains are spatially uncorrelated. I conclude that their products are not close substitutes, which provides an explanation for why price promotions have not raised market share. I do find spatial price correlation, however, among proximate outlets of separate franchisees within the same chain. This finding implies that customers view proximate locations of a chain as substitutes.

Notes: This paper studies vertical integration by an essential-good monopolist into complementary markets. Unlike previous studies of complementary products, consumers are allowed to purchase some components of a complementary basket, but not others. Two different pricing strategies by the integrated firm may emerge. In mass-market equilibria, the price of the complement under integration is zero and it is given away with the essential good. Niche-market equilibria have more conventional pricing. This dichotomy is consistent with consumer software pricing. Integration enhances consumer and total surplus, unless it leads to exit by the higher-quality rival, in which case welfare is reduced. Exit is most likely when it is least damaging to consumer welfare. Integration reduces innovation by the rival firm. The effect on innovation by the integrated firm is ambiguous, but numerical computation of an extended model indicates that integration increases the innovation of the integrated firm and enhances welfare.

Notes: Abstract In Maputaland, South Africa vegetative and microclimatic changes on mined dunes drive the composition of the dung beetle fauna toward convergence with that in natural dune forest on unmined dunes. We assessed the pattern of these changes using a 23-year vegetational chronosequence on mined dunes, which passes from grassland (approximately 1 year) to open Acacia shrubland thicket to Acacia karroo-dominated woodland (approximately 9 years). Across this sequence, which represents successional stages in the restoration of dune forest, there was a sequential trend toward convergence in dung beetle species composition in both the entire species complement and, particularly, in shade specialist species. However, species abundance patterns showed a trend toward convergence only in early chronosequence Acacia woodland, followed by a decline in similarity between dung beetle assemblages of older Acacia woodland and unmined natural forest. This trend toward divergence was common both to the entire species complement, which includes widespread taxa, and to species endemic to Maputaland or the east coast. These trends in similarity and dissimilarity between dung beetle assemblages closely parallel the greater physiognomic and microclimatic similarity between early Acacia woodland and natural forest and the relative dissimilarity of older Acacia woodland. In conclusion, although percentage similarities between dung beetle assemblages of approximately 12-year woodland and natural forests were comparable with those between each natural forest stand, decline in similarity in older woodland stands suggests that lasting convergence in dung beetle species abundance will only be attained once the Acacia woodland is replaced by secondary natural forest.

Notes: Abstract We investigated effects of fire frequency, seasonal timing, and plant community on patchiness and intensity of prescribed fires in subtropical savannas in the Long Pine Key region of Everglades National Park, Florida (U.S.A.). We measured patchiness and intensity in different plant communities along elevation gradients in “fire blocks.” These blocks were prescribed burned at varying times during the lightning season and at different frequencies between 1995 and 2000. Fire frequency, seasonal timing, and plant community all influenced the patchiness and intensity of prescribed fires. Fires were less patchy and more intense, probably because of drier conditions and pyrogenic fuels, in higher elevation plant communities (e.g., high pine savannas) than in lower elevation communities (e.g., long-hydroperiod prairies). In all plant communities fires became increasingly patchy and less intense as the wet season progressed and moisture accumulated in fuels. Frequent prescribed fire resulted in increased patchiness but a wider range of intensities; higher intensities appeared to result from regrowth of more flammable vegetation. Our study suggests that frequent early lightning season prescribed fires produce a wider range of post-fire conditions than less frequent late lightning season prescribed fires. Our study also suggests that natural early lightning season fires readily carried through pine savannas and short-hydroperiod prairies, but lower elevation long-hydroperiod prairies functioned as firebreaks. Natural fires probably crossed these firebreaks only during drier years, potentially producing large landscape-level fires. Knowledge of how patchily and intensely fires burn across a savanna landscape should be useful for developing landscape-level fire management.

Notes: Abstract To characterize the altitudinal and successional trends in microbial biomass and to understand their role in soil nutrient dynamics during the aggradation phase (vegetation recovery) of abandoned shifting cultivation systems, we determined the soil properties and microbial C and N in jhum (slash-and-burn) cultivation systems at different altitudes and 1-, 7-, and 16-year-old fallow agricultural lands at lower and higher altitudes in the northeastern Indian hills. Density of ground vegetation was lower in the undisturbed forest than in the jhum fallows. In general, 1-year jhum fallow had greater herbaceous vegetation both at lower and higher altitudes. Although woody plants were observed in 7- and 16-year-old jhum fallows, their density was highest in the forest. Soil moisture, organic C, and total N also increased gradually with increasing altitude and progressive secondary succession. Soil pH showed a negative correlation with altitude (as also confounded by soil type) and fallow age. Both microbial C and N had a close correlation with altitude and fallow age. Contribution of microbial C to soil organic C was 2.0–2.6% and microbial N to total N 1.4–2.2% in jhum fields, 2.4–4.3% and 1.2–2.1%, respectively, in jhum fallows, and 2.5–2.9% and 1.6–1.9% in the forests. Microbial C and N showed a negative correlation with herbaceous plant density. Microbial biomass in the jhum fallows and forest stands had a positive relationship with woody vegetation. Along an altitudinal and/or successional gradient, microbial C and N were positively correlated with water-holding capacity, soil moisture, organic C, and total N and negatively correlated with soil pH. Microbial C and N were positively correlated with each other. Therefore, the study suggests that the altitudinal and successional dynamics of microbial C and N are linked to, among other properties, soil organic matter and total nitrogen contents in the soil during community development after land abandonment from shifting cultivation.

Notes: Abstract Successful control of invasive exotic plants depends to a large degree on the regeneration potential of the target exotic species and other species that might also be influenced by the removal effort. In coastal grasslands of California, exotic French broom (Genista monspessulana) forms both dense stands aboveground and abundant seed banks belowground. Land managers attempt to reduce broom cover and the seed bank through prescribed burning, but before this study, no investigators had examined the effect of repeated burning on French broom and associated grassland species. We found that the soil seed bank of stands that were burned had fewer broom seeds than unburned areas but that repeated burning did not reduce the seed bank beyond what was observed after one fire. Fire also did not have any consistent effect on the seed banks of other grassland species. We also examined the relationship between broom stand age and seed bank size but did not find a strong relationship between them. Our data suggested that the broom seed bank stays constant or declines slightly with stand age. We did, however, find that nonbroom seed numbers decreased as broom stands aged. Our results suggest that fire does reduce the size of the broom seed bank and that control of broom need not be limited to only the youngest stands.

Notes: Abstract Arid and semiarid ecosystems in the Mediterranean are under high risk of desertification. Revegetation with native well-adapted evergreen shrubs is desirable, but techniques for successful establishment of these species are not fully developed. Transplant shock is a key hurdle to plantation success. The application of a drought-preconditioning treatment during the last months of nursery culture is a potential technique for reducing transplant shock. This technique has been widely applied in boreal habitats and humid temperate areas. Three representative Mediterranean species (Pistacia lentiscus, Quercus coccifera, and Juniperus oxycedrus seedlings) were exposed to classic drought-preconditioning treatment consisting of reductions in the watering regime. The effects of preconditioning on seedling quality were assessed by cell water relationships (pressure–volume curves), minimal transpiration, leaf capacitance, chlorophyll fluorescence, and gas exchange. Moreover, seedlings were exposed to transplant shock (intense drought period) during which water potential (predawn and midday) and maximal photochemical efficiency were evaluated to establish seedling performance. Results showed that preconditioning did not affect cell water relationships and minimal transpiration in any of the three species. Preconditioned seedlings of P. lentiscus maintained higher water content during desiccating conditions as a consequence of an increase in leaf water content at full turgor. These changes allowed plants to maintain higher net CO2 assimilation rates and an elevated photosystem II status, facilitating an increase in drought survival. Preconditioning improved the performance of Q. coccifera and J. oxycedrus seedlings, but these two species were much less responsive than P. lentiscus seedlings. Finally, results suggest that sensitivity to drought preconditioning may be related to drought tolerance or avoidance strategy of each species. Drought-related strategies should be considered to optimize management scale preconditioning.

Notes: Abstract Having evolved in an environment with large, severe, and frequent disturbances, including massive floods, fires, and impacts of extinct and extirpated fauna, woodland herbs may be adapted to such disturbance processes. Present lack of such disturbances may contribute to present rarity. We test the hypothesis that transplanting with disturbance simulation can be used to restore the threatened woodland herb, Hydrastis canadensis (goldenseal). Three disturbance-simulation treatments (soil turnover, fertilization, and both) and a control were randomly applied to 100 blocks in goldenseal habitat, and a single rhizome was transplanted into each treatment. Transplanting was effective with 85% of the transplants surviving, 41% flowering, and 34% fruiting; thus, transplanting may increase area of occupancy. Soil turnover alone and combined with fertilization caused a significant increase in plant size available to support production of fruit. Increased flower and significantly increased fruit production were also characteristic of soil-turned plots. Results support the hypothesis that some woodland herbs are rare due to lack of certain disturbance, call for consideration of soil disturbance as a potentially important and beneficial influence on woodland herbs regardless of light effects, and suggest that transplanting into soil-overturned plots may restore goldenseal. The assumption that undisturbed conditions are optimal may impede effective management of rare woodland flora, highlighting the need for a more flexible approach.

Notes: Abstract The success of revegetation efforts in southwestern U.S. riparian meadows has been limited because natural recolonization is often poor and little is known about establishment of transplanted native meadow species such as sedges. To evaluate their potential use in riparian restoration, the survival and growth of transplanted wildlings of three sedge species, Carex lanuginosa (woolly sedge), C. nebrascensis (Nebraska sedge), and C. rostrata (beaked sedge), were assessed. Transplanting occurred during two seasons (summer and fall) using two transplant sizes (295 and 680 cm3) at seven montane meadow sites in Arizona. Survival was similar among species, but shoot numbers were greater for C. lanuginosa (12.7 shoots/wildling) compared with C. nebrascensis (5.5 shoots/wildling) and C. rostrata (7.9 shoots/wildling). Survival was significantly greater for the summer transplant season (55.1%) versus fall (24.1%). Survival and growth were greater for the larger transplant size (46.1% large vs. 33.0% small; 8.1 shoots/wildling large vs. 6.4 small). Wildling survival was related to depth to groundwater for each species. Survival was highest for C. lanuginosa (78.6%), C. nebrascensis (88.2%), and C. rostrata (64.3%) where the groundwater depth was −48 to −60, −28 to −47, and −8 to −27 cm, respectively. These results suggest that restoration will be most successful if transplanting occurs in summer, using large wildling transplants when under stressful conditions such as waterlogged or dry soils, and when species are planted at appropriate groundwater depths.

Notes: Abstract Lowland temperate grasslands dominated by Themeda triandra (kangaroo grass) are an endangered ecosystem in southeastern Australia. Grass biomass must be removed frequently to maintain plant diversity, but few studies of the impacts of different biomass removal techniques have been undertaken, and no rapid monitoring schemes have been developed. Low species densities in many reserves (due to past stock grazing) make it difficult to assess the effects of management regimes on plant diversity. Management impacts could be assessed by planting indicator species in replicated enhancement plots and subjecting these plots to adaptive management trials. A protocol for selecting potential indicator species is described, based on a regional quadrat database, using clearly defined criteria. Potential indicator species need to be conspicuous, easy to identify and abundant in high quality diverse grassland remnants, to have relatively broad ecological tolerances, to occur in sites that are relatively species rich and have a comparatively low cover of dominant exotic species, to commonly persist at low densities in long-grazed reserves, to be responsive to changes in management, and to have been studied ecologically. Only three species from western Victorian grasslands satisfied these criteria: Calocephalus citreus (lemon beauty-heads), Chrysocephalum apiculatum (common everlasting), and Leptorhynchos squamatus (scaly buttons). All are widespread, herbaceous, hemicryptophytic daisies. Despite a number of caveats, the scheme has the potential to provide a more clearly focused framework for grassland ecosystem management than currently exists.

Notes: Abstract A growth experiment with native plants in pots exposed to natural environmental conditions evaluates the use of sewage sludge as a soil amendment in restoration of a southern California salt marsh. Sludge containing desirable organic matter but also undesirable heavy metal contaminants was mixed with a readily available matrix soil to reduce metal concentrations to levels below legal limits for land applications of sludge. Soil nutrient analysis revealed expected increases in total nitrogen and total phosphorus content with increasing sludge concentration. Soil metals analysis, however, revealed decreases in metal content with increased sludge concentration, a trend evidently caused by higher than expected metal content in the matrix soil. Five artificial soil mixtures ranging from 0 to 70% sludge were accompanied by natural wetland soil controls. Pots containing these soils were placed into a natural salt marsh. The pots were then planted with two native salt marsh plant species, Salicornia virginica and Frankenia grandifolia. Aboveground biomass was harvested after 12 months. Plant growth displayed no obvious change with increasing sludge concentration. Over the concentration ranges used, increased nutrient content did not stimulate plant growth and increased metal content did not inhibit plant growth. Plants grew better in natural wetland soil than in artificial soil mixtures, a trend probably caused by the substantially finer texture and higher organic content of natural soil. All sludge treatments differed more from the natural soil than from each other, implying that within the ranges examined, soil texture and organic content exerted more influence on plant growth than did metal or nutrient concentration. These results suggest that incorporating this sewage sludge in the soil of the restored salt marsh will neither benefit nor harm the plants that will live there and that greatest plant growth will be achieved by mixing the sludge with a fine-grained matrix soil.

Notes: Abstract Post-mining coastal dune rehabilitation north of Richards Bay, KwaZulu-Natal started 20 years before field work for the present study commenced. This resulted in the development of a known age sere of coastal dune forest succession. These rehabilitating areas are fragmented by roads that may act as ecological edges. To establish whether roads affect regenerating bird, millipede, and rodent assemblages, multivariate techniques were applied to test for existence of edge and core assemblages within seral stages representative of the coastal dune forest successional sere. Edge and core assemblages were identified for both the bird and millipede communities but not for the rodent community. Low rodent numbers may have concealed edge effects, but the absence of edge and core assemblages could also be ascribed to the absence of a forest core. In the bird community species composition, richness, density, and total number of species contributed to the identification of edge and core assemblages. Within seral stages the species composition of millipedes differed between the edge and core assemblages. However, if the site was the same age the number of species in edge and core assemblages was similar. The generality of the edge concept should be approached with caution when dealing with taxa comprising species with such diverse natural histories as in the present study. It should also be kept in mind that some species require forest interiors for survival.

Notes: Abstract A population of Hemideina crassidens (the Wellington tree weta) was monitored over a 4-year period after the eradication of Rattus exulans (the Polynesian rat kiore) and Gallirallus australis australis (the South Island weka) from Nukuwaiata (Chetwode Islands), Pelorus Sound, New Zealand. A novel survey technique (entrance scores) was used in combination with a conventional technique (random searches for active weta) to measure changes in weta population parameters after the removal of predation pressure and to investigate impacts of exotic predators on tree weta. Tree weta density did not increase markedly over the 4-year period, but the proportion of active adults did increase. Weta were observed to move into larger and more crowded galleries (refuges), to occupy galleries closer to the ground, and to spend less time sitting in gallery entrances. It was concluded that endemic tree weta are well adapted to withstand some introduced vertebrate predators but are able to live a more “relaxed” lifestyle in the absence of this predation. The most significant change detected was in weta age structure, with adults increasing their proportion of the population.

Notes: Abstract To determine the effects of sward height and gap size on the emergence and subsequent development of Trollius europaeus, seeds were introduced into artificially created gaps in mown and unmown wet meadow grassland in Ayr, Scotland. Emergence and establishment of nondormant seed (previously leached in running tap water and soaked in gibberellic acid) placed in a range of circular gaps (25 mm, 50 mm with and without root barrier, 100 and 200 mm diameter) were monitored over 305 days. Trollius demonstrated high field emergence (mean, 46% of viable seed sown) in this experiment. Emergence was not significantly affected by either sward height or gap size, although emergence was greater in mown swards. The critical factor determining subsequent survival of seedlings was slug predation rather than sward height or gap size. However, losses due to slug predation were significantly greater in unmown swards, resulting in more seedlings in mown swards. One hundred eleven days after sowing (September) seedling numbers had declined substantially in both unmown and mown swards, and by day 305 (April) seedlings were extinct in both sward types. The implications of the research for the restoration and management of T. europaeus are discussed.

Notes: Abstract We used differences in soil carbon δ13C values between forested sites and grasslands dominated by the C4 grass Schizachyrium scoparium (little bluestem) to detect the presence of former grasslands in the historical landscape of the coastal sand plain of Martha's Vineyard, Massachusetts, U.S.A. Soil δ13C was measured at (1) sites with long-term forest or grassland vegetation and (2) sites with known histories where forest vegetation invaded grassland and where forest converted to grassland. The δ13C of soil under long-term grassland was –24.1‰ at 0 to 2 cm depth and –23.4‰ at 2 to 10 cm and was enriched by 3.4‰ and 2.8‰ compared with soil under long-term forest. In forests that invaded grasslands dominated by S. scoparium, soil δ13C decreased as C derived from trees replaced C from S. scoparium. This decline occurred faster in surface soils and in the light soil organic matter fraction than in the mineral soil. In forests that converted to grasslands, soil δ13C increased and the rate of increase was similar in surface and mineral soil and in the different soil organic matter fractions. Rates of change indicated that soil δ13C could be used to detect changes in vegetation involving the presence or absence of S. scoparium during the last 150 years. Application of this model to a potential grassland restoration site on Martha's Vineyard where the landscape history was not known indicated that the site was previously unoccupied by S. scoparium during this time. The δ13C of surface mineral soil can be useful for detecting the presence of historic S. scoparium grasslands but only in the period well after European settlement of these coastal sand plain landscapes.

Notes: Abstract Coral reef degradation has been widely reported for the past 20 years. Because the recovery rate is usually low, various methods of restoration have been explored in different regions of the world. Among the effective and commonly used methods to restore coral communities is the transplantation of coral colonies or fragments. In this investigation fragments of Acropora pulchra were used in a semiprotected nursery in southern Taiwan between 1996 and 1998 to test, in situ, the possible effects of different factors on the generation of new branches and the initial skeletal extension rates of transplants. The variables under study here were the origin and length of the fragments, their new orientation, presence of tissue injury, and position in the fragment. All these factors were found to make a difference in either one or both aspects of coral growth (i.e., branching frequency and skeletal extension rate). These two factors clearly determine the success rate of a small fragment developing into a large colony that has a much higher probability to survive and grow on its own. It is now obvious that the efficiency of coral generation through fragment culture can be enhanced if the variables examined here are taken into consideration. Once coral colonies are formed, they can be fragmented again to generate more corals or can be transplanted to a suitable site.

Notes: Abstract Historic fire return intervals in Artemesia tridentata (big sagebrush) ecosystems have been altered by livestock grazing, fire suppression, and other land management techniques resulting in ecological changes in these areas. Increases in abundance of woody vegetation may be causing declines in native herbaceous understory species. We examined the effects of prescribed fire on the morphology, abundance, and phenology of nine abundant forb (herbaceous dicot) species used selectively by Centrocercus urophasianus (Sage Grouse). In September 1997 prescribed fire was applied to four of eight randomly assigned 400-ha A.t. wyomingensis (Wyoming big sagebrush) study plots at Hart Mountain National Antelope Refuge, Oregon. Livestock had not grazed experimental plots since 1991. Burning caused morphological changes such as significantly greater numbers of racemes and flowers per raceme in Astragalus malachus (shaggy milkvetch-Legumoideae) (9 in burn vs. 6 in control; 23 in burn vs. 21 in control, respectively). Also, prescribed burning caused greater numbers of flowers in Phlox gracilis (microsteris-Polemoniaceae) (57 vs. 13), greater numbers of umbels and umbelletts in Lomatium nevadense (Nevada desert parsley-Umbellifereae) (4 vs. 2 and 59 vs. 31, respectively), greater numbers of flower heads in Crepis modocensis (Modoc hawksbeard-Compositae) (32 vs. 21), and greater number of flowers/cm3 in Phlox longifolia (longleaf phlox-Polemoniaceae) (0.11 vs. 0.06). Crown volume of Crepis modocensis (7,085 vs. 4,179 cm3) and Astragalus malachus (2,854 vs. 1,761 cm3) plants was greater in burned plots than control plots. However, burning resulted in a smaller crown area of Antennaria dimorpha (low pussytoes-Compositae) (20 vs. 37 cm2). Phenology and time of flowering were also affected by fire. The period of active growth for each species was extended later into the summer in burned plots ( p 〈 0.01). In addition, Crepis modocensis and Lomatium nevadense flowered 12 to 14 days earlier in burned plots. Fire had no effect on frequency, density, and relative abundance of seven of the nine studied species. Fire reduced the frequency and relative abundance of A. dimorpha and Phlox longifolia and reduced the density of A. dimorpha.

Notes: Abstract Since 1990 under the Eastern Habitat Joint Venture over 100 small wetlands have been restored in Prince Edward Island, Canada. Wetlands were restored by means of dredging accumulated sediment from erosion to emulate pre-disturbance conditions (i.e., open water and extended hydroperiod). In 1998 and 1999 we compared waterfowl pair and brood use on 22 restored and 24 reference wetlands. More pairs and broods of Ring-necked Ducks, Gadwall, Green-winged Teal, and American Black Ducks used restored versus reference wetlands. In restored wetlands waterfowl pair density and species richness were positively correlated with wetland/cattail area, percent cattail cover, and close proximity to freshwater rivers. In addition, a waterfowl reproductive index was positively correlated with percent cattail cover. Green-winged Teal pair occurrence in restored wetlands was positively correlated with greater amounts of open water and water depths. American Black Duck pairs occurred on most (86%) restored wetlands. Restored small wetlands likely served as stopover points for American Black Duck broods during overland or stream movements, whereas they likely served as a final brood-rearing destination for Green-winged Teal broods. We suggest that wetland restoration is a good management tool for increasing populations of Green-winged Teal and American Black Ducks in Prince Edward Island.

Notes: We examine bargaining in a dynamic context where exchange between two parties affects the potential surplus from future trade. In this setting traders negotiate current contracts anticipating the impact of their agreement on future exchanges. We show that in growing environments these dynamic considerations will often ameliorate bargaining inefficiencies associated with private information and facilitate exchange as both parties cooperate to nurture the relationship. In contrast, we find that in declining environments dynamic considerations will often exacerbate bargaining inefficiencies and hinder trade, as both parties are hesitant to let the relationship mature. These findings have implications for preferences to form long-lived relationships.

Notes: We investigate knowledge spillovers and externalities in the disagglomeration and growth of the advertising-agency industry. A simple model of high demand, low wages, and externalities associated with clusters of related industries can explain the dispersion of advertising agency employment across states. Other factors affected the industry growth rate within states. Consistent with Jacobs and Porter but contrary to Marshall, Arrow, and Romer, competition, but not specialization, enhanced growth. In accord with Porter (1990), growth increased with buyer cluster size. Diversity had no effect on growth. Despite improvements in telecommunications and transportation reducing effective distances, location still matters.

Notes: We test empirically for network effects and preannouncement effects in the DVD market. We do this by measuring the effect of potential (incompatible) competition on a network undergoing growth. We find that there are network effects. The data are generally consistent with the hypothesis that the preannouncement of DIVX temporarily slowed down the adoption of DVD technology.

Notes: We develop a new approach to endogenizing technological spillovers. We analyze a game in which firms can first invest in cost-reducing R&D, then compete on the human-capital market for their knowledge-bearing employees, and finally enter the product market. If R&D employees change firms, spillovers arise. We show that technological spillovers are most likely when they increase total industry profits. We use this result to show that innovation incentives are usually stronger for endogenous than for exogenous spillovers and that endogenous spillovers may reverse the result that innovation incentives are stronger under quantity competition than under price competition. Finally, we explore the robustness of our results with respect to contractual incompleteness and the number of R&D workers.

Notes: The patent system encourages innovation and knowledge disclosure by providing exclusivity to inventors. Exclusivity is limited, however, because a substantial fraction of patents have some probability of being ruled invalid when challenged in court. The possibility of invalidity—and an ensuing market competition—suggests that when an innovator's capability (e.g., cost of production) is private information, there is potential value to an innovator from signaling strong capability via a disclosure that transfers technical knowledge to a competitor. We model a product-innovation setting in which a valid patent gives market exclusivity and find a unique signaling equilibrium. One might expect that as the probability that a patent will be invalid becomes low, greater disclosure will be induced. We do not find this expectation to be generally supported. Further, even where full disclosure arises in equilibrium, it is only the less capable who make full disclosures. The equilibrium analysis also highlights many of the novel and appealing features of enabling knowledge disclosure signals.

Notes: This paper analyzes the effect of competition among downstream firms on an upstream firm's payoff and on its incentive to integrate vertically when firms in both segments negotiate optimal contracts. We argue that as downstream competition becomes more intense, the upstream firm obtains a larger share of a smaller downstream industry profit. The upstream firm may encourage downstream competition (even excessively) in response to high downstream bargaining power. The option of vertical integration may be a barrier to entry downstream and may trigger strategic horizontal spinoffs or mergers. We extend the analysis to upstream competition.

Notes: This paper studies the welfare consequences of a vertical merger that raises rivals' costs when downstream competition is a la Cournot between firms with constant asymmetric marginal costs. The main result is that such a vertical merger can nevertheless improve welfare if it involves a downstream firm whose cost is low enough. This is because by raising the input price paid by the nonmerging firms the merger shifts production away from those relatively inefficient producers in favor of the more efficient firm. Yet, there is a trade-off between the gain in productive efficiency and the loss in consumers' surplus caused by the higher downstream price that follows a higher input price. It is also shown, through an example, that this result extends to price competition with differentiated products.

Notes: In competitive telecommunications markets each carrier relies on competing networks to terminate internetwork calls. Regulators typically require the calling party's network to pay a termination fee to the called party's network equal to the terminating network's “incremental cost” of completing the call, effectively imposing all of the costs on the calling party's network. These payments can affect retail prices and therefore consumption. I show that when both parties benefit from a call, they should bear its costs in proportion to the benefit they receive. Therefore, imposing all of the costs of an internetwork call on the calling party's network can be inefficient if these costs are reflected in the calling party's usage rates. A system in which two networks exchange traffic at specified points on a bill-and-keep basis imposes some of the cost on each network, which will then be imposed on the parties. This can generate more efficient network utilization, even with unbalanced traffic between networks. Thus, regulators may improve the efficiency of telecommunications markets by establishing bill-and-keep intercarrier compensation rules.

Notes: This paper introduces the subject of private politics, presents a research agenda, and provides an example involving activists and a firm. Private politics addresses situations of conflict and their resolution without reliance on the law or government. It encompasses the political competition over entitlements in the status quo, the direct competition for support from the public, bargaining over the resolution of the conflict, and the maintenance of the agreed-to private ordering. The term private means that the parties do not rely on public order, i.e., lawmaking or the courts. The term politics refers to individual and collective action in situations in which people attempt to further their interests by imposing their will on others. Four models of private politics are discussed: (1) informational competition between an activist and a firm for support from the public, (2) decisions by citizen consumers regarding a boycott, (3) bargaining to resolve the boycott, and (4) the choice of an equilibrium private ordering to govern the ongoing conflicting interests of the activist and the firm.

Notes: More powerful managers make more important decisions. Therefore, firm performance is more informative about the abilities of such managers, who, realizing that they are more visible, are more eager to improve performance. If this reputation effect exists, how should firms allocate power? I analyze the optimal allocation of power and derive implications for several issues that often arise in management practice: the choice of departmentation criteria, the importance given to seniority, and the width of job definitions. Finally, I show that the model is consistent with the empirical evidence on managerial succession.

Notes: The idea that an industry with sunk costs may be contestable even in the absence of long-term contracts has received little attention informal economic theory yet is sometimes popular among practitioners. This paper formally illustrates the argument. In an infinitely repeated game, there exists a class of contestable outcomes in which the monopolist sells only on the spot market and charges low prices along the equilibrium path to prevent customers from resorting to long-term contracts. The crucial test for contestability is the level of transaction costs in the latent contract market.

Notes: I consider an infinite-period race where players choose between low- and high-variance motion technologies. I provide sufficient conditions under which, in equilibrium, the leader chooses a safe technology and the laggard a risky one, thus formalizing the sports intuition that the laggard has nothing to lose. Various examples and empirical implications are presented.

Notes: Transaction-cost and agency theorists have frequently cited trucks as prototypical user-owned assets, and have consequently predicted a predominance of self-employed drivers who contract with motor carriers. In fact, owner-operators accounted for less than one-third of US trucking activity conducted by large interstate trucking firms in 1991, a proportion that has changed little since deregulation. Given the predictions of organizational economists, why is self-employment in the interstate trucking industry not the dominant organization form?We propose that transaction costs and agency costs are indeed important in the trucking industry. In the absence of externalities across hauls, contracting between carriers and owner-operators is preferred for traditional agency reasons. However, when the outcome of one haul imposes externalities on other hauls or on the carrier's reputation, an owner-operator will not internalize all costs associated with poor outcomes. Given problems of noncontractibility of maintenance effort, carrier ownership of the vehicle is the preferred organizational form in such a case. We also propose that vehicle idiosyncrasy can create thin market conditions that encourage carrier ownership of vehicles. A study of the organization and operations of 354 trucking firms for 1991 provides evidence consistent with these predictions.

Notes: In 1985, Demsetz and Lehn argued both that the optimal corporate ownership structure was firm-specific, and that market competition would drive firms toward that optimum. Because ownership was endogenous to expected performance, any regression of profitability on ownership patterns would yield insignificant results. To test this hypothesis, we use the zaibatsu dissolution program from late-1940s Japan as a natural experiment: an exogenous shock to the equilibrium ownership structure. Through that program, the US-run occupation removed the more prominent shareholders from many of the most successful Japanese companies. By focusing on the way firms and investors responded to the mandated selloff, we accomplish two goals: (a) we avoid the endogeneity problem that has plagued much of the other research on the subject, and (b) we clarify the equilibrating dynamics by which competitive markets move firms toward their optimal ownership structure. With a sample of 637 Japanese firms for 1953 and 710 for 1958, we confirm the equilibrating mechanism behind the Demsetz-Lehn hypothesis: between 1953 and 1958, the ex-zaibatsu firms did retructure their ownership patterns. As of 1953, the unlisted ex-zaibatsu and new firms still had not been able to negotiate the transactions necessary to approach their profit-maximizing ownership structures. Even the listed firms had not fully undone the effect of the occupation-induced changes on managerial practices. By 1958 the firms had done this, and the earlier correlation between profitability and ownership disappeared. By then, firm profitability showed no correlation with ownership, whether under linear, quadratic, or piecewise specifications. We further find no evidence that ex-zaibatsu firms sought to strengthen their ties to banks over 1953–1958.

Notes: The study aims to provide a critical review of the literature on the consumer interest in the UK in organic food, with a particular focus on organic meat. Given that people are more likely to purchase products if they have faith in them, the regulation of organic food standards is reviewed to explore issues affecting consumers. This is followed by a review of the organic meat sector. Aspects of the consumer interest considered in this paper include consumer information, consumer access, consumer safety, consumer choice and consumer representation. As the literature on organic food/meat in the UK is extensive, it was therefore necessary to be selective with regard to the publications suitable for this review. Most of the literature selected for this paper has been drawn from UK publications, although several European and international sources have also been used. The review found that there is a considerable level of interest in the UK organic meat sector. As the regulation of organic food produced is set at varying standards across the European Union, this could lead to consumers being misled regarding the quality of products offered. It was also found that, although consumers perceive organic foods as healthier, more nutritious and tasting better than non-organic products, the literature shows that this may have only a limited basis on fact. Contamination of organic products with pesticides and even genetically modified ingredients is always possible. Organic farmers are permitted to use other ingredients in organic meat products that may be harmful to health. Escherichia coli and Salmonella risks associated with conventional meat also appear to affect organic meat. Consumers need clear, accurate and reliable information about organic meat. They also need to be provided with safe products, a choice of organic products, access to organic products and to be represented effectively.

Notes: ‘Development’ and the globalization of consumption is leading to a breakdown of biological and cultural diversity, erosion of food security, an increase in violence and devastation for the global biosphere. We urgently need to shift away from economic globalization and homogenization towards localization and diversification.

Notes: The promises and pitfalls of agricultural biotechnology have long been debated. The public is often thwarted because consumers frequently perceive as risky, and therefore undesirable, those advances that they do not understand or of which they are unaware. A comparative study of the introduction of a biotechnology innovation in the United States (US) and in the European Union (EU) is a case in point. In the US, despite concerns of consumer protection and environmental groups that the use of genetically produced growth hormone in milk-producing cows will adversely impact the safety of the milk supply, scientific evidence and governmental findings appear to indicate that milk from treated cows is identical in quality, taste and nutritional value to milk from untreated cows. Experience to date in the US demonstrates some consumer resistance to milk from those cows that have received the growth hormone, which typically leads to a 10% increase in milk production. In fact, if there is no perceived differentiation between the two forms of milk, the issue offers little choice to consumers at large, and may result in economic benefit only to selected dairy farmers, as well as the producers of the genetically produced growth hormone. This situation in the US is an example of dysfunctional technology transfer, with perceived desirable benefits to a few, and perceived undesirable benefits to society-at-large. The information suggests that the US may have reacted hastily in approving the use of bovine growth hormone in milk-producing cows. The EU has taken a divergent approach by enacting moratoriums against its use. The differences identified in this study, contrasting responses to the bovine somatotrophin issue in the US and EU – driven in part by general consumer attitudes towards biotechnology – may provide insights into the issues and challenges that will be faced by both advocates and opponents of global proliferation of certain advances in biotechnology.

Notes: The purpose of this article is to describe how households in Novgorod the Great, Russia, deal with food provision in everyday life. The study focuses on changes experienced in food provision and consumption in Russian society, in order to illustrate how households respond to the transformation towards a market economy. The study reflects women's perspective on food provision. Students from Novgorod the Great visited 105 households and asked the women in the household to answer a questionnaire. Results from the study show that in order to cope with changes in society related to economic reforms, Russian households had changed both their food consumption and food production patterns. There was no big difference between urban and rural households. Nearly all of the households were self-sufficient in the provision of vegetables and potatoes. Many households had a ‘dacha’ (plot), where they produced most of what they needed. Among the changes experienced during recent years (i.e. during the end of the 1990s), a decade after perestroika was initiated, households mentioned the rise in food prices and the decrease of income. Households reported that they consumed less fruit and/or meat. Some households also mentioned that the quality of nourishment had decreased, thereby indicating lower general quality, lower nutrition value, or less healthy foodstuffs.

Notes: Localization: A Global Manifesto. Ed. by Colin Hines (2000). London. Published by Earthscan Publishing. ISBN 1-85383-612-5 (softcover). In Canada, the book is available from for Can$29.00. In the UK, the book is available at for £10.99 or earthinfo@earthscan.co.uk

Notes: Many researchers have studied and documented the financial literacy of youth. Even more have developed educational programs or curricula to teach financial and consumer issues to youth; however, few have actually evaluated the effectiveness of their programs. The Money Talks: Should I be Listening? curriculum, developed by a University of California Cooperative Extension team, was created to appeal to teenagers as it increased their financial literacy. In order to develop a program that young people would readily use, and from which they would learn, teenagers were surveyed prior to program development to determine the topics that were relevant to them, the educational format that appealed to them, and when and where they preferred to receive the information (Varcoe, Peterson, Garrett, Martin, Rene, & Costello, 2001).This paper discusses the effectiveness of The Money Talks: Should I be Listening? curriculum on the financial knowledge and behaviour of participants using the series. The curriculum was designed for use as a part of school curriculum as well as for presentation in other venues.The findings indicate that using the curriculum did improve the financial literacy of high school students with significant positive changes in both knowledge and behaviour. They have a better understanding of the value of savings and have changed behaviours. It is interesting to note that the males demonstrated a significantly greater increase in knowledge from pre-test to post-test than females. Perhaps the females have more interest in or knowledge of financial issues prior to participation in this project?Overall the results of this study are consistent with the findings of others. Research based curricula in personal finance seem to yield results. This age group has specific requirements for method of delivery and location of the seminars suggesting that it is important to keep the materials interactive. To address this issue, a web-site was added to the program. Included on the web-site are interactive games and a video on the importance of saving. The teens are naturally more interested in learning about the consumer and financial issues they perceive as salient in their lives at that particular time. Educators should identify topics of interest to the teens and develop, or use existing, interactive methodology to present the information.

Notes: In a world where the role of women in decision-making is seldom adequately appreciated, they make a remarkable contribution due to their hard work and sense of confidence. It is observed that women are mostly involved in repetitive and monotonous household work irrespective of the fact that they share most of family responsibilities and perform a wide range of duties in and outside home. On the other hand men perform activities, which require skills, but there is sufficient evidence, which show a clear, although slow shift of stereotype sex roles.In early societies, decision-making was predominantly done by menfolk being the breadwinner of the family. With modernization and education women have been empowered to make the best use of human and non-human resources in management of the family with respect to efficient use of time and energy. So, a study was undertaken to know how far the working women of Faridkot district participate in the decision-making process with the following objectives:〈list style="custom"〉(a) to find out the level of participation of working women in the decision-making process as consumer.(b) to find out the level of difficulty among working women at different steps of the decision-making process.The present investigation pertaining to Faridkot district of Punjab state of India was exploratory in nature. A sample of 100 working women was selected by simple random sampling procedure. The responses were recorded through a well structured and pretested questionnaire including an index developed to measure level of participation and difficulty as realized by working women in the decision-making process. After collecting the data, it was analysed by employing simple statistical tests like frequency percentagesThe important findings emanated out of the present investigation are as follows:〈list style="custom"〉• Most of the respondents were middle aged, educated up to graduation level, having nuclear family, small size of family with monthly income more than Rs.5000.00. It was also observed that majority of the respondents were in the teaching and medical professions.• Working women were found to be involved more in the case of food items (79.0–93.0%) as compared to non-food items (6.0–46.0%) with an exception of their major participation (78.0%) at the stage of identifying the problem in case of non-food items.• The study revealed that the time consumed at various steps of consumer decision-making process is minimum for most of the steps in case of food items but moderate to maximum in case of non-food items. But for analysing the alternatives the time consumed was moderate to maximum for both the categories.• Findings also revealed that difficulty level was from moderate to high (32.0–98.0%) in most of the steps in case of food items whereas, in case of non-food items it was from low to high (11.0–78.0%)

Notes: The   main   criteria   that   consumers   use   during   the   decision making process when purchasing food has traditionally been a combination of prices, incomes, taste and social attitudes, with price being seen as the main determinant. However in the past 10 years risk has become a ‘new’ criterion that can affect the consumer's decision whether or not to purchase a particular food item. The effect of the increased awareness of risk has been observed during the numerous food scares in the last decade and in trends for the demand for foods that connote a healthy image.This research, carried out in Northern Ireland, looked at how consumers quantified and managed risk. The research involved 202 primary food consumers and identified the factors that were perceived to be important from both a societal and a personal perspective.Using principal component and cluster analysis societal food risks were seen as either processing or dietary and personal food risks were seen as either extrinsic or intrinsic. Further investigation into the attributes of the personal risk revealed a three-factor solution described as fear, involvement and newness.Although these factors cannot be used as predictors of the risk associated with a particular food, they help to describe and explain how the risk may be managed. The relationship between two of the factors, involvement and fear, provides a framework for understanding the way consumers manage their perception of the risk, particularly of high-risk items. Consumer and scientific knowledge of the risk in question, and the degree of control over the risk were seen as important. The conceptualisation of the mechanism by which risks are processed and acted upon provides information regarding risk management and communication strategies that should be employed by educators, food retailers and government policy makers.

Notes: People are becoming more health conscious nowadays, but most of them are not able to adopt a lifestyle with adequate physical exercise and a healthier eating pattern. Many attempt to compensate by taking ‘health foods’. Despite the recent economic recession, the functional food market expands rapidly in Asian countries. Recent statistics indicate a huge increase in weight loss and functional food product advertising expenditure in Hong Kong and other Asian countries. In a massive survey conducted by the Hong Kong Consumer Council, it was found that 85% of the medicines, health food and therapies sampled contain questionable claims and misleading messages (Consumer Council, 1999). In fact, young people do not understand much about modern food processing, in particular those present in low energy and functional foods, and they know very little about the modern food marketing strategies. The situation is detrimental to consumer welfare especially to the younger generation.This study attempts to reflect critically on the implications of these issues for the health and well-being of young people in Hong Kong. It explores directions for designing relevant and effective education programmes to empower young people in understanding food advertising strategies and making informed decisions on food choice. The paper will begin with a critical review on the current situation in Hong Kong. An interview survey on preservice and in-service teachers’ perception towards misleading food advertising and labelling will then be reported. The situations at schools will be defined and problems faced by teachers in providing relevant consumer education programmes to students will be identified. Finally, the study will look to the future, with a view to developing students’ critical skills in evaluating claims offered in food advertisements.

Notes: The Centres for Disease Control and Prevention estimate that 76 million people get sick, more than 300 000 are hospitalised, and 5000 Americans die each year from food-borne illness. Research over the past 40 years has shown, however, that food irradiation can decrease the incidence of food-borne illness and disease. Despite this benefit, food irradiation has been the focus of much controversy for years. Proponents of irradiation claim that it will improve food product safety by reducing harmful bacteria. Opponents, on the other hand, raise concerns about its long-term health effects, nutrient loss, and worker safety at irradiation facilities. The debate intensified recently when the US government approved the use of irradiation to kill E. coli 0157:H7 and other harmful bacteria in ground beef and other raw meat. The US Department of Agriculture and the Food and Drug Administration are also expected to decide soon whether to allow the process to be used on sandwich meats, hot dogs, and similar packaged food products.This study examines consumer willingness to pay for irradiated beef products. About 58% of the respondents are willing to pay a premium for irradiated beef. An ordered probit with sample selection model was estimated. Our findings suggest that females and those who think that improper handling contributes to food poisoning are more likely to pay a premium of 50 cents per pound of irradiated beef than others. Those who trust the irradiation technology are more likely to pay a premium of between 5 and 25 cents per pound for irradiated beef.

Notes: A recent application of biotechnology to food is genetic modification. Genetically modified (GM) plants, animals and processed foods have been introduced to the international marketplace in the 1990s. As scientific and technological progress in modern biotechnology continues at a breakthrough pace, the consumers are presented with different types and levels of information that is potentially relevant for making choices.Findings from studies of consumer attitudes and awareness towards GM products have varied greatly. Many studies, however, have indicated that public opinions about GM products are not fully formed and the task of informing the public is far from over. This study expands on previous research by examining the factors that influence the search for information about GM products. Utilizing the theory of consumer behaviour and information search, we analyse consumers’ information search patterns about GM products. Specifically, we estimate the probability that consumers search for information actively, passively or do not search for information at all, and the factors influencing this search.An ordered probit model is formulated to measure the factors, both economic and behavioural, that influence in-formation search by consumers for GM products. Variables representing the informational attitudes and behaviour related to GM products have the greatest impact on the probability of searching for information about GM products. With the exception of age, demographic factors are not significant. The results point to information search, not, for the genetically modified characteristic, but instead for the absence of the characteristic.