ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1993.tb00011.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractIn ecological restoration, nonindigenous species can pose a major problem because they are often aggressive and can overwhelm native species, thus altering ecosystem structure. This article identifies the circumstances in which prospects for use of restoration technology in controlling invaders are favorable or unfavorable, the factors that make certain species good colonizers, and the characteristics that make ecosystems susceptible to invasion. It discusses prospects for using restoration technology in controlling nonindigenous species by influencing hydroperiod, photo‐period, thermoperiod, edaphic conditions, and availability of biological control agents so as to produce ecological conditions that are inhospitable to invaders. The limitations of restoration are discussed, as well as specific ecological situations in which it is likely to be the method of choice for control of nonindigenous species. Use of fire, flooding, manual removal, shading, substrate removal, and herbicide application as control techniques in conjunction with restoration efforts are considered. Specific examples, including the techniques employed, indicate the potential for controlling nonindigenous species in the process of ecosystem restoratio

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1993.tb00012.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractIn prairie restoration, use of seeds from nonlocal sources has been of concern to restorationists. We examined the specificity between vesicular‐arbuscular mycorrhizal fungi obtained from a single location and little bluestem obtained from three localities. Seed was obtained from three sources: (1) a commercial seed supplier in Nebraska, (2) Sand Ridge State Forest (SRSF), Mason County, Illinois, the site from which the experimental soil containing the mycorrhizal inoculum was obtained, and (3) Sand Prairie Scrub Oak Nature Preserve (SPSO), 32 km southwest of SRSF. Plants were grown in three substrates: (1) autoclaved soil, (2) autoclaved soil to which a mycorrhizal fungal‐free sieving of nonautoclaved soil was added, and (3) nonautoclaved soil. All plants grown in nonautoclaved soil were colonized by mycorrhizal fungi, whereas none of those grown in other substrates were colonized. Plants grown from SRSF seeds produced significantly (p<0.05) more biomass than those grown from Nebraska seeds (X̄± SE, SRSF = 0.54 ± 0.04 g, SPSO = 0.49 ± 0.03 g, Nebraska = 0.37 ± 0.03 g). Plants grown in nonautoclaved soil, regardless of seed source, produced less biomass (0.27 ± 0.02 g) than plants grown in autoclaved soil (0.58 ± 0.03 g) or autoclaved soil plus sievings (0.59 ± 0.03 g).The results provide no clear indication of a host‐endophyte specificity. However, the data suggest that the local genotypes ofS. scopariumare better adapted to their native soil environment than are genotypes from oth

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1993.tb00013.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe microbial community in a soil stripped and stored during opencast coal mining was analyzed. There were significant effects of soil disturbance on the microbial community: in particular, there were large decreases in the total microbial biomass, as determined by ATP analysis, and numbers of fungal propagules as a result of the store construction process, but there was no significant effect on the numbers of bacteria. During the subsequent months of storage there was a flush in the numbers of bacteria, with gram‐negative bacteria showing an increase of nearly 700% in comparison to the control. During this time there was a steady accumulation in the amount of ammonium in the deepest part of the soil store, indicating the onset of anaerobiosis. These changes may be interpreted in terms of lifestyle strategy theory (Grime 1979). The bacteria exhibit behavior typical ofR‐strategists, or ruderal species, taking advantage of the nutrients made available by the death of fungal biomass during store construction. Fungi respond asC‐strategists, or competitors, and they are severely affected by store construction‐and unable to persist deep in the anaerobic part of the store. In contrast, anaerobes,S‐strategists or stresstolerators, are able to survive under the same conditions. These changes have serious implications for the restoration of systems using stored topsoil as a resource. The microbial population has been altered in terms of its size and composition. Many of the fungi required for adequate breakdown and incorporation of organic matter will be absent, and the soils will be generally poor in microbial biomass. This will lead to inadequate nutrient cycling and poor soil structural stability, two factors essential for the restoration of a self‐sustainin

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1993.tb00014.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractHerbaria are potentially important repositories of living seeds that could be useful for recovery of rare plant species. To examine this capacity, we tested seed germination of rare milkweed (Asclepias) and milkvetch (Astragalus) species representing different collection dates and different herbaria. These groups have contrasting seed characteristics, with greater potential for longevity in the nonpermeable hard‐coated milkvetch seeds. Twelve‐year‐oldAsclepias lanuginosaseeds failed to germinate. However, we achieved 45% germination from three‐year‐oldAsclepias meadiiseeds, but germination dropped to 0% after ages of four to five years.Astragalus neglectusseeds germinated from 97‐, 48‐, and 28‐year‐old herbarium specimens, andAstragalus tennesseensisseeds germinated from a four‐year‐old collection. Seedlings produced from these experiments were incorporated intoex situgarden populations for recovery or restoration of rare species populations. Different herbarium pest control techniques may have significant bearing on the viability of seeds stored on herbarium specimens. Microwaving can cause precipitous loss of seed viability, while deep‐freezing appears to allow some seeds to remain viable. Potentially live seeds of rare species should be stored under conditions that enhance th

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1993.tb00015.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe goal of this study was to use terrestrial arthropods to help evaluate the progress of a riparian restoration effort along the San Luis Rey River in California by comparing characteristics of the arthropod community at the reconstructed system to those of a naturally occurring riparian woodland used as a reference site. Insects and other arthropods were sampled throughout 1989–1991 using pan trapping and sweep sampling of dominant plants. Assemblages of taxa were monitored as indicators of functional groups that influence ecosystem processes: pollinators, herbivores, predators, parasites, and detritivores. Relative abundances of indicator assemblages were compared between sites to evaluate the establishment and maintenance of processes critical for the natural function of the reconstructed riparian ecosystem. A major objective of this project was to create habitat for the Least Bell's Vireo, so a group of potential prey items was designated to indicate vireo food resources. Over 230,000 arthropods were identified to order or family and by size. Insect communities developed rapidly at the restored habitat. Although the abundance of all arthropods was lower at the reconstructed site than at the reference site, the same orders were present after three years in similar proportions at both locations, and mean abundances were within an order of magnitude of each other. Abundance of certain groups, such as detritivores, suggested that arthropods had propagated rapidly at the restoration site, a possible indication of resiliency. Relatively low numbers of other arthropods, such as predators and parasites, at the reconstructed site indicated the need for continued monitoring. The decline of pollinators and herbivores by 1991 at the reconstructed site suggested that they may have immigrated or been introduced with transplanted vegetation in 1989, but have had difficulty colonizing the site. Although the Least Bell's Vireos were seen foraging at the restored site after three years, no nests were found. Nesting is anticipated, however, as the site mature

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1993.tb00016.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe Pinelands National Reserve and UNESCO Biosphere encompass a large portion of southern New Jersey's Pine Barrens. Within the core preservation zone of these Reserves lies the Warren Grove Weapons Range, a military installation where exercises during the past 50 years have devastated portions of the indigenous pygmy pine‐oak forest. In 1987, restoration efforts were initiated to identify materials and techniques that promote a diverse and productive native plant community atop drastically disturbed portions of the range. We used trial plantings to examine fertilizer and sewage compost fertility amendments, the effect of different native plant mixtures (including the dwarfed race of pitch pine,Pinus rigida), the influence of the ectomycorrhizal fungusPisolithus tinctoriuson the growth of pines and associated species, and mulch applications to conserve moisture and add organic matter. Following two growing seasons, test plantings exhibited 25% of the vegetation production found in the surrounding pine‐oak community, 50% canopy closure, and levels of diversity comparable to the reference site. Maximum biomass and cover were achieved following the application of 16 Mg/ha compost and the establishment of pitch pine seedlings. Pitch pine was the dominant species in all plots where it was planted, with herbaceous species comprising the balance of the developing vegetation. Amendments of seeded grasses,P. tinctorius, and mulch influenced species composition but failed to enhance total plant production. We recommend restoring drastically disturbed sites in the pine plains with cultural input of compost to the spoils and planting of pitch pines and other woody species to accelerate the structural blending of reforested sites with the surrounding native vegetat

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1993.tb00017.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractIn order to extend quarrying near Thrislington Plantation, County Durham, England, 8.5 ha of magnesian limestone grassland was relocated over a period of eight years from October 1982. The effects of this on the flora and invertebrate fauna were examined within theFestuca‐Helianthemumcommunity at five plots relocated at different times. Plants were sampled with a point‐quadrat, and invertebrates by pitfall trapping. Comparisons were made between age of the relocation, numbers of species and individuals, and diversity of flora and invertebrates. The plots were examined using the percentage similarity measure. The plots showed an initial change in some aspects of community structure for flora and invertebrate fauna, followed by a “recovery” period. This was particularly evident in the numbers of species and species diversity of plants and in the numbers of individuals and species diversity of invertebrates. Bare ground, left by the relocation process, was still evident between relocated turfs in the early plots, but it was successfully colonized by resident species in later plots. These results have implications for the future management of this and similar sites, particularly with respect to the emphasis placed on subsequent monitoring and the need to consider invertebrate faunas when implementing management str

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1993.tb00018.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Books reviewed in this article:Directing Ecological Succession.James O. LukenSoil Restoration: Advances in Soil Science, vol. 17.Rattan Lai and B. A. Stewart, editors

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1993.tb00019.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY