ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1994.tb00044.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractCommunity classification has emerged from ecology textbooks into the arena of environmental impact evaluation and mitigation. This development is especially apparent in southern California, where the fate of a community called coastal sage scrub is being decided. Regional plans for development, mitigation, preservation, and restoration are being formulated that will permanently affect the natural landscape. This paper demonstrates the potential for the name of a plant community to affect tradeoffs in planning processes that are intended to offset removal of habitat by development. The discussion focuses on two types of classification systems. One system is hierarchical, with established nomenclatorial rules that allow natural variation to refine the community definitions. Names of plant associations directly reflect the dominant species in the association, as inArtemisia californica—Eriogonum fasciculatum(California sagebrush—California buckwheat). The second system is nonhierarchical, in which observations of natural landscapes are fit into established definitions of community types, such as Diegan coastal sage scrub. Advantages and disadvantages of both types of systems are discussed and illustrated by two examples of problems in classifying coastal sage scrub. The discussion concludes with the point that the name of a community has the potential to significantly affect the extent to which equal tradeoffs between community types are actually achieved in mitigation and restoration effo

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1994.tb00045.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractSeveral landscape restoration alternatives were evaluated in the Gorecht area, a cultivated river plain in the northern part of the Netherlands. A landscape analysis was performed to investigate the hydrological functioning of this area. Groundwater composition in the area was assessed by using distribution patterns of indicative plant species. Results proved to be consistent with an interpolation of actual data of the groundwater composition. Groundwater flow was simulated with hydrological models to explain the observed patterns in water chemistry. It appeared that upwelling Ca‐rich groundwater is now absent in the area, contrary to the past situation. Because a constant supply of Ca‐rich water is an essential condition for mesotraphent fen vegetation, we concluded that under the present conditions the regeneration prospects for these vegetation types are poor. We suggest that the plan to regenerate groundwater‐fed fens be abandoned for a plan to create surface‐water‐fe

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1994.tb00046.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractLand rehabilitation is proposed as a management strategy to reverse the negative consequences of tropical deforestation and land degradation. We first define the concepts associated with ecosystem modification—conversion, damage, and degradation—and those associated with ecosystem repair—restoration, rehabilitation, and reclamation. We then present a scheme of sustainable land use in the tropics, with illustrations of how rehabilitation and restoration activities fit into the overall scheme of the use of land. Because damaged lands cannot contribute effectively to sustained economic development, land rehabilitation is a necessary step for increasing the chances of attaining sustainability. Approaches for rehabilitating ecosystems are discussed, including the management of stressors and subsidies in relation to their point of interaction in the ecosystem. Finally, we illustrate the concepts of ecosystem rehabilitation of damaged, degraded, and derelict lands with examples of case studies from dry to humid life zones in island and continental situations throughout the tropics. The case studies demonstrate that opportunities for success exist, even with severely degraded lands, but a considerable amount of research remains to be done before we have a full understanding of the complexity of the task faci

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1994.tb00047.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThis article contributes to the worldwide trend of using microbiological methods for bioindication of the influence of abiotic, biotic, and anthropogenic factors on the soil environment, especially on the plough layer of soils. It compares two approaches to assess microbial biomass‐C: (1) chemical treatment of soil samples by CHCl3vapor, followed by extraction, and (2) heat treatment in the range of 62–65°C for 24 hours, followed by extraction. It recommends the analysis of different forms of organic carbon, the total carbon of soil organic mass, and microbial biomass‐C and other forms of organic carbon extractable with 0.5 M K2SO4and 0.5 M (NH4)2SO4respectively. It presents a simple mathematical model suitable for assessment of microbial recuperation of the topsoil (0–15 cm) after restoration. The relation between the measured values and the values calculated with the model expressed as percentages expresses the quality of restoration achieved and the stage of disturbance of the living microbial part of the topsoil. It indicates not only the ecological impact but also the deficit and stress situations, to which the living microbial part of the topsoil is exposed in the l

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1994.tb00048.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe foundation of a successful revegetation or restoration program is quality native seed. This requires careful collection, processing, and storage. Mature seed should be collected from healthy, local stands with a sufficiently broad genetic base. Careful identification of the site characteristics and seed‐lot tracking are essential. Yearly variation in seed production and seed quality can be very high, and an early determination of seed quality can prevent expensive failures. Nondestructive evaluation using X‐rays is effective and economical, but techniques such as staining, inspection, and germination tests can also be helpful. Cleaning, dewinging, and upgrading seed before storage can (1) reduce weight and bulk, (2) improve storage life, (3) increase germination, and (4) make greenhouse production and field planting easier and more economical. The seeds of many native plants can lose their viability quickly if they are not stored under controlled conditions. Seeds in storage must also be protected from rodents, pests, and disease. Dormancy is common in the seeds of many native species, and experimentation is often necessary to determine the best way to break seed dormancy. This can be complicated by year‐to‐year and plant‐to‐plan

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1994.tb00049.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1994.tb00050.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Books reviewed in this article:Ecological Principles of Nature Conservation.L. Hansson, editorSaltmarsh Ecology.P. Adam

ISSN:1061-2971    

DOI:10.1111/j.1526-100X.1994.tb00051.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY