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At a meeting in Brazil in March, the Convention on Biological Diversity moved a step closer to finalizing an international regulatory regime for access to and benefit sharing of genetic resources. Discussions now under way will be influential in determining policies governing biodiversity research and bioprospecting.
A new database about to be launched for zoos and aquariums will overhaul outdated record-keeping systems. Through the Zoological Information Management System, keepers, curators, and veterinarians will have access to integrated, up-to-date information about collections worldwide to track animals, diagnose diseases, and communicate treatments.
Although strategies to conserve biodiversity (e.g., the establishment of reserves and the management of flagship, umbrella, indicator, and keystone species) are valuable, they entail practical and conceptual difficulties. A focus on niche construction and ecosystem engineering, however, could provide new insights and methods for conservation biology. Many organisms modulate the availability of resources to other species by causing state changes in biotic or abiotic materials (ecosystem engineering), in the process frequently changing the selection to which the ecosystem engineers and other organisms are exposed (niche construction). We describe growing evidence that organisms have significant nontrophic impacts on ecosystem structure, function, and biodiversity, and outline established means of identifying key species involved in niche construction. On the basis of this engineering perspective, we propose a number of measures that could be employed to enhance conservation efforts.
An understanding of the factors governing grass–tree coexistence in savannas and exclusion of trees in grasslands remains elusive. We contend that progress in understanding these factors is impeded by a reliance on a falsification approach and an excessive concern over type I errors (false positives), which results in premature rejection of hypotheses, inadequate attention to scale, and a miring rather than galvanizing of ecological discussions. An additional hindrance to progress may be that investigations tend to focus on processes within either savannas or grasslands, while ignoring the boundary between the two. We propose a new scientific framework for identifying determinants of savanna and grassland distribution, which advocates (a) the recognition of ecosystems and biomes as complex adaptive systems, (b) a scientific methodology based on adaptive inference, and (c) explicit consideration of patch boundaries at various scales. Analysis of processes operating at dynamic savanna–grassland boundaries should permit better separation of ultimate from proximate factors controlling grass–tree interactions within the individual biomes. The proposed savanna–grassland framework has potential for application in other areas of ecology facing similar problems.
The hierarchical structure of natural systems can be useful in designing ecological studies that are informative at multiple spatial scales. Although stream systems have long been recognized as having a hierarchical spatial structure, there is a need for more empirical research that exploits this structure to generate an understanding of population biology, community ecology, and species–ecosystem linkages across spatial scales. We review studies that link pattern and process across multiple scales of stream-habitat organization, highlighting the insight derived from this multiscale approach and the role that mechanistic hypotheses play in its successful application. We also describe a frontier in stream research that relies on this multiscale approach: assessing the consequences and mechanisms of ecological processes occurring at the network scale. Broader use of this approach will advance many goals in applied stream ecology, including the design of reserves to protect stream biodiversity and the conservation of freshwater resources and services.
Many conifer forests experience stand-replacing wildfires, and these fires and subsequent recovery can change the amount of carbon released to the atmosphere because conifer forests contain large carbon stores. Stand-replacing fires switch ecosystems to being a net source of carbon as decomposition exceeds photosynthesis—a short-term effect (years to decades) that may be important over the next century if fire frequency increases. Over the long term (many centuries), net carbon storage through a fire cycle is zero if stands replace themselves. Therefore, equilibrium response of landscape carbon storage to changes in fire frequency will depend on how stand age distribution changes, on the carbon storage of different stand ages, and on postfire regeneration. In a case study of Yellowstone National Park, equilibrium values of landscape carbon storage were resistant to large changes in fire frequency because these forests regenerate quickly, the current fire interval is very long, the most rapid changes in carbon storage occur in the first century, and carbon storage is similar for stands of different ages. The conversion of forest to meadow or to sparser forest can have a large impact on landscape carbon storage, and this process is likely to be important for many conifer forests.
Many authors have advocated the use of power analysis for designing more sensitive and efficient ecological studies. However, few manuscripts report using power analysis for improving the study design, perhaps because of the wide range of tests routinely used by most ecologists and the limitations of most power analysis software. UnifyPow, an excellent freeware macro that runs within SAS, easily and accurately calculates power or sample sizes for a wide range of statistical tests for a broad range of statistical models. Despite its potential contribution to the field, UnifyPow is virtually unused by ecologists. Perhaps this is because UnifyPow was developed by medical statisticians or because there is no manual, although there is extensive online documentation. I briefly review the flexibility and breadth of UnifyPow; describe how it works; and, using ecological examples, demonstrate how to use it to calculate power for an extremely wide range of statistical tests.
Habitat conservation plans (HCPs) permit the incidental take of threatened or endangered species listed under the federal Endangered Species Act. The US Fish and Wildlife Service (USFWS) and the NOAA Fisheries Service endorse multispecies HCPs, claiming that they offer advantages for both conservation and development. However, the conservation benefits of multispecies plans to individual covered species may be overestimated. We reviewed the species selected for coverage in 22 multispecies HCPs from USFWS Region 1. We found that conservation measures were often not clearly defined, and that the presence of the species in the planning area was not even confirmed for 41 percent of covered species. While we do not question the conservation value of multispecies plans, our study suggests that changes are needed to achieve full conservation potential.
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