Biomedical subjects

R L Pressey

Publications and source records attributed to R L Pressey.

5 recordsLinked to original sources

PubMed2002

Representing biodiversity: data and procedures for identifying priority areas for conservation.

Biodiversity priority areas together should represent the biodiversity of the region they are situated in. To achieve this, biodiversity has to be measured, biodiversity goals have to be set and methods for implementing those goals have to be applied. Each of these steps is discussed. Because it is impossible to measure all of biodiversity, biodiversity surrogates have to be used. Examples are taxa sub-sets, species assemblages and environmental domains. Each of these has different strengths and weaknesses, which are described and evaluated. In real-world priority setting, some combination of these is usually employed. While a desirable goal might be to sample all of biodiversity from genotypes to ecosystems, an achievable goal is to represent, at some agreed level, each of the biodiversity features chosen as surrogates. Explicit systematic procedures for implementing such a goal are described. These procedures use complementarity, a measure of the contribution each area in a region makes to the conservation goal, to estimate irreplaceability and flexibility, measures of the extent to which areas can be substituted for one another in order to take competing land uses into account. Persistence and vulnerability, which also play an important role in the priority setting process, are discussed briefly.

Animals↗

PubMed2002

Persistence and vulnerability: retaining biodiversity in the landscape and in protected areas.

An objective of biodiversity conservation activities is to minimize the exposure of biodiversity features to threatening processes and to ensure, as far as possible, that biodiversity persists in the landscape. We discuss how issues of vulnerability and persistence can and should be addressed at all stages of the conservation planning and implementation process. Procedures for estimating the likelihood of persistence and for measuring degrees of vulnerability at different spatial and temporal scales using subjective assessments, rules of thumb and analytical and simulation models are reviewed. The application of information on vulnerability and persistence to conservation planning and management is discussed under the headings of natural dynamics, replication of protection, levels of representation, source and sink population structures, refuges and critical resources, reserve design, habitat fragmentation and levels of management.

Animals↗

PubMed2002

Integrating biosystematic data into conservation planning: perspectives from southern Africa's Succulent Karoo.

In this paper we explore the role that biosystematists can play in conservation planning. Conservation planning concerns the location and design of reserves that both represent the biodiversity of a region and enable the persistence of that biodiversity by maintaining key ecological and evolutionary processes. For conservation planning to be effective, quantitative targets are needed for the spatial components of a region that reflect evolutionary processes. Using examples from southern Africa's Succulent Karoo, we demonstrate how spatially explicit data on morphological variation within taxa provide essential information for conservation planning in that such variation represents an important surrogate for the spatial component of lineage diversification. We also provide an example of how the spatial components of evolutionary processes can be identified and targeted for conservation action. Key to this understanding are the recognition and description of taxonomic units at all spatial scales. Without the recognition of subspecific variation, it is difficult to formulate evolutionary hypotheses, let alone set quantitative targets for the conservation of this variation. Given the escalating threats to biodiversity, and the importance of planning for persistence by incorporating ecological and evolutionary processes into conservation plans, it is essential that systematists develop hypotheses on the spatial surrogates for these processes for a wide range of lineages. The important questions for systematists to be asking are (1) how is variation distributed in the landscape, and (2) how did it come about? Conservation planners too need to highlight these spatial components for conservation action.

Africa↗

PubMed2001

Rapid plant diversification: planning for an evolutionary future.

Systematic conservation planning is a branch of conservation biology that seeks to identify spatially explicit options for the preservation of biodiversity. Alternative systems of conservation areas are predictions about effective ways of promoting the persistence of biodiversity; therefore, they should consider not only biodiversity pattern but also the ecological and evolutionary processes that maintain and generate species. Most research and application, however, has focused on pattern representation only. This paper outlines the development of a conservation system designed to preserve biodiversity pattern and process in the context of a rapidly changing environment. The study area is the Cape Floristic Region (CFR), a biodiversity hotspot of global significance, located in southwestern Africa. This region has experienced rapid (post-Pliocene) ecological diversification of many plant lineages; there are numerous genera with large clusters of closely related species (flocks) that have subdivided habitats at a very fine scale. The challenge is to design conservation systems that will preserve both the pattern of large numbers of species and various natural processes, including the potential for lineage turnover. We outline an approach for designing a system of conservation areas to incorporate the spatial components of the evolutionary processes that maintain and generate biodiversity in the CFR. We discuss the difficulty of assessing the requirements for pattern versus process representation in the face of ongoing threats to biodiversity, the difficulty of testing the predictions of alternative conservation systems, and the widespread need in conservation planning to incorporate and set targets for the spatial components (or surrogates) of processes.

Biological Evolution↗

PubMed2000

Systematic conservation planning.

The realization of conservation goals requires strategies for managing whole landscapes including areas allocated to both production and protection. Reserves alone are not adequate for nature conservation but they are the cornerstone on which regional strategies are built. Reserves have two main roles. They should sample or represent the biodiversity of each region and they should separate this biodiversity from processes that threaten its persistence. Existing reserve systems throughout the world contain a biased sample of biodiversity, usually that of remote places and other areas that are unsuitable for commercial activities. A more systematic approach to locating and designing reserves has been evolving and this approach will need to be implemented if a large proportion of today's biodiversity is to exist in a future of increasing numbers of people and their demands on natural resources.

Animals↗