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Population viability analysis?

abstract1 (full description below): Pp. 3-9 in D. F. Williams, S. Byrne, and T. A. Rado (eds) Endangered and Sensitive Species of the San Joaquin Valley, California. California Energy Commission, Sacramento, California and the Wildlife Society, Western Section.
Population Viability Analysis. PDF/Acrobat file     SoulĂ©, M. E.

Abstract. A perennial issue in conservation is viability, particularly the assessment of the kinds and levels of risk or vulnerability associated with various population sizes and different geographic distributions of the species in question. The smaller a population, both in numbers and space, the more kinds of hazards it is likely to encounter. Population viability analysis (PVA) is a unifying conceptual approach to the problem of risk assessment under actual field conditions. PVA uses many of the components of minimum viable population (MVP) assessment, but differs from it in being more contextual. It relies less on "rules of thumb" and more on the long-term dynamics of populations in particular places, and on the potential genetic consequences of these dynamics. PVA identifies hazards, evaluates them, examines the interactions between them, identifies the kinds of information required for further analysis, and may produce a set of contingent MVP estimates. Several conditions can militate against an adequate WA. These include (1) insufficient natural history information, (2)in sufficient population and environmental data, (3)inadequate metapopulation (turnover in patches) data, (4) incorrect application of the principles of PVA, and (5) inability to associate levels of jeopardy (risk) with levels of population size and spatial distribution. PVA appears to be our best hope for quantifying the vulnerability and viability of threatened and endangered populations.