Lawrence L. Master

A Standard Lexicon for Biodiversity Conservation: Unified Classifications of Threats and Actions

An essential foundation of any science is a standard lexicon. Any given conservation project can be described in terms of the biodiversity targets, direct threats, contributing factors at the project site, and the conservation actions that the project team is employing to change the situation. These common elements can be linked in a causal chain, which represents a theory of change about how the conservation actions are intended to bring about desired project outcomes. If project teams want to describe and share their work and learn from one another, they need a standard and precise lexicon to specifically describe each node along this chain. To date, there have been several independent efforts to develop standard classifications for the direct threats that affect biodiversity and the conservation actions required to counteract these threats. Recognizing that it is far more effective to have only one accepted global scheme, we merged these separate efforts into unified classifications of threats and actions, which we present here. Each classification is a hierarchical listing of terms and associated definitions. The classifications are comprehensive and exclusive at the upper levels of the hierarchy, expandable at the lower levels, and simple, consistent, and scalable at all levels. We tested these classifications by applying them post hoc to 1191 threatened bird species and 737 conservation projects. Almost all threats and actions could be assigned to the new classification systems, save for some cases lacking detailed information. Furthermore, the new classification systems provided an improved way of analyzing and comparing information across projects when compared with earlier systems. We believe that widespread adoption of these classifications will help practitioners more systematically identify threats and appropriate actions, managers to more efficiently set priorities and allocate resources, and most important, facilitate cross-project learning and the development of a systematic science of conservation.

Species richness and patterns of invasion in plants, birds, and fishes in the United States

We quantified broad-scale patterns of species richness and species density (mean # species/km2) for native and non-indigenous plants, birds, and fishes in the continental USA and Hawaii. We hypothesized that the species density of native and non-indigenous taxa would generally decrease in northern latitudes and higher elevations following declines in potential evapotranspiration, mean temperature, and precipitation. County data on plants (n = 3004 counties) and birds (n=3074 counties), and drainage (6 HUC) data on fishes (n = 328 drainages) showed that the densities of native and non-indigenous species were strongly positively correlated for plant species (r = 0.86, P < 0.0001), bird species (r = 0.93, P<0.0001), and fish species (r = 0.41, P<0.0001). Multiple regression models showed that the densities of native plant and bird species could be strongly predicted (adj. R2 = 0.66 in both models) at county levels, but fish species densities were less predictable at drainage levels (adj. R2 = 0.31, P<0.0001). Similarly, non-indigenous plant and bird species densities were strongly predictable (adj. R2 = 0.84 and 0.91 respectively), but non-indigenous fish species density was less predictable (adj. R2 = 0.38). County level hotspots of native and non-indigenous plants, birds, and fishes were located in low elevation areas close to the coast with high precipitation and productivity (vegetation carbon). We show that (1) native species richness can be moderately well predicted with abiotic factors; (2) human populations have tended to settle in areas rich in native species; and (3) the richness and density of non-indigenous plant, bird, and fish species can be accurately predicted from biotic and abiotic factors largely because they are positively correlated to native species densities. We conclude that while humans facilitate the initial establishment, invasions of non-indigenous species, the spread and subsequent distributions of non-indigenous species may be controlled largely by environmental factors.

How many endangered species are there in the United States

Only about 15% of the known species in the United States have been studied in sufficient detail to determine whether or not they are imperiled. Any estimate of the total number of imperiled species in this country must therefore rely on extrapolations from this small number of comparatively well-studied species to a much larger number of poorly studied ones. We review the best available data on the status of plants, animals, and fungi in the US and conclude that the actual number of known species threatened with extinction is at least ten times greater than the number protected under the Endangered Species Act (ESA). The key to developing a more accurate picture of the extent of species endangerment is to obtain more data on the following groups (in decreasing order of priority): (1) invertebrate animals; (2) fungi; and (3) marine organisms. However, given the slow pace at which species are being protected under the ESA, and the rapid rate at which natural areas are being destroyed, a more urgent task is ...

INTEGRATING REPRESENTATION AND VULNERABILITY: TWO APPROACHES FOR PRIORITIZING AREAS FOR CONSERVATION

Reserves protect biodiversity by ameliorating the threats to the persistence of populations. Methods for efficient, systematic reserve selection have generally been designed to maximize the protection of biodiversity while minimizing the costs of reserves. These techniques have not directly addressed the factors threatening species at specific sites. By incorporating measures of site vulnerability into reserve selection procedures, conservation planners can prioritize sites based on both representing biodiversity and the immediacy of factors threatening it. Here we develop two complementary approaches for identifying areas for conservation based on species composition and potential threats facing the species. These approaches build on two established methods of systematic reserve selection. The first approach in- volves mapping irreplaceability (a statistic derived from reserve selection theory that mea- sures the potential importance of a site for protecting all species) and the degree to which the area is vulnerable to threats from three basic anthropogenic factors (the percentages of a site devoted to agriculture, to urban and suburban development, and to open mines). We classified areas with respect to both irreplaceability and the three indicators of vulnerability, producing a continuous ranking of all sites based on these factors. Our second approach was to incorporate site vulnerability into a reserve selection algorithm. This approach allowed us to locate those sets of sites that protected all species and were most likely to be threatened by human activities. These two analyses can provide regional-scale guidance for conservation in the Mid-Atlantic region of the United States, and they demonstrate two potential tools for solving complex conservation-planning problems.