Challenging Wallacean and Linnean shortfalls: knowledge gradients and conservation planning in a biodiversity hotspot

Abstract

Knowledge about biodiversity remains inadequate because most species living on Earth were still not formally described (the Linnean shortfall) and because geographical distributions of most species are poorly understood and usually contain many gaps (the Wallacean shortfall). In this paper, we developed models to infer the size and placement of geographical ranges of hypothetical non-described species, based on the range size frequency distribution of anurans recently described in the Cerrado Biome, on the level of knowledge (number of inventories) and on surrogates for habitat suitability. The rationale for these models is as follow: (1) the range size frequency distribution of these species should be similar to the range-restricted species, which have been most recently described in the Cerrado Biome; (2) the probability of new discoveries will increase in areas with low biodiversity knowledge, mainly in suitable areas, and (3) assuming range continuity, new species should occupy adjacent cells only if the level of knowledge is low enough to allow the existence of undiscovered species. We ran a model based on the number of inventories only, and two models combining effects of number of inventories and two different estimates of habitat suitability, for a total of 100 replicates each. Finally, we performed a complementary analysis using simulated annealing to solve the set-covering problem for each simulation (i.e. finding the smallest number of cells so that all species are represented at least once), using extents of occurrence of 160 species (131 real anuran species plus 29 new simulated species). The revised reserve system that included information about unknown or poorly sampled taxa significantly shifted northwards, when compared to a system based on currently known species. This main result can be explained by the paucity of biodiversity data in this part of the biome, associated with its relatively high habitat suitability. As a precautionary measure, weighted by the inferred distribution data, the prioritization of a system of reserves in the north part of the biome appears to be defensible.

New record of Amphisbaena fuliginosa (Squamata, Amphisbaenidae) for the Cerrado Biome, in an area of extensive cattle ranching

“…The color pattern of our specimen is similar to that described by Vanzolini (2002) for other specimens from Goiás state, corroborating the uniform color pattern observed for Cerrado populations (Vanzolini 2002 Richness and distribution of the herpetofauna in Cerrado biome is probably under estimated (Bini et al 2006), and many species have been recently described (e.g., Silva et al 2005, Torres-Carvajal 2005. The discovery of A. fuliginosa so far south of its previously known localities indicates that this species have a wider distribution in this biome.…”

Combining multiple models to predict the geographical distribution of the Baru tree (Dipteryx alata Vogel) in the Brazilian Cerrado

“…Most tropical plants species are still poorly characterised with respect to their geographical distribution, a problem referred to as "Wallace shortfall" (Whittaker et al, 2005;Bini et al, 2006). Geographical distribution modelling has become an important tool in filling this gap and in furthering ecology, conservation and evolution studies.…”

Registros de espécies de mamíferos e aves ameaçadas em Mato Grosso do Sul com ênfase no Sistema Estadual de Unidades de Conservação

“…O mapeamento dos registros de ocorrência de espécies ameaçadas não deve ser visto como uma atividade finalista, mas sim como o primeiro passo para o conhecimento da ocorrência e padrão de distribuição das espécies nas diversas regiões ecológicas e biomas brasileiros, diminuindo os grandes déficits de conhecimento sobre a identidade e distribuição das espécies da região tropical (Bini et al, 2006). Nosso estudo apresenta um panorama abrangente dos registros de espécies ameaçadas nas UC's, mas certamente não engloba muitos registros disponíveis fora de unidades de conservação.…”