Maciel et al. 2015d (Conference Paper) Aechmea

The Wallacean Shortfall in Aechmea

Author(s):—J.R. Maciel, M.F. Siqueira & M. Alves in Benko-Iseppon, A.M.; Alves, M. & Louzada, R. (2015) An overview and abstracts of the First World Congress on Bromeliaceae Evolution. Rodriguésia 66(2): A1-A66.

Publication:— (2015).

Abstract:—Biodiversity database of hyperdiverse taxa and regions are limited for providing an accurate picture of speciesdistributions. This problem is named the Wallacean Shortfall and represents the main difficulty for Neotropicalbiogeographic studies. An alternative to face this problem is ecological niche modelling (ENM). However, we do not know how Wallacean Shortfall affects ENMs assumptions, especially the sample sufficiency assumption. Thus, herein we developed a comparative analysis of environmental spaces among potential and observed distributions of 18 Aechmea species from northeastern Brazilian Atlantic Forest. A principal component analysis was made for four environmental datasets of each species: 1) from bioclim models, 2) from maxent models, 3) from convex hull of species distributions, and 4) from observed distributions. The twofirst axes were used in a kernel density analysis to compare the environmental spaces these four datasets. All analyses were performed in the R software environment and its associated packages. Patterns of geographic distributions of the 18 species can be classified as wide distribution, occurring continuously from Central America to Brazi (1 species) and disjunctly between Amazonia and Atlantic Forest (3species); Atlantic distribution, occurring on the East Coast of Brazil (4 species); and endemic to the northeastern Atlantic Forest (10 species). Species with wide and Atlantic distributions show higher adjustment between observed and expected distribution, as opposed to endemic species that show low adjustment. In general, species with low adjustment also show fewer occurrence points than species with higher adjustment. The evidence suggests that the Wallacean Shortfall affects the quality of Aechmea species models differently, but widely distributed species show good environmental sampling and might be good biological models for ENMs studies, while endemic species require customization of the approaches used.

Keywords:—Ecological Niche Modeling; Distribution; Bromelioideae.