Diversidade de anfíbios em gradientes altitudinais em áreas de Brejos-de-Altitude no Nordeste Brasileiro

Abstract

The species are distributed unevenly on the planet and all groups of organisms are subject to historical and ecological factors that can limit and define its distribution. Some groups of animals, such as amphibians are good ecological models for biogeographic studies, because they are poorly dispersed and strongly linked to reproductive sites, and can be widely used in studies that attempt to elucidade patterns of local and/or regional diversity. This work is divided into two parts: Firstly, we tested the influence of altitudinal gradients on the spatial distribution of amphibians assemblage low elevation mountains of Northeaster Brazil, This is the first work on analyze the distribution of amphibian’s assemblages along short elevations in northeastern Brazil, and this is the first study that proposes this question. We find amphibians assemblages are distributed along a mountain conic (Maranguape Mountain) and platô (Ubajara National Park), and we seek to define which areas of greater richness and diversity and the causal factors. We have established four quotas along each of the elevations: 200, 400, 600 and 800 meters above sea level, and collect amphibians using active search and pitfalls traps. We found 29 species of amphibians in the Maranguape Mountains (Manuscript I) and 25 species for Ubajara National Park (Manuscript II). The geographic distribution of amphibians occurring in two elevations includes species widely distributed, species distribution associated with South American open formations and distribution restricted to Brejos de Altitude. There was an increase in richness with altitude in the National Park Ubajara (Manuscript III), and a richness of curve humped format of the Maranguape Mountains (Manuscript I). We also found significant differences between the abundance and β- diversity along the altitudinal levels, and we believe that the results are associated with geomorphological differences and phytophisiognomic regions. We also tested if the Brejos de Altitudeare a transition area between the Amazon Forest and Atlantic through the similarity in species of amphibians, and found a strong relationship between the species composition of the“Brejos de Altitude” with the Atlantic Forest of the northeastern portion and the Caatinga (Manuscript IV). Despite the low similarity with Amazonian areas, we believe that species with disjunct distribution may indicate that the "Brejos de Altitude" also showed a significant link to such areas, and present a case relictual distribution and disjunct species Caecilia tentaculata Linnaeus, 1758, with occurrence for the State of Ceará (Manuscript V).