GRADIENTE DE ALTITUDE E RIQUEZA DE ESPÉCIES: COMO O ESTUDO DOS MOLUSCOS TERRESTRES CONTRIBUI COM ESTA QUESTÃO?

Abstract

ALTITUDINAL GRADIENT AND SPECIES RICHNESS: HOW THE STUDY OF LAND SNAILS CONTRIBUTES  WITH  THIS  ISSUE?  Considering  the  growing  interest  on  the  distribution  of  species along altitudinal gradients and the potential of molluscs as good subjects for this kind of studies, this work aimed to check the current knowledge on land snails species richness concerning altitudinal gradients, using scientometric analysis of articles related to the topic. Bibliographic databases until May 2011 were extracted from the sites Web of Science, Scopus e Scielo, using key words and expressions linking altitude and land snail. The expression altitudinal gradient was the most recorded. We located in the Scopus database 80 publications and in the Web of Science database only six publications, these last also located in the Scopus database. Only 11 articles were somehow relating land snail species richness to altitudinal gradient. In relation to increasing altitude, three publications did not find any pattern; two publications found a monotonic richness decrease; four publications found a peak of richness at intermediate altitudes; two publications found the two last cited patterns.  Most  of  articles  found  the  peak  of  richness  at  intermediate  altitudes  pattern,  apparently  the  most frequently observed pattern in nature. Only six publications clearly had the aim to relate species richness to altitudinal gradient using land snail communities. In Brazil, where the diversity of land snail still shows a wide gap of knowledge, nothing was published about land snail distribution according altitudinal gradients. Considering  the  great  potential  of  land  snails  to  contribute  to  the  question  of  altitudinal  gradients,  it  is recommended that efforts should be made to stimulate studies aiming these objectives.

Keywords: Diversity; elevation; gastropods; Mollusca; richness.