GAIN OR LOSS OF SPECIES? REVEALING SPATIAL AND TEMPORAL ?-DIVERSITY OF MACROINVERTEBRATES IN WATERSHEDS DURING A SUPRA-SEASONAL DROUGHT IN SEMI-ARID REGION

Código

XXV-SBRH1194

Autores

Daniele Jovem-Azevêdo, Carlinda Raílly Medeiros Rodrigues, Evaldo de Lira Azevêdo, Wilma Izabelly Ananias Gomes, Maria João Feio, JOSELINE MOLOZZI

Tema

27 - Qualidade da Água, Compostos Emergentes e Micropoluentes

Resumo

Beta diversity provides information on the relationship between local and regional diversity and how the communities vary in space, providing important insights for decision making on biodiversity conservation. Here, we analyzed over time the effect of an increasingly stronger supra-seasonal drought in the ?-diversity of macroinvertebrates from six reservoirs located in the semi-arid region of Brazil (Piranhas-Assu and Paraíba river watersheds). The sampling occurred two times: June 2014 (period of higher water volume) and March 2015 (period of lower water volume). A null model was employed to determine the deviation between the observed ?-diversity and that expected at random. The temporal beta diversity between the sampling months was determined using the temporal beta diversity index (TBI). The greatest diversity variation occurred among watersheds (?3 scale) and both periods, with proportions of 38.3 and 38.0%, respectively. The abundance of benthic macroinvertebrates showed a significant loss of species in some studied reservoirs (p<0.05). For the presence and absence species, reservoirs of the Piranhas-Assu river watershed did not show significant differences in loss (p>0.05). However, in the Paraiba river watershed, the Cordeiro and Poções reservoirs showed a significant temporal species loss (p<0.05), while in the Sumé reservoir there was a species gain (p<0.05). These results indicate that, under the future of climate change scenarios of more frequent and intense drought periods, the loss of species may become higher than species gain, resulting in poor-communities and few tolerant dominant species.