Environmental spatial-temporal heterogeneity of streams in a Cerrado-Caatinga ecotone

Abstract

Environmental spatial-temporal heterogeneity is an important factor for structuring the biodiversity of ecosystems, including lotic systems that have been strongly influenced by land use and occupation. Thus, the present study aimed to identify if there was a spatial-temporal difference of the structural and physical-chemical variables which the streams of the Environmental Protection Area of the Inhamum, as well as if there was difference of environmental heterogeneity which the samples during the period of 2012 to 2015. The ordernation indicated temporal effects on the streams, because there were two groups formed, the first formed by the samples of 2012-2013 and the other by 2014-2015, but which did not present differences as to their heterogeneity. Temperature, conductivity, depth, width and flow were important in the structuring of the streams, but due to being in an area with a wide canopy cover and high habitat integrity, there was a small range of variation in the values of these variables. These results demonstrate the importance of the maintenance of the canopy cover to guarantee the habitat integrity and to provide the conservation of the environmental characteristics of streams in tropical biomes.