Spatial and temporal variation of edge effects in coastal fragmented communities

Abstract

Fragmentation is a phenomenon that produces the rupture of the continuity of a habitat. These can be in marine, aquatic or terrestrial environments. Habitats may be considered isolated patches with their particular communities. Each patch has an edge zone, edge fence and inner zone. The ecotone is found at the edges of two patches. There is a mobility of species due to the connectivity between patches, and variations of univariate descriptors, i.e. species richness and individual abundances, is expected. This study shows differences in species richness and individual abundance of the epifauna community inhabiting intertidal macroalgae. For this purpose, samples were collected in different months from the coastal locations where fragmented habitats were found. It allows us to evaluate the differences in communities that are affected by the edge effect and also by the spatial and temporal differences. As a result there is a tendency for abundance to be higher in the inner of the patch zone while species richness remains similar among the patch zones, i.e. edge, near edge and inner areas. There is also a greater difference between communities at Roque Tortuga between March and May while Rincón de los Castellanos showed greater similarity in its epifauna community. And it is observed that the patch effect is not the main impact that generates a difference between epifaunal communities. For a more precise understanding of fragmentation and the edge effect, it should be studied how it affects other substrates, in other locations or even in other marine ecosystems.