Efectos de las características de la hojarasca sobre la diversidad alfa y beta de ensambles de invertebrados en una cuenca hidrográfica tropical

The aims of this study were to: a) investigate the importance of environmental and/or spatial factors on the composition of the invertebrate community, and b) examine the alpha (α) and beta (β) diversities of the invertebrate community associated to the leaf breakdown process at three different spatial scales (stream reach, stream order and sub-basin). The abiotic variables and colonization of invertebrate community in two detritus ( Eucalyptus cloeziana and Inga laurina ) were evaluated in 14 sampling sites. For both detritus types, the communities were influenced by environmental matrix. High invertebrate α diversity was related to an increase in water flow velocity (outflow) and orthophosphate levels. High canopy openness and, consequently, high temperatures, showed negative effects on invertebrate α diversity. The α diversity in high-quality litter ( E. cloeziana ) was mainly influenced by stream order, while β diversity was mainly influenced by sub-basins. However, in low-quality litter ( I. laurina ), α diversity was mainly influenced by sub-basins, and the β diversity by sampling sites. These findings indicated that changes in detritus quality of the riparian vegetation resulted in significant changes of invertebrate α and β diversity in these communities.