El rol de los macroinvertebrados acuáticos en la descomposición de hojarasca en ríos altoandinos tropicales
Year: 2012
Type: dissertation
Abstract: High-altitude tropical streams have very low water temperature throughout the year; \ntherefore, decomposition rates of decaying organic matter are expected to be slow. Moreover, \nin general, shredders have been reported to be scarce in high-altitude tropical streams.The \nobjective of this study was to examine the relative importance of macroinvertebrates in litter \nprocessing in two types of high-altitude páramo streams. A decomposition experiment was \nconducted in three streams running through mix shrub-land páramo and Polylepis forest, all \nbetween 3700-3900 masl. In each stream, leaf decomposition of three plant species of \ndifferent foliar quality was determined: Alnus acuminata (Betulaceae), Gynoxis \nspp.(Asteraceae) and Baccharis latifolia(Asteraceae), using coarse mesh bags (10 mm) during \na period of 63 days. These bags allowed access of invertebrates to the leaves. Percentage of \nmass loss was significantly higher in Polylepis forest than in mix shrub-land, higher for \nB.latifolia than forGynoxis spp. than forA. acuminata.Relative abundance of shredders in \nPolylepis forest streams (22%) was higher than in mix shrub-land streams (17%), although not \nsignificant differences were found. The results suggest that decomposition rates in tropical \nhigh-altitude streams are between intermediate and fast, compared to similar studies in tropical \nlow-altitude and temperate zones. Moreover, these findings show that paramo streams with \ndifferent type of riverside vegetation have different decomposition rates of organic matter. \nStreams the go through Polylepis forest decompose fast litter coming from the vegetation, and \nthis highlights the importance of vegetation type, leaf quality, and streams intrinsic qualities, \nin this key ecosystemic process. This processing can be explained because of the variation of \nthe aquatic invertebrate community composition between the two types of paramo, since \nPolylepis forest streams had more diversity and dominance of invertebrate shredders. This \nstudy highlights the value of investigating ecological processes in poorly-known ecosystems \nsuch as the paramo, and its relation with the structure and composition of lotic communities.
Authors: Pontón Cevallos, José Fernando
Language: Spanish
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDG: Life on land
Open Access status: green
OpenAlex ID: W2290705428