Composición y aspectos funcionales de los macroinvertebrados acuáticos presentes en una microcuenca de cabecera en los Andes de Risaralda, Colombia

The aquatic macroinvertebrates present in this ecosystem play a critical ecological role, allowing for the understanding of energy and nutrient flow dynamics, as well as trophic relationships. However, few studies have focused on the structure and composition of aquatic macroinvertebrates in Andean headwaters streams. From 2012 to 2016, surveys were conducted twice a year in seven sampling reaches along the Dalí Creek, evaluating the fluvial habitat index and sampling its dominant microhabitats for aquatic macroinvertebrates. A total of 34,144 organisms were collected, grouped into 147 taxa, and classified into six functional groups. The collector and litter fragmenter groups were the most abundant, with the rocky substrate being the microhabitat with the highest diversity. The results showed significant differences in taxa richness between microhabitats, with a positive correlation between taxa richness and the fluvial habitat index of the sampled reaches. This suggests that even in headwaters, the heterogeneity of the reaches and microhabitats determines the composition and abundance of aquatic macroinvertebrates. The study highlights the importance of understanding the relationships between physical and biological processes in aquatic ecosystems, particularly in headwaters streams. The findings of this study contribute to the knowledge of the ecological dynamics of Andean rivers and the processes occurring between terrestrial and aquatic systems. The microcuenca Dalí is a unique ecosystem, characterized by a high degree of heterogeneity in its bio-physical conditions and biodiversity. The presence of material allochthonous, microhabitat heterogeneity, and vegetation cover influence the community of aquatic macroinvertebrates, either positively or negatively. The study's results confirm that the microcuenca Dalí presents the typical pattern of headwaters streams, with environments that are highly heterogeneous and dynamic. The research conducted in this study contributes to the understanding of the ecological dynamics of Andean rivers and the processes occurring between terrestrial and aquatic systems. The findings of this study have implications for the conservation and management of aquatic ecosystems in the Andes, highlighting the importance of preserving the natural heterogeneity of these ecosystems. The study's results also have implications for the understanding of the relationships between physical and biological processes in aquatic ecosystems. The findings suggest that the heterogeneity of the reaches and microhabitats determines the composition and abundance of aquatic macroinvertebrates, even in headwaters streams. This knowledge can be used to inform conservation and management efforts, as well as to improve our understanding of the ecological dynamics of Andean rivers.