El papel funcional de las larvas de anfibios en los ecosistemas acuáticos temporales

Programa de Doctorado en Estudios Medioambientales ; The structure and dynamics of ecological communities is determined and regulated by several key processes that influence in the species distribution and abundance (e.g., selection, drift, speciation, and dispersal), and by ecological interactions as competition and predation. The relative importance of competition and predation will depend largely on the local assemblage of species, the type of predators, or the degree of niche segregation. Amphibians constitute an ideal system to address these questions, as they are key species in the trophic webs with a profound role in several ecological processes. Moreover, the effect of amphibian larvae in the aquatic systems and their trophic niche largely depend on their complex ecological interactions with competitors and predators, as they respond to them altering their morphology and behavior. As amphibians continue showing generalized dramatic and global population declines, it is essential to fully characterize the functional role of amphibians in the natural systems to understand the possible consequences of their local declines and extinction. The main objective of this thesis is to know the regulatory potential of amphibian larvae according to the environmental conditions, focusing on the research about their role over other trophic levels, and their interactions with the aquatic vegetation, comparing their effects in Mediterranean and Neotropical systems. By means of experiments with mesocosms, which simulate the environmental conditions in controlled conditions, I evaluated the effect of a guild of amphibian larvae from Doñana National Park on several biological and physicochemical parameters of the system. We detected an important effect of amphibian larvae on these parameters, mostly when at high larval density, causing a marked reduction of plants biomass, increasing water turbidity and several nutrients like the ammonia. Amphibian larvae also affected algae abundance, indirectly inferred by estimating ...