INIBIOMA   20415
INSTITUTO DE INVESTIGACIONES EN BIODIVERSIDAD Y MEDIOAMBIENTE
Unidad Ejecutora - UE
artículos
Título:
Top predator fish assemblages in Northern Patagonia, Argentina. What factors regulate their patterns of distribution and abundance?
Autor/es:
LALLEMENT M. E; RECHENCQ M; SOSNOVSKY A; MACCHI P.J; LALLEMENT M. E; RECHENCQ M; SOSNOVSKY A; MACCHI P.J; FERNANDEZ MA; VIGLIANO P.H; FERNANDEZ MA; VIGLIANO P.H
Revista:
AUSTRAL ECOLOGY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2018
ISSN:
1442-9985
Resumen:
The biogeography of fish has been reorganized drastically and repeatedly worldwide.According to assemblages theory, there are three factors that regulate it; restriction of dispersion, environmental restrictions and biotic interactions. The first two factors act at regional scale and delimit the action area of the third, which acts at a local level. Salmonid introductions started in Patagonia in 1904, and since then it has restructured trophic webs and increased the number of top predators. This situation allowed us to evaluate in a natural setting how communities at different geographic scales are formed. We studied two large basins in Patagonia, close to each other and with different assemblages of top predatory fish. We hypothesized that differences in the structuring of the top predator assemblages between and within the basins is due to 1) environmental factors and dispersion processes facilitated by connectivity at a regional scale; and 2) biotic interaction (internal dynamic) between the native perch and salmonids, the former acting as a modulator of the top predator assemblages at the local scale. To test these hypotheses we analyzed top predator assemblages of 16 lakes and 1 reservoir, as well as their environmental characteristics. We performed a cluster analysis related the resulting assembly groups with environmental factors in a tree model and analyzed diets using a similarities test to study biotic interactions. At the regional and local scale water basin, connectivity degree, area, temperature and Zoogeographic integrity coefficient (ZIC) were important factors in the structuring of top predator assemblages. At the local scale creole perch modulates the salmonid populations through feeding and the ensuing distribution of resources. Our work showed that the structure of the top predator assemblages was due to a combination of local and regional factors that act in a synergic way as postulated by the assemblage theory togive the current top predator assemblages.