Structure and dynamics of food webs in Andean Lakes

MODENUTTI, BE; BALSEIRO, EG; QUEIMALIÑOS, CP; AÑÓN SUÁREZ, DA; DIEGUEZ, MC; ALBARIÑO, RJ

LAKES & RESERVOIRS RESEARCH AND MANAGEMENT

Blackwell Publishing

Lugar: Oxford; Año: 1998 vol. 3 p. 179 - 186

1320-5331

Food webs from oligotrophic Andean lakes of Bariloche region (41°S) are studied pointing out their peculiarities in comparison with North Hemisphere studies. The endemic species composition, the extended euphotic zone and the oxygenated bottom allow a particular structure of pelagic and benthic food web. Experimental work with pelagic communities indicates that the models based only on zooplankton body size are questionable and also that nutrient enrichment does not necessarily conduct to a positive effect on herbivorous populations. Invertebrate predation effects depend on the lake and on the type of predator, while vertebrate predation does control crustacean populations. The characteristic low species richness of top predators is likely to change through the introduction of exotic salmonids. Benthic food web is quite particular with slow decaying organic matter rate and easily altered by the introduction of exotic tree species.