Integrating spatial patterns and processes in food web and environmental studies: from 'who eats whom' and 'who eats where' to 'who eats whom and where'

摘要

Recently, habitat-specific carbon sources and fluxes have emerged as keystone processes for lake ecosystems (Schindler & Scheurell 2002, Vadeboncoeur et al. 2002, Bertolo et al. 2005, Karlsson & Bystrom 2005, Vander Zanden et al. 2006). Within-lake habitat boundaries allow spatially distinct (i.e. lit-toral-benthic vs. pelagic) and often asynchronous primary producer-consumer population dynamics to occur. These constitute distinct carbon fluxes that can merge via cross-habitat foraging by mobile secondary or tertiary consumers such as fish. Cross-habitat foraging thereby decouples consumer success from local constraints of productivity and prey dynamics (Pons et al. 1997, Schindler & Scheuerell 2002), affecting trophic interactions, direction of energy flows (trophic cascades) and stability of food webs (Schindler et al. 1996, Post et al. 2000, Vadeboncoeur et al. 2005).