Are large complex ecosystems more unstable? A theoretical reassessment with predator switching

Multi-species Lotka-Volterra models exhibit greater instability with an inc rease in diversity and/or connectance. These model systems, however, lack t he likely behavior that a predator will prey more heavily on some species i f other prey species decline in relative abundance. We find that stability does not depend on diversity and/or connectance in multi-species Lotka-Volt erra models with this 'predator switching'. This conclusion is more consist ent with several empirical observations than the classic conclusion, sugges ting that large complex ecosystems in nature may be more stable than previo usly supposed. (C) 2000 Elsevier Science Inc. All rights reserved.