Motivation and benefits of complex systems approaches in ecology. Ecosystems 1449–1456

Studies of complex systems in other disciplines provide models and analytical strategies for under-standing ecosystems and landscapes. The emphasis is on invariant properties, particularly processes that create scaling relations over wide ranges of scale, both in time and space. Translations between levels of ecological organization may be accomplished by succinct characterizations of processes that operate at fine scales, followed by renormalization group analy-sis to reveal patterns at broad scales. The self-organized patterns found in simple ecosystem, landscape, and forest-fire models may be explained as feedback between the system state and control parameters. Critical phenomena and phase transitions are expected in open, dissipative systems where long-range correla-tions defy predictions based on average population densities, a concept that becomes irrelevant as nonsta-tionary conditions prevail. Thus, complexity theory for open systems relates to the ecology of self-entailing ecosystems that function as their own environments and thereby create constraints through emergence. Key words: complex systems; scaling; renormaliza-tion; level of organization; universality