INFLUENCE OF PRODUCTIVITY ON THE STABILITY OF REAL AND MODEL-ECOSYSTEMS

The lengths of food chains within ecosystems have been thought to be l imited either by the productivity of the ecosystem or by the resilienc e of that ecosystem after perturbation. Models based on ecological ene rgetics that follow the form of Lotka-Volterra equations and equations that include material (detritus) recycling show that productivity and resilience are inextricably interrelated. The models were initialized with data from 5- to 10-year studies of actual soil food webs. Estima tes indicate that most ecological production worldwide is from ecosyst ems that are themselves sufficiently productive to recover from minor perturbations.