The long and short of food-chain length

• Published in: Trends in Ecology & Evolution 2002-06, Vol.17 (6), p.269-277
• Main Author: Post, David M.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; community organization; disturbance; ecosystem size; energy flow; food-chain length; Fundamental and applied biological sciences. Psychology; General aspects; interaction strength; resource availability; Synecology
• ISSN: 0169-5347; 1872-8383
• DOI: 10.1016/S0169-5347(02)02455-2

Food-chain length is a central characteristic of ecological communities that has attracted considerable attention for over 75 years because it strongly affects community structure, ecosystem processes and contaminant concentrations. Conventional wisdom holds that either resource availability or dynamical stability limit food-chain length; however, new studies and new techniques challenge the conventional wisdom and broaden the discourse on food-chain length. Recent results suggest that resource availability limits food-chain length only in systems with very low resource availability, and call into question the theoretical basis for dynamical stability as a determinant of food-chain length. Evidence currently points towards a complex and contingent framework of interacting constraints that includes the history of community organization, resource availability, the type of predator–prey interactions, disturbance and ecosystem size. Within this framework, the debate has shifted from a search for singular explanations to a search for when and where different constraints operate to determine food-chain length. What determines food-chain length? New studies and new techniques suggest a complex and contingent framework of interacting constraints that includes the history of community organization, resource availability, predator-prey interactions, disturbance, and ecosystem size