This book is based on the premise that the study of ecological communities should be a composite analysis of system properties (community structure, community energetics) and population properties (life history patterns, adaptive strategies) backed by a thorough understanding of the physical- chemical environment. Too frequently community ecology takes a much narrower focus. This may partly be the result of perceived antagonisms between schools of thought in ecology. Despite their rather separate origins, the multiple theoretical and methodological tools that now exist must be applied synthetically to real communities if the progress of the past two decades is to continue into the next two. This book has a case history format, which increases the opportunity for detailed analysis, although I have attempted to maintain the general per- spective of a community ecologist and to draw extensively from the literature whenever it seems profitable to do so. The case history data are for Lake Lanao, a large tropical lake. The main zooplankton data base used in the analysis is entirely original and unpublished, although the detailed support- ing data on the physical-chemical environment and the phytoplankton com- munity have been presented in numerous journal articles and are thus abstracted or used selectively to meet the needs of zooplankton community analysis.