This course combines lectures with field and indoor laboratory exercises to explore factors that determine the distribution and abundance of plants and animals in natural systems. The course begins with an overall view of global patterns and then builds from the population to the ecosystem level. An emphasis is given to basic ecological principles and relates them to current environmental issues. Selected topics include population dynamics (competition, predation, mutalism); community interactions (succession, food chains and diversity) and ecosystem function (biogeochemical cycles, energy flow). Format: lecture/laboratory, six hours a week. Evaluation will be based on problem sets, lab reports, hour exams, and a final exam. Prerequisites: Biology 101 and 102, or Environmental Studies 101 or 102, or permission of the instructor. No enrollment limit (expected: 35). This is a quantitative/formal reasoning course. Required course in the Environmental Studies Program. Satisfies distribution requirement in major.