Successional changes in ecosystems; forest-stream interactions; population dynamics of forest stands; patterns and rates of decomposition; disturbance regimes in forest landscapes. Perennial research themes at the Andrews Forest LTER site include successional changes in forest ecosystems spanning 500 yrs; population dynamics of forest stands; forest-stream interactions; patterns and rates of decomposition; disturbance regimes in forest landscapes and watersheds; and hydrology at multiple scales. The research program has been diverse throughout the history of the Andrews Forest, with many dominant themes persisting over the years, but also with attention to current issues in science and society. Emphasis in the 1950s centered on development of road systems and harvest of old-growth forests, and assessment of their effects on watersheds. Research in the 1960's focused on effects of logging on water, sediment, and nutrient losses from small watersheds. During the International Biological Program of the 1970s, basic studies centered on the structure and function of forest and stream ecosystems, particularly in old-growth forests. In the 1980s, these basic studies continued under LTER funding and were augmented with applied research in silviculture, wildlife, landscape ecology, and other topics. The central question currently guiding the Andrews Forest LTER studies is: How do land use (mainly forestry and roads), natural disturbances (mainly fire and floods), and climate change affect three key ecosystem properties: carbon dynamics, biodiversity, and hydrology. These three ecosystem properties are of high scientific and social interest, and they represent three rather different types of ecological response to landscape patterns. The research is organized in Component Areas of traditional, disciplinary focus, such as carbon dynamics, hydrology, and disturbance, and Synthesis Areas, which integrate work over several Component Areas. The Andrews Forest program also includes a strong partnership of the research community with the land managers of the Willamette National Forest. We work together to develop and test new approaches to management of forests, watersheds, and landscapes, based on the most current science findings.