In the sixth funding cycle of Long-Term Ecological Research at the H.J. Andrews Experimental Forest (LTER6) we focused on the ways that topographic complexity in our mountainous forested ecosystem influenced interactions between factors that drive ecosystem change (e.g., land use, natural disturbances, and climatic variations) and how ecosystems respond (e.g., carbon and nutrient dynamics, biodiversity, and hydrology). In this funding cycle we maintained and used the continuity of our long-term experiments and measurement programs, some of which have been in place for more than 50 years, to help us understand these interactions over time. 

During the past six years we have made discoveries that have enhanced our understanding of this ecosystem and have important implications for its management.  Specifically, we found that flows of air and water are episodically coupled to, and decoupled from, larger regional weather patterns. We also discovered that ecosystem processes and biodiversity in upper elevations, which were expected to be most sensitive to climate change, were mitigated by interactions between topography and atmospheric dynamics, in turn limiting simple generalizations about elevational effects. We found that tree mortality in mature and old-growth forests is increasing, possibly as a result of climate change, but the mechanisms causing this increased mortality are currently not well understood. Our examination of biological timing (phenology) revealed that the emergence of leaves and insects varied by >40 days between years and also from low to high elevation within a given year; and that birds seek habitats with low temperature variability. We discovered that recent policy and land-use changes might correspond with decreases in biodiversity associated with meadows and early successional habitats. We found that disturbance and land-use history have a lasting imprint on carbon and hydrology that may be currently overriding climate change and topographic controls. And finally we discovered that social forces have limited use of “ecologically-based” forest practices – indicating that a decision point for determining the future of forestry on federal lands may be imminent, in turn setting the stage for new applications of Andrews Forest ecological and social science.

We engaged in a variety of broader impacts efforts: including training and development of scientists and scientific knowledge of citizens on multiple levels, including K-12 teachers and students, undergraduate students, graduate students and early-career researchers; encouraging multidisciplinary, collaborative research; forging stronger alliances between biophysical scientists and social scientists; actively disseminating scientific knowledge through strong science/management partnerships and contribution to adaptive management strategies; fostering many science/humanities connections; and enhancing our cyberinfrastructure at the Andrews Forest and our own contribution to innovations in cyberinfrastructure.

Last Modified: 12/15/2015
Modified by: Michael P Nelson