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  LTER Program

Overview of the Andrews Forest Program.

The Andrews Forest Program includes a wide range of research, education and outreach activities, all are connected to the H.J. Andrews Experimental Forest, although not all of them take place on the site itself. The site is supported as a partnership between the Willamette National Forest, the PNW Research Station, and Oregon State University. Support for research, education and outreach programs comes from a wide variety of sources that are constantly evolving as opportunities and the interests of participating researchers change.

The largest source of research support is from the National Science Foundation (NSF) for the Andrews Forest LTER program. (Note: the abbreviation "HJA" is used to refer to the H.J. Andrews Experimental Forest) and "AND" is the designation for the Andrews LTER program), The H.J. Andrews Experimental Forest is one of 25 LTER sites. We are currently in the seventh, six-year funding cycle of the AND LTER, and we use the term "LTER7" to refer to the current funding cycle.

The LTER7 Central Question and conceptual development of the Andrews LTER research program.

The Andrews LTER7 Central Question, " How do climate, natural disturbance, and land use as controlled by forest governance interact with biodiversity, hydrology, and carbon and nutrient dynamics?" had its foundation developed in LTER3 (our third funding cycle). At the time we knew that addressing this question would require decades of supporting measurements, experimentation, and conceptual advances as well as integration and synthesis across disciplinary boundaries. This question serves more as common framework for our long-term studies than as a specific, achievable goal. In each funding cycle we have focused on different themes and specific hypotheses that help us explore critical dimensions of the Central Question.

Long-Term Research Categories
Andrews Related Research
Cross-Site Research
Regional Research
International Research/ILTER
LTER Grants and Reports

Evolution of Andrews LTER research themes

In pursuit of the Central Question we have focused on a process-based understanding of landscape dynamics (LTER3); effects of early succession on ecosystem dynamics and impact of species attributes on ecosystem dynamics (LTER4); and small watershed behavior and temporal behaviors (LTER5). Work under the integrated themes has improved our understanding of the system's behavior. During LTER5 we made significant progress in understanding how our system's climate is influenced by topography and how this introduces asynchrony across our forested landscape, phenomena. We also gained insights into the complexities of interacting biogeochemical cycling in small watersheds in small W\watersheds. These findings and insights inspired a focus in LTER6 on the roles of topography on all interactions between drivers and responders, including feedback responses, and stimulated an interest in how the highly diverse topography of the HJA may influence ecosystem responses to potential climate change. In LTER7 we re-examine our guiding central question and conceptual framework using the lens of “connectivity,” focusing on how intermittent, spatially variable flows of air, water, nutrients, organisms, and information may mitigate or accentuate the expression of regional and global climate change and land-use in mountain ecosystems.

Goals, Hypotheses and Objectives of LTER7

The conceptual organization of LTER7 highlights three complementary goals. The complex terrain and dense canopy cover of our site profoundly influence biodiversity, ecosystem processes and services, and their likely responses to climate variability and change. Therefore, in Goal I we aim to understand the patterns, driving processes, and dynamics of atmospheric and hydrologic connectivity in mountainous ecosystems. For Goal II, we aim to understand the consequences of the patterns, driving processes, and dynamics of biophysical connectivity for ecosystem processes and biotic communities and in Goal III we are expanding our inquiry to consider the Andrews Forest as a coupled natural/human-based system. It is important to acknowledge that we knew in advance that the LTER core budget allocations from NSF would be insufficient to accomplish these goals. In all cases we rely on researchers to leverage LTER funds to both accomplish and expand the core goals. For Goal III, we will begin to examine connections between forest governance and landscape pattern and process, and the ways in which public perceptions and valuations of federal forest landscapes and LTER science influence those connections.