Long-Term Ecological Research at the H.J. Andrews Experimental Forest (LTER5)

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Harmon0218088The Andrews LTER program seeks to understand the long-term dynamics of forest and riverecosystems of the Pacific Northwest. The Central Question guiding Andrews LTER research is:How do land use, natural disturbances, and climate change affect three key sets ofecosystem services: carbon and nutrient dynamics, biodiversity, and hydrology? Theseecosystem services represent scientifically and socially important, tractable variables, and theirresponses are posited to represent different classes of ecosystem behavior at the landscape scale.Climate, land use, and natural disturbances are the major drivers of change in the PacificNorthwest region. The approach used to address this question will be multi-faceted involvingretrospective analysis, time series observations, experiments, and use of simulation models forsynthesis, extrapolation in time, and interpolation in space. The principal spatial scale ofinference for LTER studies is the Andrews Forest and adjacent upper Blue River watershed, anarea of 16,000 ha. Work associated with the LTER will be coordinated with studies aimed atregional questions. The principal temporal extent of proposed LTER studies spans the past 500yr and to several centuries projected into the future. This proposal represents the strategic plan ofactivities designed to advance science for individual disciplines, integration, and cross-sitecomparisons. Thus, the Andrews LTER is used as the core of a larger set of integrated studies.Essential long-term studies will be continued and others added to increase spatial andtemporal overlap of scales. The standard 5 LTER core activities will be addressed by work inseven component areas: (1) climate, (2) hydrology, (3) disturbance, (4) ecophysiology,(5) carbon and nutrient dynamics, (6) biodiversity, and (7) stream-forest interactions. In thisgrant cycle, studies continue to examine the interaction of the drivers of change and respondingprocesses and taxa, but the conceptual emphasis will be on temporal behavior, its causes, andits consequences for ecosystem change. We will examine temporal behavior over time scales ofdays to hundreds of years focusing on: (1) modulation, (2) temporal lags, (3) spatial coherence,(4) path dependence, (5) hysteresis, and (6) alternative stable states. Exploring these aspects oftemporal behavior help to address the Central Question by quantifying natural temporalvariability and providing insights into mechanisms that control processes. A major goal will beto test predictive rules (i.e., hypotheses) regulating temporal behaviors. Another focus ofsynthesis will be small watersheds, an important landscape unit providing opportunity forintegration of climatic, ecosystem, and hydrological processes as well as knowledge of temporaland spatial scaling. The ultimate goal in this integration is to create a spatially 3-dimensional(including subsurface and air flow) understanding of the temporal dynamics of the 3 states ofmatter involved in biogeochemical and hydrologic cycles within a watershed. Past experiments,long term records of climate, stream flow, nutrient exports, and vegetation change, as well asmodeling will enhance this integration effort. By understanding this key landscape unit, futurebroader-scale efforts will be strengthened.Andrews science and scientists continue to advance understanding and management offorests and streams of the Pacific Northwest through communication with students, teachers,policy makers, land managers, and the general public. Information management, an essentialactivity for both research and education, emphasizes ease of use, increased accessibility, andportability of many forms of information.