Wind River Experimental Forest

The Wind River Experimental Forest (WREF) contains one of the few remaining old-growth forests left in the Pacific Northwest. The canopy tower operates under a special use permit with the Gifford Pinchot National Forest, the U.S. Forest Service Pacific Northwest Research Station, and the University of Washington.

SEFS has been a long-time research partner at WREF, working together on canopy tower operations and other projects. The canopy tower is located in south-central Washington on the Thornton Taft Munger Research Natural Area (RNA), adjacent to WREF and the Gifford Pinchot National Forest. RNAs are part of a national network of ecological areas designated in perpetuity to maintain biological diversity on National Forest System lands, and the canopy tower is used to perform long-term monitoring of key ecosystem processes and climate variables, to develop new monitoring capabilities in cooperation with the Forest Service and other institutions, and to promote new research and outreach activities.

Dr. Jerry Franklin, professor

Research at WREF

Below is a sampling of ongoing projects at the canopy tower. For more information on these and other projects at WREF, contact Ken Bible.

Forest Dynamics Plot installed in 1994 to characterize the old-growth forest within which the canopy crane is sited. Originally 4-ha in size, the forest plot has been expanded twice and is now 25.6 ha (800 x 320 m) and part of the Smithsonian Center for Tropical Forest Science global network of over 40 forest plots established to better understand forest change, particularly the changing rates, causes, consequences and climate correlates of tree mortality. Important sub-populations (for example, large-diameter trees) are relatively rare, so studying them requires very large numbers of trees, and understanding tree mortality requires a knowledge of each tree's local neighborhood.

Microclimate Dataset 1998 to present, using instrumentation on the canopy tower and the forest floor to provide site microclimate data in a standard format essential to most environmental studies (e.g., precipitation, air temperature, wind, relative humidity, solar radiation). Although there have been different methods of data collected over the years from various research projects, sensor packages are now owned and operated for long-term monitoring. Data are processed in-house and made available via controlled Internet portals and other distributed network data centers.

The Forest Service Climate Tower Network installed a node on the canopy tower in 2011 as part of their network to perform intensive climate and carbon cycle research at more than a dozen sites across the United States where ecological and meteorological measurements are taken from towers extending above the forest canopy. This program enhances capabilities for addressing key carbon cycle uncertainties including improved accuracy, precision, stability and redundancy in air temperature measurements; improved accuracy in precipitation (especially frozen) measurement; improved accuracy and precision of carbon dioxide carbon stable isotope ration analysis.

AmeriFlux, 1998 to present, operates and maintains instrumentation on the canopy tower for measurement of carbon dioxide exchange between the forest and the atmosphere using the eddy covariance method. Data are used to interpret the seasonal and multi-year patterns in net ecosystem productivity, which is the difference between carbon fixed through photosynthesis and released via respiration. Data are processed in-house and uploaded to the AmeriFlux network, which covers carbon dioxide flux data collected in North and South America, and to the Fluxnet program, a world-wide consortium of eddy covariance sites. AmeriFlux/Fluxnet data teams further process data into a suite of standardized data products for final distribution.

Chun-Ta Lai, San Diego State University, installed in 2010 a water vapor isotope laser at the canopy tower to improve understanding of water isotope fractionation in atmospheric vapor and its source. This research project aims to establish a premium water isotope research station with high quality, frequent and uninterrupted atmospheric vapor isotope measurements to investigate vapor isotope fractionation and its applications on ecosystem-atmosphere water and carbon dioxide exchange. Research builds upon current understanding of water vapor isotopic fractionation under the influence of vegetation-atmosphere interaction. This project will evaluate a number of critical assumptions in hydrospheric isotope models, identify key fractionation processes, and develop mechanistic algorithms to address caveats that mask the potential of hydrogen and oxygen isotope tracers in hydrological and carbon cycle research.

Chris Still, Oregon State University, installed in 2014 a FIR thermal imagery camera next to the above-canopy phenocam on the canopy tower. Temperature is a primary environmental control on biological systems and processes at a range of spatial and temporal scales. Its influence is fundamental, ranging from controls on enzymatic reactions to ecosystem biogeochemistry to large-scale species distributions. Temperature is also an essential characteristic of climate. Indeed, much of the concern about the impact of climate warming on the biosphere is motivated by the pervasive influence of temperature on organisms. Although scientists often focus on air temperature, the radiative or skin temperature of an organism such as a plant is actually more relevant in many cases. However, until now direct measurements of organismal temperature from thermal imaging have been challenging due to sensor and computational limitations. This project will also support numerous applied research questions, and has wide implications for the biological response of ecosystems in a warming world. Particular focus will be on diagnosing the thermal responses of forests to drought, heat waves, freezing, and wind chill. Our work will provide fundamental knowledge about the thermal regime experienced by the forest canopy, and help us better understand connections between organismal temperature and biological processes like flowering, photosynthesis, respiration and transpiration.

PhenoCam is a network of high-resolution digital cameras used for reducing uncertainties about the role of terrestrial ecosystems in the global carbon cycle requires better understanding of phenological events such as spring leaf emergence and autumn senescence which exert strong control on forest ecosystem. Phenology has been shown to be a robust integrator of the effects of year-to-year climate variability and long-term climate change on natural systems (e.g., recent warming trends).

Wind River Experimental Forest has been chosen as the candidate core site for NEON’s Domain 16 with the canopy tower designated as the advanced tower in NEON’s fundamental instrument package. Within the Wind River Experimental Forest, several sites have been identified for NEONs fundamental sentinel package, aquatic array and biodiversity plot system.