Research

Forests

Current Research

Current research at the Climate Impacts Group (CIG) on Pacific Northwest (PNW) climate and forest ecosystems includes:

Climate and Forest Ecosystems

• Direct Impacts of Climate on Forest Growth, Disturbance and Function. Stakeholders in Pacific Northwest forests are a diverse group, ranging from the timber industry to forest managers on public lands to outdoor enthusiasts. Principal concerns of these groups include potential declines in forest productivity, changing forest species composition, and loss of wilderness values and biodiversity. We are using basic research in climate-vegetation relationships to provide estimates of future changes to forests of the PNW in direct response to changing climate.
• Forest Ecosystems, Disturbance, and Climatic Change in Washington State. We addressed the role of climate in four forest ecosystem processes and project the effects of future climatic change on these processes. First of all, we analyzed how climate affects Douglas-fir growth across the region to understand potential changes in future growth. Secondly, we used existing analyses of climatic controls on future potential tree species ranges to highlight areas where species turnover may be greatest. Thirdly, we examined the relationships between climate and area burned by fire, and projected future area burned in response to changing climate. Finally, we evaluated the influence of climatic change on mountain pine beetle (MPB) outbreaks by quantifying both host-tree vulnerability and MPB adaptive seasonality.
• Climatic Mediation of Treeline in the Western U.S. At upper and lower treeline, climate variability, particularly at decadal scales, is important in structuring broad pulses of tree establishment. Bioclimatic models that incorporate both the climatic and biotic factors limiting tree establishment are likely to improve predictions of future biogeographic distributions of treeline species. This project investigates the role of climate in treeline establishment over the last century in 9 mountain ranges in the western U.S.

Climate, Fire and Forest Hydrology

• Landscape Scale Change in Forest Composition and Structure due to Climate Change, Hydrology, Wildfire, and their Interactions. Predicting how forests will look and function in the future is difficult because of the complex interactions between climate, hydrology, fire, and forest growth. We are linking state of the art models of hydrology (DHSVM) and forest landscape disturbance and succession (LANDCLIM), and projecting forest landscape change under a range of climate scenarios developed by CIG.

Climate, Disturbance Regimes and Carbon Dynamics

• Simulating the Effects of Climate-Driven Changes in Disturbance Regimes and Productivity on Net Ecosystem Carbon Balance of Forested Landscapes. The goal of this research is to develop a landscape model that can incorporate the multiple pathways through which climate change can affect net biome production of Pacific Northwest forested landscapes. The model will allow for testing of alternative disturbance regime scenarios (e.g., combinations of forest management and changing fire severity, frequency, and extent) and changes to net ecosystem productivity (NEP) that may be expected with projected changes in temperature and precipitation in the Pacific Northwest.

Related Work

Forest ecosystem research at the CIG benefits from externally funded, climate-related research projects and programs that key CIG research personnel conduct or are otherwise affiliated with, including the following:

• Climate, Air Quality, and Wildfire. In this project, we are using an ensemble modeling approach that will address the impacts and uncertainties related to the effects of global change on regional air quality in the U.S. Contact: Eric Salathé.
• Paleoreconstructions of Pacific Northwest Streamflow. Paleoclimatic streamflow reconstructions derived from proxy records (such as tree-rings) play an important role in water resources planning and management.  In Idaho, for example, an unprecedented (in the historic record) five-year drought has severely stressed existing water resources and water resources policy.  Contact: Alan Hamlet .