Environmental Change Research Group - University of Oregon Geography

Paleoecology Lab - University of Oregon

Research Projects

	Forest responses to climate change Species will shift their ranges in response to future climate change but the mode and tempo of such changes is largely speculative. The duration of migrational lags depends upon dispersal rates dispersal distances (existence of refugial or disjunct populations) and colonization success. We address these biogeographical questions using a retrospective approach involving statistical treatment of pollen and macrofossil data and quantitative climate reconstruction using a variety of paleoclimate proxies from lake sediments. Specific projects under this theme include: The Clearwater Refugium of northern Idaho. Was this area of disjunctions and endemism in the "inland temperate rainforest" established by long-distance dispersal from coastal populations or in situ persistence in refugia? Funding from the National Science Foundation. Fire-mediated forest compositional change in infrequent-fire ecosystems on the Olympic Peninsula, Washington State.
	Forest disturbance regimes: a long-term perspective The historical range of variability of disturbance regimes is an important baseline to guide ecosystem management and to aid studies of ecosystem dynamics and species coexistence. For forest disturbances the observational record does not adequately characterize this variability over time spans relevant to tree life cycles. Paleoecological methods provide unique long-term data for reconstructing disturbance regimes. Precedent for fire in primary dipterocarp forests and forest peatlands of West Kalimantan, Indonesia, using radiocarbon dating of soil charcoal across several habitat types. Funding by the NSF. Climate Change, Fire History and Redwood Abundance across Space and Time. Methods focus on soil-charcoal dating in Humboldt County. Funding by the Bureau of Land Management. A research-coordination-network, the Novus RCN focuses on reconstructing ecosystem processes with respect to past disturbances. Led by Kendra McLauchlan at Kansas State University. Mountain pine beetle outbreaks linked to forest governance and climate change. Co-PI on an NSF Coupled Human and Natural Systems grant. Erosion history and variability: Sediment buried in Oregon Coast Range points to a frosty past. Fire frequency and severity of the late Holocene in the Siskiyou Mountains of southwest Oregon. Other projects and collaborations: On a wet British Columbia island, historical fires likely were human products Coastal Oregon aquatic responses to late Holocene climate change. Oregon Sea Grant co-PI with David Sutherland and Josh Roering.
	Tree-ring records of forest growth and disturbance dynamics A persistent challenge to the study of growth rates of tree species is attributing causal factors to long-term growth trends. Factors affecting growth rates vary from simple mechanisms such as stand dynamics and the natural growth trends of trees to insect outbreaks soil nutrition climate and interactions of all these factors. Interactive effects of insects fire and climate on fuel loads and fire behavior in mixed conifer forest. Past funding from the Joint Fire Science Program. Detecting growth declines using novel dendroclimatic analytical approaches.