Land management strategies and
land use within urban-suburban, agricultural and forested
landscapes can have significant impacts on local and
regional carbon, water and energy cycles, but their gross
and net effects are complex and not well understood. As a
result, a better understanding of the interactions and
feedbacks between ecological systems, human actions, and
changes in climate is needed to drive the decision making
process at local to landscape and regional scales.
We are studying the effects
of land use and land cover on carbon, water and energy
exchange with the atmosphere in current and future climates
across a gradient of urban-suburban
agricultural and forested
landscapes. The approach integrates new time-series analysis
of satellite data to discriminate land cover changes, tall
tower CO2 observations, and tower flux data and modelling of the surface-atmosphere exchange of carbon dioxide, water, and energy..
Oregon has strong gradients from
high population/high forest productivity/mesic climate in
the west to low population/low productivity/arid climate in
the east, and land use is changing to reduce GHG emissions.
The study focuses on (1) the effects of conversion of
semi-arid sagebrush to irrigated bioenergy production on
carbon, water and energy cycling, and resulting heating or
cooling effects, and (2) the effects of afforestation of
idle land and rangelands deemed suitable for forests or
poplar crops on exchanges of carbon, water and energy under
future climate conditions.
Questions are: How do current land uses and cover affect
carbon dynamics, and carbon, water and energy exchanges,
including cooling/warming effects? Given possible climate
trajectories, what land-use strategies will reduce carbon
dioxide emissions while optimizing sustainability of native
vegetation, food crops and bioenergy crops?