Our Work

 

Dr. Scott Goetz (principal investigator) setting up a data logger in an aspen regrowth stand in central Alaska. 

Our current work explores how carbon sequestration rates following fire vary across the entire boreal forest region of North America on an interannual basis. In order to carry out this work it is necessary to obtain accurate measurements of carbon fluxes at fine spatial and temporal scales over large areas.

Accounting for every source and sink of carbon within the boreal ecosystem across the spatial extent necessary for this study would require an unrealistic number of field measurements. Instead, we employ a number of different approaches that emphasize the use of satellite observations of the land surface and the inference of ecological variables such as tree cover, leaf area index (LAI), the fraction of absorbed photosynthetically active radiation (FPAR), and other indices of canopy light harvesting that drive the photosynthetic process. We also use these data sets and derived maps to drive models of carbon exchange, which are subsequently validated by a suite of ground based field measurements.

An IKONOS image (4m resolution) depicting a portion of the 1999 burn.  Burned areas are darker due to their spectal characteristics.

We are currently conducting field and satellite remote sensing studies in the Delta Junction / Upper Tanana River Valley of interior Alaska, particularly in a chronosequence of fires from 1956, 1987, 1994, and 1999. The remote sensing studies use a variety of satellite systems (AVHRR, Landsat, IKONOS, and MODIS) to monitor the effects of fire. Field studies focus on estimating patterns of biomass burning during fire, as well as the influence of fire on patterns of soil moisture, temperature, and forest recovery. Measurements in the Delta region also include net CO2, water and energy fluxes using eddy covariance from towers deployed at several locations.