Principal Investigator (PI):
K. Jon Ranson (GSFC) Co-P.I.:Elissa R. Levine (GSFC), Robert G. Knox (GSFC),
James A. Smith (GSFC) Co-I.: Virginia L. Kalb (GSFC), Andrew D. Friend (ITE
Edinborough), Darrel L. Williams (GSFC), John F. Weishampel (Univ. Central Florida)
The Forest Ecosystem Dynamics
(FED) Project at GSFC is concerned with modeling and monitoring ecosystem processes
and patterns in response to natural and anthropogenic effects. The project uses
coupled ecosystem models and remote sensing models and measurements to predict
and observe ecosystem change. An important consideration in the northern/boreal
forest ecosystems that we are addressing is the influence of spatial heterogeneity
on process scaling and the expression of that heterogeneity in remote sensing
imagery. The overall objective of the FED Project is to use models of forest
dynamics, soil processes and canopy energetics to understand how ecosystem response
to change affects patterns and processes in northern and boreal forests and
to assess the implications for global change. The approach is to use coupled
submodels of forest, soils, and energy processes to predict ecosystem response
in terms of forest growth (e.g., biomass, LAI, NPP attributes ) and development
(i.e., species composition change over time). There is also a significant role
in the project for remote sensing research to relate ecosystem response to observable
scene attributes.
The project presently is focused on high latitude areas including northern hardwood
and evergreen Boreal forests. These forests are susceptible to climate change,
are under increasing harvesting pressure for lumber and paper, and are widely
disturbed by wildfires. Climate change could have potentially large effects
in these areas by driving changes in forest composition and structure and soil
properties which, in turn, could alter carbon balance and albedo across the
circumpolar boreal forest. Complicating the understanding of how northern forests
would respond to change is the large variability in forest composition and structure
across the landscape. This variability is largely the result of variations from
soil properties and local topography, but also occur from wildfire and human
activities
To understand these effects, the project uses ecosystem models including gap-type forest succession models with improved species specific physiology; soil physics and snow models with moisture and temperature routines; and canopy-soil energetics models that describe the intra- and extra-canopy radiation fluxes. These models are either currently in a spatially explicit format or are being developed. To relate forest attributes to ground-based, airborne and spaceborne optical and microwave sensors we use remote sensing models including one, two and three dimensional optical, thermal and microwave scattering models. The models can be configured to operate at local to regional scales (i.e., 101 - 105 m). The combination of ecosystem and remote sensing models provide a mechanism for testing process level attributes important for regional and coarser scales models.
Unique capabilities available for the FED Project include a modeling environment designed to couple forest, soils and canopy energy dynamics models, a biogeochemical model that combines population dynamics and physiological processes for diverse species, recently developed forest growth and remote sensing models with three-dimensional structure, and extensive field and remote sensing data sets developed at Maine under the FED project and in Canada under BOREAS. These tools allow us to quantify differences between models designed for different spatial and temporal scales, as well as the effects of spatial resolution, per se.
Forest Ecosystem Dynamics--Phase II Abstract (1992-1994)