7#(d&&&&&&.'''' ' ' ' '>x'' ''*('&''''('=''''''.c1.Duke Forest, North Carolina; Titles of Investigations: I. Estimation of Total Aboveground Biomass in Southern United States Old-Field Pine Stand Using SIR-C/X-SAR Data II. Biomass Modeling of Pine Forests of North America with SIR-C/X-SAR for Input to Ecosystem Models Principal Investigators: I. Dr. Eric S. Kasischke Environmental Research Institute of Michigan (ERIM) II. Dr. Frank Davis University of California, Santa Barbara Site Description: The Duke Forest is located immediately west- southwest of Durham, North Carolina. There are 3400 ha within the Duke Forest, 800 of which are old-field loblolly pine stands. The ages of these pine stands range from 1 to greater than 100 years, and represent the successional stages of southern pine species. Numerous ecological studies have been performed on test stands within the Duke Forest, the earliest being in the 1930's. Thus, much of the baseline understanding of ecology of these forests already exists. The need to develop remote sensing techniques to monitor and study temperate forest ecosystems is especially compelling. The fact that such forests occupy approximately 36 percent of the earth's forested land surface should itself provide sufficient justification for such development. Add to this the fact these forests produce over 75 percent of the forest products (timber and fiber) used by human society, and the social and economic justification for understanding their status and dynamics on a regional and global scale becomes clear. In addition, temperate forests are especially important in studies of trace gas fluxes from the earth's surface. Most temperate forests have been disturbed to a lesser or greater extent over the past two centuries, and are in various stages of succession. This fact greatly affects their carbon source-sink relationships, and may contribute greatly to fluxes in carbon dioxide. Recent studies (e.g. Tans, et al., 1990) indicate that an understanding of the carbon dynamics of temperate region forests may be crucial to balancing the earth's carbon budget. Radar remote sensing studies at the Duke Forest began in earnest in 1989, when a comprehensive data set was collected by the NADC/ERIM and the NASA/JPL airborne SARs as part of a three-year study funded by NASA Headquarters. In addition, ground-truth has been collected for some 100 different forest stands to support analysis of the SAR data. Analysis of these data sets is just being completed, and the results are in the process of being published. The Duke Forest is also a test site being imaged by the ERS-1 SAR, as part of the ESA-sanctioned ERS-1 Forestry Experiment, and JERS-1 SAR, as part of a NASDA-sanctioned JERS-1 Validation Experiment. As part of these studies, a corner reflector array (6 trihedral reflectors) has been deployed in and around Duke Forest, and test sites specifically designed for these experiments are being established. These test sites will be monitored throughout 1992 and 1993. The results of these two research activities will aid in refining the experimental design for the SIR-C/X-SAR Duke Forest Experiment. Objectives: The focus of the experiments being conducted at the Duke Forest, North Carolina site is to refine our understanding of microwave scattering from forested terrains, and to develop algorithms to predict aboveground biomass of coniferous forests utilizing spaceborne SAR data. The Davis and Kasischke studies focus on development of techniques to utilize SAR data in nutrient cycling models for temperate forests in the southeastern U.S. The Kasischke study is focusing on upland forests. These ecosystems process studies will be aided by the theoretical modeling studies of forest structure and biomass being performed in the Davis study. Duke Forest, in the Piedmont region of North Carolina, will also support investigations by Kasischke in his research being conducted as part of the EOS SAR Facility Instrument Team. Specifically, the following objectives will be addressed: I. a) Validate a radar tree scattering model using scatterometer and SAR data collected over old-field loblolly pine stands. b) Determine what short-term physiological changes within loblolly pine forests result in significant changes in radar backscatter signature. c) Develop a model that predicts the total aboveground biomass as a function of multifrequency, multipolarization radar signature. d) Evaluate utility of biomass estimation algorithm utilizing SIR-C/X-SAR data set. II. a) Integrate existing forest biophysical measurements in our Mount Shasta test site with calibrated aircraft SAR for development and testing of our forest radar backscatter model in Ponderosa pine forests. b) In collaboration with Kaschiske and Christensen, integrate forest biophysical measurements from Duke Experiment Forest and calibrated SIR-C/X-SAR images for model application to loblolly pine forests. c) Apply model to identify major backscattering components from conifer forests at X-, C-, and L-band and at four polarizations. d) Develop an algorithm to retrieve forest biomass and structure from SAR images. Field Measurements: I. a) Measurement of tree height, diameter, and density for approximately 30 to 40 additional test stands. b) Measurement of ground and tree moisture and tree water potential for four stands during SIR-C/X-SAR overflights. c) Monitoring of weather conditions during SIR-C/X-SAR overflights. d) Deployment and monitoring of calibrated corner reflectors. II. a) Field data to be collected during the SIR-C/X-SAR missions will include extensive scatterometer and dielectric measurements on individual trees. These data will be incorporated into a scattering model. Crew Observations: 1) Crew Journal: Describe the weather conditions and forest canopy at the site. 2) Cameras: Hercules and Hasselblad will be used to photograph the forests at the site. Coverage Requirements: The minimum coverage requirements for this test site are four multiple look angle (4) passes, preferably from the same look direction. Anticipated Results: I. a) An understanding of what forest characteristics within a loblolly pine forest influence radar scattering at X-, C- and L-bands. b) Validation of a theoretical scattering model for the forest geometry of old-field loblolly pines. c) An evaluation of the utility of multifrequency, multipolarization for estimating aboveground biomass in old-field loblolly pine forests and other pine forests in the southeast U.S. II. a) Further our understanding of the microwave scattering mechanisms of forests with respect to radar wavelength, polarization, and incidence angle with special emphasis on estimation of above-ground biomass with respect to magnitude, patchiness, partitioning, spatial distribution, and height distribution; and b) Provide methods to quantitatively estimate biophysical parameters of forest stands from SAR images as input to a spatially-distributed ecosystem model of western pine forests.  !#;=/0 R ^ a@ABTVWXmo     %!"#=>12L 0 Q R S T ` atTUmrarar! 8F@! 8F@! ! ! ! ! ! ! ! !  ! 0@ ! 0@! ! &mnhiABVW9:ͼͼͫͫ|m_PPPB ! 88! 8 8 @ ! 88@! 8 8 @ ! 88 ! 0 ! 0! ! 8@! 8@! 8@! 8F@! 8F@WXopɺ 8@ 0 008 8 @ 0 ! 0! 0 8 @ ! 88:New York 10 point,timesCourier& ,  'Pm !" HH(FG(HH(d'@=/RBH -:LaserWriter Times(= Duke ForestSIR-C Education Karl Erickson Karl Erickson