Mapping and monitoring conifer mortality using remote sensing in the Lake Tahoe Basin
- Boston Univ., MA (United States)
A prolonged drought in the western US has resulted in alarming levels of mortality in conifer forests. Satellite remote sensing holds the potential for mapping and monitoring the effects of such environmental changes over large geographic areas in a timely manner. Results from the application of a forest canopy reflectance model using multitemporal Landsat TM imagery and field measurements, indicate conifer mortality can be effectively mapped and inventoried. The test area for this project is the Lake Tahoe Basin Management Unit in the Sierra Nevada of California. The Landsat TM images are from the summers of 1988 and 1991. The Li-Strahler canopy model estimates several forest stand parameters, including tree size and canopy cover for each conifer stand, from reflectance values in satellite imagery. The difference in cover estimates between the dates forms the basis for stratifying stands into mortality classes, which are used as both themes in a map and the basis of the field sampling design. Field measurements from 61 stands collected in the summer of 1992 indicate 15% of the original timber volume in the true fir zone died between 1988 and 1992. The resulting low standard error of 11% for this estimate indicates the utility of these mortality classes for detecting areas of high mortality. Also, the patterns in the estimated mean timber volume loss for each class follow the expected trends. The results of this project are immediately useful for fire hazard management, by providing both estimates of the degree of overall mortality and maps showing its location. They also indicate current remote sensing technology may be useful for monitoring the changes in vegetation that are expected to result from climate change.
- OSTI ID:
- 6527974
- Journal Information:
- Remote Sensing of Environment; (United States), Vol. 50:3; ISSN 0034-4257
- Country of Publication:
- United States
- Language:
- English
Similar Records
Chernobyl doses. Volume 2. Conifer stress near chernobyl derived from landsat imagery. Technical report, 29 September 1987-28 February 1992
Satellite Earth observation data to identify climate and anthropogenic pressures on Bucharest periurban forests