Remote sensing of forest decline and Enaphalodes rufulus outbreak in the Arkansas Ozarks, U.S.A.

摘要

A widespread oak decline event was reported in the Arkansas Ozarks during the late 1990's. Ground-based monitoring attempts have been successful at recording the progression of this event, but are extremely laborious and as a result are only possible in a few locations. Remote sensing technologies offer the ability to substantially decrease labor and time required to collect large-scale forest biophysical data. Remote sensors allow continuous samples to be acquired across large tracts of land that would only be represented by a few widely spaced sampling points in traditional terrestrial sampling schemes. Remotely sensed data from large study areas can be acquired in minutes or hours, which greatly reduces cost compared to long-term field sampling activities. Additionally, changes of biophysical variables ongoing during long-term data collection can be avoided. Sampling bias caused by multiple individuals collecting field data is also reduced.;Geographically-referenced digital remote sensor data from the Arkansas Ozarks have been acquired using two fundamentally different remote sensor systems: a hand held spectroradiometer, and aerial LIDAR (Light Detection and Ranging). Spectroradiometer data were used to identify the spectral signatures of northern red oak decline, and methods for applying this information to aerial imagery were described. LIDAR data were used to estimate total aboveground biomass. Biomass estimates will allow subsequent remote sensing and hazard modeling to estimate quantifiable changes in biomass at the landscape level.