Phase II :Nationwide Maps
This objective centers on producing national maps (spatially explicit, wall‐to‐wall estimates) of forest disturbance using the NAFD results as training, and key "predictor" variables as input. Exploration of the relationship between forest disturbance rates (observed on NAFD products) and nationally available surrogates for potential drivers of this disturbance using Random Forests are being conducted at several spatial scales ranging from 0.5 to 50 km, and at 2 and 6 year time intervals.
The potential drivers of disturbance include: 1) the North America Decadal LEDAPS maps, current forest type and abundance as represented by MODIS‐based aboveground live tree biomass, forest probability and forest type maps, ownership and demographic information. Ancillary data used to assist the modeling effort include other LTSS being constructed by the Monitoring Trends in Burn Severity (MTBS) project, as well as data generated by other efforts. In addition, biennial extractions from the MODIS reflectance product MCD43A4 are also being investigated as a surrogate for current disturbance to enhance the models’ predictive performance. The strongest of these models will be used to map forest disturbance rates over the conterminous US for the 2000‐2006 timeframe.