Percentage canopy cover - using Landsat imagery to delineate habitat for Myanmar's endangered Eld's deer (Cervus eldi)

摘要

Percentage canopy cover data derived from Landsat Enhanced Thematic Mapper (ETM+) sensor data, validated with field measurements, provide a useful tool for delineating Myanmar's Eld's deer (Cervus eldi) habitat. The current extent and condition of remaining Eld's deer habitat is unknown, but the species prefers dry dipterocarp forest. This habitat type has widely varying canopy cover and cannot be accurately delineated with traditional remote sensing techniques. New maps based on estimates of percentage canopy cover represent the variability of dry dipterocarp forests more accurately than maps of strict classes of habitat. Over 500 field measurements of canopy cover were used to train Landsat ETM+ data that were analysed with regression-tree analysis. The resulting satellite-based estimates of canopy cover were compared with an independent set of field validation points (r= 0.539, P < 0.001, n = 114). The satellite-based estimates also showed potential for predicting the presence of Eld's deer (r =0.636, P < 0.01, n= 14). The results from the predictive maps are in accordance with previous field studies demonstrating the species' preference for dense, dry dipterocarp forest. Patterns of percentage tree-canopy cover across the study area were negatively correlated with human population density (r= —0.307, P < 0.001, n = 223), suggesting potential further threats to Eld's deer populations if the human population continues to grow.