Remote Sensing of Forest Regeneration in Highland Tropical Forests

Abstract

Extensive post-agriculture forest regeneration has been observed in Celaque National Park (CNP), Honduras. Landsat TM images were useful in classifying these highland tropical forests into four regeneration stages and one degraded class. Regeneration stages were best separated in a plot of Landsat bands TM5 and TM4. TM5 had the best correlation with regeneration stage followed by TM2. NDVI could not discriminate forests past the early regrowth stage due to the rapid saturation of the index. A clear successional path was observed in the Tasseled Cap feature space. Forest development was characterized by a continuous decrease in Brightness, a continuous increase in Wetness, and a rapid initial increase in Greenness followed by a gradual decrease. Regenerating forests followed spectral paths more similar to lowland tropical than to temperate forests. Early rapid increases in NIR reflectance and the Tasseled Cap Greenness index were in line with those of tropical lowland rainforests and unlike those found in temperate forests. Temperate oldgrowth forests may exhibit higher levels of Greenness and lower levels of Wetness than equivalent highland tropical forests due to the effects of canopy opening and senescence that tend to occur in aging temperate forests. Highland tropical forests are expected to regenerate more slowly than lowland tropical forests but this was not the case in CNP.