Quantifying coconut palm extent on Pacific islands using spectral and textural analysis of very high resolution imagery
Burnett, M.W., T. D. White, D. J. McCauley, G. A. De Leo, and F. Micheli
Native forests on islands throughout the global tropics face increasing pressure from the human-driven expansion of coconut palm (Cocos nucifera) planted for the purposes of coconut oil harvest. Conversion from native forests to Cocos monocultures leads to drastic ecological consequences in island environments and alters terrestrial and marine food webs through a variety of cascading effects and feedbacks. Despite the ecological significance and geographic range of Cocos expansion, large-scale assessments of coconut proliferation are still lacking due to the isolated nature of many islands where Cocos is found.
This case study evaluates the effectiveness of applying grey-level co-occurrence matrix (GLCM) textural features to very high resolution (0.5–2 m) WorldView-2 imagery to resolve the canopy heterogeneity problem and map the extent of Cocos spread on 21 islets of Palmyra Atoll, a protected United States National Wildlife Refuge in the Northern Line Islands.
Their findings demonstrate the effectiveness of a joint high-resolution textural and spectral approach for remotely quantifying the spread of Cocos and its impacts on native tree communities throughout the tropics, including remote island locations.