Synchronicity between Satellite-Measured Leaf Phenology and Rainfall Regimes in Tropical Forests
2009
Park, Sunyurp
<p><i>The seasonal and interannual cycles of the canopy phenology of Hawaiian tropical ecosystems were extracted from seven-year MODIS VI data. NDVI responded sensitively to surface greenness of dry-to-mesic ecosystems, but it showed little change as mean annual precipitation (MAP) surpassed 2,000 mm. Canopy greenness seasonality was strongest in dry areas, and its strength had an inverse relationship with MAP (r = -0.75, P < 0.0001). Study results report that the photosynthetic activity of dry biomes responded synchronously to annual rainfall patterns. As MAP increased, the enhanced vegetation index (EVI) had significant variations among wet biomes, and its canopy greenness cycles lagged behind seasonal rainfall cycles. As a result, greenness peaks of dry-to-mesic environments occurred in the wet season, whereas those of wet environments (MAP > 2,000 mm) occurred in the dry season. This result leads to a conclusion that forest productivity of perhumid environments may be limited by reduced solar hours.</i></p>
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