Summary Results from:
Authors: A.R. Huete, N. Restrepo-Coupe, P. Ratana, K. Didan, S.R. Saleska, K. Ichii, S. Panuthai, M. Gamog
Source: Agricultural and Forest Meteorology,148, (2008) 748-760
Link to: Access Publication
Abstract:
In this study, we investigated the seasonal patterns and relationships of local site tower flux measures of gross primary productivity (GPP) with independent Moderate Resolution Imaging Spectroradiometer (MODIS) satellite greenness measures across three Monsoon Asia tropical forest types, encompassing drought-deciduous, dry evergreen, and humid evergreen secondary tropical forests. In contrast to neotropical forests, the tropical forests of Monsoon Asia are more extensively degraded and heterogeneous due to intense land use pressures, and therefore, may exhibit unique seasonal patterns of ecosystem fluxes that are more likely water-limited and drought-susceptible.
Our results show significant phenologic variability and response to moisture and light controls across the three tropical forest sites and at the regional scale. The drier tropical forests were primarily water-limited, while the wet evergreen secondary forest showed a slight positive trend with light availability. Satellite EVI greenness observations were generally synchronized and linearly related with seasonal and inter-annual tower flux GPP measurements at the multiple sites and provided better opportunities for tower extension of carbon fluxes than other satellite products, such as the MODIS GPP product. Satellite EVI-derived GPP images revealed strong seasonal variations in photosynthetic activity throughout the Monsoon Asia tropical region.