Phenology and Seasonal Ecosystem Productivity in an Amazonian Floodplain Forest

Remote Sensing

Thiago S. F. Silva¹  Humberto R. Da Rocha²  Letícia D. M. Fonseca³  Iane B. Tavares³  Laura S. Borma³  Yadvinder Malhi⁴  Sami W. Rifai⁴  Gabriel B. Costa⁵  Ricardo Dalagnol⁶ 

[1] Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, FK94LA, UK;Department of Atmospheric Sciences - IAG, University of São Paulo, SP 05508-090, Brazil;Earth System Science, National Institute for Space Research - INPE, São José dos Campos, SP 12227-010, Brazil;Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, OX13QY, UK;Federal University of Western Para, Santarém, PA 68040-260, Brazil;Remote Sensing Division - INPE, São José dos Campos, SP 12227-010, Brazil;

关键词: tropical wetlands;    floodplain phenology;    eddy covariance;    GPP;    MODIS;    MAIAC;    seasonality;   

DOI  :  10.3390/rs11131530

来源: DOAJ

【 摘 要 】

Several studies have explored the linkages between phenology and ecosystem productivity across the Amazon basin. However, few studies have focused on flooded forests, which correspond to c.a. 14% of the basin. In this study, we assessed the seasonality of ecosystem productivity (gross primary productivity, GPP) from eddy covariance measurements, environmental drivers and phenological patterns obtained from the field (leaf litter mass) and satellite measurements (enhanced vegetation index (EVI) from the Moderate Resolution Imaging Spectroradiometer/multi-angle implementation correction (MODIS/MAIAC)) in an Amazonian floodplain forest. We found that ecosystem productivity is limited by soil moisture in two different ways. During the flooded period, the excess of water limits GPP (Spearman’s correlation; rho = −0.22), while during non-flooded months, GPP is positively associated with soil moisture (rho = 0.34). However, GPP is maximized when cumulative water deficit (CWD) increases (rho = 0.81), indicating that GPP is dependent on the amount of water available. EVI was positively associated with leaf litter mass (Pearson’s correlation; r = 0.55) and with GPP (r = 0.50), suggesting a coupling between new leaf production and the phenology of photosynthetic capacity, decreasing both at the peak of the flooded period and at the end of the dry season. EVI was able to describe the inter-annual variations on forest responses to environmental drivers, which have changed during an observed El Niño-Southern Oscillation (ENSO) year (2015/2016).

【 授权许可】

Unknown