Ecosystem productivity and its response to environmental variable of moist Indian sal forest.

The network of eddy covariance (EC) based flux-towers is growing rapidly in India to accurately account carbon source/sink capacity of forest and managed ecosystems. Sal (Shorea robusta) forests representing about 16% of the total Indian forested area, a very important component of Indian carbon budget. One year observation on ecosystem scale CO₂/H₂O flux and other micrometeorological observations were analysed for elucidating diurnal and seasonal pattern of fluxes along with their response to biophysical and environmental factors of an Indian sal forest. Daily average air temperature ranged between 10.31 °C to 32.36 °C. Maximum Net Ecosystem Exchange (NEE) of -5.51 g C m^-2 day^-1 occurred on the 244 DOY due to ideal condition for photosynthesis. Environmental factors governing carbon flux components agreed with the incident of maximum and minimum NEE, Gross Primary Productivity (GPP) and Ecosystem Respiration (Re) in Barkot Flux Site (BFS). Clear variation in monthly NEE, GPP and Re was observed during the study. Higher LAI and sufficient moisture condition resulted to higher absorption of carbon during September-March. During pre-monsoon (April-June) NEE was lowered due to reduce LAI and high VPD. During the rainy season (July-August) the carbon sequestration potential was highly reduced due to cloudy condition and rain accelerated Re. Annual GPP, Re and NEE of BFS was 2916.19 g C m^-2 yr^-1, 2408.32 g C m^-2 and -507.89 g C m^-2 yr^-1. [ABSTRACT FROM AUTHOR]