Atmospheric temperature and humidity demonstrated strong correlation with productivity in tropical moist deciduous forests.

Abstract

Tropical forests sequester six times higher carbon than that released by humans annually into the atmosphere. These biodiversity-rich tropical forests have high net primary productivity (NPP), which differs among constituent plant communities. Tropical moist deciduous forests occupy 179,335 km2 of India's geographical area and constitute 44% of the country's total protected area (PA) forests. The productivity of these forests has neither been estimated specifically nor precisely. We measured the annual NPP of three predominant distinct community types, viz., mixed (DM), sal (SM), and teak (TP), in a tropical moist deciduous forestin northern India. The NPP was estimated from tree biomass data collected from nine long-term ecological research (LTER) plots of 1ha each representing the above three community types. The estimatedannual NPP were 10.28, 6.25, and 9.79Mgha-1year-1 in DM; 8.93, 7.09, and 10.59Mgha-1year-1 in SM; and 14.57, 7.14, and 13.56Mgha-1year-1 in TP for the years 2010, 2011, and 2012, respectively. The NPP was correlated with tree density, height and DBH, species richness, diversity, microclimatic and edaphic variables, and leaf area index (LAI) using principal component analysis (PCA) and generalized linear modeling (GLM). Air temperature and humidity were strongly related to NPP in all the community types, while "complementarity" and "selection effects" contributed to the NPP in both the sal and mixed forestcommunities with equal importance, and the NPP in teak plantation ould point to "dominance effect."