Analysis of carbon dioxide, water vapour and energy fluxes over an Indian teak mixed deciduous forest for winter and summer months using eddy covariance technique

Abstract

In the present study, we report initial results on analysis of carbon dioxide (CO 2), water vapour (H 2 O), and energy fluxes (sensible and latent heat flux) over teak mixed deciduous forests of Madhya Pradesh, central India, during winter (November 2011 and January 2012) and summer (February-May 2012) seasons using eddy covariance flux tower datasets. During the study period, continuous fast response measurements of CO 2 , H 2 O and heat fluxes above the canopy were carried out at 10 Hz and averaged for 30 minutes. Concurrently, slow response measurements of meteorological parameters are also being carried out. Diurnal and seasonal variations of CO 2 , H 2 O and heat fluxes were analysed and correlated with the meteorological variables. The study showed strong influence of leaf off and on scenario on the CO 2 , H 2 O and energy fluxes due to prevalence of deciduous vegetation type in the study area. Maximum amount of CO 2 was sequestered for photosynthesis during winter (monthly mean of −25 μmol/m 2 /s) compared to summer (monthly mean of −2 μmol/m 2 /s). Energy flux analysis (weekly mean) showed more energy being portioned into latent heat during winter (668 W/m 2) and sensible heat during summer (718 W/m 2).

Carbon dioxide, water vapour and energy fluxes over a semi-evergreen forest in Assam, Northeast India

“…During the monsoon months, VPD attained the diurnal peak at late afternoon hours which correspond to less negative CO 2 flux above the canopy possibly due to the partial stomatal closure with an increase in VPD after a threshold value. Our results are well corroborated with the findings of Jha et al (2013). A sudden decrease in CO 2 flux in the ecosystem in the month of July may be attributed to the low VPD in July (resulted due to higher rainfall) compared to other monsoon months.…”

“…Flux measurements in the forest ecosystem have been carried out in many sites across the world, but relatively very few studies have been conducted in the Indian subcontinent. However, Jha et al (2013) have measured CO 2 , water vapour and energy fluxes in a teak mixed deciduous forest in central India during 2011 and 2012 using the EC technique. The EC data were also used by Watham et al (2014) to study the monthly and annual variations of CO 2 and H 2 O fluxes over a mixed forest plantation in Terai central forest division, Uttarakhand, India.…”

Estimating gross primary productivity of a tropical forest ecosystem over north-east India using LAI and meteorological variables

“…Measured fluxes were used in conjunction with the MODIS surface temperature and reflectance data to calculate GPP over a wheat field in north India (Patel et al 2011). In other related studies, flux and climate data were analyzed over mixed deciduous forests in central India (Jha et al 2013), north India (Watham et al 2014) and mangrove forest in Gangetic delta in east India (Rodda et al 2016). In some cases, these studies calculated the GPP using site level observations.…”

Seasonal Variations of Carbon Dioxide, Water Vapor and Energy Fluxes in Tropical Indian Mangroves

“…One of the main objectives of NCP is to establish a network of EC flux towers in different representative forest ecosystems in the Indian subcontinent to understand their CO 2 source and sink strengths [23][24][25]. As part of this, an eddy covariance flux tower was established in mangrove forests in the Sundarbans Biosphere Reserve in April 2012 and has been taking measurements since then.…”