Study and implementation of microwave and optical data for assessment of carbon balances for wetlands under changes of biomass and humidity conditions

The results of measurements of CO₂ exchange in various wetland communities were elaborated for the area of Biebrza National Park in north-eastern Poland. The research has been done within ongoing ESA-PECS and National Research Project (No N N526 160040) realized in the Institute of Geodesy and Cartography, Remote Sensing Department in Warsaw. CO₂ flux measurements were performed with a static chamber method from April till September from 2010 - 2012. For each of the classified wetlands vegetation habitats the relationship between soil moisture and backscattering coefficient has been examined and the best combination of microwave variables ENVISAT ASAR (wave length, incidence angle, polarization) has been used for mapping and monitoring of soil moisture. Carbon input to an ecosystem occurs through the process of photosynthesis. The rate of photosynthesis (CO₂ uptake) is referred to as gross primary production (GPP). CO₂ is in turn released to the atmosphere through respiration. The difference between GPP and R_eco is referred to as net ecosystem exchange (NEE). By estimating the direction of NEE, it is possible to determine whether a surface is a likely source or a sink of carbon. The NEE has been related to biomass and soil moisture which was also related to the ratio of NDVI and Ts from NOAA/AVHRR.