Variation in NEE and its response to environmental factors in an extremely arid desert wetland ecosystem

Abstract

In order to study the net ecosystem CO2 exchange (NEE) variation and its response to environmental factors, CO2 flux and related environmental factors were monitored from May until September. The diurnal NEE variations in this region showed a U-shaped distribution. The average daily CO2 absorption in July was the largest. The study area is a carbon sink during the growing season. At the soil depth of 40 and 80 cm, due to the influence of underground water, the soil water content had a significantly negative correlation with NEE. The increase in relative air humidity can facilitate stomata opening, which also improves CO2 absorption. Additionally, the increase in air temperature, soil temperature and photosynthetically active radiation (PAR) all promote plant photosynthesis, which leads to a negative correlation with NEE.