Using continuous stable isotope measurements to partition net ecosystem CO₂ exchange into photosynthesis and respiration of a corn-soybean rotation ecosystem

The isotopic measurements combined with the micrometeorologiocal observations were used to partition the net ecosystem CO₂ exchange (NEE) of a C₃-C₄ rotation agricultural ecosystem into photosynthesis and respiration. The isotopic method provides real-time partitioning of NEE, and should lead to better understanding of the short-term ecophysiological processes than the regression method. The results showed that the partitioned photosynthesis and respiration were in accordance with the temperature regression method in magnitude during the full canopy stage. The partitioning was most sensitive to δ¹³C_b.