Abstract: Stem CO₂ efflux rate (F_CO2) is a key component of the carbon cycle in forest ecosystem, accounting for 14%–48% of autotrophic respiration. To study the affecting factors of F_CO2 would contribute to the understanding of global carbon cycle and of the responses of forest ecosystem to global climate change. This paper reviewed the effects of biotic and abiotic factors on F_CO2, and indicated that these factors not only directly or indirectly affected the F_CO2, but also acted interactively. Their contributions to F_CO2 varied temporally and spatially. Though a considerable advancement has been achieved in recent years, some issues are still needed to be further studied: 1) partitioning the F_CO2 with effective methods, and analyzing the relationships between the F_CO2 components and related affecting factors to reveal the F_CO2 variation mechanism, 2) incorporating the biotic and abiotic factors into F_CO2 dynamic models to improve the accuracy of simulating F_CO2, and 3) further approaching the temperature-adaptability of F_CO2.

Key words: Regional agro-ecosystem, Environmental quality, Assessment