涉及生态系统生态学与稳定同位素生态学。以ChinaFLUX为依托，完善了复杂地形条件下基于涡度相关技术的碳水通量长期观测的方法论，保证了数据的可靠性，提高了观测数据的有效率；发展了大气水汽δ18O 和δD 和CO2的δ13C原位连续观测的方法论，解决了仪器非线性响应难题，突破了涡度相关与稳定同位素技术协同观测的技术瓶颈；重点开展生态系统尺度典型森林、草地和农田生态系统碳、水和氮耦合循环，发现了通常使用的生态系统呼吸作用对温度和水分的耦合影响的连乘模式的局限性，提出了干旱胁迫条件下生态系统呼吸量的评价方法。未来工作重点以ChinaFLUX为依托，开展δ18O、δD和δ13C稳定同位素技术和涡度相关技术在森林、草地和农田生态系统水碳循环研究中的应用。

代表性论文与专利：
1) Wen, X.F., Lee, X. Sun, X.M., Wang, J.L., Hu, Z.M., Li, S.G., and Yu. G.R., 2011. Dew water isotopic ratios and their relations to ecosystem water pools and fluxes in a cropland and a grassland in China.
2) Wen, X.F., Lee, X. Sun, X.M., Wang, J.L., Tang, Y.K., Li, S.G., and Yu. 2011: Inter-comparison of four commercial analyzers for water vapor isotope measurement.
3) Zhang, S.C., Sun, X.M., Wang, J.L., Yu, G.R., Wen, X.F. *, 2011. Short-term variations of water vapor isotope ratios reveal the influence of atmospheric processes other than precipitation. Journal of Geographical Sciences, 2011, 21(3): 401-416 (通讯作者)
4) Wen, X.F., Zhang, S.C., Sun, X.M.,Yu, G.R., Lee, X., 2010. Water vapor and precipitation isotope ratios under the influence of the Asian monsoon climate. Journal of Geophysical Research-Atmospheres, 115, D01103, doi:10.1029/2009JD012408
5) Wen, X.F., Wang, H.M., Wang, J.l., Yu, G.R., Sun, X.M., 2010. Ecosystem carbon exchange of a subtropical evergreen coniferous plantation subjected to seasonal drought, 2003-2007. Biogeosciences, 7, 357-369
6) Wen, X.F., Sun, X.M., Zhang, S.C., Yu, G.R., Sargent, S.D., Lee, X., 2008. Continuous measurement of water vapor D/H and 18O/16O isotope ratios in the atmosphere. Journal of Hydrology, 349, 489-500.
7) Wen, X.F., Yu, G.R., Sun, X.M., Li, Q.K., Liu, Y.F., Zhang, L.M., Ren, C.Y., Fu, Y.L., Li, Z.Q., 2006. Soil moisture effects on the temperature dependence of ecosystem respiration in a subtropical pinus plantation of southeastern China. Agricultural and Forest Meteorology, 137: 166-175
8) Wen, X.F., Yu, G.R., Sun, X.M., Liu, Y.F., 2005. Turbulence flux measurement above the overstory of a subtropical Pinus plantation over the hilly region in southeastern China. Science in China Ser. D Earth Sciences, 48(SI), 63~73
9) 温学发, 孙晓敏, 王建林, 张心昱, 于贵瑞, 李胜功, 李旭辉. 2010. 恒定氢氧稳定同位素比值的水汽发生器及用途. 国家发明专利, 申请号: 201010223551.6.
10) 温学发, 孙晓敏, 王建林, 于贵瑞, 李胜功. 2011. 水汽氢氧稳定同位素通量的模拟装置与方法. 国家发明专利, 申请号: 201110004555.X.