Leaf Area Rather Than Photosynthetic Rate Determines the Response of Ecosystem Productivity to Experimental Warming in an Alpine Steppe

作  者:Li F, Peng YF, Zhang DY, Yang GB, Fang K, Wang GQ, Wang J, Yu JC, Zhou GY, Yang YH*
影响因子:3.621
刊物名称:Journal of Geophysical Research-Biogeosciences
出版年份:2019
卷:124  期:7  页码:2277-2287

论文摘要:

Gross primary productivity (GPP) plays an important role in mediating the feedback between land carbon (C) cycle and climate warming. However, knowledge about the mechanisms regulating the response of GPP to warming is still limited. Based on a fouryear field manipulative experiment, we examined the warming effects on GPP and the potential mechanisms in a typical alpine steppe on the Tibetan Plateau. Our results revealed that elevated temperature significantly increased GPP over the study period. The warminginduced increase in GPP was driven by the increased leaf area index, which was derived from the increase in aboveground biomass of forb. By contrast, warming had no significant effects on photosynthesis per leaf area, likely due to the offset of warminginduced increase in leaf nitrogen concentration and decrease in soil moisture. These results demonstrate that leaf area rather than leaf photosynthetic rate determines the response of ecosystem productivity to climate warming in this alpine steppe. More studies in other ecosystems are called for to test the observed mechanisms responsible for warming effects on GPP, so as to improve predictions of terrestrial C cycle under changing environment.

全文链接:https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019JG005193