Though one of the most vulnerable terrestrial ecosystems, wetlands provide multiple ecosystem services, most notably storing carbon. It is now widely recognized that climate change could have a large impact on high-latitude wetlands. A key question is how climate change will affect the distribution pattern of wetland plant communities, and to what extent the transitions among different wetland plant communities respond to regional warming? To answer this question, we estimated the total SOC storage with 139 soil profiles in the Xing'anling Mountains and performed ensemble species distribution modelling for 11 dominant wetland plant communities by using numerous vegetation plots. Results show that 4.5-23.8% of the high-latitude wetlands in the study area would be lost following widespread thawing of permafrost under different climate warming scenarios by the end of this century. The total wetland SOC in the Xing'anling Mountains is estimated to be 1.58 Pg, about 25.5-29.3% of the total of China's wetlands, however, predicted wetland loss could put 5.4-20.5% (0.08-0.32 Pg C) of the total SOC storage at risk of instability. Our results also predicted a significant northward migration of southern Deyeuxia angustifolia communities driven by future climate changes. This wetland succession could profoundly reduce future carbon sequestration capacity of wetlands in the study area. The findings presented here are helpful for both current reserve management and future conservation planning of wetlands in the study area.

Though one of the most vulnerable terrestrial ecosystems, wetlands provide multiple ecosystem services, most notably storing carbon. It is now widely recognized that climate change could have a large impact on high-latitude wetlands. A key question is how climate change will affect the distribution pattern of wetland plant communities, and to what extent the transitions among different wetland plant communities respond to regional warming? To answer this question, we estimated the total SOC storage with 139 soil profiles in the Xing'anling Mountains and performed ensemble species distribution modelling for 11 dominant wetland plant communities by using numerous vegetation plots. Results show that 4.5-23.8% of the high-latitude wetlands in the study area would be lost following widespread thawing of permafrost under different climate warming scenarios by the end of this century. The total wetland SOC in the Xing'anling Mountains is estimated to be 1.58 Pg, about 25.5-29.3% of the total of China's wetlands, however, predicted wetland loss could put 5.4-20.5% (0.08-0.32 Pg C) of the total SOC storage at risk of instability. Our results also predicted a significant northward migration of southern Deyeuxia angustifolia communities driven by future climate changes. This wetland succession could profoundly reduce future carbon sequestration capacity of wetlands in the study area. The findings presented here are helpful for both current reserve management and future conservation planning of wetlands in the study area.