Metallic protection of soil carbon:divergent drainage effects in Sphagnum vs.non-Sphagnum wetlands  

作　　者：Chengzhu Liu Yunpeng Zhao Lixiao Ma Guoqing Zhai Xingqi Li Chris Freeman Xiaojuan Feng 

机构地区：[1]State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China [2]China National Botanical Garden,Beijing 100093,China [3]University of Chinese Academy of Sciences,Beijing 100049,China [4]School of Natural Sciences,Bangor University,Bangor LL572UW,UK

出　　处：《National Science Review》2024年第11期93-103,共11页国家科学评论（英文版）

基　　金：supported by the National Natural Science Foundation of China(42025303,42230501 and 31988102).

摘　　要：The established paradigm assumes that drainage may decrease the vast soil organic carbon(SOC)reservoir in global wetlands.Yet drainage can also promote SOC stabilization by fostering the accrual of metal-bound organic carbon(bound OC)upon oxygen exposure.Here,this emergent mechanism is tested for the first time at a regional scale,using literature data and a nationwide,pairwise survey of drained wetlands across China.We show that long-term(15–55 years)drainage largely increased metallic protection of SOC(bound OC%)in non-Sphagnum wetlands,but consistently decreased bound OC%in Sphagnum wetlands following replacement of the‘rust engineer’Sphagnum by herbaceous plants.Improved SOC stock estimates based on 66 soil profiles reveal that bound OC increases can compensate for the loss of unbound SOC components in non-Sphagnum wetlands with substantial accrual of reactive metals.Metallic stabilization of wetland SOC is hence a widespread but overlooked mechanism that is heavily influenced by vegetational shifts.Incorporating this novel mechanism into models will improve prediction of wetland SOC dynamics under shifting hydrological regimes.

关 键 词：wetland drainage vegetational change metal-organic associations carbon sequestration 

分 类 号：P467[天文地球—大气科学及气象学]