Wetlands play an important role in the global carbon cycle, but there are still considerable uncertainties in the estimation of wetland carbon storage and a dispute on whether wetlands are carbon sources or carbon sinks. Xiaoxing'anling are one of several concentrated distri-bution areas of forested wetland in China, but the carbon storage and carbon sink/source of forested wetlands in this area is unclear. We measured the ecosystem carbon stor-age (vegetation and soil), annual net carbon sequestration of vegetation and annual carbon emissions of soil hetero-trophic respiration of five typical forested wetland types (alder swamp, white birch swamp, larch swamp, larch fen, and larch bog) distributed along a moisture gradient in this area in order to reveal the spatial variations of their carbon storage and quantitatively evaluate their position as carbon sink or source according to the net carbon balance of the ecosystems. The results show that the larch fen had high carbon storage (448.8 t ha -1 ) (6.8％ higher than the larch bog and 10.5–30.1％ significantly higher than other three wet-lands ( P < 0.05), the white birch swamp and larch bog were medium carbon storage ecosystems (406.3 and 420.1 t ha -1 ) (12.4–21.8％ significantly higher than the other two types ( P < 0.05), while the alder swamp and larch swamp were low in carbon storage (345.0 and 361.5 t ha -1 , respectively). The carbon pools of the five wetlands were dominated by their soil carbon pools (88.5–94.5％), and the vegetation carbon pool was secondary (5.5–11.5％). At the same time, their ecosystem net carbon balances were positive (0.1–0.6 t ha -1 a -1 ) because the annual net carbon seques-tration of vegetation (4.0–4.5 t ha -1 a -1 ) were higher than the annual carbon emissions of soil heterotrophic respiration (CO 2 and CH 4 ) (3.8–4.4 t ha -1 a -1 ) in four wetlands, (the alder swamp being the exception), so all four were carbon sinks while only the alder swamp was a source of carbon emissions (- 2.1 t ha -1 a -1 ) due to a degraded tree layer. Our results demonstrate that these forested wetlands were generally carbon sinks in the Xiaoxing'anling, and there was obvious spatial variation in carbon storage of ecosystems along the moisture gradient.

Biao Wang;Changcheng Mu;Huicui Lu;Na Li;Yan Zhang;Li Ma

Center for Ecological Research,Northeast Forestry University,Harbin 150040,People's Republic of China;Faculty of Forestry,Qingdao Agricultural University,Qingdao 266000,People's Republic of China

林业研究（英文版）

[1]Biao Wang;Changcheng Mu;Huicui Lu;Na Li;Yan Zhang;Li Ma-.Ecosystem carbon storage and sink/source of temperate forested wetlands in Xiaoxing'anling, northeast China)[J].林业研究（英文版）,2022(03):839-849

Xiaoxing,alder,birch,fen,bog,seques

Ecosystem,carbon,storage,temperate,forested,wetlands,anling,northeast,China,Wetlands,play,important,role,global,cycle,there,still,considerable,uncertainties,estimation,dispute,whether,sources,sinks,one,several,concentrated,bution,areas,this,unclear,measured,vegetation,soil,annual,net,sequestration,emissions,respiration,five,typical,types,swamp,white,larch,distributed,along,moisture,gradient,order,reveal,spatial,variations,their,quantitatively,evaluate,position,according,ecosystems,results,show,that,had,higher,than,significantly,other,three,were,medium,two,while,low,respectively,pools,dominated,by,was,secondary,At,same,balances,positive,because,heterotrophic,CH,four,being,exception,only,due,degraded,tree,layer,Our,demonstrate,these,generally,obvious

0.30553