Wetland ecosystem is an important part of the terrestrial ecosystem,and it plays a significant role in the global carbon cycle.The wetlands are also major sources of dissolved organic carbon(DOC).The studies on DOC flux in wetlands have focused on its relation with carbon cycle recently.It was reported that there have been significant spatial and temporal variations of DOC in the wetlands associated with sloughs,streams and rivers in boreal and sub-boreal hemisphere.Changes in DOC concentration and flux are considered to be related to a variety of factors affected by global climate change and human activities.The estimation of DOC concentration and flux from the terrestrial biosphere has been of great attention because of its importance for the status of carbon storage in the wetlands and the potential impact on global biogeochemical cycle.In this paper,it is discussed the sources,compositions and characteristics of DOC,furthermore reviewed the research methods and the influential factors as well as some estimated models of DOC flux.As a conclusion,some suggestions and prospects for the direction of the future study have been addressed.
