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Carbon budgets of wetland ecosystems in China

Author:
Xiao, Derong, Deng, Lei, Kim, Dong‐Gill, Huang, Chunbo, Tian, Kun
Source:
Global change biology 2019 v.25 no.6 pp. 2061-2076
ISSN:
1354-1013
Subject:
biosphere, carbon, carbon sinks, climate change, climatic factors, data collection, ecosystem respiration, emissions, gross primary productivity, lakes, marshes, net ecosystem production, rivers, soil, surveys, temperature, terrestrial ecosystems, uncertainty, China
Abstract:
Wetlands contain a large proportion of carbon (C) in the biosphere and partly affect climate by regulating C cycles of terrestrial ecosystems. China contains Asia's largest wetlands, accounting for about 10% of the global wetland area. Although previous studies attempted to estimate C budget in China's wetlands, uncertainties remain. We conducted a synthesis to estimate C uptake and emission of wetland ecosystems in China using a dataset compiled from published literature. The dataset comprised 193 studies, including 370 sites representing coastal, river, lake and marsh wetlands across China. In addition, C stocks of different wetlands in China were estimated using unbiased data from the China Second Wetlands Survey. The results showed that China's wetlands sequestered 16.87 Pg C (315.76 Mg C/ha), accounting for about 3.8% of C stocks in global wetlands. Net ecosystem productivity, jointly determined by gross primary productivity and ecosystem respiration, exhibited annual C sequestration of 120.23 Tg C. China's wetlands had a total gaseous C loss of 173.20 Tg C per year from soils, including 154.26 Tg CO₂‐C and 18.94 Tg CH₄‐C emissions. Moreover, C stocks, uptakes and gaseous losses varied with wetland types, and were affected by geographic location and climatic factors (precipitation and temperature). Our results provide better estimation of the C budget in China's wetlands and improve understanding of their contribution to the global C cycle in the context of global climate change.
Agid:
6438180