Publication Date:
2014-03-07
Description:
Trees outside forests (TOF) play important roles in national economies, ecosystem services, and international efforts for mitigating climate warming. Detailed assessment of the dynamics of carbon (C) stocks in China's TOF is necessary for a full picture evaluating the role of the country's trees in the national C cycle. In this study, we first explore the changes in biomass C stocks of China's TOF over the last three decades, using the national forest inventory data in six periods from 1977 to 2008. According to the definition of the forest inventory, China's TOF could be categorized into three groups: woodlands, shrubberies, and trees on non-forest lands (including four-side greening trees and scattered trees). We estimated biomass C stocks of woodlands and trees on non-forest lands by using the provincial biomass-volume conversion equations derived from the data of low canopy forests, and those of shrubberies with the mean biomass density method. Total TOF biomass C stock increased by 63.1% from 827 Tg C (1 Tg = 1012 g) in the initial period of 1977–1981 to 1349 Tg C in the last period of 2004–2008. As a result, China's TOF have accumulated biomass C of 522 Tg during the study period, with 12 Tg, 276 Tg, and 234 Tg in woodlands, shrubberies, and trees on non-forest lands, respectively. The annual biomass C sink of China's TOF averaged 19.3 Tg C yr–1, offsetting 2.2% of the contemporary fossil-fuel CO2 emissions in the country. These estimates are equal to 16.7 ~ 20.7% of the contemporary total forest biomass C stock and 27.5% of the total forest biomass C sink in the country, suggesting that TOF are substantial components for accounting China's tree C budget.
Print ISSN:
1810-6277
Electronic ISSN:
1810-6285
Topics:
Biology
,
Geosciences
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