Belowground carbon pools and dynamics in China's warm temperate and sub-tropical deciduous forests

Abstract

Abstract.We report the first estimates of pools and dynamics of microbes, roots, plant litter and soil organic carbon (SOC) in three dominant types of China's vast deciduous forest area: Betula platyphylla, Quercus liaotungensis, and Quercus aliena var. acuteserrata. Organic matter degradation rates overshadowed litter inputs as the main determinant of the soil carbon stocks. Across the three forests, rates of litter decomposition were also indicative for turnover rates of SOC. Litter and SOC decay was faster in the subtropical than in the warm-temperate forests. Among the latter, SOC turnover was highest in the forest producing the higher-quality litter. Microbial biomass was, as expected, correlated with SOC content. Microbial activity, in contrast, was highest at the sub-tropical forest, despite the lower SOC availability, lower fraction of labile SOC, and lower soil microbial biomass. These results may contribute to increased understanding of controls over belowground carbon cycling in deciduous forests.

Determinants of soil organic carbon sequestration and its contribution to ecosystem carbon sinks of planted forests

“…This work is based on an integrated analysis of data extracted from the literature, but there were some limitations based on inconsistency in the data reported. We had to use a regression model to estimate forest biomass C ( Figure S2) for the cases that only reported DBH but not biomass C. Ecosystem C sequestration should also include belowground root (Moser et al, 2011;Vesterdal et al, 2006;Xiao et al, 2010) Inadequate data may restrict the representativeness in this study. It is expected that the contribution of the soil C sink to the ecosystem C sink of planted forests could become more certain when abundant observed data across a wider domain are available.…”