Rapid Responses of Soil Microbes and Active Organic Carbon to Eco-restoration in Karst Region
Eco-degradation problem generally occurs in karst region, and reforestation as an eco-restoration practice has been received more and more attention. Soil active organic carbon fractions generally show more sensitive response to environmental change and disturbance than soil total organic carbon, and also responses of soil microorganisms are sensitive. However, no information is available on soil active organic carbon and microbes following reforestation in time scales in karst region. Guzhou village representative for karst landscape was selected to conduct this study. We selected four reforestation sampling areas with a chronosequence of 2, 4, 8 and 12 years and one arable sampling area as control. As compared to the arable system, soil total organic carbon content did not change under 2-yr, or 4-yr reforestation, but significantly increased by 24% under 8-yr reforestation. Soil water soluble organic carbon, particulate organic carbon and labile organic carbon contents were significantly higher 62%, 36%and 38%, respectively under 2-yr reforestation than the arable system, and showed an increasing trend with reforestation ages. Relative contents of these carbon indicators also showed similar patterns. Consistently, soil microbial biomass carbon content, basal respiration and microbial quotient were significantly higher 56%, 27%and 54%, respectively under 2-yr reforestation than the arable system, and showed an increasing trend with reforestation ages. Microbial metabolic quotient showed opposite pattern. Our results indicate that these active organic carbon and microbial indicators can provide early indication for karst eco-restoration.
soil microbesoil organic carboneco-restorationkarst region
国家科技期刊平台
NSTL
万方数据
维普
