Influence of Soil Organic Carbon on Soil Biological Activities Among Secondary Forests of Guiyang City
PENG Yan1, LI Xinqing2
1. Development and Planning Office, Guizhou University for Nationalities, Guiyang 550025, China2. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
Abstract：The secondary forest, as an integral part of Karst forest ecosystem, may be the future of a forest. The soil organic carbon is an important part of the soil organic matter and its content has a major impact on soil biological activities and is also an important indicator of the soil fertility. To understand the effects of soil organic carbon on soil biological activities, three sample plots are taken, including a shrub, a Ligustrum lucidum forest and a pine forest and they are compared with the tilled field in the suburbs of Guiyang City during the sampling time (June, 2008-May, 2009). The data show that the shrub is characterized by low substrate carbon utilization, weak biochemical processes and less available nutrients of plants and microbes based on per gram soil organic carbon, although with the highest soil organic carbon among the sample plots. The Ligustrum lucidum forest is marked by high nitrogen cycle rate, rich in denitrification enzyme and serious gaseous nitrogen loss, while, the pine forest is characterized by high decomposition speed and strength, high soil microbial and enzyme activities, strong soil biochemical processes and low gaseous nitrogen loss based on per gram soil organic carbon. Generaly speaking, the organic carbon content limits the size of soil microbial communities, affects soil enzyme activities in shurbs, influences the microbial nitrogen conversion rate and organic matter decomposition rate indirectly but has no significant effects on denitrification in the study area. Therefore, the most appropriate way to the remediation of degraded desertification soil is to allow the natural plant communities to develop in order to improve site conditions in the early stage of the soil remediation and then to select appropriate tree species with the mixed model of coniferous-broadleaved species.
2011, Vol. 29 
