Soil organic carbon mineralization with urban plant communities in Shanghai

Key words: 
• soil science /
• plant community /
• soil organic carbon mineralization /
• microbial biomass carbon /
• rate of soil organic carbon mineralization

Abstract: Soil samples for five typical urban plant communities：Osmanthus fragrans，Lolium perenne，Cinnamomum camphora，Taxodium ascendens，and Bambusa multiplex，were collected in Shanghai Gongqing Forest Park. Laboratory incubation tests were then used to analyze soil microbial biomass carbon （MBC） and to examine soil organic carbon（SOC） mineralization with its dynamic patterns. Analyses included fitting to a logarithmic equation and a correlation analysis. Results showed that SOC and MBC had significant differences among the different plant communities，but both decreased with increasing soil depth. Daily SOC mineralization was significantly different （P＜0.05） with O. fragrans＞L. perenne＞C. camphora ＞ T. ascendens ＞ B. multiplex. For a given plant community，SOC mineralization decreased as soil depth increased with the extent of decrease different for each plant community. SOC mineralization patterns for all plant communities were alike：decreasing rapidly as incubation began and then being relatively constant fitting a logarithmic equation. Cumulative SOC mineralization was O. fragran＞L. perenne＞C. camphora＞ T. ascendens＞B. multiplex and was linearly correlated with the incubation time. Thus compare to lawn （L. perenne），deep-rooted plants could increase SOC and MBC，thus increasing the soil carbon pool.［Ch，3 fig. 4 tab. 20 ref.］