Abstract:

castnea mollissima forest is an important economic forest that has been intensively managed in southern China recently. Consequently, soil quality was getting worse and worse with the intensive management. The effects of C. mollissima intensive management on soil biological properties was studied by sampling soil from C. mollissima stands with different history of intensive management in Anji City, Zhejiang Province. Three soil samples from natural shrubbery were collected. The soil microbial biomass carbon under C. mollissima stand with 5,10 and 20 year's intensive management were decreased by 15.89%,49.16% and 55.13% respectively, and the differents were significant (P<0.05). There is no significant difference between the proportions of soil microbial biomass carbon to soil total organic carbon under the C. mollissima stand during 5 years intensive management and the natural shrubbery, however, it decreased apparently until 10-year's intensive management and then kept constant afterward. Compared with shrubbery, The soil AWCD (average well color density)value under C. mollissima stand decreased by 79.26%, 63.20% and 68.50% respectively after 5, 10 and 20-year's intensive management, with significant difference(P<0.05). Indexes of Shannon and McIntosh reflecting soil microorganism diversity were lower in intensive management C. mollissima stands than that in natural shrubbery. Combining AWCD value with diversity indexes, the soil microbial functional diversity of intensive management C. mollissima stand was decreased noticeably during the first-10 year's intensive management, but no change observed afterward.

Key words: Castanea mollissima, intensive management, soil, microbial biomass carbon, microorganism diversity