Effect of Target Tree Management in Subtropical Secondary Evergreen Broad-leaved Forest

In October 2017, subtropical secondary evergreen broad-leaved forest in Suichang county, Zhejiang province was sampled with age group of 20-30-year, 30-40-year and 50-60-year. 3 quadrats with area of 50 m × 50 m were established for traditional and target tree management treatment in each sample area, with no management as control. In October 2020, investigations were carried out on species composition, stand structure, growth, undergrowth vegetation and soil physio-chemical properties, and comparison was made on the result in 2020 and that in 2017. The results showed that target tree management could improve mingling and reduce contagion of the forest. The basal area of DBH and annual growth rate in quadrat with target management was the highest, that with traditional management the second, that in the control stand the lowest. The density of young trees,the diversity index of understory and herb layer in quadrats with traditional management was significantly lower than in those with target management and control. There were no significant differences in soil bulk density, total porosity, pH, organic carbon content, total N, total P, total K and available K content among different sample areas, except available P, which reduced in quadrat with target tree management.