無瓣海桑根際土壤理化性狀和土壤酶活性

In order to provide theoretical basis for artificial afforestation, sustainable development and protection of mangrove, physicochemical properties and enzyme activities of rhizosphere soil in Sonneratia apetala at different ages in Futian Mangrove Reserve were studied. The results showed that rhizosphere soil in S. apetala at different ages was neutral or slightly acidic （pH 6.70-7.04）, and all respiratory rates were relatively high, and over 112 mg ·kg^-1·h^-1. The water and organic matter contents in soil were increased with increasing of tree age. Microbial biomass C, total N and total P contents were increased significantly from 1 year old to 7 years old, and then decreased with increasing of tree age. It indicated that the soil fertility reached a maximum at 7 years old, and then declined with increasing of tree age. The activities of urease, cellulose and β-glucosidase reached a maximum at 7 years old as change trends of microbial biomass C, total N and total P contents, and then declined with increasing of tree age. It indicated that the growth peak of S. apetala came at 7 years old, metabolisms of the microbes in the rhizosphere were active, and the soil enzyme activities related with C/N nutrient metabolism was up to the most values at 7 years old. Activities of phosphatase and aryl sulfatase were increased with increasing of tree age. There was no significant difference among the activities of dehydrogenase in rhizosphere soil of S. apetala at different ages. The Soil enzyme activities were extremely significantly positive correlated with total N, total P and microbial biomass C contents, but dehydrogenase activity.