摘要
Introduction:Soil microbial community plays a crucial role in the ecological processes of soil ecosystem.Forest species introduction often changes profoundly soil ecological processes in the forest.Larix kaempferi(Lam.)was introduced to China from Japan as a timber tree species in the 1960s.The activity and functional diversity of soil microorganisms in the L.kaempferi forest in Dalaoling National Forest Park in Hubei Province,China,was studied to evaluate the effects of this exotic species on the local soil ecosystems.Methods:Quadrates were set up randomly in the L.kaempferi forests cultivated in 1990 and 1996 and the surrounding Pinus armandii forest cultivated in 1990.Soil samples were collected using a soil corer at five locations along the diagonals in each quadrat.The activity and functional diversity of soil microorganisms were tested using the BIOLOG technique in laboratory.Results:The diversity,activity,and carbon utilization pattern of soil microorganism community and soil physicochemical properties were all impacted by the introduced species.The average well color development(AWCD)and Shannon’s richness index(H)of the soil microorganism community in the L.kaempferi forest decreased with the increase in forest age and were significantly lower than those in the surrounding native P.armandii forest.The carbon source utilization pattern of soil microorganism community in a 23-year-old L.kaempferi forest differed significantly from a 17-year-old L.kaempferi forest and the P.armandii forest.The introduced species also resulted in the changes of soil physicochemical properties.The organic material content,total nitrogen,available nitrogen,and total phosphorus in the soil of L.kaempferi forest were significantly lower than those in the soil of P.armandii forest.Conclusions:Introduction and long-time cultivation of L.kaempferi significantly altered the soil microbial functional diversity and activity and the soil physicochemical properties.The alteration increased with the increase of forest age.
基金
by the National Natural Science Foundation of China(51379105).
