Effects of Afforestation on the Abundance,Biomass Carbon and Enzymatic Activities of Soil Microorganism in Sandy Dunes

Abstract

In order to investigate the effects of afforestation on soil microbial abundance,microbial biomass carbon and enzymatic activities in sandy dunes,around 20-year-old Pinus sylvestris var.mongolica(PSM) and Populus simonii Carr.(PSC) mature forests were selected in Horqin Sandy Land,and mobile dunes were set as controls(CK).The results showed that PSM and PSC plantation could improve soil physiochemical properties and increase microbiological activities significantly.Soil microbial abundance,microbial biomass carbon and enzymatic activities showed an order of PSCPSMCK.Soil total microbial abundance in PSM and PSC were 50.16 and 72.48 times of that in CK,and the differences were significant among PSM,PSC and CK.Soil microbial biomass carbon in PSM and PSC were 23.67 and 33.34 times of that in CK,and the difference was insignificant between PSM and PSC.Soil enzymatic activities,including dehydrogenase(DEH),peroxidase(PER),protease(PRO),urease(URE) and cellobiohydrolase(CEL) activities in PSM and PSC were 19.00 and 27.54,4.78 and 9.89,4.05 and 8.67,29.93 and 37.46,9.66 and 13.42 times,repectively,of that in CK.Pinus sylvestris var.mongolica and Populus simonii Carr.are both efficient tree species to improve soil physiochemical and microbiological properties in sandy land,and moreover,they are both efficient tree species to fix mobile dunes in Horqin Sandy Land.Cmic∶C ratio is an efficient indicator to estimate soil stability and availability,and based on an overall consideration of plantation stability and sustainability,Pinus sylvestris var.mongolica was better than Populus simonii Carr.to fix mobile dunes in sandy land.