Soil Microbial Community and Enzyme Activities of Peatlands under Different Water Table Control Conditions
Water table,which determines the mechanism and intensity of peat soil carbon cycling,is the most important environmental properties in the degraded peatlands.In this study,the 0-50 cm peat columns were collected from the Baijianghe peatland in Changbai Mountains and incubated at different water tables in laboratory.There were 3 water table treatments:continuous flooding,continuous low water table,and fluctuating water table.Soil physical and chemical properties,active organic carbon components,microbial phospholipid fatty acids,and enzyme activities were analyzed to reveal the variation patterns and mechanisms of soil microbial community and activities among different water tables.The results showed that,compared with continuous flooding treatment,soil pH was decreased after short-term drainage.Compared with continuous flooding,soil easily oxidized organic carbon and microbial biomass carbon concentrations of 0-20 cm were significantly decreased,but the easily oxidized organic carbon of above 20-50 cm increased under continuous low water table.Soil microbial biomass carbon concentration was significantly higher under fluctuating water table treatment than that under continuous low water table treatment.Soil water content,total nitrogen,and carbon/phosphorus ratio were the main factors affecting the change of soil active organic carbon components.Soil microbial phospholipid fatty acid concentrations were significantly lower under continuous low water table treatment than those under continuous flooding and fluctuating water table treatment.Except fungi,different type of microbial phospholipid fatty acids showed a trend of fluctuating water table was higher than continuous flooding.Compared with continuous flooding,the continuous low water table treatment had no significant effects on soil oxidase activities,but was found to increase the soil hydrolytic enzyme activities of 0-20 cm.Soil activities of polyphenol oxidase and hydrolase of above 20-50 cm showed a trend of continuous flooding was higher than continuous low water table.Compared with continuous low water table,peroxidase activity was increased but hydrolytic enzyme activities were decreased in 0-20 cm after fluctuating water table treatment.Soil organic carbon and total nitrogen were the main factors affecting soil microbial phospholipid fatty acids,but soil microbial biomass carbon was the main factor affecting soil enzyme activity.The results will help clarify the microbial mechanism of soil carbon cycling of peatlands under future climate change.
peatlandcontinuous low water tablewater table fluctuationmicrobial phospholipid fatty acidsoxidasehydrolytic enzyme
NETL
NSTL
万方数据
维普
