Ecological Stoichiometry Of Soil And Soil Extracellular Enzyme C,N And P In Different Forest Types In Cold-temperate Forests

Daxinganling National Nature Reserve is a typical cold temperate ecosystem,its vegetation types and climatic conditions are very different from other forest areas in China.The long-term low temperature environment in this area inhibits the activity of soil extracellular enzymes and accumulates a large amount of organic matter.For the cool forest soil,soil extracellular enzymes of carbon(C),nitrogen(N),phosphorus(P)ecological characteristics of chemical measurement,based on the distribution of the Daxinganling of 4kinds of typical forest types(Ledum palustre-Larix dahurica forest,Rhododendron dauricumLarix dahurica forest,Rhododendron dauricum-Betula platyphylla forest,Pinus pumila forest)in different depth of soil samples as the research object,determination of 0-5 cm,5-20 cm,Correlation analysis and principal component analysis were conducted for soil C,N,P contents,three soil extracellular enzyme β-glucosidase(BG),β-1,4-N-acetylglucosidase(NAG)and acid phosphatase(AP)activities,soil p H,mechanical composition,water content and bulk density.Study the Daxinganling cool-temperate forest soil of different in different forest types and soil exoenzyme C,N and P ecological vertical distribution characteristics of chemical measurement,correlation,and the relationship between the physical and chemical properties of soil,to meet cool forest ecosystem C,N and P cycle and soil biochemistry-soil mechanism of extracellular enzyme effects related to provide certain scientific basis.The main results are as follows:(1)The ecological stoichiometry of soil extracellular enzyme C,N and P in four forest types of cold-temperate zone were significantly different,and decreased with the deepening of soil depth,which was significantly affected by vegetation type and season.(2)In the 0-5cm layer,the content of soil C and BG in the Ledum palustre-Larix dahurica forest and Rhododendron dauricum-Betula platyphylla forest were significantly higher than those in other forest types in July August and September;the content soil of N and NAG in Rhododendron dauricum-Betula platyphylla forest were significantly higher than those in other forest types;the content of soil P in Pinus pumila forest was significantly lower than that in other forest types;the soil C/N and soil extracellular enzyme C/N in Ledum palustre-Larix dahurica forest were significantly higher than those in other forest types in June and July;the soil N/P and soil extracellular enzyme N/P in Rhododendron-Birch forest were significantly higher than those in other forest types In July;the soil extracellular enzyme C/P of Pinus pumila forest was significantly higher than that in other forest types in June;the soil C/P and soil extracellular enzyme C/P in Rhododendron dauricum-Betula platyphylla forest were significantly higher than those in other forest types in June and July.In 5-20 cm soil layer,the content of soil C and soil BG in Rhododendron dauricum-Betula platyphylla forest were significantly higher than those in other forest types in July and August;the content of soil N and NAG in Rhododendron dauricum-Betula platyphylla forest were significantly higher than those in other forest types in June,August and September;the soil of AP in Rhododendron dauricum-Larix dahurica forest was significantly higher than that in other forest types in June and July,and the soil of AP in Pinus pumila forest was significantly lower than that in other forest types in September;the soil C/P and soil extracellular enzyme C/P in Pinus pumila forest were significantly higher than those in other forest types in June and September.(3)Soil C,N,P ecological stoichiometry is closely related to soil extracellular enzyme C,N,P ecological stoichiometry.Soil BG was positively correlated with soil C,soil NAG was positively correlated with soil N,and soil AP was negatively correlated with soil P.Soil C and N contents were positively correlated with soil extracellular enzyme C/N and N/P.Soil P content was positively correlated with soil extracellular enzyme C/P.Soil N/P and C/P were positively correlated with soil extracellular enzyme C/N,and negatively correlated with soil extracellular enzyme N/P.(4)The results of principal component analysis showed that p H and mechanical composition were the main factors influencing soil C,N,P ecological stoichiometry,while water content and bulk density were the potential driving factors influencing soil C,N,P ecological stoichiometry.