Study On Soil Microorganism And Soil Enzyme Activity Along A Chronosequence Of Eucalyptus Plantation

The degradation of forestland and biodiversity loss that are main two ecology problems of Eucalyptus plantation now in Guangxi province. This study of Guang Xi Huang Mian state-owned forest farm in north GuangXi area 1-5 years of eucalyptus plantation as the research object, supplemented by pinus massoniana plantation for comparison,(Soil organic matter,total nitrogen, total phospHorus, total potassium, available nitrogen, available phosphorus and available potassium, microbial biomass C and microbial biomass N and microbial biomass P and soil pH value).Study of different forest of eucalyptus plantation soil nutrient elements (soil organic carbon, total nitrogen, total phosphorus, total potassium, available nitrogen, available pHospHorus and available potassium, microbial biomass carbon and microbial biomass nitrogen and microbial biomass p and soil pH value) of the dynamic change characteristics and soil microorganisms (bacteria, fungi, actinomycete) number and soil enzyme activities (sucrase, urease, acid phosphatase, catalase) the seasonal change rule, and using the correlation analysis to the relationship between the measurement indicators for further discussion.Aimed at comprehensive systematic analysis of eucalyptus plantation soil microorganisms and the related factors, the relationship between ecological environment in order to understand the north guangxi region of eucalyptus plantation soil fertility, in order to improve the soil quality of eucalyptus plantation and sustainable use of land resources, and eucalyptus artificial forests provide certain theoretical basis to continue as a going concern. The main results were as follows:(l)The soil nutrient content and soil microorganism quantity and soil enzyme activity of three indexes has obvious vertical variation trend, with the increase of soil depth of soil layer and shows the tendency of decline.(2)The variations of soil nutrient elements in different tree age of eucalyptus plantation as follows:the soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), available nitrogen (AN) four nutrient element content is lower than pine (control) Lin;Total phosphorus (TP), available phosphorus (AP), available potassium (AP), microbial biomass carbon (MBC) and microbial biomass p (MBP) 6 to 5 nutrient element content of indicators were higher than pine; And the content of microbial biomass n (MBN),4 years of living eucalyptus forest slightly greater than the pine forest land,1,2,3,5 gradient eucalyptus forestland are less than four old pine.Tree different gradient of eucalyptus forest land nutrient elements exist certain differences, in addition to total nitrogen and available p 5 old gradient difference is not obvious, the rest of the eight kinds of nutrient elements show obvious difference.soil.(3)The different age of eucalyptus plantation soil microorganism quantity and soil enzyme activity are there was a seasonal variation law.Three kinds of soil microbial number of seasonal change rule is:the seasonal changes of bacteria and actinomycetes were:autumn> summer> spring> winter;Fungi number of seasonal change is usually spring material winter> autumn> summer.Seasonal variation of soil enzyme activity are as follows:soil invertase:autumn> summer> spring> winter.Urease:summer> autumn> spring> winter.Acid phosphatase:summer> autumn> spring> winter;Catalase:summer> autumn> spring> winter.(4)The different tree eucalyptus plantation soil microorganisms and soil enzyme activity varied with the change of old gradient. Spring:contrast plantation> 2 years> 1 year> 5 years> 3 years> 4 years;Summer:1 years> 2 years> 3 years≈contrast plantation> 4 years> 5 years;Autumn:1 years> 2 years> 3 years> 5 years> 4 years≈contrast plantation;Winter:contrast plantation> 1 years> 2.years> 3 years> 5 years> 4 years;The change of the soil actinomycetes as follows:the change of the four seasons are:1 years> 2 years> 4 years> 3 years> contrast plantation> 5years;The change of soil fungi is:spring:1 year> contrast plantation> 5 years> 2 years> 3 years> 4 years;Summer:contrast plantation> 2 years> 1 years> 4 years> 3 years> 5 years;Autumn: contrast plantation> 5 years> 3 years> 1 years>2 years> 4 years;Winter:reference> 1 year 2 years> 3 years> 4 year> 5 years.Soil enzyme activity varied with the change of old gradient for, four kinds of soil enzyme activity were present eucalyptus forest below the pine (contrast) Lin, four seasons presents a certain consistency.The change of the invertase is:the four seasons are:1 year< 2 years< 4 years< 3 years 5 years Lin;The changes of soil urease activity is:spring, autumn and winter three seasons are characterized by:3 years< 1 year<4 years< 5 years; Summer:3 years< 2 years< 1 year< 4 years< 5 years;The change of soil acid phosphatase:spring and autumn is shown as:5 years> 4 years> 2 years> 1 year>3 years;Summer:4 years≈5 years> 2 years> 1 year>3 years;Winter:5 years> 4 years>1 year> 2 years> 3 years;Soil catalase activity change for: spring, autumn and winter are:4 years>5 years≈3 years> 2 years> 1 year;Summer is:5 years> 4 years> 3 years> 1 year>2 years(5)By the correlation analysis results show that the eucalyptus plantation soil enzyme activity and soil nutrient index there is a certain relationship, and most of the nutrients present significant (P < 0.05) or extremely significant(P< 0.01) positive correlation;Four of eucalyptus plantation soil enzymes (sucrase, urease, acid phosphatase and catalase activity and bacteria and actinomyces appear significantly (P<0.05) or very significant (P<0.01) negative correlation with fungi present a certain number of negative correlation, but the correlation was not significant (P>0.05); there were significantly (P<0.01) positive correlation between four kinds of soil enzyme activity.(6) The pinus massoniana after planting eucalypt soil nutrient status present vacancies on phosphorus and potassium deficiency phenomenon.(7) The eucalyptus plantations of pinus massoniana plantation transformation, to a certain extent, the phenomenon of the decline of soil fertility.Therefore, it is suggested that through reasonable artificial management measures, to create a good living environment for eucalyptus plantation soil microorganisms, is beneficial to the improvement of soil quality, to better promote the sustainable development of eucalyptus plantation industry.