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The Impactof Different Management Measures On Plant Diversity And Soil Fertility In Eucalyptus Forest Land

Posted on:2019-02-22Degree:MasterType:Thesis
Country:ChinaCandidate:Q MaFull Text:PDF
GTID:2370330545967765Subject:Ecology
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In this paper,the eucalyptus forest land is taken as the research object,and four different management measures were adopted,which refers to manually clear forest land and weeding,only apply base fertilizer(A treatment),clear forest land by burning and conduct chemical weeding,apply base fertilizer and top dressing.(B treatment),manually clear forest land and weeding,apply base fertilizer and top dressing(C treatment),CK treatment was the control of forest land((manually clear the residue of eucalyptus cutting land and cutting off the root germination of eucalyptus,keep the shrub plants on the woodland and wait the shrub slope to be naturally restored).The plant diversity and the growth of eucalyptus trees were monitored regularly every year by setting fixed sample plots,and soil samples were collected every other year to test its nutrient content and enzyme activity.By exploring the impacts of different management measures on soil nutrients(organic matter,total nitrogen,alkali-hydrolyzed nitrogen,available phosphorus and rapidly available potassium),soil enzyme activities(sucrase,acid phosphatase,catalase and urease),plant diversity and the growth of eucalyptus,employing methods of variance analysis,correlation analysis,principal component analysis and other analysis method to conduct statistical analysis on the experiment result.The results show that:(1)The management measures of burning mountain and chemical weeding will lead to the decrease of soil organic matter and total nitrogen content in eucalyptus forest land,the huge loss of rapidly available nutrients,and the failure of topdressing to supplement soil nutrient content effectively.The correlation analysis of soil nutrient content showed that there was a positive correlation among soil nutrients(P<0.05).(2)The soil sucrase activity of treatment A,B and C decreased year by year,and the decrease of B treatment was the most significant one(P<0.01),but the activity of soil acid phosphatase was not obvious in the forestland treated with A and C measuredemonstrated a declining trend in the forestland treated with B measure;the soil catalase activity in B forest land was higher than that of other treatment forest land before afforestation,and then it decreased year by year,and there was significant difference between B treated forest land and CK treated forest land(P<0.05);The soil urease activity of forest land treated with A,B and Cmeasure show evident decline when compared with CK treatment land(P<0.05),among which the B treatment demonstrates the biggest decrease.The correlation analysis showed that there was a positive correlation among soil acid phosphatase,soil alkaline hydrolyzed nitrogen and rapidl available potassium(P<0.05),a negative correlation between soil catalase and soil alkali-hydrolyzed nitrogen(P<0.05),and no significant correlation among other enzyme activities and soil nutrients(P>0.05).The results of principal component analysis showed that the sequence of contribution rate of soil fertility was available potassium>organic matter>total nitrogen>available phosphorus>alkali-hydrolyzed nitrogen>acid phosphatase>urease>catalase>sucrase.(3)The management measures of burning mountain and chemical weeding will lead toa large-scale decrease of plant diversity,the change of vegetation structure,and the forest land will not be restored until 5 years after the disturbance is stopped.Through the correlation analysis of plant diversity and soil fertility,it is found that there was an evidentpositive correlation between plant richness and soil organic matter and available potassium content(P<0.05),and there was a positive correlation between woody plant richness and soil total nitrogen,rapidly available potassium content and acid phosphatase activity at 0.05 level.(4)The DBH,height and volume growth of eucalyptus treated withB measure showed a tendency to besmaller than those treated with A and C measure,however,the difference was not significant(P>0.05).It was showed in correlation analysis that there was no significant correlation between eucalyptus growth and soil fertility and plant diversity(P>0.05).(5)There is no obvious difference between the growth of Eucalyptus in A treatment?B treatment and C treatment.Then,A treatment have the advantages of imposing small ecological impact on eucalyptus forest land and resulting in comparatively lower tending cost,which can be preferably considered as a forestland management measure during the production of eucalyptus forest.
Keywords/Search Tags:eucalypt, woodland management, soil nutrient content, soil enzyme activities, plant diversity, growth
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