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Effects Of Different Vegetayion Restoration Models On Plants,Soil And Microorganisms In The Mashan Karst Area

Posted on:2022-09-02Degree:MasterType:Thesis
Country:ChinaCandidate:Y N ZhangFull Text:PDF
GTID:2480306536452264Subject:Ecology
Abstract/Summary:PDF Full Text Request
Currently,vegetation restoration in karst areas has relatively little overall research on plants,soils,and microorganisms.In particular,there is a lack of comparative studies on pure and mixed forests of nitrogen fixing species.This research took the precious nitrogen-fixing tree species pure Dalbergia odorifera plantation(DOP),pure Acrocarpus fraxinifolius plantation(AFP),and their mixed plantation(MDA)as the research objects,natural restoration shrub land(SL)were used as the control.Field surveys,indoor biochemical analytical testing and statistical analysis methods were used,to study the plant diversity,soil physical and chemical properties,soil enzyme activity,soil microbial community structure,and microbial carbon source utilization capacity of different vegetation restoration models to reveal the effects and mechanisms of different vegetation restoration modes on plants,soil and microorganisms,and to provide scientific basis for the selection of tree species and stand types and management in the vegetation restoration of rocky desertification in karst areas.The main findings are as follows:(1)There were significant differences in the composition and diversity of understory plants in different vegetation restoration modes.There were 43 species of plants in SL community,and the dominant plant functional groups were fern plant functional groups(Fe FG),woody plant functional groups(WFG)and gramineae plant functional groups(GFG),and the dominant species were Nephrolepis cordifolia(IV: 31.00),Vitex negundo(17.91),and Ottochloa nodosa(8.71).DOP,AFP and MDA species composition were 48,41,and 37 species,their common advantage plant functional groups were forb plant functional groups(Fo FG),Fe FG and GFG,the dominant species corresponding to Torilis scabra(16.26),Nephrolepis cordifolia(14.72),Arthraxon hispidus(9.37);Bidens pilosa(23.37),Nephrolepis cordifolia(11.65),Miscanthus floridulus(8.12);Bidens pilosa(25.87),Arthraxon hispidus(9.42),Nephrolepis cordifolia(8.30).The Shannon-Wiener index and Simpson index of DOP were signally higher than those of SL(P<0.05),but there were no notable differences between other stands and SL(P>0.05).(2)There were no significant differences in the contents of soil organic matter,organic carbon,total nitrogen,total phosphorus,total potassium,available phosphorus,available potassium and ammonium nitrogen between the three plantations at 0-10 cm,but the contents of soil organic matter,organic carbon and available phosphorus were significantly higher than those in SL.On the contrary,the soil ammonium nitrogen contents of the three plantations were memorably lower than that of the SL,while soil total N,total P,total K and available K of the three plantations had no significant difference with SL.The soil nitrate nitrogen content of DOP was significantly higher than that of other stands and SL,but the exchangable calcium content was significantly lower than that of SL.The soil exchangable Mg in AFP was strikingly higher than that in other stands and SL.The soil cation exchange capacity of MDA was significantly higher than that of DOP and SL.The remediation effect of the three plantations on 10-20 cm soil was similar to that of 0-10 cm soil,but the intensity was obviously weakened.(3)Soil microbial community structure,function and enzyme activities were significantly affected by different vegetation remediation modes.PLFA contents of soil microbial community in plantations were lower than that in SL.Except for fungi,the PLFA contents of other microbial communities in DOP were higher than those in other stands.The ratio of fungi and bacteria in DOP was lower than that in other stands and SL.Soil microbial carbon utilization capacity of DOP was signally higher than that of other stands,but had no significant difference with SL.However,the utilization of soil microbial carbon sources in the MDA and AFP were significantly lower than that in the SL.The activity of soil hydrolase in artificial forests were lower than that in SL,but the activity of soil hydrolase in DOP was higher than that in other stand.The activity of oxidase in DOP and MDA were significantly lower than that in SL.The phenoloxidase activity in AFP was significantly higher than that in the other two stands and SL,while the other two stands were significantly lower than that in SL.There were no significant differences in soil peroxidase activity between AFP and SL,but it was significantly higher than DOP and MDA.(4)The comprehensive evaluation of the restoration effects of the three plantations revealed that DOP had the most obvious effect on the restoration of understory plant diversity,soil physical and chemical properties,soil microbial community structure,soil enzyme activity and soil microbial function.Therefore,DOP is a better choice to restore the karst rocky desertification ecosystem in the south subtropical region.
Keywords/Search Tags:Karst area, Vegetation restoration, Plant diversity, Soil physical and chemical properties, Soil enzyme activity, Microbial community structure, Microbial carbon source utilization
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