Study On The Highness Class Structure Of Different Defense Lines On Sandy Coast Of Dongshan Dao In Fujian Province

Regarding to the study on the highness class structure of defferent defense line,nowadays we pay little attention to it in the protection forest area so that we are necessary to carry on this study。This paper studied on five defese line on sandy coast in dongshan dao,Fujian province.We carry on system survey to five defese line by means of the method of contiguous quadrat transect.We apply the method of comparative analysis on importance value,the structure and dynamic of the dominant population,theβdiversity (Cody index,Morisita-Horn index,Bray-Curtis index,Routledge index) and niche to studing the highness class structure,stability,self-renewal capacity and recovering succession of different defense line,which is to reveal he change discipline of different defense line.Comparing the effects of the study on the highness class structure of defferent defense line on the recovering succession,it is helpful to the reasonable structure configure of protection forest system and further provides theoretical basis for discussing on the construction and mangement of the protection forest system.The results are as follows:1.With the defense line passing backward, the importance value of Casuarina equisetifolia show the descending trend in the arbor layer and shrub layer,however,the importance value of Litsea glutinosa show the rising trend in the arbor layer and shrub layer,the results of DUNCAN: In the arbor layer,the importance value of Casuarina equisetifolia and Litsea glutinosa among No5 and No4 and No3 indicate significant difference at 0.05 level,In the shrub layer,the importance value of Litsea glutinosa among No5,No4 and No3 indicate significant difference at 0.05 level,the importance value of Casuarina equisetifolia among No2and No3 and No4 indicate significant difference at 0.05 level.2.The lost stabe rates of the Litsea glutinosa population between No4 and No5 is approach,(the lost stabe rates of No4: 73.5 %,the lost stabe rates of No5: 75.5 %) which shows that itpossess favorable adaptability and growth,howerver,The lost stabe rates of No5 is further larger than No4.With the recovering succession going on,the community of No4 become to stable.The lost stabe rates of Casuarina equisetifolia population and community between No2 and No3 areminus,which show that it is unstable.From No2 to No5,the community become more and more stable.The size structure of Casuarina equisetifolia is narrow base,which shows that it is desecending population;The size structure of Litsea glutinosa is wide base likely to Pyramid, which shows that it is growing population;With the recovering succession going on,the community of between No4 and No5 become more and more stable.The weighting average rate of change of the Casuarina equisetifolia among No2,No3,No4 are minus,which shows that it is desecending population,the desecending ability of the population is ordered:No2> No3> No4;The weighting average rate of change of the Litsea glutinosa between No4 and No5 are postive;which shows that it is growing population,the growing ability of the population is ordered:No5> No4.3.This paper base on the analysis ofβdiversity,which indicate that from 2-3 to 8-9 heightclass,The relationship of indexes (βC,βR)is as follws:No5> No4> No3,which indicate that from 3-4 to 8-9 heightclass,The relationship of indexes (CMH,CN)is as follws:No3> No4> No5.We carry on the correlationship comparison to No3,No4and No5 betweenβdiversity indexes and the height class,which indicate that the correlationship between indexes (βC,βR ) correlationship betweenCMH indexes highness are not significant.The rule of change between indexes (βC,βR )and indexes (CMH,CN)is nearly opposite,which show that on the height class the higher the alternation rare.There is no eminent discrepancy inβC1,βR1, CN1, CMH1 between No2 and No3,There is no eminent discrepancy inβC1,βR1, CN1, CMH1 between No4 and No5,There is eminent discrepancy inβC1,βR1, CN1, CMH1 between No2,No3 and No4,No5.The relationship of indexes(TotalβC) is as follws:No5> No4> No3> No2,which show that the nearer the mainland,the more the species,The stronger the self-generation.4.With the defense line passing backward,the nearer the mainland,the stronger species ues space resource,the more the species mumbers,the fewer the simirarity speceis ues space resource,With the recovering succession going on,between No1 and No2 become to stable,Becausethe population of the Casuarina equisetifolia is desecending,No3 become to stable.With the Casuarina equisetifolia of the No4 desecending,the population of Litsea glutinosa gradually take place of the population of Casuarina equisetifolia , which controll the all community.However,niche similarity and overlap of the both Casuarina equisetifolia,Litsea...