Study On Quantitative Ecology Of Betula Platyphylla Communities In Cutting Blank Of Qiliyu Region, Shanxi

This thesis takes Betula platyphylla Communities in thecutting blank of Qiliyu region as the research object,On thebasis of field investigation to make a comprehensive andsystematic study by using quantitative ecology methods inorder to provide some scientific theoretical reference forgrowth,development and protection of Betula platyphylla.Thisstudy contains Community characteristics、Species dive-rsity、interspecific relationship、age structure、population dynamics、Spatial pattern.The results show that:(1)There are totally117species of Betula platyphyllaCommunities in research plant community,belonging to35families and83genera among which there is1species(Equisetum arvense)of Pteridophyte in Family1(Equisetaceae),Genus1(Equisetum),2species (Pinus tabulaeformis and Larixprincipis-rupprechtii)of Gymnosperm in Family1(Pinaceae),genera2(Larix and Pinus),The rest are Angiosperms.(2)The type of distribution was diverse, including6distributiontypes of Family and11distribution types and variant of Genus.The areal types of all Family and Genus are north temperate share thelargest proportion.And overall, the flora belongs to temperate zonein nature.(3)The species diversity of the3layers of Betula platyphyllacommunities were studied by using Margalef and Patric richnessindices, Shannon-Wiener and Simpson diversity indices, Pielou andAlatalo evenness indices,Simpson dominance indices, respectively.The results showed that: The change trend of Margalef and Patricrichness indices was similar to that of Shannon-Wiener diversityindex,the species diversity of Betula platyphylla communitiesbelongs to herb layer＞shrub layer＞tree layer,but the Pielou andAlatalo evenness indices was not obvious.(4)In view of2×2contingency table,some quantitative analysis methods such as chi-square test,Pearson correlationcoefficient and Spearman rank correlation coefficient testare used to do interspecific correlation analysis of survivalcommunities of Betula platyphylla community. According toresults from chi-square test,there are65species-pairs showpositive correlation and88specie-pairs show negative corr-elation among all153species-pairs,the ratio of positive and negative correlation is0.74;with regard to Pearson correl-ation coefficient, there are58species-pairs are positivelycorrelated and95species-pairs are negatively correlated,the ratio of positive and negative correlation is0.61;as forSpearman rank correlation coefficient test,there are68species-pairs having positive correlation and85having negative correlation among all153species-pairs, the ratio of posit -ive and negative correlation is0.8.The majority of the overall is negative association,So Species dependent on each ot-her or competition degree is not strong in this communitywhich is in the stability.(5)The age structure of the Betula platyphylla population ofthe Qiliyu region followed a spindle shape,which indicated thatthe population was declining;mortality rate and vanishing rateis almost the same change trend,all peak level appeared in ageclass5, and the survival curve of the populations was Deeveytype Ⅰ;Four survival functional curves showed that the Betulaplatyphylla populations decreased at young stage,grew very qui-ckly at mature stage and stably at old stage.Time sequence pr-ediction models for different populations after2a,5a,7a yearsindicated that the numbers of old individuals would increase,while young stage and mature stage are declined.(6)Through replacing time with space,using Point patternanalysis to study the spatial pattern and individual association ofBetula platyphylla.The results show that:The densities of nineage-classes varied in the order: age-classⅣ＞age-class Ⅴ＞age-classⅢ＞age-classⅡ＞age-class Ⅵ＞age-classⅠ＞age-classⅦ＞age-classⅧ＞age-class Ⅸ. The spatial patterns of differentage-class individauls and the spatial association between theindividauls had a relationship with the spatial scale. The individualsof all age-class tended to disperse randomly within a small-scaleand a large-scale, clumped within a middle-scale;It showedrandomly distribution for the less number in each age class in thecorresponding. The relationships among each age group turned no-significant or negative association with the Increases of thescale,except a positive relationships between Age group young andage group middle.