Study On Quantitative Ecology Of Pteroceltis Tatarinowii Natural Communities In Lishan Nature Reserve, Shanxi, China

On the basis of field investigation and indoor measurement, this thesistakes Pteroceltis tatarinowii as the research object to make a comprehensiveand systematic study on the Pteroceltis tatarinowii natural communities inLishan nature reserve, applying the method of quantitative ecology fromcommunity ecology and population ecology. This study contains communitynumerical classification and ordination, community diversity, populationphenotypic of leaf and seed, population interspecific relationship of dominanttree species, population quantitative dynamics and population spatial patternanalasis of individuals in different age-classes and so on. The results showthat:(1) The Pteroceltis tatarinowii natural communities were classified into12associations by TWINSPAN. The result of DCA and CCA clearly reflect therelationship between the distribution pattern of natural communities andenvironmental gradients. The first CCA ordination axis of quadrats isnegatively correlated with soil water content, and negatively correlated withslope secondly, and positively correlated with alatitude. The second CCAordination axis of quadrats is positively correlated with humidity and soil watercontent, then negatively correlated with slope and litterfall. The first CCAordination axis of species is negatively correlated with slope and litterfall, andpositively correlated with humidity. The second CCA ordination axis of species is positively correlated with soil water content, and negatively correlated withalatitude and slope.The soil water content is a decisive element to Pteroceltistatarinowii natural community.(2) The species richness of tree stratum and shrub stratum are similarwhich are obviously lower than herb stratum. The trend of dominance in eachlife form was the same as the species richness. Species diversity index fordifferent strata is in the following order:herb stratum＞shrub stratum＞treestratum.As for the evenness, shrub stratum is similar to herb stratum and bothare with small variation among communities. Then tree stratum of differentcommunities change large in evenness.(3) Analysis of variance for lot traits showed differences and significantdifferences between populations. The mean phenotypic differentiationcoefficient among populations was40.082%, compared to59.918%withinpopulations. In different individuals within populations, the differentiationcoefficient of phenotypic traits of leaf area, leaf length, leaf mean width, petiolelength, leaf dry weight, fruit area, fruit length, fruit mean width, carpopodiumlength, fruit dry weight, seed length, seed width was5.47%,7.78%,8.60%,12.13%,29.85%,33.33%,41.36%,46.75%,69.60%,72.15%,76.00%and77.98%, respectively. Some traits were plus-minus correlated and positivelycorrelated. The leaf mean width, petiole length, fruit mean width, seed lengthwere thought to be the most important traits that ware easy to measured inPteroceltis tatarinowii Maxim. According to UPGMA cluster analysis, the8populations of Pteroceltis tatarinowii Maxim. could be divided intothree-groups.(4) The frequency of dominance of Pteroceltis tatarinowii in Lishan wasranked an A class by Raunkiaer’s law of frequency. Pteroceltis tatarinowiidominated in the canopy more than in the subcanopy and understory. BothSpearman rank correlation(SRC) coefficients and Person correlationcoefficients indicated that the number of positive covariation couplets was lower than those negative covariation couplets in the forest community, thehighest negative covariation couplets was Pteroceltis tatarinowii with diospyroslotus. In all significant or positively significant covariation couplets whichcontain Pteroceltis tatarinowii, Pteroceltis tatarinowii with another species wasalways significant or very significant negative correlation. The slope, litterfalland soil water content had significant correlations with the three axis in CCAplot. The categorization of18plant species found in the canopy was madeaccording to the characteristics of the species along the second axis. Soilwater content was the most effective factor influencing the distribution ofPteroceltis tatarinowii. Cluster Analysis divided the dominant tree species inLishan natural forest of Pteroceltis tatarinowii into three categories.(5)In different habitats of Reserve, the DBH structure of Pteroceltistatarinowii populations differed with habitats, the population A was presentedas spindle type, belongs to stable population; the population B and C werepresented as pyramid type, belong to growth population. The populations haddefinite fluctuations in their growth dynamics, but the dynamic indices Vpiand V/piwere both greater than zero. A stable-growth type population was shown indifferent habitats. In different habitats of Reserve, the survival curves ofPteroceltis tatarinowii populations differed with habitats, inclined to be Deevey-Ⅲ type on population A and Deevey-Ⅱ tye on population B and C. In differenthabitats of Reserve, the mortality curves of Pteroceltis tatarinowii populationsdiffered with habitats, population A and C have a higher mortality at youngstage as population B and C have a higher mortality at middle stage.4)The foursurvival function curves indicated that the populations in Reserve were stableat young, decreased rapidly at mature, and declined at old stage.(6) The densities of twelve age-classes were different each other inPteroceltis tatarinowii natural populations. The young age-classes and middleage-classes had many more individuals than old age-classes, which indicatedthat the population was currently in increase. The individuals of young age-classes and middle age-classes focused on clumping distribution in space.The feature of clumping distribution became more significant with increasingscale. The spatial distribution pattern of old age-classes were tend to randomdistribution and uniform distribution.