Study On The Population Ecology Of Pteroceltis Tatarinowii In Ciconia Nigra Nature Reserve, Shanxi, China

On the basis of field investigation, Pteroceltis tatarinowii wastaked as the research object, and the methods of quadrat surveyand quantitative ecology were applied for survey the Pteroceltistatarinowii population in Lingqiu Ciconia nigra Nature Reserve.Pteroceltis tatarinowii population structure and dynamics,community characteristics, species diversity and inter-specificassociation and niche of main populations within communities wereresearched to better understand the current situation and futurepopulation development trends. For better protection of theendangered species provides scientific basis.(1) In Lingqiu Ciconia nigra Nature Reserve, zonal vegetationwas deciduous broad-leaved forest and community structure wassimple. Pure Pteroceltis tatarinowii forest was the major formationtype and distribution altitude range was600m~950m. In thecommunity, there were40species of seed plants, belonging to24families,40genera, and three kinds of ferns, belonging to twofamilies, two genera. Trees were small trees, the height was lessthan8m, Pteroceltis tatarinowii community was the main type. Inshrub layer, Vitex negundo, large shrub, was apparent dominance.Herb layer species were relatively high. In the community, thespecies richness index, Shannon-Wiener index and Pielou evenness index were all herbaceous layer> shrub layer> tree layer, butecological dominance, Simpson index, was the shrub layer> treelayer> herb layer.(2) The static life table of Pteroceltis tatarinowii population wasestablished. The population dynamics was analyzed by the curvesof survival rate, mortality rate and vanishing rate. At the same time,survival functions, quantitative analysis methods of populationdynamics were used. The results showed: The dynamics indices ofpopulation quantitative change were greater than zero. The agestructure of population was growth pattern, but fluctuation existedin the process of population development. The fitting resultsshowed that survival curve of population appeared to be of DeeveyⅡ type.The mortality rate curve and disappearance rate curve hadsimilar variation trend with the peaks in the3rd age class periods.The varied ranges of survival function and the cumulative mortalityfunction were larger at early stage than at late stage, and thevariation trend of two curves tended to be gentle at late stage. Themortality density was higher at early stage than at late stage, butthe hazard rate curve was increasing with the growth of age class.(3) Based on2×2contingency table, and by using quantitativeanalysis methods, this paper studied the inter-specific relationshipof14dominant species in Pteroceltis tatarinowii community inLingqiu Ciconia nigra Nature Reserve. Significantly positiveassociations existed among the14dominant species, whichsuggested that the community was stable. The χ2test showed thatonly13pairs were significant and highly extremely significantassociations, and Pteroceltis tatarinowii population was not significant association with other populations.Pearson’s correlationcoefficient test showed that23pairs were significant and highlyextremely significant association. Pteroceltis tatarinowiipopulation had significantly positive association with Vitexnegundo var. heterophylla and significantly negative associationwith other most species. Spearman’s rank correlation coefficienttest showed that30pairs were significant and highly extremelysignificant association. Pteroceltis tatarinowii population exitedsignificantly and highly extremely significantly negativeassociation with other most species. Species were differentlyadaptive for habitats and segregated niches, and maturity degree ofcommunity was high.(4) The niche characters of14major populations were analyzedon the use of Shannon-wiener index, Levins niche breadth, Schoenerindices (niche proportional similarity) in Pteroceltis tatarinowiicommunity. The results showed that: The two kinds of nichebreadth indexes results were consistent, niche breadth indescending order was Pteroceltis tatarinowii、 Vitex negundo、Sageretia paucicostata、Celastrus orbiculatus、Spiraea trilobata、Ulmus pumila、Indigofera tinctoria、Rhamnus davurica、Carpinuscordata、 Myripnois dioica、 Amygdalus davidiana、 Rhamnusparvifolia、 Celtis sinensis、 Fraxinus chinensis. The dominantspecies of tree layer, Pteroceltis tatarinowii, niche breadth was thegreatest, and in shrub layer niche breadth of Vitex negundo was thegrteaest.Around Pteroceltis tatarinowii, degrees of niche overlap were small.Wide niche breadth species existed larger niche overlap to narrow niche species, and narrow niche breadth species existed smallerniche overlap to wide niche species.