Study On Population Dynamic And Community Dominance Species Niche Of Quercus Liaotungensis

This research aimed at profound understand systemic ecological rules of Quercus liaotungensis community,including population dynamic variety,cause of formation of the spatial pattern,the ability to use resources of every population of Quercus liaotungensis communities and competition mechanism of populations according to investigating the spatial pattern of population,quantitative dynamics,biodiversity and dominant species niche of Quercus liaodunensis communities in Huanglong Mt. of Shannxi. The result can provide scientific basis for embedded probe into succession of Quercus liaotungensis communities and advanced management and protection of the existing forest resources in Huanglong Mt.forest region, realize the rational exploitation and eternal sustaining utilization; offer supervise for the ameliorating environments, rebuilding and restoring ecosystem. The results are as follows:1.Survival curve of Quercus liaotungensis population trend to DeeveyⅢin the whole.Flood tide of appeared inⅢage stage andⅫage stage, fluctuate frequency is high and the change scope is great.It had closed correlation to frequently activities of man.The results of spectral analysis showed that Quercus liaotungensis population renovate course occurred periodicity.2.Quercus liaotungensis population take on aggregated distribution in the whole ,but the spatial pattern intensity occurred differences at different scale, the highest aggregating intensity appeared at the quadrat of 25m2. It presented an aggregating distribution at different growth stages, As Quercus liaotungensis populations be-came older,their aggre-gating intensities came down; The spatial distribution of the populations closely related to their biological and ecological characteristics and habitat conditions ,the pattern of the spatial population distribution of Quercus liaotungensis changed as age-stage can regarded as transformation of survival politic3.Quercus liaotungensis communities can be classified into six association types by clustering method, namely A. Quercus liaotungensis—Spiraea pubescens B. Quercus liaotungensis—Ostryopsis davidiana C. Quercus liaotungensis—Lespedeza bicolor D.Quercus liaotungensis—Cotoneaster multtflorus E. Quercus liaotungensis—Sophora viciifolia VCF. Quercus liaotungensis—Rosa hugonis. Additionally, by means of the calculation of the species diversity of different Quercus liaotungensis forest and different slope, it is shown that diversity indices of each community relate closely with the their habitats; the slope directions are main factors influencing the species diversity on the indices ,actually it is water that influences them.4.The results of research of niche breadth and niche overlap of the dominant populations in Quercus liaotungensis communities,it is shown that comparing with other species, the niche breadth of Quercus liaotungensis,Pinus tabulaeformis and Betula platyphylla is bigger (LNB=1.4611,1.4132,1.2588 respectively) and the niche overlap is bigger among them too(Oik>0.7); the niche breadth of Spiraea pubescens,Ostryopsis davidiana,Atermisia sacrorum and Rosa hugonis, that are common species in Quercus liaotungensis communities, is bigger than other shrub species because they are greatly adaptive and distribute widely in the area; the niche breadth of Carex lanceolata,Saussurea mongolica,Poa pratensis and Spodiopogon sibiricus is greater than other grass species (LNB=1.4456,1.2841,1.0603,1.0573 respectively); the more the niche breadth of the populations is, the greater the ability to use resources is; the bigger the niche overlap value is, the more similar the ecological character is and the greater the similarity of using resources is.5.According to the results of research,two points should be followed in future Quercus liaotungensis forest management and utilization,one point,we should adapt different measure on different communities in order to exerting the best ecological and economic benefit.another point, imposing light jamming on survival environment of Quercus liaotungensis communities to improve the seed conversion rate to the seedling.