Study On Ecology Of Dominant Populations In Quercus Wutaishannica Communities In Pangquangou Natural Reserve, Shanxi

Based on the field investigation, the Quercus wutaishanica communities in Liushuigou of Pangquangou Nature Reserve, Shanxi were studied by the methods of quantitative vegetation ecology, including spatial point pattern, niche and population life table of the dominant population. The community structure, interspecific relationship, relationship between species and environment were analyzed, respectively. The aims of this study expected to present some scientific and theoretical basis for the conservation, utilization and management of Quercus wutaishanica communities.In the tree and shrub layers of Q. wutaishanica communities, the spatial point pattern and space correlation of dominant populations were analyzed, the results showed that:in sample 1, both the patterns of Q. wutaishanica and Picea wilsonii populations were random distribution under the scale beyond 10m; when the space scale was larger than the critical value at 2.5m the significant positive association between Q. wutaishanica and P. wilsoni populations became weak greatly. In sample 2, the patterns of Q. wutaishanica population was random distribution only at 3-5m scale and was significant aggregation distribution at the other scales; taking 2m as the critical value, the spatial pattern of Betula platyphylla population changed from clumped to nearly random distribution; when the scale is larger than 3m, their space correlation was negative association. In sample l,with increasing of scale, the patterns of Lonicera maackii population changed from distinct cluster mode to random mode, the patterns of Spiraea pubescens population had the opposite change trend for its distribution patterns compared with L. maackii population their relationship was obvious negative correlation as the increase of scale. In sample 2, Cotoneaster acutifolius population spread stochastically over different stands; the patterns of S. pubescens population was random distribution only in 0-3m scale and was significant aggregation distribution at other scales; there was no positive correlation between them. The spatial point patterns of the different age-classes of dominant populations in the tree layer were studied, the results showed:L. maackii population in sample 1 tended to clump with increasing of age-classes, both P. wilsonii population in sample 1 and B. platyphylla population in sample 2 were random distribution. The relationships between individuals in different age-classes of four dominant populations in the tree layer were almost not significantly correlated with each other.The niche breadth and niche overlapping of dominant populations of Q. wutaishanica communities were studied by using Shannon index and Pinaka index. The results indicated:the distribution ranges of Q. wutaishanica, S. pubescens and Carex lanceolata were extensive, well-adaptability to environment factors and took up more advantage status in competition, so they had widder niche breadth; Phlomis umbrosa, Aconitum sinomontanum and Triosteum pinnatifidum had narrow distribution, less effective capability to use the resource and disadvantages in competition with the other species, so their niche breadth were smaller. The niche breadth with frequency of species showed a significant positive correlation (P< 0.01), which suggested the niche breadth largely relaied on frequency of species. The niche overlapping among 15 dominant species occurred generally, except for Ph. umbrosa and A. sinomontanum, showing that there were some similaritive adaptive to environment. There was obvious overlapping between Q.wutaishanica and other dominant species. The correlation between niche overlap and niche breadth was not positive significantly.The static life table and survival functional curves of dominant populations in the tree layer of Q. wutaishanica communities were analyzed, the results indicated that in sample 1, the survival curve of Q. wutaishanica was consisted with Deevey-Ⅱ type, the survival curve of P. wilsonii was more of Deevey-Ⅲ type; Q. wutaishanica population had one peak of mortality rate in the seventh age-class period; Q. wutaishanica also had one peak of mortality rate, it is in the fourth age class. In sample 2, the survival curve of Q. wutaishanica appeared to be Deevey-Ⅱ type, the survival curve of B. platyphylla was likely to be Deevey-Ⅰtype; Q. wutaishanica had one peak of mortality rate in the fifth age class. Moreover, the hazard rate, mortality rate and vanishing rate functional curves of all of dominants had similar variation trend.