Study On Population Dynamics And Spatial Pattern Of Pinus Tabulaeformis And Quercus Wutaishanica In Lingkong Mountain

The purpose of this thesis is to better understand the plant community dynamics, the maintenance of species biodiversity, and the species spatial distribution in Lingkong Mountain Nature Reserve of Shanxi province. A4-hm2permanent plot was established for community monitoring in2011, in accordance with the standards by CTFS (Centre for Tropical Forest Science), with the target species of Pinus tabulaeformis and Quercus wutaishanica. The ecological parameters used in the study included the age structure, the spatial distribution seedlings and young trees, and the relevant correlations, to analyze the succession, stability and development trend at community level.The theory of survival analysis was employed to examine the relationships among the variables of trunk diameter, height, DBH for formulating the static life table and the survival curves of P. tabulaeformis and Q. wutaishanica. The results showed the following.(1) The age structure of P. tabulaeformis took the pyramid shape, indicating the growth phase; and that of Q. wutaishanica took the shuttle shape, indicating the stability shape.(2) The linear regressions demonstrated the relationships between tree height and DBH as y=5.14211n(x)-0.8873in P. tabulaeformis and y=4.52641n(x)-0.64in Q. wutaishanica.(3) For both species the maximal life expectancies was higher than the age of the highest mortality, and corresponded to the lowest point value of mortality density, suggesting the relatively vigorous life expectancy for the seedlings and young trees after the natural selection and intraspecific competition.(4) The survival rates for both species were found well fitting the Deevey-Ⅱ curve, indicating the stability populations, of and can be regarded as the steady species.(5) The survival analysis implied the population dynamics of P. tabulaeformis as early growth, medium-term stability and post recession; and that of Q. wutaishanica as early recession, medium-term growth and post stability.The analysis of the pattern of spatial distribution of the two species of seedlings and young trees using language R shows that the distribution of seedlings and young trees of P. tabulaeformis was somewhat complementary, while that of Q. wutaishanica were uniform as a result of clustered distribution of seedlings and low density of young trees. Generally speaking, the distributions of the seedlings of the two species were somehow aggregated with spatial complementation, which was not found among young trees. The latter was more likely uniform in distribution.Using the method of point pattern analysis—O-ring statistics, we analyze the spatial pattern and correlation between the seedlings and young trees for both species. The results are as follows.(1) The distribution of seedlings of P. tabulaeformis and the young trees of Q. wutaishanica presented significant aggregation in small scale but random distribution in large scale. Meanwhile, the distribution patterns of the young trees of P. tabulaeformis and the seedlings of Q. wutaishanica were less stable.(2) For both species the seedlings and young trees showed the positive correlation in small scale, without significant relationships in rest scales.This study indicates that the presently existing the Form of P. tabulaeformis-Q. wutaishanica was dominated by P. tabulaeformis, being in the intermediate stage in the succession from the mixed forest of broad-and needle-leaf trees to broad-leaved forest.