Study Of Species Abundance And Distribution Patterns Of Pinus Tabulaeformis And Quercus Liaotungensis In Taiyue Mountain

In this research the author surveyed a permanent4-hm2sampling plot in Lingkong Mountain of Shanxi province in North China. The data were collected for examining the species abundance in four ecotypes as categorized with geographical and environmental features such as slope: the "R" type (Ridge), the "G" type (Gentle slope), the "S" type (Steep slope), and the "V" type (Valley). The data were processed using the the random distribution-abundance model, the aggregation distribution-abundance model, the abundance in unit sample, the component abundance similarity/dissimilarity percentage, the O-Ring function, for the analysis on the species abundance distribution pattern in the sampling plot in Lingkong Mountain in a systematical way. The research results are summarized as follows.(1) The Quercus liaotungensisis and Pinus tabulaeform were dominant in the community, along with the arbors and shrubs of high abundance including the Pyrus betulifolia, Rosa xanthina, Lonicera chrysantha, and Spiraea pubescens. The community is characterized by abundant species diversity and stable structure. The number of species of scattered distribution was greater than that of densely populated.(2) Among the30species of trees and shrubs19species showed increasing trend in terms of abundance, along with the expanding horizontal space. In contrast the rest11species did not show such clines.(3) In Lingkong Mountain the distribution of plant species was more aggregated than random in the scope of small scales. However, as the research scale got larger the distribution pattern gradually turned to random.(4) In abundance of trees and shrubs species were the largest in "V" habitat but the least in "S" habitat. This suggests that the species distribution tends to prefer the "V" habitat in Ling-kong Mountain. The "R" habitat is good for the trees rather than shrubs, as evidenced by huge difference in abundance between trees and shrubs. The "S" habitat prefers the growth of shrubs in stead of trees, as evidenced by the least difference in abundance between trees and shrubs. It is noted that tree species had a broader ecological niche than shrub species.(5) The Pinus tabulaeformis showed the largest abundance in R habitat, while Quercus liaotungensis demonstrated the same characteristics in "V" habitat. Interestingly the two tree species showed the highest percentages in similarity/dissimilarity analysis (i.e. extremely similar). The largest abundance of shrubs were also observed as the Rosa xanthina in "R" and "G" habitat, Lonicera chrysantha in "S" habitat, and Spiraea pubescens in "V " habitat. It is noteworthy that the species abundance distribution depended on the scales of the sampling areas in all4habitat categories.(6) The results suggests that the extrapolation based on small-scale data to larger scale would distend errors in the study of forests found in diversified topographic landscapes and habitats.(7) The aggregation distribution-abundance model described the community data obtained in Lingkong Mountain better than the random distribution-abundance model. For both models the goodness-of-fit were dependent on the number of image pixels, i.e. the smaller size of image pixel rendered higher accuracy. Other simulation models such as the sample abundance, component abundance, percentage of similarity/dissimilarity, and the O-Ring functions are of practical significance in analyzing species abundance in specific perspectives. It is suggested to use multiple models for comparing and verifying the results for improved accuracy.