[Spatial distribution pattern of Larix chinensis population in Taibai Mt].

Larix chinensis is an endangered species only distributed in Qinling Mountains of China. It has a concentrated distribution in Taibai Mt., and plays an important role in environmental protection in the high altitude. After an investigation on fifteen 400 m2 plots, a comparative study on the spatial distribution pattern of L. chinensis population and its dynamics was made by the tests of discrete distribution pattern and aggregation intensity. The results showed that at different sampling areas, L. chinensis populations all performed the pattern of clustering distribution. As the sampling area increased, the congregating intensity of L. chinensis population appeared the pattern of high-->low-->high, but the highest congregation occurred in the areas of 100 m2 and 25 m2. The clustering intensity went down from low to high altitude, and the area with the highest clustering intensity occurred on that of 25 m2 in low altitude, 150 m2 in middle altitude, and 100 m2 in higher altitude. The clustering intensity in shade slope was higher than that in sunny slope, and the area with the highest clustering intensity was 100 m2 on shade slope, and 150 m2 on sunny slope. With the population age increased, the distribution pattern had a trend from clustering to random, the clustering intensity decreased somewhat, and the area with the highest clustering intensity was 150 m2 in young or old stages, and 100 m2 in middle stage. The distribution pattern of L. chinensis population was related to its ecological characteristics, community composition, and environmental factors. In situ conservation should be strengthened in the future. In lower altitude or on shade slope, the measurements of thinning no-aim in tree and shrub species should be taken; while in higher altitude area or sunny slope, thinning shrub species in patch form would be better for L. chinensis populations block renovating. The fostering area for L. chinensis populations should be suit to the area with the highest clustering intensity of populations.