Abstract: Based on the self-correlation theory in geography and the National GIS database (1∶250000), the human activity intensity (HAI) and its spatial characteristics in the upper reach of Minjiang River were quantified and spatialized by calculating the weighted factors of roads, settlements and terrain. The results showed that the size and distribution pattern of HAI varied with the counties in the study area. In Heishui County, HAI was the strongest and had the most uniform distribution; in Lixian and Maoxian Counties, both the size and the distribution of HAI were close to the average; in Wenchuan County near Chengdu Plain, the HAI was rather low and distributed unevenly because of its covering Wolong Giant Panda Natural Reserve; while in Songpan County, it was low in HAI due to the low density of roads and settlements. It was a realistic and efficient way to delineate and analysis the HAI by gaining and integrating the factors of roads, settlements and terrain, which would benefit the further research of landscape pattern change.

Key words: Hepatacodium miconioides, Natural population, Genetic diversity, Genetic differentiation, RAPD