The change of land use and landscape pattern from 1991 to 2007 in Wuhan city was discussed based on Landsat5-TM data in 1991,2002,and 2007 with the support of GIS.Results showed that the landscape pattern in Wuhan city had been changed a lot during the last 16 years.The area of agricultural land and building land increased constantly,while those of water and forest land reduced.The landscape pattern could be characterized by gradually decreasing of landscape fragmentation degree,landscape diversity and landscape heterogeneity.The main reasons which led to the change in landscape pattern were the development of urbanization.

In this research, a reliable DNA extraction from different variety of Amorphophallus xiei was developed for RAPD analysis.The results revealed that the high quality DNA was extracted by the modified CTAB method and 8 random primers were used to identify the variety.The way of leaf dividing, the number of bulb and the strips of leafstalk in 9 varieties were analyzed.The results showed the Nei's similarity of coefficients were in the range of 0.440～0.800, the average Nei's similarity of coefficient was 0.714, the maximal similarity of coefficient was 0.008 between clone 1 and clone 8, the minimal Nei's similarity of coefficent was 0.440 between clone 1 and clone 3.These 9 varieties were clustered into 3 groups by UP-MGA analysis.The strips of leafstalk were suggested to be the main index for selected variety in Amorphophallus xiei.

Niche breadths and overlaps of dominant species in restoring succession processes plant community in Huangpuchuan Watershed were measured using a series of indices proposed by Levins,Shannon-Wiener,and ecological significance of niche breadths and overlaps of each community was analyzed.The results show that each typical community is marked absolutely by one species with the largest niche breadth.Dynamic changes of niche breadth in restoring succession are correspondingly related with the changes of populations.Greater niche overlaps will result in more similarities in ecology and resource use of populations, thus leads to a more intense interspecific competition.Competition is a potential dynamic mechanism promoting different plant communities to the climax community in the watershed.