| The virgin forest of Dabie Mountain has been almost distroied completely. Structures of communities were uncomplicated and the anti-interference ability was also inadequate, as well as the soil erosion gravely in areas of present forest communities. The research project has been carried out into characteristics of different forest communities and their hydrological functions in this area. Forest communities have been classified, and the relationshiop between species diversity of different forest communities and their environmental parameters in mid-Dabie Mountain have been studied as well. Accoding to characteristics of communities structure, niche widths of main dominate species and overlaps among main species, inter-specific association among main species, spatial distribution patterns of dominate species, water holding capacity for different vegetation type litter and soil as well as the microclimate of different communities, from this research some conclusions can be listed as follows:1. According to the physical characteristics and structural features of local communities 10 communities can be classified by means of TWINSPAN and CCA. Then, 6 communities types has been futher grouped in order to provide practical guidance to local forest management and ecological restoration, which were coniferous forest community, needle broad-leaved mixed forest community, deciduous broad-leaved forest community, evergreen broad-leaved and deciduous broad-leaved forest community, C. seguinii+Q. variabili forest community, P. taiwanensis forest community. The succession trend of middle low altitude community in this area follows:coniferous forest community-needle broad-leaved mixed forest community-deciduous broad-leaved forest community-evergreen broad-leaved and deciduous broad-leaved forest community.2. The research of species diversity, species richness and species evenness coincidenced with the hypothesis of "mid-altitude bulge" and "intermediate-disturbance"; Both the species diversity and the species evenness was significantly affected by thinning. The community succession trend and changes of species diversity were also affected by environmental parameters in this mid-low altitude area. Whereas, there was no obvious regularity for species diversity dynamic and environmental parameters variety in high altitude forest communities in this area studied.3. The niche widths of main dominate species in different communities changed according to the succession trend in the mid-low altitude. Generally speaking, the changes of niche widths of main dominate species coincidenced with replacement of dominant species in the succession process. The further research on relationship between niche width changes and mechains of main dominate species substitute especially for Castanea Seguinii+Pinus taiwanensis-Viburnum dilatatum-Arthraxon hispidus forest community should also be conducted in the near future. It was feasible for species niche overlap index and species characteristic as the main evaluation criteriain in terms of majority species relationships in different community succession.4. The inter-specific association among main species can be represented as followes: the main species of early successional communities can be described as negative correlation, while in the later successional communities showed positive correlation. Dominate tree species inter-specific association was analysised and compared with the methods of Fisher exact test, Pearson correlation coefficient and Spearman rank correlation coefficient in this text. Although there were some connectivities between main domaint species in this area, independent patterns of main domaint species were also obviouse. The inter-specific association among mian domaint tree species was not strong as for the interaction between species of community and environment. It was essential that study of inter-specific association combine with niche widths research for futher understanding of species relationships as well as species diversity especially for rare and endangered species protection, and for maintaining the stability of communities in this area.5. With a comparative analysis of t test, Poisson distribution and the Morisita index of fit test methods, main domaint species spatial patterns and difference have been studied for different stages of community in its succession. In the succession of mid-low altitude communities, dominant species spatial patterns developed from the aggregated distribution to the random one gradually. However, high altitude distribution pattern of dominant species showed an aggregated one being due to local climate conditions and plot size calculation scale. The species spatial patterns were not only relation to both the species ecology and biological characteristic, but also closely linked to the role of species competitive exclusion. The overall scale analysis showed that all dominant species can be described as aggregated distribution pattern. The basic relatationship of individual species showed ai single individual pattern as well.6. Although the changes of light intensity, air temperature and relative humidity in communities were largely affected by the community structure, there were not so much light intensity varieties between different heights (0.5m,1.3m) in a community. The light intensity in interior communiy for coniferous forest community was smaller than that of needle broad-leaved mixed forest community, light intensity both in evergreen broad-leaved and deciduous broad-leaved forest community were also smaller than that of deciduous broad-leaved forest community. Overall, light intensity in interior community for high altitude coniferous forest communities were larger than that of in high altitude needle broad-leaved mixed forest community. For different communities the largest light intensity in a day appeared at different time, the maximum relative humidity and temperature among interior community were mainly caused by altitude. When the air temperature and relative humidity were higher than 23℃,63%(high altitude,20℃, 39%) respectively, the air temperature, relative humidity of interior communiy was lower than those of the outside communities; Also, the air temperature and relative humidity were lower than 17℃,48%(high altitude,16℃,20%) respectively, the air temperature, relative humidity of interior communiy is higher than those of the outside communities.7. The forest litter storage increase trend followed the successional gradient in mid-low altitude forest communities in this area, while there was no obvious regularity in high altitude forest communities. Water holding capacity was greatly affected by litter type and its component. There was also no obvious regularity in soil bulk density according to forest community succession. Although non-capillary porosity, being taken as an important indicator of soil and water conservation, decreased with soil depth, there was no regularity overall. However, the change of non-capillary porosity in forest communities succession did not coincide with varieties of soil water-holding capacity. |
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