The Effect Of Tourism Disturbance On Woody Plant Communities And Its Ecological Response Mechanism In Suo Buya Scenic Spot

The research which is based on theories and methodologies of phytocoenology, ecology and tourism begins with the tourism disturbance intensity. It studies the effect of species composition, floristic element, species diversity, important of dominant species, niche, community physiognomy and aesthetic effect of landscape on the woody plant communities in Suo Buya scenic spot. This paper discusses the ecological response mechanism and response pattern which caused by tourism disturbance and it also analyzes the variation of the vegetations main characteristic index which responds to different tourism disturbance intensity. The conclusions are as follows:1 The tourism disturbance intensity of the natural vegetation in Suo Buya is connected very closely with the tourism path's distance. With closer the tourism path, the greater the intensity, further from the path, the intensity becomes weaker.2 Tourism disturbance changes the community's species composition on the level of family, genera and species. The variety trend is that the intermediate disturbance increases and the light disturbance weaken. Compared with the slight disturbance community, the disturbance makes the family quantity of intermediate disturbance community increased by 29.7%, genera quantity increased by 28.07% and the species quantity increased by 37.70%. But the family quantity variation of the light disturbance community is not obvious, the genera quantity decreased by 8.73%, and the species quantity decreed by 8.20%.3 Tourism disturbance effect on the floristic element, presented on the family level as that pantropic distribution and widespread distribution type increase, but the north temp distribution type changes a little. On the level of genera, intermediate disturbance increased 16 generas, and the light disturbance decreased 5 generas. The effect on the species diversity shows that intermediate disturbance community>light disturbance community>slight disturbance community, and the species of shrub layer responds sensitively to tourism disturbance.4 Tourism disturbance doesn't change the basic type of the community, which is the conifer and broadleaf mixed forest dominated by Cunninghamia lanceolata, Pinus massoniana. But the dominant position of the Pinus massoniana and Cunninghamia lanceolata has changed. The other broadleaved condominant in the light, intermediate disturbance community, such as Nyssa sinensis, Quercus fabric and Cinnamomum septentrionale were replaced by heliophile such as Liquidambar formosana, Populus adenopoda and Betula luminifera. The disturbance hasn't so much influence on the species composition of dominant species of the shrub layer. 5 The research of dominant population niche shows that the Cunninghamia lanceolata and Pinus massoniana of the community and the Eurya alata, Symplocos stellaris and Camellia oleifera of the shrub layer has the bigger niche breadth. They adapt to the environment well and fully use the resources. Because of the tourism disturbance, the niche breadth of Pinus massoniana of the tree layer has decreased by 55% in the intermediate disturbance community. The dominant position of the Pinus massoniana, Symplocos stellaris and Camellia oleifera of shrub layer was replaced by Rhus chinensis. Only 20.8% of the pairs of population in the tree layer has the phenomenon of niche overlap, which shows that the competition among the species of tree layers. The intense competition of the pairs of the population happens among Schima superba and Daphniphyllum oldhami, Schima superba and Quercus acutissima, Quercus acutissima and Symplocos stellaris, Quercus acutissima and Liquidambar formosana. Because of the similarity of the biological characteristics and ecological characteristics, the 9 dominant species of shrub layer, such as Viburnum dilatatum, Nyssa sinensis, Symplocos stellaris, Rhododendron mariesii, Betula luminifera, Symplocos sumuntia, Cerasus pseudocerasus and Dendrobenthamia angustata compete intensely about the usage of resources, the niche overlap is above 0.5.6 The effect of the tourism disturbance on vegetation landscape physiognomy is the intermediate disturbance community < light disturbance community < slight disturbance community. Compared with contrary community, the average breast, height, canopy of the intermediate disturbance community drops respectively 1.81m, 1.62cm and 1.88m. But the influence of the light disturbance community is relatively weak. Meanwhile, it also affects the aesthetic effect of landscape. It shows that the greater the disturbance intensity, the lower the landscape important level.7 The ecological response mechanism of the Suo Buya vegetation community on the tourism disturbance, which changes the agent. Therefore, the vegetation varies on each level. The response of Suo Buya vegetation on different disturbance intensity shows the trend that intermediate disturbance community > light disturbance community>slight disturbance community.