| Taking the mixed bamboo (Phyllostachys heterocycla cv. Pubescens) forest in Yanling County, Hunan Province, and pure bamboo forest in Changning County, Sichuan Province as the research object, using conventional bamboo forest management practices and the concept of forest sustainable management, several single or combined forest management practices were studied to compare their effect to biodiversity and productivity of bamboo forest. This paper compared the different effect of management practices on the biodiversity of bamboo forest community and productivity of bamboo forest, using methods of experimental design, field survey and quantitative ecological methodologies to find out the appropriate management practices for bamboo forest. The main conclusions are as follows:1. Overview of bamboo forest community structure in experimental plots(1) There were 165 species belonging to 139 genus and 85 families in the experimentalplots of Hunan Province. The highest abundance of species was found in the shrub layer whose main families were Rosaceae, Euphorbiaceae and Lauraceae. The grass layer had the next highest abundance mainly made up of Compositae, Rubiaceae, and Magnolia. The main families in tree layer were Moso, Rosaceae, Lauraceae, and Fagaceae with a total of 18 families 33 species.(2) There were 81 vascular plants belonging to 72 genus and 44 families in the experimental plots of Sichuan Province, Angiosperms were dominant and constituted 85.19% of all species.(3) The species of plants in the mixed bamboo forest were more than that in the pure bamboo forest.2. Study on the effects of different practices on plant biodiversity(1) The results from mixed bamboo forest in Hunan Province Among five experimental bamboo forest management practices (mixed vegetation diversity management; adjustment of species composition; adjustment of the ratio of bamboo and trees; conventional top-cutting; top-cutting + adjustment of bamboo structure; and no management practice) with the controlled trial in the experimental plots in Hunan province, there was no statistically significant difference among abundance index, species diversity index and evenness index of tree, shrub and grass layers between everyone in five practices and the controlled trial respectively.On the other hand, the abundance index of tree and the diversity index of shrub with mixed vegetation diversity management were significantly higher than that with top-cutting + adjustment of bamboo structure; the Alatalo evenness index of areas under conventional top-cutting management was significantly higher than that with other practices; the average diameter of bamboo with top-cutting + adjustment of bamboo structure was significantly higher than that with other practices apart from adjustment of species composition.(2) The results from pure bamboo forest in Sichuan ProvinceAmong four bamboo forest management practices (top-cutting; no tillage; intercropping hardwood; retaining understory vegetation) in the experimental plots in Sichuan province, there was no statistically significant difference among abundance index, species diversity index and evenness index of the plant.In comparison of combined management practice - the conservation practices (fertilization stump + remaining understory vegetation + no tillage + cleaning undergrowth) and the conventional practices top-cutting + loosening soil + fertilization) with the controlled trial, there was no statistically significant difference among abundance index, species diversity index and evenness index of plant in either of comprehensive management practice with the controlled trial respectively.(3) Both of the results above suggested that the indicators of plant diversity were less sensitive to the short-term silvicultural practice in the bamboo forest, more importantly, short-term silvicultural practice were not harmful to biodiversity of plant of bamboo forest.3. Study on the effects of different practices on productivity of bamboo forest(1) The results from mixed bamboo forest in Hunan Province Among the comparison of five silvicultural practice (mixed vegetation diversity management; adjustment of species composition; adjustment of the ratio of bamboo and trees; conventional top-cutting; top-cutting + adjustment of bamboo structure; and no management practice) with the controlled trial in the experimental plots in Hunan province, all of bamboo average diameter, average density and bamboo yield with cilviculturalsilvicultural practice were statistically significantly higher than that of the controlled trial.(2) The results from pure bamboo forest in Sichuan Province Among four bamboo forest management practices (top-cutting; no tillage; intercropping hardwood; retaining understory vegetation) in the experimental plots in Sichuan province, there was no statistically significantly difference among bamboo average diameter, average density , bamboo yield and new bamboo number.However, between the comparison of combined managment practice with the controlled trial, bamboo average diameter, average density and yield with protective practices (fertilization stump + remaining understory vegetation + no tillage + cleaning undergrowth) was statistically significantly higher than that of the controlled trial, and it was statistically significantly higher than that of conventional practices (top-cutting + loosening soil + fertilization).(3) Based on the results above, silvicultural practices maybe have a positive effect on bamboo forest productivity; but it seemed that simple practices was not enough to increase the productivity of pure bamboo forest; at the same time, the indicators of new bamboo was less sensitive to the short-term silvicultural practice in the bamboo forest.4. Appropriate managment practice Using methods of assignment scoring valuation and considering the comprehensive effect on biodiversity of bamboo forest community structure and productivity of bamboo forest, the appropriate were respectively as follow:(1) Appropriate management practice in Hunan ProvinceBased on the results of 3 (1) and 4 (1), using methods of assignment scoring creening, the practice of mixed vegetation diversity management may be the most suitable magement practice to coordinate the contradiction the effect on biodiversity of bamboo forest community structure and productivity of mixed bamboo forest(2) Recommended management practice in Sichuan ProvinceBased on the results of 3 (2) and 4 (2) above, among four practices (top-cutting; no tillage; intercropping hardwood; retaining understory vegetation), the practice of retaining understory vegetation could be considered as the option of bamboo management practice because as it keeps both biodiversity of bamboo forest community structure and higher productivity of bamboo forest.As to comprehensive management practice, based on the results of 3 (2) and 4 (2), conservation practices could be considered as the recommended management practice to achieve recovery of bamboo community and sustain productivity of bamboo forest. The above conclusions were resulted from observation to short-term effects of biodiversity of plant and productivity of bamboo on specific management practices for Moso bamboo forest, which were limited the conditions and results of this experiment. After further research to get more epxerimental data, the long-term effects of iodiversity of plant and productivity of bamboo on practices could be further studied. |
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