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【答案】应助回帖
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爱与雨下(金币+2): 2012-01-07 10:37:48
小小佐罗2(金币+50, 翻译EPI+1): ★★★很有帮助 辛苦你了 2012-01-07 10:37:53
爱与雨下(金币+10): 2012-01-31 12:22:50
爱与雨下: bb代发 2012-01-31 12:22:59
[Abstract] [Objective] In order to provide some background knowledge for vegetation, productivity and ecological protection of degraded grassland in alpine area of Tibet, the composition of vegetation species, available soil stocks, species composition characteristics, the number of fermentable seeds, and the ecological characteristics in different degraded grassland of Nakchu are systematically investigated. [Methods] A typical sampling method was used, in which 4 different levels of degradation of four typical alpine meadow were selected in the project area, and 16 quadrats were selected by using line transect method. In fact, a volume of 10 cm × 10 cm × 10cm (including ground litter) soil samples was taken on the first day of each month to be used as seed bank samples, and seed banks and seed, chemical processing plants and determined germination et al. were summarized and analyzed. [Results] It was shown that the largest number of seeds (530 ± 80.002 grains/m) was obtained for the moderately degraded grassland at Nagqu alpine, followed by severe and very severe degradation of grasslands (250 ± 44.723 grains/m), with mild degradation grass seed stock for at least (216 ± 21.335 grains/m). Most species in the seed bank are Cyperaceae, the Rosaceae, Compositae, Gramineae, and so on. Under laboratory conditions, the number seeds that can germinate in the seed bank of mild degradation of grassland was the least, followed by severe and very severe degradation of grasslands, and the largest number of seeds that can germinate was obtained in moderately degraded grassland seed bank. Use of appropriate drug which was composed of GA3 (0.02% and 0.05%) and KNO3 (0.2%) to treat seeds from grassland soil could break the seed dormancy effect on the role of promoting seed germination. However, when with treatment of H2SO4, whatever the concentration, it can not promote seed germination, while the opposite results were obtained. [Conclusions] there are mainly Kobresia alpine at slightly degraded grassland in Tibet Kobresia, and a large number of them were fed to cattle and sheep. The rodent damage resulted in a smaller amount seeds for many plant species. Due to the increase of asteraceae and rosaceae species at moderate and severe degradation of grassland, the retained seeds in seed bank were increased. There were no sedge plants, but mainly Asteraceae, Rosaceae and cruciferous plants for very severe degraded grassland. With the increase the proportion of non-food plants, and very few could fed to the cattle and sheep, a larger number of plants seeds therefore obtained in its seed banks.
可能是太长了太专业，没人帮你搞，只能试试了。仅供参考。 |
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