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Research on Stellera Chamaejasme Community Seed Bank Function Grouping Characteristic and Plant Restoration in Alpine Degraded Grassland

Author: ZhangQiPeng
Tutor: ZhaoChengZhang
School: Northwest Normal University
Course: Physical Geography
Keywords: Alpine degraded grassland Chamaejasme community Seed bank Aboveground vegetation Functional group Vegetation restoration
CLC: S812
Type: Master's thesis
Year: 2010
Downloads: 77
Quote: 0
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Abstract


Alpine poisonous weed degraded grassland Northwest, a major degradation type, the degraded grassland spreading the of natural grassland excellent pasture production capacity, constitutes a serious threat to the safety of livestock production, excessive use of lawn leading to alpine grassland degradation the direct cause, and fall into the \, the on chamaejasme community a series of studies, results show that: 1) chamaejasme aboveground vegetation total of 18 species from the families and genera composition, Gramineae, there are three kinds of leguminous plants, chrysanthemum plants and other plants; divided into functional groups, five kinds of perennial grasses, a biennial weeds species, 10 kinds of perennial weeds, including perennial grasses and perennial weeds in chamaejasme communities each gradient respectively dominate dominance, while a biennial weed status in chamaejasme community is not prominent. The size of the biomass of different functional groups in the vegetation gradient difference is obvious. 2) chamaejasme community soil seed bank statistics total to 20 species belonging to 13 families, which Gramineae four kinds, three kinds of Asteraceae and Leguminosae other Division 1, the view of the functional groups from the vegetation, soil seed library, five kinds of biennial weeds, perennial grasses pasture four kinds, 11 kinds of perennial weeds. Chamaejasme community soil seed bank overall performance departmental rotation the dominant genus species composition is more concentrated and poisonous weeds and density characteristics. 3) perennial grasses in the seed bank density with the increase of degraded gradient is reduced until it disappears, perennial weeds exist at each vegetation gradient greater density; Species number and density presents 0 to 5cm gt; 10 ~~ 15cm gt; ~ 10cm in distribution law, each soil layer density differences are significant; 4) ground vegetation ecological dominance, Shannon-Wiener diversity index, Margalet richness index and Pielou index value size order of perennial weeds a biennial weeds in perennial grasses; seed bank in different gradient (0 ~ 15cm) Shannon-Wiener index, evenness and richness index fluctuations trend is basically the same, but the dominance with which contrary to the trend, soil seed bank. ~ 5cm larger changes in species diversity and seed bank (0 ~ 15cm) similarity. 5), the seed bank and vegetation similarity coefficient decreases with increasing degradation gradient chamaejasme poisonous weed proliferation significantly change the structure of the functional group of the grassland community. The seed bank density and aboveground vegetation cover of perennial grasses in the vegetation degradation process obvious negative correlation of annual and biennial weeds and perennial weeds no obvious correlation (P <0.01). 6) The vegetation gradient, the proportion of the dominance of perennial grasses showed a single peak fluctuation trends the perennial weed dominance proportion fluctuation trends and perennial grasses, annual and biennial weeds vegetation in the gradient V Ⅵ missing; soil seed bank regular changes of the proportion of plant functional group dominance is more pronounced, a higher proportion of perennial weeds dominance, the average reached 57.8%, a significant trend of fluctuations in the proportion of dominance; proportion of the dominance of perennial grasses average of 13.68%, apparent decreasing trend, while a biennial weeds overall showed a more distinct upward trend.

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CLC: > Agricultural Sciences > Livestock, animal medicine,hunting,silkworm,bee > General Animal Science > Grassland Science,prairie school
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