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Comparative Study On Canopy And Soil Seed Bank Of Pinus Yunnanensis

Posted on:2017-05-12Degree:MasterType:Thesis
Country:ChinaCandidate:Z ShiFull Text:PDF
GTID:2180330488964302Subject:Ecology
Abstract/Summary:PDF Full Text Request
The canopy seed bank and soil seed bank are important forms of seed storage. But research about the capacity of storing seeds of the two kinds of seed banks is not enough. We discussed the number and vitality of the stored seeds, the fire resistance and drought resistance of Pinus yunnanensis Var. yunnanensis to find out the characteristics of seed quantity, seed vitality and ecological significance in canopy the seed bank. Results showed that:(1) The number of seeds in the canopy seed bank was 9835±816 in 100 m2 in Pinus yunnanensis forests, number of viable seeds was 7199±1012. The number of seeds on surface of the soil seed bank was 210±16 and the viable seed was 60 ±23 on surface of the soil seed bank. The number of seeds in the soil seed bank was 63±21 and the viable seed was 11±7 in the soil seed bank. The number of canopy seed bank was significantly higher than that of soil seed bank.(2) The seed vitality of canopy seed bank is better than that of soil seed bank. After the dry season, the survival rate of seeds 0cm was 40.6%, the survival rate at 2cm was 69.1% and the survival rate of seeds at 5cm was 62.9%, seed survival rate of the soil surface was significantly different(p<0.05) from the soil. The survival rate of seeds was 73.6% after the dry season and 63.2% after the rainy season in the canopy seed bank. After the rainy season, the survival rate of seeds was 8.8% at 0cm,33.71% at 2cm, and 26.9% at 5cm in soil seed bank.(3) The scale protection of cones developed the ability to fight against fire and drought. The germination rate of seeds with scale protection was significantly higher than that of seeds with no scale protection after heating in short time. The germination rate of seeds with scale protection was 48.17% and the germination rate of seeds with no scale protection was 4% after heating 10min in 200℃. The survival rate of seeds in cones (75.6%) was significantly higher than that of the non protected seeds (55.0%) in drought resistance.The ability of protecting seeds in canopy seed bank was more strategic than that of soil seed bank when habitats were burning in forests of Pinus yunnanensis, the same as the drought and the number of storing seeds. Canopy seed bank could offer its population an opportunity of renascence in the habitat with fire and drought.
Keywords/Search Tags:Pinus yunnanensis, Canopy seed bank, Soil seed bank, fire, seed vitality
PDF Full Text Request
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