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题名 高寒草地退化与围栏封育对土壤种子库及其与地上植被关系的影响
姓名 桑潮
院系 草地农业科技学院
专业 草业科学
学位名称 农学硕士
外文题名 The influence of degradation and fencing on soil seed bank and their relationship with the above vegetation in alpine grassland
第一导师姓名 龙瑞军
关键词 土壤种子库;高寒草地;围栏封育;黑土滩
外文关键词 soil seed bank;alpine meadow;fencing;Heitutan
学科 农学
摘要 为了探究不同类型和季节的土壤种子库特征,分析了三江源地区天然草地、黑土滩,退化人工草地三种草地类型不同时间的土壤种子库。针对不同海拔和干扰,采用地面调查,室内萌发等方法,分析了念青唐古拉山当雄地区阳坡围栏内外不同海拔梯度的地上群落多样性和土壤种子库特征。 1)三江源地区三种草地土壤种子库特征: ①密度的范围:2173.381-9452.362粒/m2,呈现出:黑土滩>退化人工>天然草地。②高寒草地土壤种子库有明显的垂直分布,大部分物种和种子分布于土壤上层。③土壤种子库物种组成与地上植被的物种组成相似度在不同的草地都较低。④在四月份,速效钾与种子库的种子数量和物种数量有显著的相关关系。⑤四月到十二月土壤种子库密度的变化,天然草地没有显著变化;黑土滩先减少在增加;退化人工显著减少。⑥土壤种子库中物种数量,四月>十二月>八月。 2)当雄地区念青唐古拉山脉南坡: ①单峰式函数关系能较好地表达植物群落物种丰富度、多样性和均匀度与海拔高度间的分布格局。②土壤八月种子库特征,范围为0-1245.05粒/m2,土壤中有明显的垂直分布。土壤种子库物种组成与地上植被的物种组成相似度非常低。③围栏封育显著改善了念青唐古拉山阳坡不同海拔样地的盖度。
外文摘要 We analyzed“heitutan”,natural grassland and degraded artificial grassland in April,August and December to explored the characteristics of soil seed banks.For different altitudes and interferences by human we studied the communities and the soil seed banks of Nyainqêntanglha. In the Three Rivers area:①The soil seed bank density: 2173.381-9452.362 viable seeds m-2, “heitutan” > degraded artificial grassland> natural grassland. ②There were obviously significant vertical distribution in soil.③Similarity of soil seed bank and aboveground vegetation were low.④Significant correlations was found between K and the number and species of seeds in April.⑤From April to December ,no significant differents in natural grassland;decreased and then increased in “heitutan”;significantly reduced in degraded artificial grassland.⑥The number of species in the soil, April> December> August. In Nyainqentanglha southern slope: ①The relationship between the altitudinal and the index of diversity would be well explained by unimodal function.②The soil seed bank in August were 0-1245.05 viable seeds m-2.③Fencing significantly improved the coverage.
研究领域 草地生态
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