摘要
选择青藏高原黄河源区封育三年的灌丛草地、小嵩草退化草地和黑土滩等3个高寒草地群落为研究对象,利用镜检法,对其土壤种子库的规模、物种组成、空间分布及与地上植被的相关性进行研究。结果表明,1)小嵩草退化草地、黑土滩、灌丛草地围栏内外土壤种子库密度分别为(9 938±1 780)粒/m2和(15 330±1 827)粒/m2、(4 074±459)粒/m2和(3 640±486)粒/m2、(9 879±1 453)粒/m2和(12 899±1 695)粒/m2,且只有小嵩草退化草地围栏内外表现出差异显著。2)3种高寒草地群落围栏内外土壤种子库物种数目差异不显著,但禾本科与莎草科种子在土壤种子库中所占的比例表现为围栏内>围栏外,草地围栏能提高原生植被土壤种子库比例。3)各样地的土壤种子库的Shannon-Wiener多样性指数、Simpson多样性指数和Pielou均匀度指数有着相同的变化规律:黑土滩>灌丛草地>小嵩草退化草地;Margalef丰富度规律为:小嵩草退化草地>黑土滩>灌丛草地。3种高寒草地群落土壤种子库与地上植被的Sorensen相似性指数大小范围为0.32～0.64,变化为:黑土滩>小嵩草退化草地>灌丛草地,围栏内>围栏外。4)土壤种子库主要集中在0～5cm土层中,平均占土壤种子库的比例为88.56%。黑土滩群落围栏内外5～10cm层土壤种子库种子数所占的比例要显著大于灌丛草地与小嵩草退化草地。围栏封育能够提高退化高寒草地土壤种子库数量,对退化草地的恢复有重要作用。
In the Yellow River source region of the Qinghai-Tibet Plateau,we selected three different alpine grassland communities（shrub grassland,Kobresia pygmaea degraded grassland and black-soil） through three years of enclosure.Microscopic examination was used to research the size of soil seed banks,species composition,spatial distribution and correlation between vegetation and soil seed banks.The results showed that： 1） The density of soil seed banks within and outside the fence of K.pygmaea degraded grassland,black-soil and shrub grassland respectively were（9 938±1 780） and（15 330±1 827） seeds/m2,（4 074±459） and（3 640±486） seeds/m2,and（9 879±1 453） and（12 899±1 695） seeds/m2,respectively but only the K.pygmaea degraded grassland within and outside the fence had significant differences.2） The number of species in soil seed banks in the three alpine grassland communities within and outside the fence was not significantly different,but the proportion of grass and sedge seeds in the soil seed banks were greater within than outside the grassland fence which increased the proportion of native vegetation in the soil seed bank.3） The Shannon-Wiener diversity index,Simpson diversity index and Pielou evenness index of the soil seed banks had the same pattern in each community and： black-soilshrub grasslandK.pygmaea degraded grassland： K.pygmaea degraded grasslandblack-soilshrub grassland by the Margalef richness rules.The range of Sorensen similarity index between soil seed banks and vegetation in the three alpine grassland communities was 0.32-0.64 in the sequence and black-soilK.pygmaea degraded grasslandshrub grassland,and withinoutside.4） Soil seed banks were mainly in the 0-5 cm soil layer with an average proportion of 88.56% of the total soil seed bank.While the overall differences within and outside the fence of the three grassland communities were not significant,the proportion of black-soil soil seed numbesr in the 5-10 cm layer was significantly greater than those of the shrub grassland and K.ygmaea degraded grassland.Thus grassland enclosure improved grassland soil seed bank status,had a greater significant effect for degraded grassland,and played an important role in grassland maintainance and recovery.
出处
《草业学报》
CSCD
北大核心
2012年第5期23-31,共9页
Acta Prataculturae Sinica
基金
国家自然基金(No.41171417
30600426
30730069)
中央高校基本科研业务费专项资金(lzujbky-2010-8)资助
关键词
高寒草地
封育
土壤种子库
灌丛草地
小嵩草退化草地
黑土滩
alpine meadow
enclosed
soil seed bank
shrub grassland
Kobresia pygmaea degraded grassland
black-soil
