【作者】 马琼芳；

【导师】 崔丽娟；

【作者基本信息】 中国林业科学研究院 ， 生态学， 2013， 博士

【摘要】 准确探讨物种多样性和生产力之间的相关关系，将有利于认识生物多样性的维持机制；研究生物量大小及其影响因素，阐明地上生物量与地下生物量的分配机制，将有助于预测生态系统对全球气候变化的响应；准确估算土壤有机碳库，分析其影响因素，将有助于探索全球气候变化与陆地生态系统碳循环之间的相互影响和反馈机制。我们于2011-2012年在若尔盖高寒沼泽调查了32处样地，收集了植被样方数据、生物量数据、土壤碳氮等理化性质数据和水位等实测数据，结合研究区高程数据、同时期的TM遥感影像数据、以及若尔盖高寒沼泽分布区及其周边共12个气象站点1971－2000年共30年的年平均降水量和年平均温度数据，借助相关分析、方差分析、CCA分析、RDA分析和Ⅱ类回归等经典的统计方法和克里格插值等地学统计手段，研究了若尔盖高寒沼泽物种丰富度与生产力的相关关系、生物量大小分配机制及其影响因素、土壤碳库及其影响因素。主要结果如下：(1)若尔盖高寒沼泽中共有147个种植物，隶属于39科98属。随地表积水的减少，多样性指数基本呈增加趋势。水分和土壤养分条件是影响物种分布的主导因子，其次是裸斑面积及啮齿动物活动。在样地水平上，若尔盖高寒沼泽物种丰富度与地上生物量没有相关关系。(2)若尔盖高寒沼泽地上、地下和总生物量分别为367.05、3680.36和4048.01g/m2，若尔盖高寒沼泽地上、地下和总生物量由西北向东南递减，随着温度、降水的增加而减少，随水分含量和养分含量的增加而增加。地形因子对样地生物量的水平分布没有影响，但微地形能改变生物量的空间差异。地上—地下生物量之间存在显著的异速生长关系，支持相关生长假说。(3)若尔盖高寒沼泽土壤有机碳密度为140.67(76.89-275.75) kg/m2(2m)，生态系统总碳储量(2m)为392.72Tg，其中，生物量碳库占总碳储量的1.3%。国家尺度上的研究过大估计了若尔盖高寒沼泽土壤有机碳库的大小，资料来源、样本容量、估算方法等因素的差异是造成碳储量估算不确定性的主要原因。(4)若尔盖高寒沼泽和北极苔原生态系统具有相似的浅植物根系垂直分布机制、相近的根冠比值和较大土壤碳密度大小，可能与较低的温度和降水和较强的紫外线有关。更多还原

【Abstract】 Accurate investigating of spatial distributions and environmental controls of carbonstorage in Zoige marsh ecosystems is important for predicting the consequences of globalchange and designing sustainable rangeland management.In the current study, we collected datasets about vegetation quadrats, abovegroundbiomass and underground biomass, physicochemical properties of the soil and the waterelevation from32sites of the Zoige marsh during July and August2011-2012when thebiomass production approximately reached a pleatu. We collected the TM remote sensingimage data, the average annual precipitation and mean annual temperature data from1971to2000at the Zoige alpine swamp. Using the class II regression, analysis of variance, CCA, RDAanalysis, correlation analysis and other classic statistical methods and Kriging geostatisticalmethods, we examined the relationship between species richness and aboveground biomass.The biomass allocation in Zoige marsh and spatial distributions were estimated. Potentialenvironmental controls for the carbon storage in Zoige marsh were analyzed. The main resultsare as follows:(1)There are147species in Zoige marsh, belonging to39families and98genera.Environmental factors are important determinants of the distribution of native plant species inZoige marsh. We found no relationship between species richness and aboveground biomass,which was possibly due to their no variations along the environmental factor gradients.(2)The average aboveground biomass (AGB), belowground biomass (BGB) and totalbiomass (TB) for Zoige alpine marsh were367.05,3680.36and4048.01g·m-2, respectively.The micro-topography (hummock-hollow topography) can lead to the spatial variations ofbiomass in local scale. Biomass descends from north to south and increases from the center tothe edge of the swamp. Lake depression has a higher biomass than river gully. There were positively allometric relationship (p<0.05) between aboveground biomass components andbelowground biomass especially for sites with a low level of soil nutrients.(3)The average0-30cm、0-50cm、0-100cm、0-200cm soil organic carbon density for Zoigealpine marsh were19.48(9.72-44.65)、32.54(17.58-42.52)、77.97(44.06-127.77) and140.67(76.89-275.75), respectively. Zoige alpine swamp with a total area of2754.52km2mainlydistributed in Zoige County, Hongyuan County, Aba County and Maqu County. The total Cstock in Zoige alpine swamp (0-200cm) was392.72Tg,which is lower than the past research ofnational scale estimation. The main uncertainty factors in carbon stock estimation include thedifferences in data sources, samples and estimation methods.(4)Our results indicate that there are similarities in vertical distribution of the roots，R/S(BGB/AGB) ratio and soil organic carbon density between high altitude marsh ecosystems andhigh latitudes peatlands partly were due to the similarities of cold temperature and lowprecipitation.更多还原