短花针茅荒漠草原物种多样性及生产力对长期不同放牧强度的响应

发布时间：2018-03-19 13:34

本文选题：载畜率　切入点：物种组成　出处：《西北植物学报》2017年11期 　论文类型：期刊论文

【摘要】：以内蒙古四子王旗短花针茅(Stipa breviflora)荒漠草原为研究对象,从植物个体尺度入手,通过2016年野外群落调查试验,对荒漠草原不同放牧处理[载畜率分别为0(CK)、0.91(LG)、1.82(MG)、2.71(HG)羊/(hm2·a-1)]下的物种组成、植物多样性与生产力的关系进行分析,以揭示荒漠草原群落中的物种组成、物种多样性及其功能群多样性对不同载畜率的响应机制。结果表明:(1)对照区的植物种最多,有13科30种,轻度放牧区只比对照区少野韭(Allium ramosum)1种植物,而中度放牧区和重度放牧区的植物种分别较对照区减少了30%和40%,其中减少的物种大多属于多年生杂类草与多年生根茎禾草两大功能群。(2)多年生丛生禾草在植物群落中占比始终最大(29%~78%),且随着载畜率的增加而增加,而其他功能群均随载畜率增加呈减小的趋势。(3)两种多样性指数中,除了功能群多样性的Margalef丰富度指数,其他多样性指数均在对照区达到最大值,且大小依次为对照轻度中度重度放牧区。(4)物种多样性的3个α多样性指数与草地生产力存在显著正相关关系,功能群多样性指数则与生产力无相关关系。研究认为,长期放牧使得荒漠草原群落结构趋于简单化,使多年生丛生禾草形成优势单种;且载畜率的增加使得短花针茅荒漠草原植物的多样性及生产力均显著下降,高水平的多样性会导致高水平的草地生产力,比较2种多样性指数指标,物种多样性指标对荒漠草原生产力的贡献更大。
[Abstract]:The species composition of desert steppe of Stipa breviflora, Siziwang Banner, Inner Mongolia, was studied on the basis of plant individual scale and field community investigation in 2016. The relationship between plant diversity and productivity was analyzed to reveal the response mechanism of species composition, species diversity and functional group diversity to different stocking rates in desert steppe communities. There are 30 species belonging to 13 families and only Allium ramosum)1 species in light herding area. In moderate grazing area and heavy grazing area, the plant species decreased by 30% and 40, respectively, in which most of the decreased species belonged to two major functional groups of perennial hybrid grass and perennial rhizomatous grass. The percentage in the middle of the fall was always the largest, 29% and 78%, and increased with the increase of the stocking rate. However, the other functional groups showed a decreasing trend with the increase of stocking rate. Among the two diversity indices, except the Margalef richness index of functional group diversity, the other diversity indices reached the maximum in the control area. The three 伪 -diversity indices of species diversity were positively correlated with grassland productivity, while the functional group diversity index had no correlation with productivity. The community structure of desert steppe tended to be simplified by long-term grazing, which resulted in the formation of dominant single species of perennial herbage, and the increase of stocking rate significantly reduced the diversity and productivity of the desert steppe of Stipa breviflora. High level of diversity will lead to high level of grassland productivity. Compared with two indexes of diversity, the index of species diversity contributes more to the productivity of desert steppe.
【作者单位】：内蒙古农业大学草原与资源环境学院草地资源教育部重点实验室;
【基金】：国家自然科学基金(31560140,31260124) 内蒙古科技重大专项项目 “西部之光”人才培养计划国家重点研发计划(2016YFC0500500)
【分类号】：S812

【相似文献】