由于全球变化和人类活动的加剧，物种多样性的丧失及其对生态系统功能的影响引起了国际社会和科学界的关注。内蒙古草原草地生态系统生物多样性和生产力关系研究可以为对草原地区的多样性保育、植被恢复理论与实践，以及草地生态系统管理提供科学依据。本文通过典型取样法沿水分梯度在内蒙古草原不同草地类型的代表性群落的典型地段进行了植被、土壤调查，分析了水分梯度上内蒙古草原的生物多样性和生产力变化特征、二者关系及其尺度效应。同时，在典型草原区选取了羊草围栏样地，分析时间尺度上围栏对羊草群落生物多样性和生产力的变化特征及二者关系。主要结论如下：1． 围封并没有导致建群种的更替，但在群落中居于优势地位的几种禾草间的相对优势度随围封时间有较大变动；长期（28年）围封条件下，物种丰富度最高，物种的分布也变得相对均匀，物种多样性达到最高值；同时群落结构趋于复杂，向稳定的方向发展。围封使羊草群落的地上现存量有了明显增长，但并未随围封时间出现明显变化；围封对群落地下生物量没有显著影响。从群落的生物多样性和生产力角度来讲，围封使羊草群落结构和功能均得到恢复，长期围封可有效提高群落的生物多样性，但生产力无显著变化。2． 围栏禁牧条件下，除了对照放牧样地外，不同围封年限样地的物种丰富度与生产力关系一般为非线性正相关，物种多样性与生产力关系的模式与生产力测度指标有关，与地上生产力关系一般为非线性正相关，而与总生产力关系一般为单峰模式。但长期围封样地及群落恢复演替过程中生物多样性与生产力均呈现出显著的非线性正相关关系。3． 空间尺度从景观到区域时，物种多样性与生产力关系模式的转变与生产力所采用的测度指标有关。用地上现存量来衡量生产力时，除荒漠草原外，无论是景观尺度还是区域尺度上，内蒙古草原的生物多样性和生产力关系均呈显著的非线性正相关模式；而用总生物量来表征生产力时，从景观尺度到区域尺度，物种丰富度、多样性指数与生产力关系从非线性正相关变为单峰模式。4． 区域尺度上，生物多样性等级从功能群多样性到群落多样性时，丰富度与生产力关系无变化，均为非线性正相关，多样性与生产力关系则从单峰形式转变为非线性正相关模式。功能群丰富度指数与地上初级生产力、总初级生产力呈非线性正相关，而功能群多样性与地上初级生产力、总初级生产力的关系模式则为显著的单峰形式；群落丰富度、多样性与地上初级生产力、总初级生产力均为显著的非线性正相关关系。

Species loss across the world has been accelerated due to global change and human activity. Relationships between biodiversity and ecosystem functions have received much more attention in the past decades. Temperate grassland has been acknowledged as the key region for biodiversity monitoring and research. Relationships between plant biodiversity and primary production in temperate grassland of Inner Mongolia are of great importance on biodiversity conservation, vegetation restoration and reconstruction, ecosystem management. This study would provide scientific basis for the mentioned above. This thesis had studied the biodiversity, primary production characteristics, relationship between biodiversity and primary production and the scale dependence with time, and also on different space scales. The main results are as follows:(1) The constructive species were not changed in the enclosure Leymus chinensis plots. However, the important values of grass plants dominated changed in different enclosure plots. The long-term enclosure plot has highest species richness, relative high evenness and the highest diversity. It also had relative complex community structure and tended to be more stable. The standing crop increased significantly under enclosure. However, it didn’t continue to increase with time. Enclosure didn’t change the community below-ground biomass. In terms of community structure and function, enclosure had improved the biodiversity and primary production. Long-term enclosure had increased community species diversity. However, it had not changed the community production significantly. (2) Relationships between species richness and primary production in different enclosure plots were generally non-linear positive pattern, except the grazing plot. Relationships between species biodiversity and primary production in different enclosure plots had different pattern according to the primary production indicators used. Relationships between species biodiversity and primary production were non-linear positive pattern when above-ground biomass was used as surrogate of production, but they were unimodal pattern when above and below ground biomass was used. However, relationships between species richness and diversity were all non-linear positive patterns in long-term enclosure plot and in the restoration process.(3) Relationship patterns between species diversity, including species richness and production transformed differently from the landscape to the region scale due to the primary production indicators used. Relationships between species diversity and production in landscape and region scale were all non-linear positive pattern when above-ground biomass was used as surrogate of production, except the desert steppe. But they transformed from non-linear positive to unimodal pattern from landscape to region scale when above and below ground biomass was used.(4) In the region scale, relationships between function group richness and community production were non-linear positive pattern, but relationships between function group diversity and community production were unimodal patterns. They were all non-linear positive patterns when community diversity was used. As the result, relationships between richness and community above-ground production, above and below ground biomass were all non-linear positive pattern in the region scale when function group diversity and community diversity were used as biodiversity indicator, but they transformed from unimodal to non-linear positive patterns.