针茅

By using the method of space substituting time, alpine-cold steppe in different ages of enclosing was studied. We selected 4 flat plots with relatively uniform topography and enclosed time were 1-year old exclosure (E1), 3-year old exclosure(E3), 5-year old exclosure (E5), unexclosure. The grasslands were freely grazing pasture, grazing rate of 5.7 sheep / hm2. After enclosure, it was used as spring pasture, 5.7-grazing sheep / hm2. Unexclosure plot were 5.7-grazing sheep / hm2 in addition to the winter.

本文，运用空间代替时间的方法对不同围封年限的草地进行研究，结果表明：（1）随着围封年限的延长，天山赖草种群在群落中的地位逐渐弱化，优良牧草羊茅和紫花针茅种群在群落中的优势逐渐体现出来，群落由天山赖草+黄花棘豆群落类型逐步向羊茅+紫花针茅群落类型过渡。

Ordosica community and increased from A. ordosica community to C. komarovii community. The meso-xerophyte decreased gradually with the strong xerophyte gradually increasing during the desertification of the grassland.

结果表明：在鄂尔多斯草地荒漠化过程中，植物群落退化的趋势为本氏针茅群落→本氏针茅+油蒿群落→油蒿群落→油蒿+牛心朴子群落→牛心朴子群落。

In Salsola passerina -Reaumuria soongorica community, the first ordination axes explains the salinization gradient, along the order of Caragana tibetica community,Salsola passerina-Oxytropis aciphylla community,and Reaumuria soongorica-Salsola passerine community,soil alkalization increases. The second ordination axis explains soil structure gradient, along the order of Caragana tibetica community, Reaumuria soongorica-Salsola passerina community and Salsola passerina community, soil texture becomes coarser. In the Stipa breviflora-Stipa grandis community, the first ordination axis indicates the soil water gradient, and the second ordination axes explains hydrothermal coupling gradient. In the Prunus mongolica-Ulmus glaucescens community, the first ordination axis explains the soil pH gradient, along the order of Ulmus glaucescens-Prunus mongolica community, Prunus mongolica-Potentilla fruticosa community, and Potentilla fruticosa-Prunus mongolica community, soil pH value reduces. The second ordination axis explains soil structure gradient, along the order Prunus mongolica-Ulmus glaucescens community, and Prunus mongolica-Potentilla fruticosa community, the contents of silt and clay increase, and soil texture suggests a fine trend.

在珍珠猪毛菜-红砂群落，第一排序轴反映了土壤盐碱化梯度，沿着藏锦鸡儿群落—珍珠猪毛菜、猫头刺群落—珍珠猪毛菜、红砂群落序列，土壤盐碱化程度不断增强；第二排序轴则反映了土壤结构梯度，沿着藏锦鸡儿群落—珍珠猪毛菜、红砂群落—珍珠猪毛菜、猫头刺群落序列，土壤质地逐渐粗化；在短花针茅-大针茅群落，第一排序轴反映了土壤水分梯度，第二排序轴反映了海拔梯度上的水热组合梯度；在蒙古扁桃-灰榆群落，第一排序轴反映了土壤pH梯度，沿着灰榆、蒙古扁桃群落—蒙古扁桃、金露梅群落—蒙古扁桃群落序列，土壤pH值逐渐下降；第二排序轴主要反映了土壤结构梯度，沿着蒙古扁桃群落—灰榆、蒙古扁桃群落—蒙古扁桃、金露梅群落序列，土壤中粉粒、粘粒含量逐渐增加，土壤质地呈细化趋势。

In Salsola passerina-Reaumuria soongoriea community, the first ordination axes explains the salinization gradient. along the order of Caragana tibetica community, Salsola passerina-Oxytropis aciphylla community, and Reaumuria soongorica-Salsola passerine community, soil alkalization increases. The second ordination axis explains soil structure gradient, along the order of Caragana tibetica community, Reaumuria soongorica-Salsola passerina community and Salsola passerina community, soil texture becomes coarser. In the Stipa breviflora-Stipa grandis community, the first ordination axis indicates the soil water gradient, and the second ordination axes explains hydrothermal coupling gradient. In the Prunus mongolica-Ulmus glaucescens community, the first ordination axis explains the soil pH gradient, along the order of Ulmus glaucescens-Pnuius mongolica community, Prunus mongolica-Potentilla fruticosa community, and Potentilla fnuicosa-Prunus mongolica community, soil pH value reduces. The second ordination axis explains soil structure gradient, along the order Prunus mongolica-Ulmus glaucescens community, and Prunus mongolica-Potentilla fruticosa community, the contents of silt and clay increase, and soil texture suggests a fine trend.

在珍珠猪毛菜－红砂群落，第一排序轴反映了土壤盐碱化梯度，沿着藏锦鸡儿群落－珍珠猪毛菜、猫头刺群落－珍珠猪毛菜、红砂群落序列，土壤盐碱化程度不断增强；第二排序轴则反映了土壤结构梯度，沿着藏锦鸡儿群落－珍珠猪毛菜、红砂群落－珍珠猪毛菜、猫头刺群落序列，土壤质地逐渐粗化；在短花针茅－大针茅群落，第一排序轴反映了土壤水分梯度，第二排序轴反映了海拔梯度上的水热组合梯度；在蒙古扁桃－灰榆群落，第一排序轴反映了土壤pH梯度，沿着灰榆、蒙古扁桃群落－蒙古扁桃、金露梅群落－蒙古扁桃群落序列，土壤pH值逐渐下降；第二排序轴主要反映了土壤结构梯度，沿着蒙古扁桃群落－灰榆、蒙古扁桃群落－蒙古扁桃、金露梅群落序列，土壤中粉粒、粘粒含量逐渐增加，土壤质地呈细化趋势。

SPSS cluster analysis and CANOCO ordination method were applied to discuss the relationship between vegetation and its environmental factors in the west slope of Helan Mountain. The results show that the vegetation community can be divided into three types, namely Salsola passerina-Reaumuria soongorica community, Stipa breviflora-Stipa grandis community and Prunus mongolica-Ulmus glaucescens community.

通过SPSS聚类分析和CANOCO排序研究了贺兰山西坡植被分布与环境因子的关系，结果表明：在海拔梯度上，贺兰山西坡植被大致可以划分珍珠猪毛菜－红砂群落、短花针茅－大针茅群落和蒙古扁桃－灰榆群落3种类型。

Grandis had the higher caloric values that were 19.03 kJ/g and 19.28 kJ/g respectively in two communities. The species with the low value were Axyris amaranthoides and Chenopodium glaucum in L. chinensis community (15.04 kJ/g), and Salsola collina in S. grandis community (12.75 kJ/g).

群落水平上，羊草群落和大针茅群落热值最高的均是大针茅，分别为19.03和19.28 kJ/g，热值最小的植物种在羊草群落中为轴藜Axyris amaranthoides和灰绿藜Chenopodium glaucum，在大针茅群落中为猪毛菜Salsola collina。

Based on these, this study was to determine the relationship between standing vegetation and soil seed bank. The main results are as follows: 1 Effects of grazing on plant communities The grazing successions were Stipa klemenzii → Salsola collina + Stipa klemenzii → Salsola collina community in the desert steppe; Stipa grandis or Leymus chinensis → Cleistogenes squarrosa + Stipa krylovii or Stipa grandis → Potentilla acaulis + Cleistogenes squarrosa community in the typical steppes and Leymus chinensis + forbs →Leymus chinensis + Stipa baicalensis community in the meadow steppe.

主要结论如下： 1放牧对植物群落的影响荒漠草原的放牧演替规律为小针茅群落→猪毛菜+小针茅群落→猪毛菜群落；典型草原为羊草或大针茅群落→糙隐子草+大针茅群落或克氏针茅群落→星毛委陵菜+糙隐子草群落；草甸草原为羊草杂类草群落→羊草+贝加尔针茅群落，这是不同物种对牧压的不同适应结果造成的。

The results showed that with the increase of grazing intensity, the annual (Salsola collina, Cleistogenes squarrosa, Artemisia frigida) replaced the perennial grasses, such as Stipa grandis, Leymus chinensis, the height of vegetative ...

从无放牧的对照样地到重度退化样地植物群落类型依次转变为：羊草+大针茅+丛生禾草、大针茅+羊草+糙隐子草+丛生禾草、糙隐子草+大针茅+羊草+丛生禾草、猪毛菜+糙隐子草+小丛生禾草。

The result showed that the mineral oil content of soil was negatively correlated with microorganism contents,the mineral oil accumulation degree of stipa was more than that of Leymus chinensis and the Fe and Zn accumulation degree of Leymus.

结果表明：土壤矿物油含量与微生物含量成负相关；针茅对矿物油积累程度高于羊草；羊草对铁、锌的积累程度高于针茅等等。

The area of Stipa gandis steppe is 2798081hm2 in Inner Mongolia, which is not only the important pasture range in middle-east region, but the main greening proctive screen. It holds an outstanding meaning in the ecology and economy. Based on the morphological characteristics, physiological properties and genetic variation, adaptability of Stipa gandis under grazing pressure were studied.

大针茅是亚洲中部草原亚区特有的蒙古草原种，以大针茅建群的草原在内蒙古的分布面积为 2798081 公顷，这一地区不仅是内蒙古中、东部地区重要的放牧场，也是京津地区的主要绿色屏障，具有不可忽视的生态和经济意义。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。