沙地生的

This research was conducted in degraded rangeland at the southwestern edge of the Mu Us sandland, Yanchi county, Ningxia, the soil seedbank features and its relation to vegetation was analyzed using similarity analysis and ordination method, the results show that seeds within soil distribute mainly in 0~5 cm soil layer, less seeds in 6~15 cm soil layer in exclosed and non-exclosed rangeland, for seeds in exclosed soil, species richness and diversity index H are higher, while D is lower, exclosure measure, generally speaking, can increase plant species and amount of vegetation and seeds in soil, some annual plants, mesophytes and halophytes appears in the soil or surface.

以毛乌素沙地西南缘宁夏盐池县的退化草场为研究对象，采用相似性分析和排序方法对封育和未封育草场土壤种子库的特征及其与地上植被间关系进行了研究，结果表明无论封育区还是未封育区，土壤种子库中的种子主要分布于0~5cm的土层，6~15cm土层的种子数很少；封育区土壤种子库的物种丰富度大于未封育区，物种多样性则表现为H 值较大，而D值较小，总体上看封育措施可以提高地上植被和土壤中种子的种类和数量，一些一年生植物、中生植物和盐生植物开始出现在地面或土壤种子库中。

The main area which changes is agricultural land, grassland with low coverage, high coverage of grass and sand..

从要收生变更的地类无工田、矮覆揭度草地、上覆揭度草地和沙地。

Most of the soil had been washed away or buried in drift after the removal of the trees; only where the streamlet ran down from the kettle a thick bed of moss and some ferns and little creeping bushes were still green among the sand.

树木被砍倒后，大部分肥沃的泥土已经或被冲走或被压到了沙土下，只有锅里渗出一条细流的地方长着一层厚厚的苔藓、一些羊齿草和贴地蔓生的灌木，在沙地中呈现出一片碧绿。

The sandy desertified lands have the tropical coastal dene c haracteristics in the district, the shape, the xerophyte and the rapid evolvemen t of land use.

海南岛西部沙漠化土地具有热带海岸沙地的地域特征、形态特征、旱生植被景观特征和土地利用快速演变特征。

By the field survey which lasting a period of 3 grown seasons and by the means of remote sense and geographic information system, we ascertain the present vegetation pattern of Hunshan-Dake sand land, find out vegetation distribution principles on the different scales in the same time . From west to east, with the increasing of dry degree, the type of plant community changed form the xeric to the mesic. The vegetation of Sand land shows the characteristic of the zonal vegetation, but dont consistent with the traditional diversification principle. The vegetation of the middle part displays a high differential characteristic, which compresses the longitudinal zonation at a certain extent. So we can say that sand land vegetation is semi-zonal.

通过对浑善达克沙地历时三个生长季的地面考察并应用遥感及地理信息系统等手段，确定了浑善达克沙地植被分布现状及浑善达克沙地植被在不同尺度下的分异规律：由西向东，沙地植被随着干燥度的降低，由旱生群落为主的区段递变为以中生群落为主的区段，表现出具有一定的地带性植被特征，但与传统的地带性植被的递变规律不相一致，沙地中段的植被表现出了高度的特异性，在一定程度上压缩了植被的经向地带性，表现出沙地特有的地带性分布规律，所以认为沙地植被是一种半地带性植被。

The aim of this research is to understand the ecological relationship between sand vegetation and environment, adaption charactristics of psammophilous plants to sandy environment and feature of plant resources in Otindag Sand Land, and further to provide theory evidence for selection optimal sand-fixation species and planning feasible process of vegetation restoration in desertification control.

本论文的目的是了解沙地植被与环境的生态关系、沙生植物适应沙地环境的特点以及沙地植物资源特征，为在沙漠化防治中选择合适的治沙物种、制定合理的植被恢复方案提供理论依据。

Caragana intermedia is a psammophilous shrub and one of the commonly occurred species in fixed and semi-fixed sand dunes in Otindag Sand Land and MU US Sand Land.

中间锦鸡儿是浑善达克沙地和毛乌素沙地固定和半固定沙丘上常见的一种沙生灌木。

But at the same time,itexisted in the fact that the water environment was amended,showingthat many lakes and ponds such as Hong Jiannuo Lake appearing andexpanding in the end of Qing dynasty.4.The vegetation in Mu Su Desert passed through several phases inhistorical times,the main phases are:the species composition ofvegetation community was gradually simplified;xeromorphous and sandyplant increased;the status of desert vegetation rose evidently.However,the change of vegetation zonation means that forest plainchanged into drought plain did not occur.5.The main modality of Mu Su Desert land degenerating has beendesertification,it had occurred before human activities intervenedintensively.Two-thirds of land has been desertification at variousdegrees.

但与此同时，也存在着局部的水环境改善，突出表现为红碱淖等湖沼在清末民初的出现和扩大。4、毛乌素沙地的植被在历史时期经历了群落种类组成渐趋简单、旱生沙生资源植物增加、荒漠植被地位明显上升等变化，但是并不存在由森林草原到干草原的地带性植被变化。5、沙漠化是毛乌素沙地土地退化的主要表现形式，在人类活动强烈干预以前就存在着，秦汉以来，有大约2／3的土地发生了程度不同的沙漠化。

The proportion of the plant species in the soil seed banks in the 4 types of sandy grasslands is dominated by annuals and biennials

4种类型退化沙地土壤种子库的种类组成以 1、2年生草本植物为主，所占比例 79%～ 88%，多年生草本和灌木所占比例很小

As a result, getting the following results:1Soil of Horqin sandy land mostly belongs to the eclipsed soil,there are the remarkable difference and regulational change about its machine constitutions, the physics and chemistry characteristics in different geography types.2A different geography of plant evolution is divided into follows:①livings of the sand②the wet living③the wasteland④livings of the salt⑤pasturing⑥natural wood.

据此，分析出以下结果：1）科尔沁沙地土壤大多属于高危风蚀土壤，其机械组成、物理化学性质在不同地貌类型中存在着显著差异并具有规律性的变化特征。2）沙地不同地貌类型区植被演替系列共分为：①沙生、②湿生、③撂荒地、④盐生、⑤放牧、⑥天然林这6个演替系列。

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。