沙地

The objective of the paper is to state the necessity of introducing Pinus pinaster Ait. in China. Firstly, generalize the biological and ecological characteristic of P. pinaster, and its utilization value. Secondly, after analyzing the natural distributions of P. pinaster and natural conditions of these areas, comparing the climate attributes of the introduced regions in our country and other countries, the possibility of introducing this species are discussed.

概括了沙地海岸松的生物学、生态学特性及其推广利用价值；通过了解沙地海岸松在国外自然分布区以及引种地区的自然概况，总结中国沿海防护林建设中出现的问题和亟待引进优良品种的迫切性，并对中国沿海地区的气候特点进行了对比分析得出，中国引进沙地海岸松的必要性和可行性。

Based on the research, the quantity of sandlot"s dust samples is concentrated in 150cm height below, and primarily are the middle and lager particles, so sandlot"s transmission of small particles is less than the other three surfaces in 150cm height above.

2经测定，在150cm高度层以下沙地风蚀物含量较大，但由于沙地地表颗粒组成以中砂粒和细砂粒为主，因而在150cm高度层以上沙地的输沙量低于其它三种地表。

Based on field experiment and measure data, ecological characteristics of soil water in different fencing sandy land in arid desert area and vegetation restoration effect of soil water variation in fencing sandy land were analyzed. In representation of Artemisa arenaria DC population, observing and researching vegetable restoration effect of soil water variation in fencing sandy land. The results indicate as follow:(1)With the vegetation development constantly in fencing sandy land, soil water utilization of vegetation increased. It made soil water content and soil water storage reduced with the increase of fencing time in sandy land.

本文通过野外实验测定数据，分析研究了干旱荒漠区不同类型封育沙地土壤水分生态特征，以及封育沙地土壤水分变化对植被恢复的影响，并以当地沙蒿种群为代表，观测研究封育沙地土壤水分变化对植被恢复的影响，结果表明：(1)封育沙地随着植被的不断生长，植被对土壤水分的利用也有所增加，从而使沙地土壤含水量和储水量随封育时间的加长而表现为一定的降低趋势。

Gramineae and Compositae by the shifting sand to the fixed sandy land, the species of which changed greatly, that indicated they were playing a great role in the recovery of the sands. Asclepiadaceae plants could serve as a indicative plants to distinguish between the types of shifting sand and other sand; Portulacaceae and Bibgnoniaceae plants, which appeared only in the fixed sandy land, has become a landmark to determine the fixed sand plants. In addition to artificially plant Caragana spp. and Artemisia spp.

豆科和藜科植物作为流动沙地的先锋物种，表现出较强的适应能力；禾本科和菊科植物由流动沙地到固定沙地，其种类变化较大，表明其在沙地恢复中发挥着巨大的作用；萝摩科植物可作为区分流动沙地和其它沙地类型的指示性植物；马齿苋科和紫薇科植物仅在固定沙地中出现，已成为判断固定沙地的标志性植物。

Brought forward and reasoned the forming mechanism of Maowusu sandy land. Based on the analysis of the development of Holocene rivers and related loess and windsandy geomorphology, the paper put forward the forming mechanism of Maowusu sandy land as follows: while the climate became dry, the exterior channels extended backwardly and cut through the remained lake system of ancient Hetao lake. This resulted in the rapid discharge of underground water. The vegetation living on this water resource was destroyed completely. Then the sand began to form.

对毛乌素沙地的形成机制进行了新的探索基于对过渡地带全新世河流及其相关的黄土和风沙地貌发育、土地利用变化等分析，提出毛乌素沙地的形成机制：在气候变干的同时，外流河谷溯源延伸，切穿了长城以北河套古湖残遗湖系，使地表地下水迅速外泄，原靠湖系水资源维系的生长在河套古湖湖滨沙堤形成的沙地上的非地带植被的生存条件被彻底摧毁，而起沙。

The analysis of chorological and spatial changes of desertification indicates that expansion of desertification mostly takes place around the four main sandy lands: Keerqin, Hulunbeier, Hunshandake and Maowusu, while situation in the central part of sandy land is kept relatively steady, with some part of these areas tending to take a favorable turn.

通过沙漠化时空演变过程分析表明：沙漠化的发展主要集中在科尔沁沙地、呼伦贝尔沙地、浑善达克沙地和毛乌素沙地的边缘，而沙地的内部则相对稳定，部分地区有逆转的趋势。

In order to explore the grain-size distribution characteristics and geo-genetic types of land desertification in Mo Us desert, the research on the grain-size characteristics of sediments since late Pleistocene has been carried out in the desert area and neighboring area such as inside desert, sand covered loess plateau, loess plateau and river valley. The research result shows that sediments of different geologic genetic types are the fundamental material source of sandy desertification in these areas and the distinguishing of different types of the sediments is the theoretical basis of classification of different geogenetic type of sandy desertification. The contribution of different geological roles on the land desertification and its significance to prevent and deal with the land desertification have also discussed.

为了研究毛乌素沙地沉积物的粒度特征与土地沙漠化的地质成因类型，通过系统研究沙地及相邻地区晚更新世以来在沙地内部、覆沙黄土区、黄土高原和河流谷地与湖泊等不同地质构造地貌条件下所形成的沉积物粒度特征，指出不同地质成因类型的沉积物是这些地区土地沙漠化的物质基础，区分不同类型的沉积物也是构成不同地质成因类型土地沙漠化分类的理论基础，探讨了不同地质作用对土地沙漠化的贡献及其对土地沙漠化防治方面的意义。

It can provide some theoretic gist for resource value of water and soil in sandy land to indicate the change and law of soil moisture character, as well as the water circulation and balance mechanism in sandy land, at the same time, it have important practical significance to protect limited water resource, improve using efficiency of water resource,control desertification, choose and educate sand binding plant, renew and restore degraded ecosystem, as well as the economy benefit of irrigative agriculture and intending trend of development.

揭示沙地土壤水分特征的变化规律以及沙地水循环和平衡机理，可以为沙地水土资源评价提供一定的理论依据，同时对于保护当地有限的水资源和提高水资源的利用效率，以及沙漠化防治，固沙植物的选育，退化生态系统的恢复与重建，灌溉农业的经济效益和未来的发展趋势都具有重要的实践意义。

At the edge of sand land, there lies a Caragana microphylla zone. From the fringe to the center of sand land, there are more mesic plant communities. A sandy environment which is different the local climate is constructed in the hinterland of the sand land, so there are more different ecological types of the plant communities.

在沙地与草原的过渡带上一般会有由小叶锦鸡儿群落组成的一个过渡带，从沙地的边缘到沙地的腹地，植物群落逐渐中生化，沙地在其腹地营造了一个超越当地气候特征的沙地环境，容纳了各类不同生态类型的植物群落。

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 split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。