Meng Xianxi, Lu Xianguo, Wang Qicun, Huang Xichou
The natural factors of land desertification in the Songnen Plain are: 1.The neotectonic movement and vicissitudes of riverbed from the Quaternary made a wide distribution of sand deposit in riverbed and flood land,which gives sufficient sand.2.It is windy and arid in spring and the reducing of precipitation in recent years made it much drier.The sand more easily spread. The artificial factors are over cultivation,over grazing and unreasonable firewood collection. Land desertification caused the farmland to be engulfed,ecological environment deteriorated and harmed the life of residents.ln order to control the land desertification,the authors put forward the following measures.1.Readjust the proportion of cultivated,forest and grass land,increase the proportion of forest and grass land.2.Plant trees to prevent the harm of wind and sand,including building a artificial ecological system of arbor,shrub and.grass on dunes,building a compound ecological system of forest,grass land and farm land in flat and ground, and building square forest network in lands that are easily harmed by desertification.3.Construct a model of tree-dimensional ecological system of agriculture between sand lump and pasture.4.In residential area,build a courtyard economic system with the unity of life,production and ecology.5.Make more jnvestment,pursue the policcy of contract considering production.
