A Study Of The Black Soil Degeneration Mechanism Within Argo-purlieu Ecotone In Temperate Zone

The ecotone also is named the ecological transition zone or ecological area, it translatesamong different attribute ecological systems. Farming-plantation ecotone is ecologicaltransition in landscape scale. At present, there are many ecological problems in this zone,such as: soil and water loss, the decrease of species variety, the polluted water problems andthe desertification land. The argo-purlieu ecotone in temperate zone changes frommountainous to plain region, from temperate mixed coniferous and broad-leaf forest totemperate forest Steppe, from dark brown forest soil to black soil, from forest landscape toagriculture landscape. It is provided with characteristic about edge effects and sensitivity ofecotone. The edge effects make that the productivity is more than other areas compared to thesame latitude. The sensitivity attribution determines that the ecotone varieties faster than otherzone in the same interfering condition. The Dahei-mountain is the borderline between hillsand plain transition, forest and grass transition which include the typical characteristics ofecotone in two sides of the mountain that it develops black soil on the mesa when their naturalinterference-properties is different among them.In this thesis, the author applies to territorial contrast analysis method to research thedegree of black soil degeneration on mesa in two sides of Dahei-mountain. Basing onfieldwork and analyzing methods in the lab, the author choose black soil organic matter, TotalNitrogen, Available Nitrogen, Total Phosphorus, Available Phosphorus and Available Kaliumto estimate the black soil properties according to single factors. Moreover, linked to soilmoisture, conductance and the content of Natrium of the black soil, the author synthesize thescores of competent and contrasts the differences between the mesas in both sides ofDahei-mountain, and then explains the mechanism of black soil degeneration in a smalldistance of horizontal scope ecotone.The thesis includes five chapters. The first chapter is foreword which introduces theprimary content and means about the ecotone in the foreign countries and our country. Thesecond chapter presents the general situation of the study area and accounts briefly for thephysical and socioeconomic characteristics along with the mainly ecological problems. Thethird chapter introduces the reasons when choosing the empirical region and the primaryexperimentation. The forth chapter statistics and analyses the empirical data. The last chapteris conclusion, the degree of black soil degeneration in the east of Dahei-mountain is moreserious than the west of Dahei-mountain. The cause why brought to the differences betweentwo sides of the Dahei-mountain is that the soil parent materials, the precipitation andquantity of heat exist differences in local scale region, it don't affect zonally the developing ofblack soil, however, come into being differentiation about sub-classifications, the higherprecipitation and less temperature urge that the degree of black soil degeneration is morebadly in the east of Daheio-mountain than west of this mountain.