关键词: 油茶, 油茶, 无性系, 电导法, 半致死温度, 耐寒性

Abstract: Land degradation and land use sustainability in ecologically fragile areas have attracted much attention in recent years, and it is necessary to study the eco-geographic pattern and land use ecological risk in such areas. African continent is one of the typical areas on the earth, which has ecologically fragile conditions. Based on the distribution data of temperature zone, dryness, terrain and vegetation, the eco-geographic regions in African continent were divided by using GIS software and landscape index model was introduced to give descriptions to each region. Also, the land use ecological risks in African continent were discussed at regional scale. It was found that: the eco- geographic pattern in African continent could be divided into 6 regions (northwestern mountainous region, northern desertification region, north- central transitional region, central basin region, eastern rift valley plateau region and southern plateau region), and 32 sub-regions. Spatial trend of drought (arid core area) was toward the central part of northern desertification region, north part of eastern rift valley plateau region and southwest part of southern plateau region. With increasing human land use activities, semi- arid and sub- humid arid areas around central basin region would be affected by land desertification risks, and areas with undulating terrain and abundant rainfalls would be affected by soil water erosion risks, respectively.