Optimized Eco-productive Paradigm In Farming-pastoral Zone Of Songnen Plain

Farming-pastoral zone of Songnen Plain is one of ecological vulnerable zones, and one of three concentrating distribution zones of saline-alkalize land which located in the west of Songnen Plain, the east of farming-pastoral zone. High sensitivity and low carrying capacity characterize the eco-geo-environment in this zone. During the last century, fragmentation and degradation of ecological environments on farming-pastoral zone of Songnen Plain had been accelerated due to the increase of population pressures and the high intensification of land use. Human's impacts on farming-pastoral zone of Songnen Plain led to vegetation changes that took place faster than that of the natural vegetation transformation, and eco-environmental degradation, such as severe soil saline-alkalization, desertification and water-soil loss. As a result, the unreasonable land-use model caused the co-existence of the low economical development and seriously eco-environmental degradation. So, the establishment of optimized eco-productive paradigm in farming-pastoral zone of Songnen Plain is crucial. The paper thus takes Changling County, a typical farming-pastoral zone of Songnen Plain, as the basic study units for optimized eco-productive paradigm. Based on analysis of observation data, maps, field investigation and literature consultation, the following results were concluded: 1. The analysis of eco-geo-environmental background Several kinds of eco-geo-environment hazards occurred in the farming-pastoral zone of Songnen Plain. At present, the land area of desertification and saline-alkalization had accounted for 34.27 % of total area, the land area of desertification and saline-alkalization was gradually extending. Frequently climatic disasters, such as drought, flood and sandstorm, occurred and affected the farming-pastoral zone of Songnen Plain. Furthermore, the shortage water recourses and groundwater quality both affected on the farming production and the development of social and economic. The mechanisms of these eco-geo-environmental hazards included geotectonic processes in the Earth's history, and exogenic causes, such as the East Asia monsoon and irrational human activities. In recent years, human activities have become the main drive factor. 2. Content of the case study Changling County in Jilin province,has been singled out as a case study. Analyzing changes of the landscape pattern, the distribution of soil, the characters of the farming and pastoral development,the results were: 1. Landscape analysis showed: From 1980 to 2000, farmland area obviously expanded and large area of woodland and grassland changed into farmland; the extension of farmland has led to the decrease of diversity, increase of fragmentation and dominance. 2. Most of soil in Changling County was low fertility, and sand land and saline-alkalize land was about 55.38 %. The effect of land-use changes on different landform showed: plate on the mount had better fertility level, and land-use changes here had little effect; slope land and lowland had higher sensitivity and low carrying capacity, which was not suitable for reclamation. 3. The total grazing resources provided by grassland, plantation and farmland was only 47.3 % of total forage resources of real needs, so that they could not satisfied with the needs of development of animal husbandry in the area. To the total forage resources available, crop stalk was accounting for 78.3 % and 2.4 times of the total forage of the real needs. The major problems for the development of animal husbandry were short of forage resources, especially for good-quality forage, and irrational utility of forage. Accordingly, in order to further the development of animal husbandry and comply with the sustainability of ecology, economy and society, it would be encourage for people to rationally exploit all kinds of available forage resources, especially cropstalk, and to establish artificial grassland to produce the high-protein forage which would decrease the stress of natural grazing space and protect or restore the degraded grassland ecosystem. 4. In Changling County, the value of primary industry was the main of Gross domestic product, i.e., agricultural output was the main economic source. Gross output value of farming and animal husbandry accounted for the 90 % of gross output of agriculture, and gross output of farming was above 60 % in gross output of agriculture. However, owing to the impact of eco-geo-environment, the distribution of soil pattern, mono-cropping, extensive product model, the development of farming and animal husbandry was low. 5.Finally, integrating with detailed analysis of Changling County, we proposed optimized eco-productive paradigm. It consists of "three circles" system, i.e., high efficient agriculture production circle, water-soil conservation and natural eological restoration circle, and pasture and ecological function circle.