基于生态位理论的安徽省江淮分水岭地区农用地变化研究

Analyzing Changes of Agricultural Land Based on the Niche Theory in Jianghuai Watershed of Anhui Province

研究运用土地生态位理论的数量生态位（宽度）和扩充压缩度数学模型,以安徽江淮分水岭地区1998~2013年农用地利用变更调查数据为基础,分析了江淮分水岭农用地生态位的变化过程。分析表明：（1）各种类型农用地之间生态位态势差变化不明显,耕地生态位突出,其他类型农用地生态位较低,农地利用结构不够合理,影响江淮分水岭的生态环境保护。（2）区域内各类型农用地的生态位竞争不明显,系统相对稳定。农用地的变化主要表现为园地、其他农用地与耕地、林地、牧草地之间弱的生态位竞争。农用地生态位整体在不断压缩,整体向系统外其他类型用地流转。（3）农用地生态系统经过15年的发展变化,目前系统比较稳定,变化小,但耕地与园地的生态位矛盾竞争使区域农用地生态系统潜伏着一定的危机。（4）需要提高园地、林地等生态保护功能用地的生态位,适当缩减耕地生态位,增加生态多样性。

Land Niche theory is one of powerful tools to study the laws of succession of land ecological system. It could not only clearly measure the changing situation, direction and speed of land ecosystem among the elements of the land ecosystem, but also reflect the succession and development of the whole system. By constructing the model of niche theory, this paper analyzes the change process of agricultur- al landuse from 1998 to 201a in Jianghuai watershed. The results show that： （1） Difference of niche situation among all sorts of land type does not significantly change~ the farmland ecosystem diversity does not significantly increase; land use structure is still not reasonable. These affect the ecological en- vironment protection in Jianghuai watershed; （2） Niche competition is not obvious in the area of each type of agricultural land, relatively stable system. Change of agricultural land is mainly manifested in the garden, among other agricultural land and cultivated land, wood land, grass land and weak ecologi- cal niche competition. Ecological niche is continuously compressed, and farmland is transferring to oth- er types of land outside ecological system; （3） After 15 years development, farmland ecological system is currently in the stable stage. But the latent crisis is the contradiction between cultivated and garden land; （4） We must adjust the structure of agricultural production, improve the niche of ecological pro- tection function, such as the garden land, woodland etc. Moreover we should appropriately reduce the niche of cultivated land to increase the ecological diversity. The results provide the theory basis of ad- justing agricultural production structure and development direction for the comprehensive treatment and protection of Jianghuai watershed in Anhui province.