北方草地畜牧业生态系统健康综合评价与诊断

Comprehensive assessment and diagnosis of the health of animal husbandry ecosystems in north China pastures

鉴于畜牧业生态系统健康与人类、社会、经济、环境等具有密切的关系,从活力、组织结构和恢复力三方面,提出区域畜牧业生态系统健康评价指标体系及等级评价模型。其中,适宜载畜量、人均养畜量、畜群结构、草地退化沙化率、良种畜比重、舍饲、半舍饲比例是我国北方牧区草地畜牧业生态系统健康状况的主要控制因子。选取内蒙古牧区、新疆牧区、青海牧区、甘肃牧区、西藏牧区五个区域,对区域内畜牧业生态系统健康分别进行评价及诊断,评价结果为:健康状况处于"中"级的牧区是内蒙古(2.7730)、新疆(2.5641)以及青海牧区(2.4673);健康状况处于"低"级的牧区是甘肃(2.2335)和西藏牧区(1.8884)。针对评价过程中暴露的活力、组织结构和恢复力问题,对5个牧区草地畜牧业生态系统健康进行了诊断,认为在中国北方牧区气候暖干化背景下,只有调整草地畜牧业发展战略,重视和确定草地资源在提供生态公共产品中的重要作用和地位,从生态效益和经济效益的要求出发,优化牧场整体生产结构,增草增畜,使草地资源得到恢复性演替,才能实现生态畜牧业的建设目标。

Abstract： Animal husbandry ecosystems that have many comprehensive characteristics can be assessed through observations of their vigor, structure and resilience. Animal husbandry ecosystems are very important to realize the healthy development of animal husbandry. Based on the significance of the health of animal husbandry ecosystems and their characteristics, an assessment system with indexes was constructed using vigor, structure and resilience. Among such indicators, livestock carrying capacity of grassland, number of livestock per capita, livestock population structure, land degradation and desertification rates, proportion of fine breed livestock, shed-bred or half shed-bred rate are the main manipulatable indicators of animal husbandry ecosystem health in north China pastures. In addition, a projection pursuit grade evaluation （PPE） model is presented for comprehensive evaluation of animal husbandry ecosystem health. Projection pursuit is a statistical technique which involves finding the most ＂ interesting＂ possible projections in multidimensional data. Such projections can then be used for optimal visualization of the clustering structure of the data, and for such purposes as density estimation and regression. Diminishment of dimension is also an important objective, especially if the aim is visualization of the data. Based on the assessment indexes system and assessment model of animal husbandry ecosystem health, grassland animal husbandry ecosystem health in north China pastures, including Inner Mongolia pastures, Xinjiang pastures, Gansu pastures, Qinghai pastures, and Tibet pastures are evaluated. The conclusions of the animal husbandry ecosystem health assessments of every region in North China pasture are as follows： the health of animal husbandry ecosystems in Inner Mongolia pastures, Xinjiang pastures and Qinghai pastures is rated ＂medium-healthy＂, while Gansu pastures and Tibet pastures are rated to be of ＂low-health＂. The ranking from the best to the worst, among the five pastures in north China, was Inner Mongolia pasture, Xinjiang pasture, Qinghai pasture, Gansu pasture and Tibet pasture. Health in the five main pastures is indeed not so good and it is influenced or limited by economic costs, infrastructures, economic scales, natural resources, water resources, soil erosion, ecological fragility, diathesis of agricultural laborers, population development and scientific and technological contributions, etc. It is suggested that related to capacity building for sustainable development of grassland animal husbandry, five main measures should be taken. First, strengthen the legal framework about and administer protection and construction according to law. Second, strengthen infrastructure construction and grassland raise the production level as a whole. Third, carry out a strategy of accelerating animal husbandry through science and technology and enhance the transformation of production means. Fourth, optimize the resource allocation, and develop intensive animal husbandry rapidly. Fifth, develop industrialization and promote added values by processing products. Finally, enhance the construction of marketing systems and increase the organization levels of farmers.