藏北高原游牧民定居引起的畜群行为变化及资源环境效应研究

Nomad is a basic form of production and lifestyle which is suitable to pastoral area, where the relationship between human and environment is harmonized. Changing nomad to settle down means to change the way of interacting between human and land system which evolved for thousands of years, and may cause series of new effects on resources use and environment management. Therefore, study on the impacts of the sedentarization on water, rangeland can help to understand the resources efficiency and ecosystem degradation raised from the sedentarization, reveal the generant mechanism of resources and environmental effects after sedentarization, and put forward countermeasures for the future. This study focus on the impacts of sedentarization on natural resources use pattern and pastoral environment in the north Tibetan plateau. Three typical sedentarization settlements in the area are taken as examples, while the other three pastoral group that is still living in nomad are also explored as the counterpart. The filed survey data , GPS tracking data, water, biomass, grassland, land use, remote sensing data are integrated in the GIS. The study includes three points, changing characteristics of herd behavior after sedentarization, and the impact factors of the herd spatial behavior; the spatial heterogeneous around the settlements after sedentarization, and the methodology for spatial function zoning; the resources and environment impacts of the sedentarization including water consumption, water pollution, grassland use, pasture degradation by overgrazing or idling. The study aims to improve the knowledge on rangeland management with the view of zoning after sedentarization based on the spatial heterogeneous analysis, and to provide a theoretical and empirical support in pasture management and sedentarization policies improvement.

藏北高原游牧民定居后，在草资源利用和草地生态、水资源和水环境方面带来一系列新问题，直接影响着牧区人与自然的协调发展。开展游牧民定居引发的畜群行为变化及资源环境效应研究，有助于从放牧方式变化-畜群行为变化入手，揭示定居活动产生的资源环境效应及其形成机制，评估定居引发的资源环境效应类型、特征及强度，有针对性地提出应对策略。本项目选取藏北高原的3个典型定居点，同时选取3个未定居牧业村组开展对比研究。基于实地调研、GPS跟踪及数据集成，以未定居牧业村组为参照，研究定居后放牧畜群行为特征及变化规律；通过分析定居地域系统内生产、生活、生态功能的变化，探究定居工程引发的空间功能分异特征与演变规律；在空间功能区分析的基础上，对定居点的水资源消耗、水污染，过牧和草场退化，欠牧和草场萎缩等资源环境效应进行量化研究。本项目将在定居后草场分区管理方面形成新认知，为游牧民定居的资源环境管理提供新策略和科学支撑。

1) 从游牧民定居后畜群行为变化入手，刻画草场空间分异及牧区聚落空间演进特征，构建游牧民定居的资源环境效应研究理论体系，丰富了聚落生态学研究内容。①定居条件下畜群行为特征：藏绵羊群平均日行距离和速度呈现先降低后升高的U型趋势。生长季（6-8月）羊群平均日行距离大于非生长季（p<0.001），平均速度快于非生长季（p<0.05）。生长季羊群放牧场海拔高于非生长季(p<0.001)。生长季羊群轨迹多在承包草场边界内部。非生长季羊群放牧范围向承包草场边界外部扩张。羊群对聚落存在明显偏好。②草地利用空间分异及牧区聚落空间演进：定居点的居住、集约生产、粗放生产等功能在空间上趋于分化。放牧圈和游牧圈发生空间重构。牧区聚落向定居化、集聚化演进。③游牧民定居的资源环境效应：区域土地利用强度增大，定居点及水源地周边超载过牧。农牧结合趋势明显，网围栏、粪肥施用等管理措施短期内改善土壤肥力、提高初级生产力。但聚落扩张、围栏建设限制了草食性动物流动性，对草地生态系统平衡、野生动物保护等提出新挑战。.2) 采用新技术，搭建游牧民定居效应研究的方法体系。引入大疆无人机、动物颈圈技术，实现畜群动态监测，获取部分时段的畜群放牧轨迹数据。运用TimeSAT模拟草地生态系统净初级生产力年际动态变化。采用放牧点数据及环境变量，基于Maxent模拟牧场分布。基于InVEST构建了人类活动影响指数，评估定居化等人类活动的空间分布格局。.3) 针对游牧民定居的资源环境效应，提出以恢复人—家畜—野生动物—草地生态系统平衡为目标，推动以减畜补饲、聚散适度、少围不围为主要措施的牧区管理建议。① 科学核算草地承载力，限定家畜存栏数量，鼓励补饲、草场流转，确保家畜和草食性野生动物总量与草地承载力相平衡。②优化聚落布局及定居规模，实现牧区聚落适度集中。③ 维持家畜与野生动物的流动性，拆除重要栖息地及野生动物迁徙通道上的围栏，仅保留草地恢复和人工种草等围栏。