基于高分辨率遥感与GPS的畜群采食行为与植被景观结构协同关系研究

Grazing is one kind of human activity which is participated in and intensified by human being to directly utilize the natural vegetation resources and influence the function and structure of ecosystem. The relationship between herd and landscape reflects on their mutual influenced and restricted synergies. At present, the studies on the herd foraging behavior especially on the precisely spatial herd tracking and positioning, and the synergetic relationship between herd foraging behavior and vegetation landscape structure are relatively few. This program takes advantage of herd tracking by global positioning system (GPS) to surmount the shortage of traditional herd following by man. With GPS collars, the herd is tracked uninterruptedly and the spatial pattern of its foraging behavior is investigated timely. The dynamic relationship has been established between herd and landscape structure by using real time high resolution remote sensing images to monitor the dynamics of vegetation on the route of herd. By examining the relationship between grazing frequency (grazing intensity) and spatial heterogeneity in the patch scale of vegetation landscape structure, the spatial autocorrelation analysis and spatial statistical regression analysis are used, the model of their interaction is built to reveal the mechanisms and feedback effects, and the synergetic relationship between herd foraging behavior and vegetation landscape structure are analyzed ultimately. The results can provide scientific basis and theoretical guidance for the sustainable development of grassland ecosystem and grazing regime.

放牧是一种人为参与的、并得到人为强化的最直接利用自然植被资源并影响生态系统功能与结构的人为活动。畜群与植被景观之间的关系，体现于它们之间相互影响、相互制约的协同关系。目前对畜群的觅食行为尤其是空间上精确的追踪和定位，以及畜群觅食行为和植被景观结构的协同关系研究还比较少。本研究利用GPS畜群跟踪技术克服了传统上牲畜觅食行为人工跟踪观察的不足，通过给畜群携带GPS设备而实现实时地无干扰跟踪，从而掌握其在空间上的觅食行为规律，并通过实时高分辨率的遥感影像监测畜群所经路径的植被生长状况变化，从而将二者建立动态链接。通过对畜群采食频率（放牧强度）和植被景观结构在斑块水平上空间异质性之间关系的分析，利用空间自相关分析、空间统计回归分析等构建二者之间相互作用模型，揭示其相互影响机制和反馈效应，从而研究二者之间的协同关系。其结果能为草原生态系统可持续发展和放牧制度制定提供科学依据和理论指导。

自课题实施以来，课题组积极开展畜群野外觅食跟踪观测实验，在放牧季同步开展了地面牧场的植被变化调查，利用卫星遥感影像及无人机、地面样方等对植被变化状况进行了同步调查，取得了大量一手实验数据，克服了2020-2021年新冠肺炎疫情对野外观测实验带来的困难。通过文献综述，明确了畜群觅食行为对植被景观的影响途径，明确了植被景观对畜群觅食行为的影响机制。基于GPS畜群跟踪定位实验，形成“天-空-地”一体化植被动态及畜群觅食行为物联网监测平台和系统，实现了真正意义上的觅食策略-植被特征及变化实时动态化一体监测。对藏牦牛和藏绵羊的觅食特征及空间行为进行了实时捕捉和动态监测，分析了其觅食习性和环境变量之间的关系，通过放牧压力热力图分析了放牧和环境变量之间的关系。. 课题组组织了十余次野外考察和实验观测，组织了1次专家咨询会和进展研讨会，参加了中国生态学大会等多个国内外学术会议。课题执行期间，召开和参与了10余次相关课题内容的国内外学术会议，组织专题咨询会议1次，组织了10余次野外考察，进行了10余次实地调研与实验，组织了多次专题报告和讲座。出版专著2部。发表论文7篇（第一、第二标注）。申请专利2项。培养博士研究生1名、硕士2名。执行期，课题超额完成了预期成果目标。