青藏高原高寒草甸灌丛化对家畜生产的作用及其机理

The woody encroachment into grassland is one of world-wide problems. The current researches across nations are mainly focused on the causes of woody encroachment and the resulted heterogeneity of soil and vegetation. To understand how animal production will react to woody encroachment is the foundation of clarifying the mechanism of this process, the optimized regulation and control, but the mechanism is unknown. Qinghai-Tibet plateau is one of the most sensitive areas to woody encroachment, but the relative researches are absent. Therefore, this project aims to explore the urgent scientific question: how woody encroachment into the alpine meadow will affect animal production under the controlled grazing experiments and herdsman grazing production. This proposal aims to pin down the threshold of the woody encroachment impact on animal productions and how animal production will respond to this change. Based on the above results, the optimized regulation methods will be developed. Role of social economic management factors and others will be quantitatively identified. The research results will also give theoretical and technological supports on the sustainable management of woody encroachment into alpine meadow on Qinghai-Tibet plateau.

草原灌丛化是世界性问题，当前国内外研究主要关注它的诱因和发生发展机制，及其导致的土壤和植被异质性。草原灌丛化对放牧家畜生产力的作用是阐明草原灌丛化发生机理的基础、实施调控的依据和目标，但是它的作用机理和调控途径尚不得而知。青藏高原高寒草甸对灌丛化较为敏感，但相关研究匮乏。为此，项目拟在对灌丛化敏感的青藏高原，控制性放牧试验和牧户放牧试验相结合，研究高寒草甸灌丛化对放牧家畜生产力的作用及其机理这一重要而紧迫的科学命题，定量生物因素、非生物环境因素和管理因素的贡献率，明确灌丛化对家畜生产力的作用阈值以及后者的响应阈值，在此基础上提出优化调控途径，确定社会经济管理等诸多因素的定量作用。研究结果还可以为青藏高原高寒草甸灌丛化的可持续管理提供理论和技术依据。

全球变化背景下，草原灌丛化是世界性问题，当前国内外研究主要关注它的诱因和发生发展机制，及其导致的土壤和植被异质性。草原灌丛化对放牧家畜生产力的作用是阐明草原灌丛化发生机理的基础、实施调控的依据和目标，但是它的作用机理和调控途径尚不得而知。本研究通过选择不同灌丛盖度草地研究对象，获得牧草和灌木营养成分季节动态数据3000个，牦牛放牧行为、血清生理生化参数、瘤胃发酵参数、瘤胃微生物区系变化等各类数据约1万个。阐明了牧草不同生长季节灌丛盖度对牧草品质和单位面积牧草产量的影响；评价了灌丛盖度对牦牛放牧行为和经济效益的影响，以及不同牧草生长阶段灌丛盖度对牦牛血液生理生化指标，瘤胃发酵参数和微生物区系的影响。高寒草甸灌丛通过改变草地牧草产量以及草地牧草空间分布影响了牦牛的放牧行为和牧草采食，进而对牦牛血液参数、瘤胃发酵和微生物区系产生影响，最终影响放牧牦牛的生产和经济效益，研究结果为青藏高原高寒草甸灌丛化的可持续管理提供理论和技术依据。