人工草地生产力和稳定性的调控机理研究：问题、进展与展望

Mechanisms regulating the productivity and stability of artificial grasslands in China: Issues, progress, and prospects

我国拥有草地总面积60亿亩,占国土面积的41.7%.长期以来,我国在畜牧业生产中过度利用草地的生产功能,忽视其生态功能,造成草地大面积退化,草-畜关系失衡.同天然草地相比,建设优质高效人工草地可以使饲草产量提高10~20倍,有望从根本上解决我国肉、奶生产中面临的优质饲草料严重短缺的瓶颈问题,进而遏制过度放牧引起的草地退化,恢复草地生态功能.目前,我国在人工草地建设中仍面临种植规模小、产量低、利用年限短等问题,草产业发展水平远落后于畜牧业发达国家.因此,开展人工草地生产力和稳定性调控机理研究是实现以科技为先导,转变畜牧业生产方式,保障我国生态安全、食物安全、生态文明建设的国家重大战略需求.本文从人工草地生产力和稳定性调控的理论基础、国内外研究现状与进展等方面系统地介绍了近年来该领域取得的最新成果.在此基础上,对人工草地生产力和稳定性调控机理研究中亟待解决的科学问题以及重要生物学和生态学机制进行了展望.

China has 400 million hectares of grasslands, occupying 41.7% of the country＇s total land area. Due to the overexploitation of grassland＇s production functions and the neglect of its ecological functions, intensive livestock grazing in recent decades has resulted in widespread grassland degradation, reduction in ecosystem services, and imbalance between forage production and livestock demands in China. Compared to natural grasslands, artificial grasslands can increase forage yield up to 10-20 times. The development of high-quality artificial grasslands could fundamentally ease the severe shortage of forage supply, break the bottleneck in meat and milk production, curb grassland degradation caused by overgrazing, and thereby restore grassland ecological functions. Therefore, understanding the mechanisms that regulate the productivity and stability of artificial grasslands is a major national strategic need in order to transform the practices of sustainable livestock production based on the scientific and technological advancements, and to promote national ecological security, food security, and the development of ecological civilization. In this study, we examined theoretical basis underlying the regulations of artificial grassland productivity and stability, including theories of ecological stoichiometry, niche differentiation, compensation, mutualism, grazing optimization, and intermediate disturbance. Then, we reviewed current research status and the latest progress that has made in this field. Finally, we proposed fundamental research questions that need to be fully addressed in future studies, regarding the effects of stoichiometry of key nutrient elements, coupled water and nutrient availability, mutualism between forage species and soil microbes, and complementarity of functional traits and multiple forage species on plant carbon assimilation, growth, reproduction, forage quality, biomass allocation, primary productivity, and ecosystem stability. We also highlighted several key biological and ecological mechanisms regulating the productivity and stability of artificial grasslands.