Dietary selection and intake affect the survival and health of mammals under extreme environmental conditions. It has been suggested that dietary composition is a key driver of gut microbiota variation; however, how gut microbiota respond to seasonal dietary changes under extreme natural conditions remains poorly understood. Sequencing plant trnL (UAA) region and 16S rRNA gene analysis were employed to determine dietary composition and gut microbiota in freely grazing yaks on the Tibetan plateau. Dietary composition was more diverse in winter than in summer, while Gramineae and Rosaceae were consumed frequently all year. Turnover of seasonal diet and gut microbiota composition occurred consistently. Yaks shifted enterotypes in response to dietary change between warm and cold seasons to best utilize nitrogen and energy, in particular in the harsh cold season. Our findings provide insights into understanding seasonal changes of diet–microbiota linkages in the adaptation of mammals to high altitudes.

The Tibetan plateau is the source of most of the major rivers of Asia and has a huge impact on the livelihoods of the population, who have for centuries engaged in traditional herding practices. Sustainable management of the plateau is of critical importance not only for maintaining livelihoods but also because of its vital ecological function. The major problem of sustainable development in these grassland-livestock systems is the conflict between forage and livestock production. Despite considerable investment of manpower, material resources and capital over many years, attempts to resolve the problem have not been successful. The magnitude of conflict between forage and livestock is addressed by presenting 19 resolution strategies based on numerous research data. Each of these strategies is evaluated in terms of how it can be implemented, its potential benefits for livestock production, current progress and the requirement for further research. The 19 strategies have been divided into four topic categories, namely; grassland-forage, livestock, economy and market, society-culture, which cover the basic elements of sustainable development in this pastoral region. It is argued that improved planning and implementation of the proposed strategies must be based on the background investigation of natural and social status of the pastoral region. Particular attention needs to be given to genetic resources and technology in order to ensure the successful implementation of these proposals. In addition to expanding the use of 18 currently practiced strategies, the authors propose a further novel strategy of replacing the current intensive form of ecological migration with a model incorporating two semi-permanent settlements. The objective of this novel strategy is to retain the nomadic element of pastoral husbandry while increasing the temporal and spatial scale of rotational stocking to reduce pasture degradation on the Tibetan plateau. It is argued that these proposals should be urgently incorporated into two national plans for the pastoral livestock industry, and the construction of an ecologically safe shelter zone on the Tibetan plateau, while ensuring a sustainable livelihood of its pastoral residents. Ensuring a successful implementation of these strategies in resolving the conflict between grassland and livestock, and promoting sustainable development on the Tibetan plateau, requires willing support at the level of national investment and policy commitment and from the herdsmen.

Root exudates and rhizosphere microorganisms play key roles in the colonization of toxic plants under climate change and land degradation. However, how root exudates affect the rhizosphere microorganisms and soil nutrients of toxic plants in degraded grasslands remains unknown. We compared the interaction of soil microbial communities, root exudates, microbial carbon metabolism, and environmental factors in the rhizosphere of toxic and non-toxic plants. Deterministic processes had a greater effect on toxic than non-toxic plants, as root exudates affected rhizosphere microorganisms directly. The 328 up-regulated compounds in root exudates of toxic plants affected the diversity of rhizosphere microorganisms. Rhizosphere bacteria-enriched enzymes were involved in the phenylpropanoid biosynthesis pathway. Root exudates of toxic plants form complex networks of rhizosphere microorganisms, provide high rhizosphere nutrients, and increase microbial carbon metabolism. The interaction between root exudates and rhizosphere microorganisms is the key mechanism that enables toxic plants to spread in degraded grassland habitats.