Abstract
China introduced the “Retire Livestock and Restore Grassland” policy in 2003. It was strengthened in 2011 by additional funding for on‐farm structures. On the Qinghai‐Tibetan Plateau (QTP), fences were erected, livestock excluded from degraded areas, rotational stocking introduced, nighttime shelters were built, forages grown, and seed sown. However, the effectiveness of these actions and their value to Tibetan herders has been questioned. We conducted a sheep stocking experiment for 5 years in an Alpine Meadow region of the QTP to evaluate stocking options recommended by Government. Cold and warm season stocking each at three rates (0, 8, and 16 sheep/ha) and continuous stocking at 0 and 4 sheep/ha were compared. We measured live weights of sheep, plant species richness and evenness, root biomass and carbon (C), nitrogen (N) and phosphorus (P) contents of the 0–10 cm of soil. We found that resting grassland from stocking during the warm season for later cold season stocking significantly reduced plant species richness and evenness and root biomass but not soil C, N, and P. During cold season stocking, live weights of sheep declined whether at a stocking rate of 8 or 16 per ha. In contrast, sheep continuously stocked on grassland at 4 per ha gained weight throughout both the warm and cold seasons and plant species richness and evenness were maintained. Warm season stocking at 8 and 16 sheep/ha increased plant species richness and root biomass but reduced plant species evenness. Resting these alpine grasslands from stocking in the warm season has adverse consequences for plant conservation. Fencing from stocking in the warm season is not justified by this study; all grassland should be judiciously stocked during the warm season to maintain plant species richness. Neither resting nor stocking during the cold season appears to have any adverse consequences but sheltering and in‐door feeding of sheep during the cold season may be more profitable than cold season stocking with use of open nighttime yards.
Highlights
Natural grasslands of the world may degrade when over-stocked (Alkemade, Reid, van den Berg, de Leeuw, & Jeuken, 2013; Steinfeld, Mooney, Schneider, & Neville, 2013)
Comparison of a range of stocked sites in Qinghai-Tibetan Plateau (QTP) grasslands that differed in perceived degradation status have demonstrated changes in plant species richness and soil attributes (e.g., Wang, Lassoie, et al, 2015; Wang, Dong, et al, 2015; Wen et al, 2013; You et al, 2014)
Simple linear regressions were computed for comparing sheep live weights, plant species richness, plant species evenness, root biomass, soil organic carbon, soil total nitrogen, soil phosphorus in relation to years
Summary
Natural grasslands of the world may degrade when over-stocked (Alkemade, Reid, van den Berg, de Leeuw, & Jeuken, 2013; Steinfeld, Mooney, Schneider, & Neville, 2013). In 2003, the Government introduced the “Retire Livestock and Restore Grassland” policy and fences were erected for resting from stocking of grassland in the warm season and for the long-term exclusion of stock from severely degraded areas, shelters for protecting stock from cold and predators were built, forages for supplementary feeding during the long cold period were grown, and grassland species were sown to renew degraded pasture. Comparison of a range of stocked sites in QTP grasslands that differed in perceived degradation status have demonstrated changes in plant species richness and soil attributes (e.g., Wang, Lassoie, et al, 2015; Wang, Dong, et al, 2015; Wen et al, 2013; You et al, 2014) In these studies, the stocking histories at the sites were not taken into account. The questions evaluated were as follows: (1) Are there any adverse consequences from exclusion of stocking during the warm season to produce “reserved” pasture for cold season stocking, (2) is continuous stocking in the warm and cold seasons an unsustainable practice, (3) is warm season only stocking (with housing of stock in the cold season) a sustainable practice, and (4) is a stocking rate for “optimal” profitability sustainable? hypotheses and predictions for each question are (1) plant and soil attributes do not change when there is no stocking during the warm season; removal of large herbivores from natural grassland will not in the midterm change soil attributes because they are slow moving but loss of plant species by rank growth in the warm season lethally shading low growing species is likely, (2) continuous stocking is not sustainable; plant and soil attributes are unaffected by continuous stocking at low stocking rates but quality of sheep would deteriorate during the cold season, (3) warm season only stocking is not a sustainable practice; the cost of feed during the cold season housing of sheep is sufficiently low for the practice to be sustainable, and (4) the optimal stocking rate for profitability is not sustainable; plant and soil attributes are not adversely changed by the stocking rate at which stock weight gain per unit of grassland is at a maximum
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
