The Animal Evolutionary Adaptation and Endangered Species Conservation Discipline Group has made new progress in the assessment of the carrying capacity of herbivores

Grassland accounts for about 30-40% of the global land surface area, is an important part of the terrestrial ecosystem, it is not only the natural habitat for wild animals to survive, but also the material guarantee for
the development of animal husbandry.
However, most previous studies on the carrying capacity of grasslands have only considered domestic animals and ignored wildlife
.
Located in the hinterland of the Qinghai-Tibet Plateau and rich in wildlife resources, Sanjiangyuan is an important ecological security barrier and an important natural pasture in
China.
In recent years, the number of wild animals has steadily increased with the increase in protection, raising concerns about
grassland overload.
Grassland overload can cause regional ecosystem imbalance, biodiversity loss, and ecosystem function decline, thus threatening regional ecological security
.
The balance of grass and livestock has become an important factor
in the ecological protection and sustainable development of the Sanjiangyuan area.

Taking Qumahe Township in Sanjiangyuan area as the research area, the remote sensing-process coupling model was used to estimate the yield of grassland edible forage and its crude protein in 2020, and then the theoretical carrying capacity
of grassland in this area was calculated.
Based on surveys and habitat adaptation analysis, the population numbers and livestock numbers of large wild herbivores Tibetan wild donkeys, Tibetan hartebeest and Tibetan antelope were obtained, and the actual livestock load was
estimated.
The bearing pressure index is calculated
using the ratio of the actual livestock load to the theoretical carrying capacity of the region.
The results show that the theoretical carrying capacity of edible pasture is 274,800 standard sheep (SHU), which is lower than the theoretical carrying capacity of crude protein in this region, so the carrying capacity of edible pasture is more in line with the Sustainable Development Goals
.
Wild large herbivores contributed about 20,700 SHU, while domestic animals contributed 256,500 SHU
.
If only livestock are considered, the carrying pressure index is 0.
93, which is not overloaded; if both wild animals and domestic animals are considered, the carrying pressure index is 1.
01, which is slightly overloaded
.
Wild animals contribute about 7.
5% to carrying pressure, and domestic animals contribute much more to carrying pressure than wild herbivores, but wildlife
still needs to be considered when estimating grassland carrying pressure.

In this study, the carrying pressure index of wild animals and domestic animals is proposed, the theoretical carrying capacity based on "food" and "nutrition" is evaluated, and the influence of wild animals on the carrying pressure of
grassland is analyzed.
Due to the large distribution of wild animals in this area, not considering wild animals will underestimate the actual livestock capacity, resulting in an underestimation
of the bearing pressure index.
The results of the study suggest that the grassland carrying pressure index, which integrates the populations of wild animals and livestock, should be used for the management of grassland ecosystems and nature reserves on the Tibetan Plateau in the future, which is of great significance for the protection of fragile grassland ecosystems on the Tibetan Plateau and the maintenance of
biodiversity and sustainable socio-economic development.

Grazing pressure index considering both wildlife and livestock in Three-River Headwaters, Qinghai-Tibetan Plateau was recently published in the academic journal Ecological Indicators (IF=6.
263
).
。 Associate researcher Cai Zhenyuan is the first author of the paper, researcher Zhang Tongzuo is the corresponding author, and the main collaborator of the article is Wang Junbang, associate researcher
of the Institute of Geographic Resources, Chinese Academy of Sciences.
The research was supported
by the National Natural Science Foundation of China Regional Innovation and Development Joint Fund (U20A2012) and the Sanjiangyuan National Park Joint Research Project of Qinghai Provincial People's Government of the Chinese Academy of Sciences (LHZX-2020-07).
The subject group relies on the Key Laboratory of Plateau Biological Adaptation and Evolution of the Chinese Academy of Sciences and the Key Laboratory
of Animal Ecological Genomics of Qinghai Province.

Paper Link: https://doi.
org/10.
1016/j.
ecolind.
2022.
109338

Distribution of major large wild herbivores in Qumahe Township (left) and habitat suitability analysis (right)