8 research outputs found
Grazing during the grassland greenup period promotes plant species richness in alpine grassland in winter pastures
Although grazing is the most common use of grassland, the ecological
function of grassland far exceeds its productivity. Therefore, the protection
of plant diversity is of the utmost importance and cannot be ignored. Existing
research on the effect of grazing on grassland mainly focuses on grazing
intensity and the type of livestock, but the consequences of the timing of the
grazing on the vegetation community remains unclear. We investigated plant
community characteristics of winter pastures in alpine meadow with different
grazing termination times (grazing before and during the grassland greenup
periods) in Maqu County, eastern QTP. The results showed that vegetation
height, coverage, aboveground biomass and Graminoid biomass were lower
in grassland when grazing happened during the greenup period compared
to grassland where grazing was terminated before the greenup period.
However, the total plant species richness and forbs richness were higher in
grassland with grazing during the greenup period compared to grassland
without grazing during the greenup period. Our structural equation modeling
reveals a potential indirect implication for the total plant species richness and
forbs richness of winter pastures mainly through a decrease in the vegetation
coverage and grass biomass abundance. Our findings imply that grazing
during the grassland greenup period may facilitate the maintenance of plant
diversity in winter pastures. These findings have important implications for
grassland ecosystem functioning and for the conservation of plant diversity.https://www.frontiersin.org/journals/plant-sciencedm2022Mammal Research InstituteZoology and Entomolog
Suitable grazing during the regrowth period promotes plant diversity in winter pastures in the Qinghai-Tibetan plateau
DATA AVAILABILITY STATEMENT : The original contributions presented in this study are
included in the article/supplementary material, further inquiries
can be directed to the corresponding authors.Vegetation is a crucial component of any ecosystem and to preserve the
health and stability of grassland ecosystems, species diversity is important. The
primary form of grassland use globally is livestock grazing, hence many studies
focus on how plant diversity is affected by the grazing intensity, differential
use of grazing time and livestock species. Nevertheless, the impact of the
grazing time on plant diversity remains largely unexplored. We performed
a field survey on the winter pastures in alpine meadows of the Qinghai-
Tibetan Plateau (QTP) to examine the effects of grazing time on the vegetation
traits. Livestock species, grazing stocking rates and the initiation time of the
grazing were similar, but termination times of the grazing differed. The grazing
termination time has a significant effect on most of the vegetation traits in
the winter pastures. The vegetation height, above-ground biomass, and the
Graminoids biomass was negatively related to the grazing termination time in
the winter pastures. In contrast, vegetation cover and plant diversity initially
increased and subsequently decreased again as the grazing termination time
was extended. An extension of the grazing time did not have any effect
on the biomass of forbs. Our study is the first to investigate the effects
of grazing during the regrowth period on vegetation traits and imply that
the plant diversity is mediated by the grazing termination time during the
regrowth period in winter pastures. These findings could be used to improve
the guidelines for livestock grazing management and policies of summer and
winter pasture grazing of family pastures on the QTP from the perspective of
plant diversity protection.The Fundamental Research Funds of China West Normal University, the Gansu Provincial Science and Technology Program and the Natural Science Foundation of Sichuan.http://frontiersin.org/Ecology_and_Evolutionam2023Mammal Research InstituteZoology and Entomolog
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Risk assessment in the plateau pika (Ochotona curzoniae): intensity of behavioral response differs with predator species
Abstract Background The ability of a prey species to assess the risk that a predator poses can have important fitness advantages for the prey species. To better understand predator–prey interactions, more species need to be observed to determine how prey behavioral responses differ in intensity when approached by different types of predators. The plateau pika (Ochotona curzoniae) is preyed upon by all predators occurring in its distribution area. Therefore, it is an ideal species to study anti-predator behavior. In this study, we investigated the intensity of anti-predator behavior of pikas in response to visual cues by using four predator species models in Maqu County on the eastern Qinghai-Tibetan Plateau. Results The behavioral response metrics, such as Flight Initiation Distance (FID), the hiding time and the percentage of vigilance were significantly different when exposed to a Tibetan fox, a wolf, a Saker falcon and a large-billed crow, respectively. Pikas showed a stronger response to Saker falcons compared to any of the other predators. Conclusions Our results showed that pikas alter their behavioral (such as FID, the hiding time and the vigilance) response intensity to optimally balance the benefits when exposed to different taxidermy predator species models. We conclude that pikas are able to assess their actual risk of predation and show a threat-sensitive behavioral response
Lightweight Public Key Encryption with Equality Test Supporting Partial Authorization in Cloud Storage
Public key encryption with equality test (PKEET) can check whether two ciphertexts are encrypted from the same message or not without decryption. This attribute enables PKEET to be increasingly utilized in cloud storage, where users store their encrypted data on the cloud. In traditional PKEET, the tester is authorized by the data receiver to perform equality test on its ciphertexts. However, the tester can only test one ciphertext or all ciphertexts of one receiver with one authorization. It means that the receiver cannot adaptively authorize the test right of any number of ciphertexts to the tester. A trivial solution is authorizing one ciphertext each time and repeating multiple times. The corresponding size of trapdoor in this method is linear with the number of authorized ciphertexts. This will incur storage burden for the tester. To solve the aforementioned problem, we propose the concept of PKEET supporting partial authentication (PKEET-PA). We then instantiate the concept to a lightweight PKEET-PA, which achieves constant-size trapdoor. Besides, we prove the security of our PKEET-PA scheme against two types of adversaries. Compared with other PKEET schemes that can be used in trivial solution, our PKEET-PA is more efficient in receivers\u27 computation and has lower trapdoor size