Search

Grazing affects plant community characteristics and the relationship between above-ground biomass and diversity, which has become a hot topic in grassland ecosystem research in recent years. The present study investigated grassland vegetation in the Two Rivers pastoral area based on 60 sampling points using sampling methods. The effects of grazing on the structural characteristics of plant communities were analysed using the α-diversity index, and the relationship between species diversity and the above-ground biomass of plant communities, as well as their changes, was explored. The results showed that grazing disturbance decreased the number of family species in the grassland plant communities and the similarity between communities; grazing activities significantly decreased the above-ground biomass of the grassland plant communities; the height and cover also showed a decreasing trend (p < 0.01), but the density of the grassland plant communities improved (p < 0.01). The Margalef index, the Shannon–Wiener index, and the Simpson index of the grassland plant communities all showed different degrees of decrease after grazing, while the Alatalo index showed an increase; biomass was positively correlated with the Margalef, Shannon–Wiener, and Alatalo indices and negatively correlated with the Simpson index (p < 0.01). Therefore, in the management and maintenance of grasslands, the impact of grazing on the structural characteristics of plant communities should be taken into account, and reasonable response policies should be implemented according to the actual local situation. This study provides a theoretical basis for grassland maintenance and management and the sustainable development of ecosystems in the pastoral areas of the two river sources of the Altay Mountains. [ABSTRACT FROM AUTHOR]

Understanding the agronomic interventions that ensure higher crop yields and minimize their chances of failure is critical for meeting global nutritional demands. Rice is a staple food crop that is prone to lodging risk, particularly when higher yields are desired. The potential role of a combined application of Zinc (Zn) and Silicon (Si) in determining the grain yield and lodging resistance has been rarely investigated under field conditions. Thus, field trials were carried out to evaluate the grain yield and lodging resistance of rice at two different locations i.e., Qionghai and Wuzhishan, under three levels of Zn (0, 40, and 80 kg ha−1) and Si (0, 120, and 240 kg ha−1). The results showed that Zn application at the rates of 40 and 80 kg ha−1 increased rice yield by 9% and 5% at Qionghai, and by 5% and 6% at Wuzhishan, respectively. The improved grain yield due to Zn application could be attributed to the increased panicles m−2, splikelets m−2, and aboveground biomass. Meanwhile, Zn failed to show any remarkable impact on stem and root lodging susceptibility. Conversely, no significant influence of applying Si on grain yield was observed, while its application at the rates of 120 and 240 kg Si ha−1 enhanced the stem and root lodging resistance (denoted by their respective safety factors, for stem (SFs) and for root (SFr) by 32% and 22% at Qionghai, and by 11% and 34% at Wuzhishan, respectively, compared to zero Si application. The improved lodging resistance in terms of SFs and SFr could be ascribed to the increased stem bending strength and anchorage strength, while self-weight moment of whole plant decreased. In summary, a beneficial role of Si in lodging resistance and Zn in yield enhancement were evidenced in the present study across the two sites. It can be concluded that by combining 40 kg Zn ha−1 with 120 kg Si ha−1, both grain yield and lodging resistance could be simultaneously improved in rice crops. [ABSTRACT FROM AUTHOR]