LANZHOU, May 19 (Xinhua) -- A new study by Chinese scientists has revealed the mechanisms by which grazing affects the ecosystem functioning of alpine grasslands on the Qinghai-Tibet Plateau, providing scientific basis for sustainable grazing management on the Qinghai-Tibet Plateau, according to Lanzhou University.
The study was conducted in collaboration of research teams from Lanzhou University and Qinghai University, with its findings published on two journals -- Functional Ecology, and Agriculture, Ecosystems and Environment, said the university.
Grazing is a traditional land use practice for alpine grasslands on the Qinghai-Tibet Plateau, and its interactions with grassland ecosystems have remained a core scientific task. However, few studies have used rhizosphere stoichiometry to assess plant-soil-microbe interaction dynamics under different grazing regimes on the plateau, according to Zhang Jinlin, a professor at the Lanzhou University.
To better comprehend such an issue, the joint study team compared rhizosphere stoichiometric changes of the degradation indicator Medicago ruthenica and dominant Kobresia humilis under yak grazing, sheep grazing and mixed grazing with various yak-to-sheep ratios.
Study results indicated that grazing disrupts the coupled carbon-nitrogen-phosphorus cycling relationships between degradation indicator species and dominant functional groups in alpine plant communities, confirming that moderate mixed grazing of yaks and Tibetan sheep at ratios of 1:2 and 1:4 can maintain ecosystem stoichiometric balance and enhance nutrient cycling efficiency and vegetation productivity.
Furthermore, the study team comprehensively reviewed the multidimensional impacts of grazing on alpine grassland ecosystems on the plateau and their sustainable management by integrating other latest grazing study findings.
Via comparative analysis, researchers found that grazing is not a single ecological disturbance factor. Moderate grazing can enhance grassland versatility, promote root exudation, microbial functional diversity, and nutrient cycling balance. Whereas, overgrazing or long-term grazing exclusion conversely reduces microbial diversity and drives plant communities toward dominance by a few species, showed the study results.
To enhance the sustainability of alpine grasslands on the Qinghai-Tibet Plateau, they proposed three sustainable grazing strategies for grazing management on the plateau in more scientific manner -- precision fenced grazing, designation of strict nature reserves, and adaptive management based on forage production.
"Looking ahead, we should continuously conduct long-term, large-scale field experiments across the plateau to validate key hypotheses and develop integrated management frameworks, thereby ensuring the plateau's alpine grasslands sustain ecological resilience, carbon sink function, and pastoral livelihoods amid ongoing climate change and socio-economic transitions," Zhang added. Enditem
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