The effects of topographical factors on the distribution of plant communities in a mountain meadow on the Tibetan Plateau as a foundation for target-oriented management

Abstract

Abstract Mountains are storehouses of biodiversity and natural resources. However, mountain rangeland is one of the most fragile ecosystems in the world due to the harsh natural conditions. The biodiversity and productivity in mountain regions are further under severe threat because of topography heterogeneity and poor management. To improve mountain rangeland management to sustain ecosystem services, we should better understand the relationships between topographical factors and plant distributions. The purpose was to elaborate on an alternative management strategy for mountain rangelands. In this study, we selected a hill covered by alpine meadow on the north-eastern Tibetan Plateau and quantified the effects of hill aspect and altitude on soil temperature, soil moisture, and plant and functional group distribution in terms of cover, height, frequency, richness, abundance and biomass in 189 quadrats on the hill. The results show that 1) with increasing altitude, the plant species cover, height, abundance, richness and biomass first increased and then decreased on the shadow aspect and on the ridge, whereas they increased linearly on the sunny aspect, 2) the altitude and aspect explained 58.6% of the total variance in the distribution of soil temperature and moisture, with aspect alone explaining 52.1% of the total variance and making the greatest contribution to the alpine meadow, and 3) the hill aspect had higher effects than the altitude on the distribution of species and functional groups in the community. The combined contributions of hill aspect and altitude and the individual effect of aspect alone were greater at the functional group level than at the species level. In conclusion, priority should be given to the differences in the soil and plant distribution caused by different aspects to provide a framework for designing tailored management plans for local farmers to preserve biodiversity on one hand whilst increasing productivity for economically viable farming and for preserving the provisioning of ecosystem services in mountain rangeland ecosystems on the other hand.