Characteristics of the aboveground biomass and diversity along altitudinal gradients in alpine meadows of the upper reaches of the Yarlung Zangbo River

Abstract

Abstract [Objective] The Yarlung Zangbo River is the most important river in the Tibetan Plateau, and the study of aboveground biomass and species diversity of the Yarlung Zangbo River is of great significance for the understanding of grassland resources and ecological conservation in the region. [Methods] This study investigated the characteristics of vegetations along elevation gradients in the alpine meadows in the upper reaches of the Yarlung Zangbo River, the distributional differences of aboveground biomass and species diversity along the gradients, and the relationship between aboveground biomass and species diversity. We also studied the effects of environmental factors on aboveground biomass and species diversity. [Results] (1) There was no significant relationship between aboveground biomass and elevation, temperature and precipitation (P >0.05). (2) Species diversity indices showed a significant negative correlation with elevations, and the Shannon-Weiner index (H ) and Patrick index (R) showed a declining trend with elevation. Species diversity showed a significant positive correlation with temperature and precipitation (P <0.05). (3) Aboveground biomass and diversity showed a negative correlation, and the explanation of aboveground biomass by the Shannon-Weiner index (H ) reached 70% (P <0.01). [Conclusion] There was no significant correlation between aboveground biomass and elevation, and species diversity indices showed a significant negative correlation with elevation. These results provide basis for the rational utilization of grassland resources and species diversity conservation in the upper reaches of the Yarlung Zangbo River basin.

Keywords

• yarlung zangbo river
• alpine meadow
• above-ground biomass
• species diversity
• altitude
• environmental factors