The Impact of Grazing Intensity on the Biomass Allocation Strategy of Two Dominant Herbaceous Plants in Subalpine Meadows

WEI Zhaozhe; LI Chunlan; CHEN Yang; ZHANG Caicai; HUANG Zhipang

doi:10.3969/j.issn.1002-2724.2025.01.006

Abstract：Subalpine meadows typically form after subalpine cold-temperate coniferous forests(e.g.,spruce and fir forests)are disrupted and subsequent prolonged grazing.The dominant plants of subalpine meadows adjust their aboveground and belowground biomass allocation strategies to respond to and adapt to long-term grazing disturbances.This study focuses on two dominant herbaceous species(Potentilla discolor and Fragaria vesca)within the Yunlong Tianchi National Nature Reserve in Yunnan,analyzing the differences in their functional traits under varying grazing intensities and the relationship between aboveground and belowground biomass allocation traits.The results show:(1)Compared to light and heavy grazing,Potentilla discolor exhibited smaller leaf area and specific root area under moderate grazing intensity,has along with a higher content of belowground dry matter.Fragaria vesca showed relatively larger leaf area and root area under moderate grazing disturbance,with its specific leaf area and comprehensive trait PCA2 increasing with grazing intensity,while belowground dry matter content showed a decreasing trend.These findings indicate that leaf area and belowground dry matter content are key functional traits for herbaceous plants to respond to grazing disturbances.(2)There is a significant linear correlation was observed between the aboveground and belowground biomass of Potentilla discolor and Fragaria vesca,with the strongest correlation occurring under moderate grazing intensity.This suggests,a strong trade-off in the allocation relationship between aboveground and belowground biomass under moderate grazing disturbance,where plants tend to increase investment in aboveground resources at the expense of belowground investment.