Abstract:

Arbuscular mycorrhizal fungi (AMF) play a vital role in maintaining the functionality and stability of plateau wetland ecosystems. However, the diversity of AMF communities along elevational gradients and their response to construction processes in the South-Tibet River Basin remain unclear. In this study, we conducted a wetland plant community survey, measured the physicochemical properties of water in situ, and collected sediment samples for further analysis across a high elevational gradient (4 200 to 5 100 m) in the South-Tibet River Basin. Results revealed that Glomus was the dominant genus within the Qinghai-Tibet Plateau wetland ecosystem. However, its relative abundance varied greatly with elevation, showing a significant declining trend with increasing elevation. Differences in AMF community composition were primarily due to species replacement. Variance partitioning analysis showed that the contribution of environmental variables to the AMF diversity-elevation patterns mainly involved sediment and water factors, with a lesser contribution from plant factors. These findings suggest that the establishment of the AMF community in the wetland habitat of the South-Tibet River Basin is predominantly governed by deterministic processes at high elevational gradients, reflecting a unique model of AMF community construction in the Qinghai-Tibet Plateau. However, further validation of these results is warranted.

摘要：

丛枝菌根真菌（Arbuscular mycorrhizal fungi，AMF）在维持高原湿地生态系统功能和促进其稳定性等方面发挥着重要作用，但AMF群落多样性及其构建过程对海拔的响应尚不清楚。本研究在藏南谷地沿4200~5100 m的海拔梯度进行了湿地植物调查、水体因子测定和土壤样品采集并分析。结果显示，藏南谷地湿地生态系统的AMF群落结构随海拔变异较大，其中以Glomus为优势属，且其相对丰度随海拔的上升呈显著下降的趋势。所有采样点中，AMF群落组成的差异以物种替换过程为主。变差分解结果表明，底泥和水体是解释AMF多样性海拔格局的主要环境因子。