Mapping soil trace elements (Fe Mn Zn Ni) on the Tibetan Plateau

Abstract. Soil Micronutrients supply sustain critical ecological functions but exhibit poorly quantified distribution patterns in high-altitude ecosystems. This study bridges this knowledge gap through a large-scale investigation across the Tibetan Plateau, a cold-arid region where cryogenic weathering, aridity, and suppressed pedogenesis interact to govern microelement cycling. We selected 526 spatially representative sites spanning climatic and edaphic gradients, analyzing six microelements (Fe, Mn, Zn, Ni, Cu, Mo) alongside multi-factorial drivers (climate, vegetation, soil, topography, human disturbances, weathering proxies). Random Forest modeling was employed to quantify controls and generate high-resolution spatial maps. Key results reveal that pronounced regional heterogeneity driven primarily by moisture-related climatic variables (mean annual precipitation, aridity index), with secondary modulation from weathering intensity and vegetation factors. Element-specific spatial patterns were observed, with Fe enrichment in southeastern/southern plateaus, Mn gradients increasing southwestward and Zn hotspots in central-eastern and western marginal zones. The machine-learning derived maps with a 1-km resolution serve for benchmarking process-based microelement cycling models and rooting for sustainable ecosystem management under climate change.