High precipitation rates increase potassium density in plant communities in the Tibetan Plateau

Potassium is essential for plant growth. However, our understanding of potassium in plant materials is limited due to a lack of systematic studies. Here, we measured potassium content in 2,040 ecosystem communities during the period 2019–2021 applying grid-sampling and explored the spatial patterns and drivers of potassium density in the Tibetan Plateau vegetation. Potassium content, density, and storage were estimated at 8.63 milligrams per gram, 21.71 grams per square meter, and 19.92 teragrams, respectively. Potassium allocation was isometric in most ecosystems, except for deserts which followed optimal partitioning. Precipitation was the main driver of potassium variations, with higher potassium in humid regions. The spatial distribution, as revealed by random forests model, indicated higher potassium in the southeastern regions but lower potassium values in the northwestern regions. Our research sheds light on climate change's impact on vegetation potassium, offering valuable data for biogeochemical cycle optimization.