Linking plant leaf nutrients/stoichiometry to water use efficiency on the Loess Plateau in China

Nutrient and hydrological cycles are tightly coupled in ecosystems. However, little is known about the relationship between leaf nutrient stoichiometry (nutrient mass ratios) and water use efficiency (WUE) in ecosystems. To fill this knowledge gap, we examined 132 plant samples distributed from the Qinling Mountains to the north of the Loess Plateau of China and observed the relationship between leaf nutrient stoichiometry and WUE in various ecosystems. Our findings suggest that a positive correlation exists between the leaf nitrogen:phosphorus (N:P) ratio and WUE, and this relationship is sensitive to plant life forms and growth conditions. Additionally, potassium (K) was related to WUE in herbs and plants under P limitation. These results link plant nutrient stoichiometry to hydraulic processes in terrestrial plants and provide useful information for ecologists studying nutrient and hydrological cycles in ecosystems.