Global-scale latitudinal patterns of twelve mineral elements in leaf litter

Abstract Litter mineral elements carry out the cycling and storage of multiple nutrients and heavy metals in soil, and thus shape many key soil processes. Driving factors of global geographic patterns of multiple litter elements along with the driving factors are largely limited to N and P. By compiling data on 12 major mineral elements (nitrogen, phosphorus, potassium, calcium, magnesium, sulphur, aluminium, iron, manganese, sodium, zinc, and copper) in leaf litter from 1, 666 species and 69 countries and 1, 018 studies, we conducted a global meta-analysis of the effects of climate, soil chemistry, plant functional types, and resorption on latitudinal patterns of multiple mineral elements in litter. We showed that leaf litter phosphorus and manganese concentrations increased and zinc concentration kept unchanged with latitude, while the other elements declined, indicative of specific climatic effects on plant physiology. The climate-related gradients including soil nutrients and woody plant distribution play a key role in the latitudinal patterns of elements (except N), while soil pH was a poor explanatory factor. Because of lower nitrogen resorption at higher temperature, nitrogen in leaf litters responded to latitude in a contrary manner as that in green leaves. Overall, we suggest that fundamental constraints on plant physiology and nutrient usage strategies lead to predictable global-scale patterns in multiple litter elements.