A new study in Plant and Soil measured leaf lipids in 53 subtropical tree species in China. Evergreen and deciduous trees turned out to allocate carbon to fats in different ways. In evergreens, leaf lipid levels tracked structural traits like leaf mass per area and thickness. In deciduous trees, lipid levels tracked nutrient traits, especially potassium and magnesium. Leaf lipids matter because they build cell membranes, cuticles, and stored carbon. The authors say lipid traits could improve how forest carbon cycle models estimate where carbon goes above and below ground. Since leaf litter lipids can persist in soil, evergreen and deciduous forests may also differ in how they stabilize soil carbon. That has implications for carbon accounting in forest projects.
