Plant functional traits are features that represent ecological strategies and determine how plants respond to environmental factors, affect other trophic levels and influence ecosystem properties. Variations in these traits have proven useful for tackling many important ecological questions at a range of scales, giving rise to a demand for standardised ways to measure them. This updated and expanded handbook retains the focus on clearly presented, widely applicable, step-by-step methods, and includes updated methods for traits previously covered as well as for new traits. This handbook has a better balance between whole-plant, leaf, root and stem, and regenerative traits, and has a particular emphasis on traits important for predicting species’ effects on key ecosystem properties.