New handbook for standardised measurement of plant functional traits worldwide

TLDR

Plant functional traits, encompassing morphological, physiological, and phenological characteristics, shape ecological strategies and determine plant responses to environmental factors, trophic interactions, and ecosystem properties, and their variation has become a key tool for addressing ecological questions across scales. The handbook addresses the urgent need for standardized, easily measurable protocols that capture trait variation predictive of plant- and ecosystem-level processes, aiming to become a standard resource for local and global studies of plant responses to environmental change. It updates and expands the widely used previous version with clear, step‑by‑step recipes, minimal theory, and new protocols for additional traits, while retaining the focus on practical, broadly applicable methods. The resulting handbook offers a balanced coverage of whole‑plant, leaf, root, stem, and regenerative traits, emphasizing those most informative for predicting species’ effects on key ecosystem properties and enabling the construction of predictive relationships and quantification of biodiversity, invasion, biogeochemical, and vegetation–atmosphere processes.

Abstract

Plant functional traits are the features (morphological, physiological, phenological) that represent ecological strategies and determine how plants respond to environmental factors, affect other trophic levels and influence ecosystem properties. Variation in plant functional traits, and trait syndromes, has proven useful for tackling many important ecological questions at a range of scales, giving rise to a demand for standardised ways to measure ecologically meaningful plant traits. This line of research has been among the most fruitful avenues for understanding ecological and evolutionary patterns and processes. It also has the potential both to build a predictive set of local, regional and global relationships between plants and environment and to quantify a wide range of natural and human-driven processes, including changes in biodiversity, the impacts of species invasions, alterations in biogeochemical processes and vegetation–atmosphere interactions. The importance of these topics dictates the urgent need for more and better data, and increases the value of standardised protocols for quantifying trait variation of different species, in particular for traits with power to predict plant- and ecosystem-level processes, and for traits that can be measured relatively easily. Updated and expanded from the widely used previous version, this handbook retains the focus on clearly presented, widely applicable, step-by-step recipes, with a minimum of text on theory, and not only includes updated methods for the traits previously covered, but also introduces many new protocols for further traits. This new handbook has a better balance between whole-plant traits, leaf traits, root and stem traits and regenerative traits, and puts particular emphasis on traits important for predicting species’ effects on key ecosystem properties. We hope this new handbook becomes a standard companion in local and global efforts to learn about the responses and impacts of different plant species with respect to environmental changes in the present, past and future.