Leaf mechanical properties as potential predictors of leaf-litter decomposability

The mechanical resistance of plant leaves to herbivores and physical disturbances have a lasting legacy impact on leaf-litter decomposition rates and nutrient leaching. However, in the past, leaf mechanics were seldom considered as key factors in regulating ecological processes related to leaf-litter decomposition. In this paper, we explored the physical strength traits of leaves, which are essential components of plant functional traits. These traits are primarily manifested through three mechanical properties: force to punch, force to tear, and work to shear. We discuss their potential applications in order to better understand trait-based factors influencing leaf-litter decomposition as well as other ecological processes. Their ecological connections and distinctions from other widely discussed plant functional traits relevant to decomposition processes were also addressed. By conducting an extensive literature survey, we further showed the importance and irreplaceability of leaf physical strength traits as potential predictors of leaf-litter decomposability compared with commonly measured plant chemical traits (e.g., carbon, nitrogen, and lignin). Recognizing leaf mechanics as vital yet previously overlooked determinants of ecological processes governing leaf-litter decomposition, we propose incorporating this set of traits into existing predictive models to improve the explanatory capability of plant species traits in regulating leaf-litter decomposition processes.