Trait-based approaches provide a useful framework to investigate plant strategies for resource acquisition, growth, and competition, as well as plant impacts on ecosystem processes. Despite significant progress capturing trait variation within and among stems and leaves, identification of trait syndromes within fine-root systems and between fine roots and other plant organs is limited. Here we discuss three underappreciated areas where focused measurements of fine-root traits can make significant contributions to ecosystem science. These include assessment of spatiotemporal variation in fine-root traits, integration of mycorrhizal fungi into fine-root-trait frameworks, and the need for improved scaling of traits measured on individual roots to ecosystem-level processes. Progress in each of these areas is providing opportunities to revisit how below-ground processes are represented in terrestrial biosphere models. Targeted measurements of fine-root traits with clear linkages to ecosystem processes and plant responses to environmental change are strongly needed to reduce empirical and model uncertainties. Further identifying how and when suites of root and whole-plant traits are coordinated or decoupled will ultimately provide a powerful tool for modeling plant form and function at local and global scales.
Bibliographical noteFunding Information:
Special thanks to T. Adams for providing data for Fig. and to K. Nara for providing images used in Fig. The authors acknowledge support from the US Department of Energy (DOE) Terrestrial Ecosystem Sciences (TES) Program, the New Phytologist Trust, and the Chinese Academy of Sciences (CAS) for supporting the workshop where the initial ideas for this manuscript were developed, as well as support from the National Natural Science Foundation of China (no. 3153000446 and 31325006). M.L.M. was partially supported by a research fellowship from CAS for Young International Researchers (no. 31350110503). C.M.I. and M.L.M. were supported by the Office of Biological and Environmental Research in the DOE's Office of Science. D.M.E. was partially supported by DOE TES DE-SC0012003. This manuscript has been authored by UT-Battelle, LLC under contract no. DE-AC05-00OR22725 with the US Department of Energy.
- below ground
- ecological modeling
- nutrient acquisition
- plant functional traits
- root economics spectrum (RES)
- trait syndromes