M. Luke McCormack
University of Minnesota
Priorities for capturing root trait variation in model frameworks
Fine roots play important roots acquiring soil nutrients and water for plant growth. However, it has been difficult to determine how traits of fine roots change across environments and how these changes impact plant and ecosystem processes.
We highlight barriers limiting our knowledge of how fine roots work in ecosystems, and importantly, we suggest tractable ways in which we might overcome those barriers. Refocusing our efforts to measure multiple aspects of roots traits and function in ways that can be rigorously compared across species will rapidly improve understanding of terrestrial ecosystems.
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.
Contacts (BER PM)
M. Luke McCormack
Department of Plant and Microbial Biology, University of Minnesota
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.
McCormack, M. L. et al. Building a better foundation: improving root-trait measurements to understand and model plant and ecosystem processes. New Phytologist, doi:10.1111/nph.14459 (2017).