A framework to assess the carbon supply‐consumption balance in plant roots

Plant uptake and transportation of resources, such as water, nutrients and photosynthates, are crucial for plant growth, and a main driver of ecosystem functioning and community responses to environmental changes (Evert, 2006; Ma et al., 2018; Steidinger et al., 2019). Plant roots form a highly branched system with great heterogeneity in structure and function, hierarchically organized from lower order distal roots to higher order basal roots. Roots of the higher branch orders predominantly consist of secondary tissues performing non-absorptive functions, such as transport, storage and anchorage, whereas resource absorption is undertaken only by a few terminal branch orders (usually the first- and second-order roots consisting of primary tissues) (Guo et al., 2008; McCormack et al., 2015).