Root traits and functioning: from individual plants to
ecosystems
Fine roots, the most distal portions of the root system, are responsible
for the uptake of water and nutrients by plants, represent the main type
of plant tissue contributing to soil organic matter accrual, and are key
drivers of mineral weathering and soil microbial dynamics (Bardgett et
al. 2014). Despite the overwhelming importance of fine root traits for
plant and plant community functioning and biogeochemical cycles, basic
information about their ecology is lacking, particularly compared to the
wealth of information developed for leaves and stems. Testing hypotheses
on how root traits underlie these ecosystem processes has been
particularly hampered due to (1) a paucity of systematically collected
data and (2) the complexity of the relationships between root traits and
root, plant and ecosystem functioning. Nonetheless, the development of
the field of root ecology in the last two decades has been outstanding,
in particular in the compilation of belowground trait datasets (Iversen
et al. 2017), methodological root ecological handbooks (Freschet et al.
2021b), novel conceptual frameworks to describe root trait diversity
(Bergmann et al. 2020), its connection with belowground plant and
community function (Bardgett et al. 2014, Freschet et al. 2021a),
species’ distributions (Laughlin et al. 2021), and scaling up traits
from the individual root to the ecosystem level (McCormack et al. 2017).
The papers that feature in this Special Issue on Root traits and
functioning: from individual plants to ecosystems cover different
climate regions, taxonomic and spatial scales, and a diversity of traits
(Table 1) and form perfect examples of this upward moment of the
belowground component in plant ecology.