Trait Definition and comments Resource uptake strategy* Mixture effects Mixture effects Mixture effects
positive negative null
Root system
Root/shoot (R/S)
Root biomass divided by shoot biomass, the strategy for plants to adjust the investment between above- and below-ground with changing in the environment and life stage (Bessler et al. 2009; Ma et al. 2019).
Capacity
(Baxendale et al. 2014)
(Bessler et al. 2009)
(Domisch et al. 2015)
Architecture
Community-weighted mean rooting depth (WRD, cm) The centroid of weighted root depth, describing the vertical distribution of roots (Archambault et al. 2019). Capacity (Oram et al. 2018) (Shu et al. 2018) (Siebenkäs & Roscher 2016)
Root length density (RLD, m m-3) Total fine root length per unit soil volume, which reflects the ability of species to compete for resources (Guderle et al. 2018). Capacity (Gould et al. 2016) (Bauhus 2000; Siebenkäs & Roscher 2016)
Morphology
Specific root length (SRL, m g-1) Root length per root dry mass, absorptive capability relative to carbon investment (Ostonen et al. 2007). Efficiency (Shu et al. 2018) (Baxendale et al. 2014; Salahuddin et al. 2018) (Gould et al. 2016)
Mean root diameter (RD, mm) Mean diameter of fine root (< 2 mm) components. Thicker RD with a slow root growth rate facilitates root penetration of denser soil; roots with thinner RD reduces dependence on mycorrhizal symbiosis (Ma et al. 2018). Efficiency (Salahuddin et al. 2018) (Gould et al. 2016) (Beyer et al. 2013)
Chemistry
Root N content (RN, %)) RN supports metabolic activity, including nutrient and water transport, enzyme functioning and mycorrhizal symbiosis (Bloom et al. 1985; Weemstra et al. 2016). In the shared soil, RN decreases with competition intensity due to nitrogen depletion (Hajek et al. 2014). Efficiency (Bauhus 2000) (Hajek et al. 2014; Salahuddin et al. 2018) (Callaway et al. 2003)