Two dimensions define the variation of fine root traits across plant communities under the joint influence of ecological succession and annual mowing

1. Quantifying the variation in community-level fine root (<2mm) traits along ecological gradients or in response to disturbances is essential to unravel the mechanisms of plant community assembly, but available surveys are scarce. Whether fine root traits covary along a one-dimensional economic spectrum, as previously shown for leaves, is highly debated. 2. We measured six fine root traits at the community-level along a 69-year succession, with or without annual mowing, offering a unique design of two nested disturbances. We examined whether (i) there is variation and covariation in community-level fine root traits along the succession and in response to mowing and (ii) morphological root traits mirrored analogous leaf traits (using previously acquired data). 3. Early-successional communities were herbaceous-dominated (48±6 % in <10 year old plots) and possessed fine roots with high specific root length (SRL), low root dry matter content (RDMC) and low root carbon concentration (...