Root respiration constitutes a critical component of carbon cycle in terrestrial ecosystems, yet there is still limited understanding on the relationships between root respiration and root traits across species at global scale. Further, root functions are overlooked in current knowledge about root traits syndromes. We thus compiled a global dataset of species-specific root respiration associated with chemical (root N concentration) and morphological (specific root length, root diameter, root tissue density) traits from more than 200 plant species.
Results/Conclusions
Our results demonstrated positive relationship between root respiration and root N concentration and specific root length, and negative relationship between root respiration and root diameter and root tissue density. These results coincided with the function-trait correlation predicted from the plant resource acquisition-conservation tradeoff. Comparatively, the correlation of root respiration and root morphology was stronger for woody plants than non-woody plants. Morphological traits exhibited relatively weak correlation with root respiration for non-woody plants. Generally, the scaling exponents of root respiration vs root traits were consistent across all species but varied between subgroups of woody and non-woody plants. Our findings provided a better understanding of root trait-function relationships among species, which was essential for improving the predictability of belowground carbon cycling by incorporating root traits in terrestrial ecosystem models.