Testing allometric scaling relationships in plant roots

• Published in: Forest Ecosystems Vol. 7; no. 1; pp. 1 - 11
• Main Authors: Deng, Qiang, Yuan, Zhiyou, Shi, Xinrong, Lock, T. Ryan, Kallenbach, Robert L.
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 23.10.2020; Springer; Elsevier Limited; KeAi Communications Co., Ltd
• Subjects: Allometry; Biomass; Biomedical and Life Sciences; Ecology; Ecosystems; Exponents; Forestry; Functional groups; Genetic transformation; Isometric; Life Sciences; Metabolic scaling; Metabolism; Plant roots; Productivity; Review; Roots; Scaling; Seedlings; Terrestrial environments; Productivity; Biomass; Allometry; Metabolic scaling; Plant roots
• ISSN: 2197-5620; 2095-6355; 2197-5620
• DOI: 10.1186/s40663-020-00269-6

Background Metabolic scaling theory predicts that plant productivity and biomass are both size-dependent. However, this theory has not yet been tested in plant roots. Methods In this study, we tested how metabolic scaling occurs in plants using a comprehensive plant root dataset made up of 1016 observations from natural habitats. We generated metabolic scaling exponents by log-transformation of root productivity versus biomass. Results Results showed that the metabolic scaling exponents of fine root (< 2 mm in diameter) productivity versus biomass were close to 1.0 for all ecosystem types and functional groups. Scaling exponents decreased in coarse roots (> 2 mm in diameter). Conclusions We found isometric metabolic scaling in fine roots, a metabolically active organ similar to seedlings or saplings. Our findings also indicate a shift in metabolic scaling during plant development. Overall, our study supports the absence of any unified single constant scaling exponent for metabolism-biomass relationships in terrestrial plants, especially for forests with woody species.