Water Content Quantitatively Affects Metabolic Rates over the Course of Plant Ontogeny


Plant metabolism determines the structure and dynamics of ecological systems across many different scales. The metabolic theory of ecology quantitatively predicts the scaling of metabolic rate as a function of body size and temperature. However, the role of tissue water content has been neglected even though hydration significantly affects metabolism, and thus ecosystem structure and functioning. Here, we use a general model based on biochemical kinetics to quantify the combined effects of water content, body size and temperature on plant metabolic rates. The model was tested using a comprehensive dataset from 205 species across 10 orders of magnitude in body size from seeds to mature large trees. We show that water content significantly influences mass-specific metabolic rates as predicted by the model. The scaling exponents of whole-plant metabolic rate vs body size numerically converge onto 1.0 after water content is corrected regardless of body size or ontogenetic stage. The model provides novel insights into how water content together with body size and temperature quantitatively influence plant growth and metabolism, community dynamics and ecosystem energetics.


Biological Sciences


This study was supported by Guazhou Desert Ecosystem Field Observation Research Station and Core Facility of School of Life Sciences, Lanzhou University, and by grants from the National Natural Science Foundation of China (31770430, 31322010, 31270753), the National Youth Top‐notch Talent Support Program to JMD, and Fundamental Research Funds for Central Universities (lzujbky‐2018‐ct06, lzujbky‐2016‐k03, lzujbky‐2015‐84).

Keywords and Phrases

allometry; body size; ecological theories; hydration; metabolic theory of ecology; water

International Standard Serial Number (ISSN)

0028-646X; 1469-8137

Document Type

Article - Journal

Document Version


File Type





© 2020 The Authors, All rights reserved.

Publication Date

01 Dec 2020

PubMed ID