Linking fine root lifespan to root chemical and morphological traits-A global analysis

• 成果类型: Article
• 署名作者: Hou, Jiawen; McCormack, M. Luke; Reich, Peter B.; Sun, Tao; Phillips, Richard P.; Lambers, Hans; Chen, Han Y. H.; Ding, Yiyang; Comas, Louise H.; Valverde-Barrantes, Oscar J.; Solly, Emily F.; Freschet, Gregoire T.
• 署名单位: Chinese Academy of Sciences; Shenyang Institute of Applied Ecology, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; University of Minnesota System; University of Minnesota Twin Cities; University of Michigan System; University of Michigan; Western Sydney University; Indiana University System; Indiana University Bloomington; University of Western Australia; Lakehead University; University of Helsinki; University of Helsinki; Colorado State University System; Colorado State University Fort Collins; United States Department of Agriculture (USDA); State University System of Florida; Florida International University; Helmholtz Association; Helmholtz Center for Environmental Research (UFZ); Universite de Toulouse; Universite Toulouse III - Paul Sabatier; Centre National de la Recherche Scientifique (CNRS)
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12122
• DOI: 10.1073/pnas.2320623121
• 发表日期: 2024-04-16
• 关键词: plant economics spectrum; functional traits; arbuscular mycorrhizal; branch order; leaf; nutrient; nitrogen; GROWTH; forest; leaves

摘要

Fine root lifespan is a critical trait associated with contrasting root strategies of resource acquisition and protection. Yet, its position within the multidimensional root economics space synthesizing global root economics strategies is largely uncertain, and it is rarely represented in frameworks integrating plant trait variations. Here, we compiled the most comprehensive dataset of absorptive median root lifespan (MRL) data including 98 observations from 79 woody species using (mini- )rhizotrons across 40 sites and linked MRL to other plant traits to address questions of the regulators of MRL at large spatial scales. We demonstrate that MRL not only decreases with plant investment in root nitrogen (associated with more metabolically active tissues) but also increases with construction of larger diameter roots which is often associated with greater plant reliance on mycorrhizal symbionts. Although theories linking organ structure and function suggest that root traits should play a role in modulating MRL, we found no correlation between root traits associated with structural defense (root tissue density and specific root length) and MRL. Moreover, fine root and leaf lifespan were globally unrelated, except among evergreen species, suggesting contrasting evolutionary selection between leaves and roots facing contrasting environmental influences above vs. belowground. At large geographic scales, MRL was typically longer at sites with lower mean annual temperature and higher mean annual precipitation. Overall, this synthesis uncovered several key ecophysiological covariates and environmental drivers of MRL, highlighting broad avenues for accurate parametrization of global biogeochemical models and the understanding of ecosystem response to global climate change.