title: Fast-cycling unit of root turnover in perennial herbaceous plants in a cold temperate ecosystem.
abstract: Roots of perennial plants have both persistent portion and fast-cycling units represented by different levels of branching. In woody species, the distal nonwoody branch orders as a unit are born and die together relatively rapidly (within 1-2 years). However, whether the fast-cycling units also exist in perennial herbs is unknown. We monitored root demography of seven perennial herbs over two years in a cold temperate ecosystem and we classified the largest roots on the root collar or rhizome as basal roots, and associated finer laterals as secondary, tertiary and quaternary roots. Parallel to woody plants in which distal root orders form a fast-cycling module, basal root and its finer laterals also represent a fast-cycling module in herbaceous plants. Within this module, basal roots had a lifespan of 0.5-2 years and represented 62-87% of total root biomass, thus dominating annual root turnover (60%-81% of the total). Moreover, root traits including root length, tissue density, and biomass were useful predictors of root lifespan. We conclude that both herbaceous and woody plants have fast-cycling modular units and future studies identifying the fast-cycling module across plant species should allow better understanding of how root construction and turnover are linked to whole-plant strategies.
authors.affiliation: Department of Ecology, College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes of Ministry of Education, Peking University, Beijing 100871, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Sun
authors.affiliation: Center for Forest Ecosystem Studies and Qianyanzhou Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: M Luke
authors.initials: ML
authors.lastname: McCormack
authors.affiliation: Center for Forest Ecosystem Studies and Qianyanzhou Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Le
authors.initials: L
authors.lastname: Li
authors.affiliation: Center for Forest Ecosystem Studies and Qianyanzhou Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Zeqing
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Center for Forest Ecosystem Studies and Qianyanzhou Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Dali
authors.initials: D
authors.lastname: Guo
mesh_terms: D018533:Biomass; D003080:Cold Temperature; D017753:Ecosystem; D028221:Larix / Q000737:chemistry / Q000254:growth & development; D010641:Phenotype; D018517:Plant Roots / Q000737:chemistry / Q000254:growth & development