title: Testing the growth rate hypothesis in vascular plants with above- and below-ground biomass.
abstract: The growth rate hypothesis (GRH) proposes that higher growth rate (the rate of change in biomass per unit biomass, μ) is associated with higher P concentration and lower C:P and N:P ratios. However, the applicability of the GRH to vascular plants is not well-studied and few studies have been done on belowground biomass. Here we showed that, for aboveground, belowground and total biomass of three study species, μ was positively correlated with N:C under N limitation and positively correlated with P:C under P limitation. However, the N:P ratio was a unimodal function of μ, increasing for small values of μ, reaching a maximum, and then decreasing. The range of variations in μ was positively correlated with variation in C:N:P stoichiometry. Furthermore, μ and C:N:P ranges for aboveground biomass were negatively correlated with those for belowground. Our results confirm the well-known association of growth rate with tissue concentration of the limiting nutrient and provide empirical support for recent theoretical formulations.
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China. turfyu@gmail.com
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yu
authors.forename: Honghui
authors.initials: H
authors.lastname: Wu
authors.forename: Nianpeng
authors.initials: N
authors.lastname: He
authors.forename: Xiaotao
authors.initials: X
authors.lastname: Lü
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Wang
authors.forename: James J
authors.initials: JJ
authors.lastname: Elser
authors.forename: Jianguo
authors.initials: J
authors.lastname: Wu
authors.forename: Xingguo
authors.initials: X
authors.lastname: Han
mesh_terms: D000704:Analysis of Variance; D018533:Biomass; D002244:Carbon / Q000032:analysis*; D008954:Models, Biological; D009584:Nitrogen / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis*; D063245:Plant Development; D010944:Plants / Q000737:chemistry; D013045:Species Specificity
chemical_list: D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen