Aim: The plant economics spectrum provides a fundamental framework for understanding functional trait variation along environmental gradients. However, it is unclear whether there is a general whole-plant economics spectrum across organs at the finer taxonomic scale (e.g. within genera), and if there is, which factors affect the trait coordination of the different organs. Here, we examined whether resource economics spectra of different organs (i.e. leaf, stem and root) can be integrated at the whole-plant level within a single genus, and how environment, intraspecific variation and taxonomic scale shape the whole-plant spectrum.

Location: China.

Time period: 2018.

Major taxa studied: Artemisia.

Results: Pairwise trait correlations and the trade-off patterns along the resource economic axis were consistent at both organ and whole-plant levels. Environmental gradients did not strongly affect the correlations among leaf, stem and root economics spectra, i.e. the intraspecific variation weakened but did not mask this coordination. Taxonomic scale did not affect the degree of trait coordination as the genus-wide whole-plant economics spectrum also emerged within each of the three subgenera.

Main conclusions: Our results support the hypothesis that the coordination of economics spectra across organs forms a whole-plant economics spectrum representing “fast-slow” resource management strategy, which is robust to recent evolution (genotypic variation, even for species within a single genus) and present-day environmental variation. Further studies should elucidate in which circumstances or phylogenetic branches the coordinated pattern found for Artemisia is representative of other widely distributed genera.

We sampled 1,022 individuals of 62 Artemisia species from 81 sites across eastern and central China in late July and August 2018. We quantified 15 economic traits that were associated with plant resource economic strategies. The whole plants were harvested for trait measurements. Oven-dried leaves, stems and roots were ground to fine powders and then examined for total carbon (C, mg g-1) and nitrogen (N, mg g-1) concentrations using an elemental analyser (Vario EL III, Elementar, Hanau, Germany). Subsamples of the fine powders of leaves, stems and roots were used to measure total phosphorus (P, g kg-1) concentrations. The 50 mg fine powder was solubilized in a Teflon cylinder using a 1:4 mixture of HClO4 (60%) and HNO3 (60%), then 3% HClO4 was added to reach a final volume of 10 ml. The final solution was digested in a MARS 5 microwave digestion system (CEM GmbH, Kamp-Lintfort, Germany), and then P concentration was measured using the Thermo Scientific iCAP 6300 (Thermo Fisher Scientific Inc., Waltham, MA, USA).