title: Winners always win: growth of a wide range of plant species from low to future high CO2.
abstract: Evolutionary adaptation to variation in resource supply has resulted in plant strategies that are based on trade-offs in functional traits. Here, we investigate, for the first time across multiple species, whether such trade-offs are also apparent in growth and morphology responses to past low, current ambient, and future high CO 2 concentrations. We grew freshly germinated seedlings of up to 28 C3 species (16 forbs, 6 woody, and 6 grasses) in climate chambers at 160 ppm, 450 ppm, and 750 ppm CO 2. We determined biomass, allocation, SLA (specific leaf area), LAR (leaf area ratio), and RGR (relative growth rate), thereby doubling the available data on these plant responses to low CO 2. High CO 2 increased RGR by 8%; low CO 2 decreased RGR by 23%. Fast growers at ambient CO 2 had the greatest reduction in RGR at low CO 2 as they lost the benefits of a fast-growth morphology (decoupling of RGR and LAR [leaf area ratio]). Despite these shifts species ranking on biomass and RGR was unaffected by CO 2, winners continued to win, regardless of CO 2. Unlike for other plant resources we found no trade-offs in morphological and growth responses to CO 2 variation, changes in morphological traits were unrelated to changes in growth at low or high CO 2. Thus, changes in physiology may be more important than morphological changes in response to CO 2 variation.
authors.affiliation: Department of Ecological Science VU University De Boelelaan 1085 1081HV Amsterdam The Netherlands.
authors.forename: Andries A
authors.initials: AA
authors.lastname: Temme
authors.affiliation: Department of Ecological Science VU University De Boelelaan 1085 1081HV Amsterdam The Netherlands ; Key Laboratory of Eco-Environment in Three Gorges Reservoir Region School of Life Science Southwest University Beibei Chongqing 400715 China.
authors.forename: Jin Chun
authors.initials: JC
authors.lastname: Liu
authors.affiliation: Department of Ecological Science VU University De Boelelaan 1085 1081HV Amsterdam The Netherlands ; Ecology and Evolution Research Centre School of Biological, Earth, and Environmental Sciences University of New South Wales Kensington 2052 Sydney New South Wales Australia.
authors.forename: William K
authors.initials: WK
authors.lastname: Cornwell
authors.affiliation: Department of Ecological Science VU University De Boelelaan 1085 1081HV Amsterdam The Netherlands.
authors.forename: Johannes H C
authors.initials: JH
authors.lastname: Cornelissen
authors.affiliation: Department of Ecological Science VU University De Boelelaan 1085 1081HV Amsterdam The Netherlands.
authors.forename: Rien
authors.initials: R
authors.lastname: Aerts
keywords: Growth response; high CO2; low CO2; morphology; plant types; relative growth rate; trade‐off