title: Carbon dynamics in aboveground biomass of co-dominant plant species in a temperate grassland ecosystem: same or different?
abstract: Understanding the role of individual organisms in whole-ecosystem carbon (C) fluxes is probably the biggest current challenge in C cycle research. Thus, it is unknown whether different plant community members share the same or different residence times in metabolic (τmetab ) and nonmetabolic (i.e. structural) (τnonmetab ) C pools of aboveground biomass and the fraction of fixed C allocated to aboveground nonmetabolic biomass (Anonmetab ). We assessed τmetab , τnonmetab and Anonmetab of co-dominant species from different functional groups (two bunchgrasses, a stoloniferous legume and a rosette dicot) in a temperate grassland community. Continuous, 14-16-d-long (13) C-labeling experiments were performed in September 2006, May 2007 and September 2007. A two-pool compartmental system, with a well-mixed metabolic and a nonmixed nonmetabolic pool, was the simplest biologically meaningful model that fitted the (13) C tracer kinetics in the whole-shoot biomass of all species. In all experimental periods, the species had similar τmetab (5-8 d), whereas τnonmetab ranged from 20 to 58 d (except for one outlier) and Anonmetab from 7 to 45%. Variations in τnonmetab and Anonmetab were not systematically associated with species or experimental periods, but exhibited relationships with leaf life span, particularly in the grasses. Similar pool kinetics of species suggested similar kinetics at the community level.
authors.affiliation: Lehrstuhl für Grünlandlehre, Department für Pflanzenwissenschaften, Technische Universität München, Alte Akademie 12, Freising-Weihenstephan, D-85354, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Ostler
authors.affiliation: Lehrstuhl für Grünlandlehre, Department für Pflanzenwissenschaften, Technische Universität München, Alte Akademie 12, Freising-Weihenstephan, D-85354, Germany.
authors.forename: Inga
authors.initials: I
authors.lastname: Schleip
authors.affiliation: Lehrstuhl für Grünlandlehre, Department für Pflanzenwissenschaften, Technische Universität München, Alte Akademie 12, Freising-Weihenstephan, D-85354, Germany.
authors.forename: Fernando A
authors.initials: FA
authors.lastname: Lattanzi
authors.affiliation: Lehrstuhl für Grünlandlehre, Department für Pflanzenwissenschaften, Technische Universität München, Alte Akademie 12, Freising-Weihenstephan, D-85354, Germany.
authors.forename: Hans
authors.initials: H
authors.lastname: Schnyder
mesh_terms: D018533:Biomass; D002244:Carbon / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism; D002247:Carbon Isotopes; D065948:Grassland; D007553:Isotope Labeling; D007700:Kinetics; D008954:Models, Biological; D010788:Photosynthesis; D010944:Plants / Q000378:metabolism*; D013045:Species Specificity; D013997:Time Factors
chemical_list: D002247:Carbon Isotopes; D002245:Carbon Dioxide; D002244:Carbon
keywords: 13C labelling; carbon (C) allocation and partitioning; carbon pool turnover; carbon residence time; functional groups; grassland; leaf life span; structural and nonstructural biomass