title: Four years of experimental warming do not modify the interaction between subalpine shrub species.
abstract: Climate warming can lead to changes in alpine plant species interactions through modifications in environmental conditions, which may ultimately cause drastic changes in plant communities. We explored the effects of 4 years of experimental warming with open-top chambers (OTC) on Vaccinium myrtillus performance and its interaction with neighbouring shrubs at the Pyrenean treeline ecotone. We examined the effects of warming on height, above-ground (AG) and below-ground (BG) biomass and the C and N concentration and isotope composition of V. myrtillus growing in pure stands or in stands mixed with Vaccinium uliginosum or Rhododendron ferrugineum. We also analysed variations in soil N concentrations, rhizosphere C/N ratios and the functional diversity of the microbial community, and evaluated whether warming altered the biomass, C and N concentration and isotope composition of V. uliginosum in mixed plots. Our results showed that warming induced positive changes in the AG growth of V. myrtillus but not BG, while V. uliginosum did not respond to warming. Vaccinium myrtillus performance did not differ between stand types under increased temperatures, suggesting that warming did not induce shifts in the interaction between V. myrtillus and its neighbouring species. These findings contrast with previous studies in which species interactions changed when temperature was modified. Our results show that species interactions can be less responsive to warming in natural plant communities than in removal experiments, highlighting the need for studies involving the natural assembly of plant species and communities when exploring the effect of environmental changes on plant-plant interactions.
authors.affiliation: Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain. a.anadon@ub.edu.|Biodiversity Research Institute (IRBio), University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain. a.anadon@ub.edu.
authors.forename: Alba
authors.identifier: 0000-0002-9447-7795
authors.initials: A
authors.lastname: Anadon-Rosell
authors.affiliation: Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain.|Biodiversity Research Institute (IRBio), University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Ninot
authors.affiliation: Instituto Pirenaico de Ecología (IPE-CSIC), Av. Nuestra Señora de la Victoria 16, 22700, Jaca, Huesca, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Palacio
authors.affiliation: CSIC, Global Ecology Unit, CREAF-CSIC-UAB, 08193, Cerdanyola Del Vallès, Catalonia, Spain.|2CREAF, 08193, Cerdanyola Del Vallès, Catalonia, Spain.
authors.forename: Oriol
authors.initials: O
authors.lastname: Grau
authors.affiliation: Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain.
authors.forename: Salvador
authors.initials: S
authors.lastname: Nogués
authors.affiliation: Instituto Pirenaico de Ecología (IPE-CSIC), Av. Montañana 1005, 50059, Saragossa, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Navarro
authors.affiliation: Instituto Pirenaico de Ecología (IPE-CSIC), Av. Montañana 1005, 50059, Saragossa, Spain.
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Sancho
authors.affiliation: Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain.|Biodiversity Research Institute (IRBio), University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain.
authors.forename: Empar
authors.initials: E
authors.lastname: Carrillo
mesh_terms: D018533:Biomass; D002980:Climate; D017753:Ecosystem; D010944:Plants; D012987:Soil; D013696:Temperature
chemical_list: D012987:Soil
keywords: Dwarf shrub; Passive warming; Plant interactions; Pyrenees; Vaccinium myrtillus