Anadon-Rosell Alba, Ninot Josep M, Palacio Sara, Grau Oriol, Nogués Salvador, Navarro Enrique, Sancho M Carmen, Carrillo Empar
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.
Oecologia. 2017 Apr;183(4):1167-1181. doi: 10.1007/s00442-017-3830-7. Epub 2017 Feb 11.
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.
气候变暖可通过改变环境条件导致高山植物物种间相互作用发生变化，这最终可能致使植物群落发生剧烈改变。我们利用开顶式生长室（OTC）进行了为期4年的实验性增温，以探究其对矮越橘生长表现及其在比利牛斯山树线交错带与邻近灌木相互作用的影响。我们研究了增温对纯林或与湿地越橘或铁锈色杜鹃混交林中矮越橘的高度、地上（AG）和地下（BG）生物量以及碳和氮浓度及同位素组成的影响。我们还分析了土壤氮浓度、根际碳氮比和微生物群落功能多样性的变化，并评估了增温是否改变了混交林中湿地越橘的生物量、碳和氮浓度及同位素组成。我们的结果表明，增温使矮越橘的地上生长出现了积极变化，但地下生长未出现变化，而湿地越橘对增温没有响应。在温度升高的情况下，不同林分类型中矮越橘的生长表现没有差异，这表明增温并未导致矮越橘与其邻近物种间的相互作用发生转变。这些发现与之前温度改变时物种间相互作用发生变化的研究形成了对比。我们的结果表明，在自然植物群落中，物种间相互作用对增温的响应可能不如在去除实验中那么明显，这凸显了在探究环境变化对植物-植物相互作用的影响时，开展涉及植物物种和群落自然组合的研究的必要性。
