Oecologia

, Volume 170, Issue 2, pp 575–584

Facilitative interactions do not wane with warming at high elevations in the Andes

Authors

    • ECOBIOSIS, Departamento de Botánica, Facultad de Ciencias Naturales y OceanográficasUniversidad de Concepción
    • Instituto de Ecología y Biodiversidad (IEB)
  • Angela Sierra-Almeida
    • ECOBIOSIS, Departamento de Botánica, Facultad de Ciencias Naturales y OceanográficasUniversidad de Concepción
    • Instituto de Ecología y Biodiversidad (IEB)
Global change ecology - Original research

DOI: 10.1007/s00442-012-2316-x

Cite this article as:
Cavieres, L.A. & Sierra-Almeida, A. Oecologia (2012) 170: 575. doi:10.1007/s00442-012-2316-x

Abstract

Positive interactions between species are known to play an important role in the structure and dynamics of alpine plant communities. The balance between negative and positive interactions is known to shift along spatial and temporal gradients, with positive effects prevailing over negative ones as the environmental stress increases. Thus, this balance is likely to be affected by climate change. We hypothesized that increases in temperature (a global warming scenario) should decrease the importance of positive interactions for the survival and growth of alpine plant species. To test this hypothesis, we selected individuals of the native grass species Hordeum comosum growing within the nurse cushion species Azorella madreporica at 3,600 m.a.s.l. in Los Andes (Chile), and performed nurse removal and seedling survival experiments under natural and warmer conditions. For warmer conditions, we used open-top chambers, which increased the temperature by 4 °C. After two growing seasons, we compared the effect of nurse removal on the survival, biomass, and photochemical efficiency of H. comosum individuals under warmer and natural conditions. Nurse removal significantly decreased the survival, biomass, and photochemical efficiency of H. comosum, demonstrating the facilitative effects of nurse cushions. Seedling survival was also enhanced by cushions, even under warmer conditions. However, warmer conditions only partially mitigated the negative effects of nurse removal, suggesting that facilitative effects of cushions do not wane under warmer conditions. Thus, facilitative interactions are vital to the performance and survival of alpine species, and these positive interactions will continue to be important in the warmer conditions of the future in high-alpine habitats.

Keywords

FacilitationPositive interactionsClimate changeGlobal warmingNurse effectCushion plantsNeighbor removalPhotochemical efficiencyAlpine

Supplementary material

442_2012_2316_MOESM1_ESM.doc (2.1 mb)
Supplementary material 1 (DOC 2101 kb)

Copyright information

© Springer-Verlag 2012