Oecologia

, Volume 175, Issue 1, pp 273–284

Moisture status during a strong El Niño explains a tropical montane cloud forest’s upper limit

  • Shelley D. Crausbay
  • Abby G. Frazier
  • Thomas W. Giambelluca
  • Ryan J. Longman
  • Sara C. Hotchkiss
Community ecology - Original research

DOI: 10.1007/s00442-014-2888-8

Cite this article as:
Crausbay, S.D., Frazier, A.G., Giambelluca, T.W. et al. Oecologia (2014) 175: 273. doi:10.1007/s00442-014-2888-8

Abstract

Growing evidence suggests short-duration climate events may drive community structure and composition more directly than long-term climate means, particularly at ecotones where taxa are close to their physiological limits. Here we use an empirical habitat model to evaluate the role of microclimate during a strong El Niño in structuring a tropical montane cloud forest’s upper limit and composition in Hawai‘i. We interpolate climate surfaces, derived from a high-density network of climate stations, to permanent vegetation plots. Climatic predictor variables include (1) total rainfall, (2) mean relative humidity, and (3) mean temperature representing non-El Niño periods and a strong El Niño drought. Habitat models explained species composition within the cloud forest with non-El Niño rainfall; however, the ecotone at the cloud forest’s upper limit was modeled with relative humidity during a strong El Niño drought and secondarily with non-El Niño rainfall. This forest ecotone may be particularly responsive to strong, short-duration climate variability because taxa here, particularly the isohydric dominant Metrosideros polymorpha, are near their physiological limits. Overall, this study demonstrates moisture’s overarching influence on a tropical montane ecosystem, and suggests that short-term climate events affecting moisture status are particularly relevant at tropical ecotones. This study further suggests that predicting the consequences of climate change here, and perhaps in other tropical montane settings, will rely on the skill and certainty around future climate models of regional rainfall, relative humidity, and El Niño.

Keywords

Drought Ecotone El Niño/Southern Oscillation Habitat model Hawai‘i 

Supplementary material

442_2014_2888_MOESM1_ESM.pdf (635 kb)
Supplementary material 1 (PDF 635 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Shelley D. Crausbay
    • 1
    • 2
    • 4
  • Abby G. Frazier
    • 3
  • Thomas W. Giambelluca
    • 3
  • Ryan J. Longman
    • 3
  • Sara C. Hotchkiss
    • 1
    • 2
  1. 1.Department of BotanyUniversity of Wisconsin-MadisonMadisonUSA
  2. 2.Center for Climatic ResearchUniversity of Wisconsin-MadisonMadisonUSA
  3. 3.Department of GeographyUniversity of Hawai‘i-MānoaHonoluluUSA
  4. 4.Department of Horticulture and Landscape ArchitectureColorado State UniversityFort CollinsUSA

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