Linking rainforest ecophysiology and microclimate through fusion of airborne LiDAR and hyperspectral imagery

Eben N. Broadbent, Angélica M.Almeyda Zambrano, Gregory P. Asner, Christopher B. Field, Brad E. Rosenheim, Ty Kennedy-Bowdoin, David E. Knapp, David Burke, Christian Giardina, Susan Cordell

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

We develop and validate a high-resolution three-dimensional model of light and air temperature for a tropical forest interior in Hawaii along an elevation gradient varying greatly in structure but maintaining a consistent species composition. Our microclimate models integrate highresolution airborne waveform light detection and ranging data (LiDAR) and hyperspectral imagery with detailed microclimate measurements. We then use modeled microclimate and forest structural and compositional variables to explain variation in spatially explicit measurements of leaf traits, including gas exchange and structure. Our results highlight the importance of: (1) species differences in leaf traits, with species explaining up to 65% of the variation in some leaf traits; (2) differences between exotic and native species, with exotic species having greater maximum rates of assimilation and foliar λ15N values; (3) structural factors, with foliar %N and light saturation of photosynthesis decreasing in mid-canopy locations; (4) microclimate factors, with foliar %N and light saturation increasing with growth environment illumination; and (5) decreases in mean annual temperature with elevation resulting in closure of the nitrogen cycle, as indicated through decreases in foliar λ15N values. The dominant overstory species (Metrosideros polymorpha) did not show plasticity in photosynthetic capacity, whereas the dominant understory species (Cibotium glaucum) had higher maximum rates of assimilation in more illuminated growth environments. The approach developed in this study highlights the potential of new airborne sensors to quantify forest productivity at spatial and temporal scales not previously possible. Our results provide insight into the function of a Hawaiian forest dominated by native species undergoing simultaneous biological invasion and climatic change.

Original languageEnglish (US)
Article number57
JournalEcosphere
Volume5
Issue number5
DOIs
StatePublished - May 16 2014
Externally publishedYes

    Fingerprint

Keywords

  • Canopy structure
  • Carnegie Airborne Observatory
  • Climate change
  • Direct and diffuse light
  • Induction rate
  • Laupahoehoe Natural Area Reserve
  • Photosynthetic active radiation (PAR)
  • Sun fleck
  • Tropical forest

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Ecology

Cite this

Broadbent, E. N., Zambrano, A. M. A., Asner, G. P., Field, C. B., Rosenheim, B. E., Kennedy-Bowdoin, T., Knapp, D. E., Burke, D., Giardina, C., & Cordell, S. (2014). Linking rainforest ecophysiology and microclimate through fusion of airborne LiDAR and hyperspectral imagery. Ecosphere, 5(5), [57]. https://doi.org/10.1890/ES13-00255.1