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Oecologia

, Volume 182, Issue 1, pp 85–97 | Cite as

Spectral determination of concentrations of functionally diverse pigments in increasingly complex arctic tundra canopies

  • Natalie T. BoelmanEmail author
  • Troy S. Magney
  • Barry A. Logan
  • Kevin L. Griffin
  • Jan U. H. Eitel
  • Heather Greaves
  • Case M. Prager
  • Lee A. Vierling
Physiological ecology - original research

Abstract

As the Arctic warms, tundra vegetation is becoming taller and more structurally complex, as tall deciduous shrubs become increasingly dominant. Emerging studies reveal that shrubs exhibit photosynthetic resource partitioning, akin to forests, that may need accounting for in the “big leaf” net ecosystem exchange models. We conducted a lab experiment on sun and shade leaves from S. pulchra shrubs to determine the influence of both constitutive (slowly changing bulk carotenoid and chlorophyll pools) and facultative (rapidly changing xanthophyll cycle) pigment pools on a suite of spectral vegetation indices, to devise a rapid means of estimating within canopy resource partitioning. We found that: (1) the PRI of dark-adapted shade leaves (PRIo) was double that of sun leaves, and that PRIo was sensitive to variation among sun and shade leaves in both xanthophyll cycle pool size (V + A + Z) (r 2 = 0.59) and Chla/b (r 2 = 0.64); (2) A corrected PRI (difference between dark and illuminated leaves, ΔPRI) was more sensitive to variation among sun and shade leaves in changes to the epoxidation state of their xanthophyll cycle pigments (dEPS) (r 2 = 0.78, RMSE = 0.007) compared to the uncorrected PRI of illuminated leaves (PRI) (r 2 = 0.34, RMSE = 0.02); and (3) the SR680 index was correlated with each of (V + A + Z), lutein, bulk carotenoids, (V + A + Z)/(Chla + b), and Chla/b (r 2 range = 0.52–0.69). We suggest that ΔPRI be employed as a proxy for facultative pigment dynamics, and the SR680 for the estimation of constitutive pigment pools. We contribute the first Arctic-specific information on disentangling PRI-pigment relationships, and offer insight into how spectral indices can assess resource partitioning within shrub tundra canopies.

Keywords

Resource partitioning PRI ΔPRI Remote sensing Shrubs Xanthophyll cycle 

Notes

Acknowledgments

This work was supported by NASA Terrestrial Ecology grant NNX12AK83G. We thank Toolik Field Station (Institute of Arctic Biology, University of Alaska Fairbanks) and the Arctic LTER for support and logistics. We thank Shannan Sweet for her assistance with the data analysis.

Author contribution statement

NTB, TSM, BAL, KLG, JUHE, HG, CMP, and LAV co-conceived, designed, and executed this study. NTB collected and analyzed the spectral data sets, while TSM and BAL conducted the pigment laboratory analyses. NTB wrote the manuscript with feedback on a previous draft from all other co-authors.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Natalie T. Boelman
    • 1
    Email author
  • Troy S. Magney
    • 2
  • Barry A. Logan
    • 3
  • Kevin L. Griffin
    • 1
    • 5
  • Jan U. H. Eitel
    • 2
    • 4
  • Heather Greaves
    • 2
  • Case M. Prager
    • 5
  • Lee A. Vierling
    • 2
    • 4
  1. 1.Lamont-Doherty Earth ObservatoryColumbia UniversityNew YorkUSA
  2. 2.Geospatial Laboratory for Environmental DynamicsUniversity of IdahoMoscowUSA
  3. 3.Department of BiologyBowdoin CollegeBrunswickUSA
  4. 4.McCall Outdoor Science School, University of IdahoMcCallUSA
  5. 5.Department of Ecology, Evolution, and Environmental BiologyColumbia UniversityNew YorkUSA

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