Mapping Arctic Tundra Vegetation Communities Using Field Spectroscopy and Multispectral Satellite Data in North Alaska, USA
Abstract
:1. Introduction
2. Materials and Methods
2.1. Study Area
2.2. Vegetation Data
2.3. Field Spectroscopy Data Collection and Pre-Processing
2.4. Satellite Data Collection and Pre-Processing
2.5. Vegetation Indices
2.6. Spectral Separability and Image Classification
3. Results
3.1. Vegetation Communities
3.2. Spectral Separability in Tundra Vegetation Communities
3.2.1. Principal Components Analysis
3.2.2. Linear Discriminant Analysis
3.2.3. Vegetation Map Validation
4. Discussion
5. Conclusions
Supplementary Materials
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Site | UniSpec DC Field Spectroscopy Measurement Collection | WorldView-2 Satellite Imagery Collection |
---|---|---|
Barrow-BEO/Barrow-BES | 11 July 2014 | 25 July 2014 |
Atqasuk | 29 July 2014 | 9 July 2014 |
Ivotuk | 16 July 2014 | 21 June 2013 |
Barrow-BEO | Barrow-BES | Atqasuk | Ivotuk | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Plant Functional Type (PFT) or Category | Wet Sedge Meadow | Mesic Sedge-Grass-Herb Meadow | Dry Lichen Heath | Wet Sedge Meadow | Tussock Tundra (Sandy Substrates) | Wet Sedge Meadow | Wet Sedge Meadow | Mixed Shrub-Sedge Tussock | Tussock Tundra (Non-Sandy Substrates) | |||||||||
freq. | % | freq. | % | freq. | % | freq. | % | freq. | % | freq. | % | freq. | % | freq. | % | freq. | % | |
sedge | 14/20 | 4–41 | 15/20 | 1–15 | 8/10 | 0.1–1 | 5/10 | 16–28 | 17/20 | 4–41 | 9/10 | 14–60 | 9/10 | 11–65 | 9/10 | 1–40 | 9/10 | 5–70 |
grass | 6/20 | 2–40 | 9/20 | 1.1–11 | 10/10 | 3–15 | – | – | 14/20 | 0.1–5 | - | - | - | - | 1/10 | 0.1 | - | - |
forb | - | - | 10/20 | 0.1–10 | 6/10 | 0.1–13 | - | - | 17/20 | 3–40 | - | - | - | - | 10/10 | 1–40 | 10/10 | 5–35 |
deciduous shrub | - | - | 3/20 | 5–10 | - | - | - | - | 13/20 | 3–31 | 3/10 | 0.1–3 | 10/10 | 5–40 | 10/10 | 3–50 | 10/10 | 0.1–6 |
evergreen shrub | - | - | - | - | - | - | - | - | 18/20 | 6–43 | 1–10 | 0.1 | 3/10 | 0.1–6 | 10/10 | 8–75 | 10/10 | 4–20 |
lichen | - | - | 19/20 | 0.2–25 | 10/10 | 3–27 | - | - | 18/20 | 0.7–51 | - | - | - | - | 9/10 | 0.1–27 | 9/10 | 0.1–4 |
moss | 12/20 | 1–100 | 20/20 | 2.2–94 | 10/10 | 25–80 | 9/10 | 5–103 | 18/20 | 6–90 | 2/10 | 0.1–6 | 10/10 | 5–75 | 10/10 | 8–70 | 10/10 | 10–88 |
bare | 2/20 | 25–50 | 3/20 | 5–10 | 4/10 | 5–20 | - | - | 11/20 | 3–10 | - | - | - | - | 5/10 | 5 | 10/10 | 5–10 |
water | - | - | - | - | - | - | 7/10 | 30–80 | - | - | - | - | 2/10 | 5–25 | 1/10 | 5 | - | - |
standing dead | 7/20 | 3–10 | 20/20 | 10–80 | 10/10 | 3–70 | 2/10 | 3–5 | 17/20 | 1–10 | 7/10 | 5–45 | 10/10 | 5–40 | 10/10 | 3–50 | 10/10 | 5–40 |
Waveband | Barrow-BEO/Barrow-BES | Atqasuk | Ivotuk | ||||||
---|---|---|---|---|---|---|---|---|---|
F | df | p | F | df | p | F | df | p | |
Blue (450–510 nm) | 26.24 | 2 | <0.001 | 27.05 | 1 | <0.001 | 9.986 | 2 | <0.001 |
Green (510–580 nm) | 43.86 | 2 | <0.001 | 28.16 | 1 | <0.001 | 7.77 | 2 | <0.001 |
Yellow (585–625 nm) | 72.5 | 2 | <0.001 | 21.1 | 1 | <0.001 | 23.1 | 2 | <0.001 |
Red (630–690 nm) | 74.51 | 2 | <0.001 | 24.97 | 1 | <0.001 | 45.37 | 2 | <0.001 |
Red edge (705–745 nm) | 45.6 | 2 | <0.001 | 14.72 | 1 | <0.001 | 8.064 | 2 | <0.001 |
Near-IR1 (770–895 nm) | 4.357 | 2 | <0.001 | 4.737 | 1 | <0.001 | 22.04 | 2 | <0.001 |
Near-IR2 (860–1040 nm) | 43.35 | 2 | <0.001 | 15.37 | 1 | <0.001 | 0.827 | 2 | 4.39 |
Barrow-BEO/Barrow-BES | Dry Lichen Heath | Mesic Sedge-Grass-Herb Meadow | Wet Sedge Meadow | Kappa Coefficient |
UniSpec | 100 | 100 | 100 | 1 |
UniSpec (+ NDVI/NDWI/EVI) | 100 | 100 | 100 | 1 |
UniSpecWV2 | 96 | 90 | 99 | 0.92 |
UniSpecWV2(+ NDVI/NDWI/EVI) | 100 | 92 | 99 | 0.94 |
WorldView-2 | 61 | 52 | 43 | 0.24 |
WorldView-2 (+ NDVI/NDWI/EVI) | 61 | 61 | 39 | 0.26 |
Atqasuk | N/A | Tussock Tundra (Sandy Substrates) | Wet Sedge Meadow | Kappa Coefficient |
UniSpec | n/a | 100 | 100 | 1 |
UniSpec (+ NDVI/NDWI/EVI) | n/a | 100 | 100 | 1 |
UniSpecWV2 | n/a | 96 | 92 | 0.88 |
UniSpecWV2(+ NDVI/NDWI/EVI) | n/a | 98 | 96 | 0.94 |
WorldView-2 | n/a | 86 | 92 | 0.74 |
WorldView-2 (+ NDVI/NDWI/EVI) | n/a | 86 | 88 | 0.71 |
Ivotuk | Mixed Shrub-Sedge Tussock | Tussock Tundra (Non-Sandy Substrates) | Wet Sedge Meadow | Kappa Coefficient |
UniSpec | 100 | 100 | 100 | 1 |
UniSpec (+ NDVI/NDWI/EVI) | 100 | 100 | 100 | 1 |
UniSpecWV2 | 90 | 96 | 83 | 0.86 |
UniSpecWV2(+ NDVI/NDWI/EVI) | 97 | 97 | 90 | 0.93 |
WorldView-2 | 59 | 64 | 50 | 0.37 |
WorldView-2 (+ NDVI/NDWI/EVI) | 55 | 67 | 53 | 0.4 |
Barrow-BEO/Barrow-BES | Mesic Sedge-Grass-Herb Meadow | Dry Lichen Heath | Wet Sedge Meadow | Barrow-BEO/Barrow-BES | Mesic Sedge-Grass-Herb Meadow | Dry Lichen Heath | Wet Sedge Meadow |
---|---|---|---|---|---|---|---|
Mesic sedge-grass-herb meadow | 46 | 5 | 9 | Mesic sedge-grass-herb meadow | 50 | 1 | 9 |
Dry lichen heath | 16 | 12 | 2 | Dry lichen heath | 11 | 17 | 2 |
Wet sedge meadow | 30 | 1 | 59 | Wet sedge meadow | 31 | 10 | 49 |
Classification accuracy | 65% | Classification accuracy | 64% | ||||
Kappa | 0.43 | Kappa | 0.43 | ||||
Atqasuk | Tussock Tundra (Sandy Substrates) | Wet Sedge Meadow | Atqasuk | Tussock Tundra (Sandy Substrates) | Wet Sedge Meadow | ||
Tussock tundra (sandy substrates) | 58 | 2 | Tussock tundra (sandy substrates) | 49 | 11 | ||
Wet sedge meadow | 9 | 21 | Wet sedge meadow | 7 | 23 | ||
Classification accuracy | 88% | Classification accuracy | 80% | ||||
Kappa | 0.71 | Kappa | 0.56 | ||||
Ivotuk | Wet Sedge Meadow | Tussock Tundra (Non-Sandy Substrates) | Mixed Shrub-Sedge Tussock | Ivotuk | Wet Sedge Meadow | Tussock Tundra (Non-Sandy Substrates) | Mixed Shrub-Sedge Tussock |
Wet sedge meadow | 4 | 40 | 14 | Wet sedge meadow | 13 | 40 | 5 |
Tussock tundra (non-sandy substrates) | 0 | 120 | 2 | Tussock tundra (non-sandy substrates) | 1 | 111 | 11 |
Mixed shrub-sedge tussock | 0 | 19 | 31 | Mixed shrub-sedge tussock | 0 | 6 | 44 |
Classification accuracy | 67% | Classification accuracy | 73% | ||||
Kappa | 0.39 | Kappa | 0.52 |
Site | Vegetation Community | Linear Discriminant Analysis (% Cover) | Linear Discriminant Analysis + NDVI, NDWI and EVI (% Cover) |
---|---|---|---|
Barrow-BEO | Mesic-sedge-grass-herb meadow | 52.5 | 51.8 |
Dry lichen heath | 3.8 | 5.5 | |
Wet sedge meadow | 43.6 | 42.7 | |
Barrow-BES | Mesic-sedge-grass-herb meadow | 28.8 | 29.3 |
Dry lichen heath | 5.1 | 5.5 | |
Wet sedge meadow | 66.1 | 65.2 | |
Atqasuk | Tussock sedge (sandy substrates) | 83.9 | 63.5 |
Wet sedge meadow | 12.6 | 32.5 | |
Ivotuk | Wet sedge meadow | 1.2 | 5.7 |
Tussock sedge (non-sandy substrates) | 59.9 | 59.4 | |
Mixed shrub-sedge tussock | 38.9 | 34.9 |
© 2016 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).
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Davidson, S.J.; Santos, M.J.; Sloan, V.L.; Watts, J.D.; Phoenix, G.K.; Oechel, W.C.; Zona, D. Mapping Arctic Tundra Vegetation Communities Using Field Spectroscopy and Multispectral Satellite Data in North Alaska, USA. Remote Sens. 2016, 8, 978. https://doi.org/10.3390/rs8120978
Davidson SJ, Santos MJ, Sloan VL, Watts JD, Phoenix GK, Oechel WC, Zona D. Mapping Arctic Tundra Vegetation Communities Using Field Spectroscopy and Multispectral Satellite Data in North Alaska, USA. Remote Sensing. 2016; 8(12):978. https://doi.org/10.3390/rs8120978
Chicago/Turabian StyleDavidson, Scott J., Maria J. Santos, Victoria L. Sloan, Jennifer D. Watts, Gareth K. Phoenix, Walter C. Oechel, and Donatella Zona. 2016. "Mapping Arctic Tundra Vegetation Communities Using Field Spectroscopy and Multispectral Satellite Data in North Alaska, USA" Remote Sensing 8, no. 12: 978. https://doi.org/10.3390/rs8120978