Abstract
Wilding conifers, the naturally regenerated scions of exotic conifer species, are a major ecological and economic issue in New Zealand. Hyperspectral imagery could provide a useful means of monitoring the efficacy of wilding control measures but little research has examined this possibility. Data were collected from an experiment, that included thirty-nine young Pinus contorta (Douglas) trees allocated to a control and two herbicide treatments (triclopyr butoxyethyl ester and diquat dibromide monohydrate). The objectives of this research were to examine the temporal impacts of herbicide on needle discolouration, spectral properties and tree physiology and to develop models to predict photosynthetic parameters from hyperspectral data. In accordance with obvious discolouration on the first day after treatment, values of net photosynthesis rate (A), electron transport rate (ETR), stomatal conductance (G) and optimal quantum yield of photosystem II (Fv/Fm) declined rapidly for plants treated with diquat. Discolouration following application of triclopyr was not evident before the second week, and values of A, ETR, G and Fv/Fm declined slower than those of diquat. Of the tested narrow-band spectral indices calculated from needle spectra photochemical reflectance index (PRI) exhibited the strongest correlation with the four photosynthetic parameters and R2 values between PRI and A, Fv/Fm, ETR and G were, respectively, 0.53, 0.46, 0.68 and 0.29. Models that used raw spectra as inputs showed that sparse partial least squares (SPLS) outperformed the three other approaches tested (PLS, Support Vector Machines, Elastic Net) and R2 values using this approach for A, Fv/Fm, ETR and G were, respectively, 0.64, 0.62, 0.65 and 0.42.
| Original language | English |
|---|---|
| Journal | Biological Invasions |
| DOIs | |
| Publication status | Published - 1 Jan 2019 |
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Keywords
- Herbicides
- Hyperspectral
- Invasion ecology
- Lodgepole pine
- Stress detection
- Wildings
Cite this
}
Hyperspectral VNIR-spectroscopy and imagery as a tool for monitoring herbicide damage in wilding conifers. / Scholten, Rebecca C.; Hill, Joachim; Werner, Willy; Buddenbaum, Henning; Dash, Jonathan P.; Gomez Gallego, Mireia; Rolando, Carol A.; Pearse, Grant D.; Hartley, Robin; Estarija, Honey Jane; Watt, Michael S.
In: Biological Invasions, 01.01.2019.Research output: Contribution to Journal › Article › Academic › peer-review
TY - JOUR
T1 - Hyperspectral VNIR-spectroscopy and imagery as a tool for monitoring herbicide damage in wilding conifers
AU - Scholten, Rebecca C.
AU - Hill, Joachim
AU - Werner, Willy
AU - Buddenbaum, Henning
AU - Dash, Jonathan P.
AU - Gomez Gallego, Mireia
AU - Rolando, Carol A.
AU - Pearse, Grant D.
AU - Hartley, Robin
AU - Estarija, Honey Jane
AU - Watt, Michael S.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Wilding conifers, the naturally regenerated scions of exotic conifer species, are a major ecological and economic issue in New Zealand. Hyperspectral imagery could provide a useful means of monitoring the efficacy of wilding control measures but little research has examined this possibility. Data were collected from an experiment, that included thirty-nine young Pinus contorta (Douglas) trees allocated to a control and two herbicide treatments (triclopyr butoxyethyl ester and diquat dibromide monohydrate). The objectives of this research were to examine the temporal impacts of herbicide on needle discolouration, spectral properties and tree physiology and to develop models to predict photosynthetic parameters from hyperspectral data. In accordance with obvious discolouration on the first day after treatment, values of net photosynthesis rate (A), electron transport rate (ETR), stomatal conductance (G) and optimal quantum yield of photosystem II (Fv/Fm) declined rapidly for plants treated with diquat. Discolouration following application of triclopyr was not evident before the second week, and values of A, ETR, G and Fv/Fm declined slower than those of diquat. Of the tested narrow-band spectral indices calculated from needle spectra photochemical reflectance index (PRI) exhibited the strongest correlation with the four photosynthetic parameters and R2 values between PRI and A, Fv/Fm, ETR and G were, respectively, 0.53, 0.46, 0.68 and 0.29. Models that used raw spectra as inputs showed that sparse partial least squares (SPLS) outperformed the three other approaches tested (PLS, Support Vector Machines, Elastic Net) and R2 values using this approach for A, Fv/Fm, ETR and G were, respectively, 0.64, 0.62, 0.65 and 0.42.
AB - Wilding conifers, the naturally regenerated scions of exotic conifer species, are a major ecological and economic issue in New Zealand. Hyperspectral imagery could provide a useful means of monitoring the efficacy of wilding control measures but little research has examined this possibility. Data were collected from an experiment, that included thirty-nine young Pinus contorta (Douglas) trees allocated to a control and two herbicide treatments (triclopyr butoxyethyl ester and diquat dibromide monohydrate). The objectives of this research were to examine the temporal impacts of herbicide on needle discolouration, spectral properties and tree physiology and to develop models to predict photosynthetic parameters from hyperspectral data. In accordance with obvious discolouration on the first day after treatment, values of net photosynthesis rate (A), electron transport rate (ETR), stomatal conductance (G) and optimal quantum yield of photosystem II (Fv/Fm) declined rapidly for plants treated with diquat. Discolouration following application of triclopyr was not evident before the second week, and values of A, ETR, G and Fv/Fm declined slower than those of diquat. Of the tested narrow-band spectral indices calculated from needle spectra photochemical reflectance index (PRI) exhibited the strongest correlation with the four photosynthetic parameters and R2 values between PRI and A, Fv/Fm, ETR and G were, respectively, 0.53, 0.46, 0.68 and 0.29. Models that used raw spectra as inputs showed that sparse partial least squares (SPLS) outperformed the three other approaches tested (PLS, Support Vector Machines, Elastic Net) and R2 values using this approach for A, Fv/Fm, ETR and G were, respectively, 0.64, 0.62, 0.65 and 0.42.
KW - Herbicides
KW - Hyperspectral
KW - Invasion ecology
KW - Lodgepole pine
KW - Stress detection
KW - Wildings
UR - http://www.scopus.com/inward/record.url?scp=85068892472&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85068892472&partnerID=8YFLogxK
U2 - 10.1007/s10530-019-02055-0
DO - 10.1007/s10530-019-02055-0
M3 - Article
JO - Biological Invasions
JF - Biological Invasions
SN - 1387-3547
ER -