Pre-Emptive Detection of Mature Pine Drought Stress Using Multispectral Aerial Imagery

Drought, ozone (O<sub>3</sub>), and nitrogen deposition (N) alter foliar pigments and tree crown structure that may be remotely detectable. Remote sensing tools are needed that pre-emptively identify trees susceptible to environmental stresses could inform forest managers in advance of t...

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Main Authors: Nancy Grulke, Jason Maxfield, Phillip Riggan, Charlie Schrader-Patton
Format: Article
Language:English
Published: MDPI AG 2020-07-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/12/14/2338
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author Nancy Grulke
Jason Maxfield
Phillip Riggan
Charlie Schrader-Patton
author_facet Nancy Grulke
Jason Maxfield
Phillip Riggan
Charlie Schrader-Patton
author_sort Nancy Grulke
collection DOAJ
description Drought, ozone (O<sub>3</sub>), and nitrogen deposition (N) alter foliar pigments and tree crown structure that may be remotely detectable. Remote sensing tools are needed that pre-emptively identify trees susceptible to environmental stresses could inform forest managers in advance of tree mortality risk. Jeffrey pine, a component of the economically important and widespread western yellow pine in North America was investigated in the southern Sierra Nevada. Transpiration of mature trees differed by 20% between microsites with adequate (mesic (M)) vs. limited (xeric (X)) water availability as described in a previous study. In this study, in-the-crown morphological traits (needle chlorosis, branchlet diameter, and frequency of needle defoliators and dwarf mistletoe) were significantly correlated with aerially detected, sub-crown spectral traits (upper crown NDVI, high resolution (R), near-infrared (NIR) Scalar (inverse of NDVI) and THERM Δ, and the difference between upper and mid crown temperature). A classification tree model sorted trees into X and M microsites with THERM Δ alone (20% error), which was partially validated at a second site with only mesic trees (2% error). Random forest separated M and X site trees with additional spectra (17% error). Imagery taken once, from an aerial platform with sub-crown resolution, under the challenge of drought stress, was effective in identifying droughted trees within the context of other environmental stresses.
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spelling doaj.art-e1f392c0bebe48cd8ebf7c9d3b8f706c2023-11-20T07:27:24ZengMDPI AGRemote Sensing2072-42922020-07-011214233810.3390/rs12142338Pre-Emptive Detection of Mature Pine Drought Stress Using Multispectral Aerial ImageryNancy Grulke0Jason Maxfield1Phillip Riggan2Charlie Schrader-Patton3Pacific Northwest Research Station, USDA Forest Service, Bend, OR 97701, USABiology Department, Portland State University, Portland, OR 97201, USAPacific Southwest Research Station, USDA Forest Service, Riverside, CA 92507, USAWestern Wildlands Environmental Threats Assessment Center, USDA Forest Service, Bend, OR 97701, USADrought, ozone (O<sub>3</sub>), and nitrogen deposition (N) alter foliar pigments and tree crown structure that may be remotely detectable. Remote sensing tools are needed that pre-emptively identify trees susceptible to environmental stresses could inform forest managers in advance of tree mortality risk. Jeffrey pine, a component of the economically important and widespread western yellow pine in North America was investigated in the southern Sierra Nevada. Transpiration of mature trees differed by 20% between microsites with adequate (mesic (M)) vs. limited (xeric (X)) water availability as described in a previous study. In this study, in-the-crown morphological traits (needle chlorosis, branchlet diameter, and frequency of needle defoliators and dwarf mistletoe) were significantly correlated with aerially detected, sub-crown spectral traits (upper crown NDVI, high resolution (R), near-infrared (NIR) Scalar (inverse of NDVI) and THERM Δ, and the difference between upper and mid crown temperature). A classification tree model sorted trees into X and M microsites with THERM Δ alone (20% error), which was partially validated at a second site with only mesic trees (2% error). Random forest separated M and X site trees with additional spectra (17% error). Imagery taken once, from an aerial platform with sub-crown resolution, under the challenge of drought stress, was effective in identifying droughted trees within the context of other environmental stresses.https://www.mdpi.com/2072-4292/12/14/2338remote sensingphysiological drought stresswithin-crown resolutionjeffrey pinesierra nevadathermal imagery
spellingShingle Nancy Grulke
Jason Maxfield
Phillip Riggan
Charlie Schrader-Patton
Pre-Emptive Detection of Mature Pine Drought Stress Using Multispectral Aerial Imagery
Remote Sensing
remote sensing
physiological drought stress
within-crown resolution
jeffrey pine
sierra nevada
thermal imagery
title Pre-Emptive Detection of Mature Pine Drought Stress Using Multispectral Aerial Imagery
title_full Pre-Emptive Detection of Mature Pine Drought Stress Using Multispectral Aerial Imagery
title_fullStr Pre-Emptive Detection of Mature Pine Drought Stress Using Multispectral Aerial Imagery
title_full_unstemmed Pre-Emptive Detection of Mature Pine Drought Stress Using Multispectral Aerial Imagery
title_short Pre-Emptive Detection of Mature Pine Drought Stress Using Multispectral Aerial Imagery
title_sort pre emptive detection of mature pine drought stress using multispectral aerial imagery
topic remote sensing
physiological drought stress
within-crown resolution
jeffrey pine
sierra nevada
thermal imagery
url https://www.mdpi.com/2072-4292/12/14/2338
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AT phillipriggan preemptivedetectionofmaturepinedroughtstressusingmultispectralaerialimagery
AT charlieschraderpatton preemptivedetectionofmaturepinedroughtstressusingmultispectralaerialimagery