Examining the Utility of Visible Near-Infrared and Optical Remote Sensing for the Early Detection of Rapid ‘Ōhi‘a Death

The early detection of plant pathogens at the landscape scale holds great promise for better managing forest ecosystem threats. In Hawai‘i, two recently described fungal species are responsible for increasingly widespread mortality in ‘ōhi‘a <i>Metrosideros polymorpha</i>, a foundational...

Full description

Bibliographic Details
Main Authors: Ryan L. Perroy, Marc Hughes, Lisa M. Keith, Eszter Collier, Timo Sullivan, Gabriel Low
Format: Article
Language:English
Published: MDPI AG 2020-06-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/12/11/1846
_version_ 1797565857300217856
author Ryan L. Perroy
Marc Hughes
Lisa M. Keith
Eszter Collier
Timo Sullivan
Gabriel Low
author_facet Ryan L. Perroy
Marc Hughes
Lisa M. Keith
Eszter Collier
Timo Sullivan
Gabriel Low
author_sort Ryan L. Perroy
collection DOAJ
description The early detection of plant pathogens at the landscape scale holds great promise for better managing forest ecosystem threats. In Hawai‘i, two recently described fungal species are responsible for increasingly widespread mortality in ‘ōhi‘a <i>Metrosideros polymorpha</i>, a foundational tree species in Hawaiian native forests. In this study, we share work from repeat laboratory and field measurements to determine if visible near-infrared and optical remote sensing can detect pre-symptomatic trees infected with these pathogens. After generating a dense time series of laboratory spectral reflectance data and red green blue (RGB) images for inoculated ‘ōhi‘a seedlings, seedlings subjected to extreme drought, and control plants, we found few obvious spectral indicators that could be used for reliable pre-symptomatic detection in the inoculated seedlings, which quickly experienced complete and total wilting following stress onset. In the field, we found similar results when we collected repeat multispectral and RGB imagery over inoculated mature trees (sudden onset of symptoms with little advance warning). We found selected vegetation indices to be reliable indicators for detecting non-specific stress in ‘ōhi‘a trees, but never providing more than five days prior warning relative to visual detection in the laboratory trials. Finally, we generated a sequence of linear support vector machine classification models from the laboratory data at time steps ranging from pre-treatment to late-stage stress. Overall classification accuracies increased with stress stage maturity, but poor model performance prior to stress onset and the sudden onset of symptoms in infected trees suggest that early detection of rapid ‘ōhi‘a death over timescales helpful for land managers remains a challenge.
first_indexed 2024-03-10T19:18:55Z
format Article
id doaj.art-6f13285db7c446f4929f1b1d44563eff
institution Directory Open Access Journal
issn 2072-4292
language English
last_indexed 2024-03-10T19:18:55Z
publishDate 2020-06-01
publisher MDPI AG
record_format Article
series Remote Sensing
spelling doaj.art-6f13285db7c446f4929f1b1d44563eff2023-11-20T03:08:06ZengMDPI AGRemote Sensing2072-42922020-06-011211184610.3390/rs12111846Examining the Utility of Visible Near-Infrared and Optical Remote Sensing for the Early Detection of Rapid ‘Ōhi‘a DeathRyan L. Perroy0Marc Hughes1Lisa M. Keith2Eszter Collier3Timo Sullivan4Gabriel Low5Department of Geography & Environmental Science, University of Hawai‘i at Hilo, Hilo, HI 96720, USACollege of Tropical Agriculture and Human Resources, University of Hawai‘i at Manoa, Hilo, HI 96720, USADaniel K. Inouye U.S. Pacific Basin Agricultural Research Center, United States Department of Agriculture, Agricultural Research Service, Hilo, HI 96720, USASpatial Data Analysis & Visualization Laboratory, University of Hawai‘i at Hilo, Hilo, HI 96720, USASpatial Data Analysis & Visualization Laboratory, University of Hawai‘i at Hilo, Hilo, HI 96720, USAUniversity of Alaska at Fairbanks, Fairbanks, AK 99775, USAThe early detection of plant pathogens at the landscape scale holds great promise for better managing forest ecosystem threats. In Hawai‘i, two recently described fungal species are responsible for increasingly widespread mortality in ‘ōhi‘a <i>Metrosideros polymorpha</i>, a foundational tree species in Hawaiian native forests. In this study, we share work from repeat laboratory and field measurements to determine if visible near-infrared and optical remote sensing can detect pre-symptomatic trees infected with these pathogens. After generating a dense time series of laboratory spectral reflectance data and red green blue (RGB) images for inoculated ‘ōhi‘a seedlings, seedlings subjected to extreme drought, and control plants, we found few obvious spectral indicators that could be used for reliable pre-symptomatic detection in the inoculated seedlings, which quickly experienced complete and total wilting following stress onset. In the field, we found similar results when we collected repeat multispectral and RGB imagery over inoculated mature trees (sudden onset of symptoms with little advance warning). We found selected vegetation indices to be reliable indicators for detecting non-specific stress in ‘ōhi‘a trees, but never providing more than five days prior warning relative to visual detection in the laboratory trials. Finally, we generated a sequence of linear support vector machine classification models from the laboratory data at time steps ranging from pre-treatment to late-stage stress. Overall classification accuracies increased with stress stage maturity, but poor model performance prior to stress onset and the sudden onset of symptoms in infected trees suggest that early detection of rapid ‘ōhi‘a death over timescales helpful for land managers remains a challenge.https://www.mdpi.com/2072-4292/12/11/1846Hawai‘ivegetation indicesCeratocystis lukuohiaCeratocystis huliohia
spellingShingle Ryan L. Perroy
Marc Hughes
Lisa M. Keith
Eszter Collier
Timo Sullivan
Gabriel Low
Examining the Utility of Visible Near-Infrared and Optical Remote Sensing for the Early Detection of Rapid ‘Ōhi‘a Death
Remote Sensing
Hawai‘i
vegetation indices
Ceratocystis lukuohia
Ceratocystis huliohia
title Examining the Utility of Visible Near-Infrared and Optical Remote Sensing for the Early Detection of Rapid ‘Ōhi‘a Death
title_full Examining the Utility of Visible Near-Infrared and Optical Remote Sensing for the Early Detection of Rapid ‘Ōhi‘a Death
title_fullStr Examining the Utility of Visible Near-Infrared and Optical Remote Sensing for the Early Detection of Rapid ‘Ōhi‘a Death
title_full_unstemmed Examining the Utility of Visible Near-Infrared and Optical Remote Sensing for the Early Detection of Rapid ‘Ōhi‘a Death
title_short Examining the Utility of Visible Near-Infrared and Optical Remote Sensing for the Early Detection of Rapid ‘Ōhi‘a Death
title_sort examining the utility of visible near infrared and optical remote sensing for the early detection of rapid ohi a death
topic Hawai‘i
vegetation indices
Ceratocystis lukuohia
Ceratocystis huliohia
url https://www.mdpi.com/2072-4292/12/11/1846
work_keys_str_mv AT ryanlperroy examiningtheutilityofvisiblenearinfraredandopticalremotesensingfortheearlydetectionofrapidohiadeath
AT marchughes examiningtheutilityofvisiblenearinfraredandopticalremotesensingfortheearlydetectionofrapidohiadeath
AT lisamkeith examiningtheutilityofvisiblenearinfraredandopticalremotesensingfortheearlydetectionofrapidohiadeath
AT esztercollier examiningtheutilityofvisiblenearinfraredandopticalremotesensingfortheearlydetectionofrapidohiadeath
AT timosullivan examiningtheutilityofvisiblenearinfraredandopticalremotesensingfortheearlydetectionofrapidohiadeath
AT gabriellow examiningtheutilityofvisiblenearinfraredandopticalremotesensingfortheearlydetectionofrapidohiadeath