Estimation of Tree Vitality Reduced by Pine Needle Disease Using Multispectral Drone Images

Sammanfattning

Multispectral imagery from unmanned aerial vehicles (UAVs) can provide high-resolution data to map tree mortality caused by pests or diseases. Although many studies have investigated UAV-imagery-based methods to detect trees under acute stress followed by tree mortality, few have tested the feasibility and accuracy of detecting trees under chronic stress. This study aims to develop methods and test how well UAV-based multispectral imagery can detect pine needle disease long before tree mortality. Multispectral images were acquired four times through the growing season in an area with pine trees infected by needle pathogens. Vegetation indices (VIs) were used to quantify the decline in vitality, which was verified by tree needle retention (%) estimated from the ground. Results showed that several VIs had strong correlations with the needle retention level and were used to identify severely defoliated trees (<75% needle retention) with 0.71 overall classification accuracy, while the accuracy of detecting slightly defoliated trees (>75% needle retention) was very low. The results from one study area also implied more defoliation observed from the UAV (top view) than from the ground (bottom view). We conclude that using UAV-based multispectral imagery can efficiently identify severely defoliated trees caused by needle-cast pathogens, thus assisting forest health monitoring.

Nyckelord

unmanned aerial vehicle (UAV); multispectral imagery; pine needle disease; Lophodermium; forest monitoring; surveillance

Publicerad i

Remote Sensing
2025, volym: 17, nummer: 2, artikelnummer: 271

SLU författare

• Huo, Langning

  • Institutionen för skoglig resurshushållning, Sveriges lantbruksuniversitet
    

• Matsiakh, Iryna

  • Institutionen för sydsvensk skogsvetenskap, Sveriges lantbruksuniversitet
    
  • Ukrainian National Forestry University

• Bohlin, Jonas

  • Institutionen för skoglig resurshushållning, Sveriges lantbruksuniversitet
    

• Cleary, Michelle

  • Institutionen för sydsvensk skogsvetenskap, Sveriges lantbruksuniversitet
    

Associerade SLU-program

SLU Skogsskadecentrum

UKÄ forskningsämne

Geoteknik
Jordbruksvetenskap

Publikationens identifierare

• DOI: https://doi.org/10.3390/rs17020271

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/140091