Early Detection of Oak Wilt Early Detection of Oak Wilt Disease in - PowerPoint PPT Presentation

Early Detection of Oak Wilt Early Detection of Oak Wilt Disease in Quercus Quercus ssp ssp. . Disease in A Hyperspectral Hyperspectral Approach Approach A Blake Weissling

Research Objectives Research Objectives � To develop and conduct an environmental To develop and conduct an environmental � investigation of the pathogenesis of oak investigation of the pathogenesis of oak wilt disease in the woodlands of central wilt disease in the woodlands of central Texas using field- - spectrometry, a spectrometry, a Texas using field controlled greenhouse experiment, and controlled greenhouse experiment, and analysis of hyperspectral hyperspectral imagery. imagery. analysis of � To build a species discriminatory spectral To build a species discriminatory spectral � library of the common tree species of the library of the common tree species of the Texas Hill Country taking into account Texas Hill Country taking into account species phenology phenology. . species

What is Oak Wilt disease? What is Oak Wilt disease? � A vascular disease commonly afflicting A vascular disease commonly afflicting � oak species oak species � Disease agent is the fungus Disease agent is the fungus � Ceratocystis fagacearum fagacearum Ceratocystis � Oak wilt ranges from central Texas to Oak wilt ranges from central Texas to � the upper midwest midwest the upper � First described in the 1930’s First described in the 1930’s � � Has killed millions of trees Has killed millions of trees � � Texas has been hit particularly hard Texas has been hit particularly hard �

National distribution of oak wilt National distribution of oak wilt

Texas occurrence Texas occurrence of oak wilt of oak wilt Disease centers in the Kerrville area

An oak wilt photo gallery An oak wilt photo gallery

Commonly affected species in Commonly affected species in Texas Texas � Quercus Quercus fusiformis fusiformis (Plateau live oak) (Plateau live oak) � � Quercus Quercus virginiana virginiana (Coastal live oak) (Coastal live oak) � � Quercus Quercus texana texana (Spanish red oak) (Spanish red oak) � � Quercus Quercus stellata stellata (Post oak) (Post oak) � � Quercus Quercus marilandica marilandica (Blackjack oak) (Blackjack oak) �

The Challenge The Challenge � To spectrally discriminate a disease To spectrally discriminate a disease- - � induced stress signal from a induced stress signal from a multitude of other stress signals as multitude of other stress signals as well as inherent spectral variability well as inherent spectral variability within and across species and within and across species and variability across time variability across time

Research Considerations and Research Considerations and Experimental Design Experimental Design Data Collection Field spectrometry Greenhouse study Hyperspectral imagery Baseline spectra Controlled inoculation Airborne and satellite leaf Observe spectral change Species ID branch Stress ID canopy

Preliminary Research Preliminary Research � Collection and analysis of leaf Collection and analysis of leaf � spectra for: spectra for: • Variance within species Variance within species • • Variance across species Variance across species • • Variance with time ( Variance with time ( phenology phenology) ) • • Effects of water loss (stress) Effects of water loss (stress) • • Effects of additive reflectance Effects of additive reflectance • • Continuum removal analysis Continuum removal analysis • • Effects of on Effects of on- - branch analysis vs. in branch analysis vs. in- - lab lab • analysis analysis

Collected radiance data Collected radiance data Solar radiance spectra at base of atmosphere H 2 O absorption Oak canopy radiance spectra

Reflectance spectra Reflectance spectra visible near infrared middle infrared chlorophyll absorption leaf H 2 O absorption the red edge

Variation within species Variation within species

Variation across species Variation across species

Phenologic influences influences Phenologic

Response of leaf reflectance to decreased water Response of leaf reflectance to decreased water content for the adaxial adaxial surface of surface of Magnolia Magnolia content for the grandiflora grandiflora

Effects of water loss Effects of water loss

Effects of water loss cont. Effects of water loss cont.

Additive reflectance phenomena Additive reflectance phenomena

Effects of additive reflectance Effects of additive reflectance

Chlorophyll absorption trough Chlorophyll absorption trough continuum removal continuum removal Width (FWHM) Area Depth

Continuum- -removed comparison removed comparison Continuum

Future work Future work � Start controlled inoculation experiment Start controlled inoculation experiment � with 20 live oak saplings with 20 live oak saplings • Analysis of spectral leaf reflectance Analysis of spectral leaf reflectance • • Detection of an infection stress signal Detection of an infection stress signal • • Crossed design with Crossed design with inoculant inoculant and water and water • regimen treatments regimen treatments � Acquire Acquire hyperspectral hyperspectral (Hyperion) data in (Hyperion) data in � June June � Begin spectral field sampling of an oak wilt Begin spectral field sampling of an oak wilt � disease center (summer) disease center (summer)

Questions? Questions?