Visualizing the Impact of Laminated Root Rot on Canopy Cover in a Second Growth Forest Over 43 Years

Abstract:

Laminated root rot is a root disease commonly found in coastal forests in the Pacific Northwest. The disease spreads through interconnected roots of conifer trees, causing decay of roots and eventual plant death. Sehome Hill Arboretum in Bellingham, WA is a second growth forest consisting of mixed coniferous and deciduous tree cover. Laminated root rot was first detailed in the Arboretum in 1990, indicating that coniferous trees in the Arboretum may have experienced dieback in recent years.

To evaluate how the canopy cover of Sehome Hill Arboretum has changed since indentification of the disease, a variety of maps displaying tree cover in the Arboretum were created in ArcGISPro using two methods, acquired remote sensing data and manually created visual delineation of spatial imaging. Infrared remote sensing data from 2006, 2013, and 2018 and spatial images from 1975, 2008, and 2013 were used, both depicting coniferous and non-coniferous canopy cover in the Arboretum. Differences in canopy cover were compared among the methods using total area of each canopy cover designation. 

Acquired remote sensing data produced results indicating that coniferous canopy cover in Sehome Hill Arboretum 4.95E6 square feet or 0.09% of total conifer canopy cover in 2018 compared to 2006. Results of the visual delineation method indicated that conifer canopy cover decreased by 5.9E5 square feet or 0.15% of total conifer canopy cover in 1975 compared to 2013. Maps created using the visual delineation method identified possible areas of concern for current and future conifer dieback.

Keywords: GIS, laminated root rot, geographic information systems, phellinus weirii, forest ecology, ArcGIS,

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