|Hunt Jr, Earle|
Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: 4/5/2013
Publication Date: 4/18/2013
Citation: Hawley, J.M., Hunt Jr, E.R. 2013. Utilizing hyperspectral and hyperspatial remote sensing to track invasive species in BARC wetland ecosystems [abstract]. 2013 BARC Poster Day, April 18, 2013. Abstract Booklet. p. 23.
Technical Abstract: Wetland vegetation is a critical component to the function of and ecological services provided by wetland ecosystems. Two non-native invasive species threaten wetland ecosystems in the Mid Atlantic region, Phragmites australis (giant reed) and Lythrum salicaria (purple loosestrife). Hyperspectral remote sensing uses contiguous narrow bands in the visible, near-infrared, and shortwave-infrared spectral regions to obtain a reflectance spectrum, which is analyzed to distinguish invasive species from native plant species. Hyperspatial remote sensing uses only a few bands in the visible and near-infrared spectral regions, but with very fine pixel resolution so there are few mixed pixels. At the Beltsville Agricultural Research Center, I compared reflectance spectra of P. australis and L. salicaria with two vital native species of cattails, Typha angustifolia and T. latifolia. Spectral angles (the angle between 2 vectors) were calculated for leaf reflectance data, and Typha spp. were separable from both P. australis and L. salicaria (> 0.1 radians). The spectral differences were largest in the shortwave infrared, and consistent with Typha leaves having higher leaf water contents. Nadir-viewing canopy digital color-infrared photographs were acquired, and the spectral angles between Typha spp. and the invasive species were not separable (< 0.05 radians for P. anstralis and < 0.09 radians for L. salicaria). I conclude that hyperspectral remote sensing has better promise for mapping wetland native and invasive species.