Authors: Austin Boardman*, Oklahoma State University, Todd D. Fagin, Oklahoma Biological Survey, University of Oklahoma, Jacqueline M. Vadjunec, Oklahoma State University
Topics: Land Use and Land Cover Change, Remote Sensing, Coupled Human and Natural Systems
Keywords: UAS, participatory research, remote sensing, land systems science, LULCC, invasive species, woody plant encroachment
Session Type: Paper
Start / End Time: 4:30 PM / 6:10 PM
Room: Marshall North, Marriott, Mezzanine Level
Presentation File: No File Uploaded
The prevalence of invasive and nuisance woody plants (e.g. one-seed juniper, cholla cactus, saltcedar etc.) on the rangelands of the Southern Great Plains has increased dramatically in recent decades. The change in vegetation poses a challenge to ranchers by reducing available forage for cattle, sequestering precipitation, and increasing fire severity. By the same token, ranchers are uniquely positioned to reduce woody plant encroachment (WPE) through modifying grazing intensity, manually removing invasive species, applying herbicides, or implementing controlled burning. We partnered with 30 landowners in Oklahoma and New Mexico to capture UAS imagery on their property. Using a participatory approach, landowners selected plots representing perceived "intact" and "encroached" areas that they were interested in monitoring. In summer 2018, we captured imagery and participant details including land management history (e.g. stocking rates and invasive plant removal/management) and environmental perceptions. We used structure-from-motion algorithms in Pix4D to construct orthophotos and digital surface models from each set of images and shared these data with participants using an online portal. We classified vegetation cover, often to species level for woody plants, using object-based image analysis in the Orfeo toolbox in QGIS. We then used logistic regression to examine the effects of terrain variation and different land management practices and perceptions on WPE severity. The results of our analysis demonstrate the utility of UAS as an effective LULCC tool in participatory research. Imagery collected through our project stands to help ranchers better understand the extent of WPE on their property and implement management strategies.