Using Aerial Images and ImageJ to Map Brazilian Pepper (Schinus terebinthifolia) in Florida.
County Extension Director
Situation: Brazilian Pepper (Schinus terebinthifolia) is classified as a noxious weed in Florida. It occurs primarily in Central and South Florida. We are currently working on a separate biocontrol project for Brazilian pepper control in Hernando County, Florida. To determine the success of the biocontrol project, we created maps of the biocontrol release site prior to release. Method: We created a map of Brazilian Pepper using drone images that are stitched together (orthomosaics) and ImageJ. ImageJ is a software developed for the National Institute of Health to count cells in images from microscopy. The aerial images were RGB (red, green, blue) and captured using a DJI Phantom 4 drone at an altitude of 121 m. The color threshold used in ImageJ to distinguish the Brazilian Pepper from all other plants was a hue of 66-80, saturation of 91-147, and brightness of 0-141 and a color space of HSB. This flight and image analysis was conducted in August 2022. Results: Using this process, we produced a map that shows the Brazilian Pepper in red. Twenty-five trees were chosen at random to ground truth and compared to the predictive map. The accessible portion of this site is approximately 16 hectares. Of the 25 predicted Brazilian pepper trees, all 25 were examined from the ground and found to be indeed Brazilian pepper (100%). Conclusion: This is the byproduct of another project, but one that may be very helpful to land managers to control invasive plants in the future. This could be adapted to other large plants such as trees and shrubs depending on the color threshold that is selected. Flying at 121 m would not be ideal for identifying small plants. For emerging stands a much lower altitude would be needed.
Poster has NOT been presented at any previous NACAA AM/PIC
This poster is being submitted for judging. It will be displayed at the AM/PIC if not selected as a State winner. The abstract will be published in the proceedings.
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Authors: Joseph Strickland, Brittany Scharf, Carey Minteer
Strickland, J. County Extension Director/Agriculture Agent IV, UF/IFAS Extension, Florida, 34744
Scharf, B. Marine Sciences Agent III, UF/IFAS Extension, Florida, 34604
Minteer, C. Assistant Professor, Indian River Research and Education Center, Florida, 34945