Developing a Baseline for Monitoring Plant Health of a Prescribed Burn in a Small Nature Preserve

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Prescribed burns are used to control noxious and invasive weeds, clear out old undergrowth, and to return nutrients to the soil. In the literature (Sever et al., 2012; João et al., 2018; Van Leeuwen, 2008), there is extensive research on using satellite imagery from the Landsat and MODIS satellites to quantify plant health after large-scale burns. This is often from wildfires instead of prescribed burns, as wildfires tend to be significantly larger in scale (e.g., 100km2) and are detectable on satellite imagery. Due to the small, controllable spatial scale of prescribed burns (~ 0.5 km2), there is little research reviewing plant health recovery after a prescribed burn, which has vital implications for land managers and conservation experts who often utilize them in areas, such as Metroparks. The early stages of a baseline map collected prior to a prescribed burn of a local nature preserve (The Land Lab in Granville, Ohio) are displayed. These preliminary results can be used to represent the ‘natural’ state of the habitat pre-burn and will be compared to results collected post-burn to quantify plant recovery over time. I used an Unmanned Aerial Vehicle (UAV) equipped with a 3-band camera capable of ‘seeing’ in the Near Infrared, visible Green, and visible Blue to create a high-quality orthomosaic image (i.e., a corrected flat surface map). The three bands utilized by the UAV are used to generate a vegetation index, the Green Normalized Difference Vegetation Index (GNDVI), allowing estimation of plant health with significantly higher resolution than satellite imagery -- pixel size of 1 inch (UAV) as compared to pixel size of 45 feet in Landsat’s highest-resolution bands. The final result will be a baseline GNDVI map for the study area over the late spring and summer months pre-burn that can be utilized to compare plant recovery and health after next year’s burn.