2016-2026 Annual Net Primary Production (ANPP) mapping of Badlands National Park

Annual Aboveground Net Primary Production (ANPP) is the net aboveground primary production in a given area in a calendar year. As such, it is a key metric of ecosystem health, carbon cycling, and the amount of energy available to herbivores. We model ANPP for Badlands National Park and surrounding region by combining field-measured herbaceous biomass data, Harmonized Landsat Sentinel (HLS) derived time-integrated NDVI (Normalized Difference Vegetation Index), and weather data with Random Forest (RF) models. Our model was trained on data from 2016-2018 and applied to weeks 10-45 (March-November) of 2016-2026. Maps of weeks 10-44 represent accumulated ANPP to date, and week 45 represents annual ANPP. Model accuracy using repeated 5-fold cross-validation yielded an R^2 of 0.67 and RMSE of 66.92 g/m^2. We post-processed our raw predictions by prohibiting week-over-week decreases in ANPP per pixel. Results show the accumulation of production over the course of the season, with the final weekly map (i.e. week 45) representing annual ANPP, not standing biomass. Weekly resolution NPP accumulation supports within-season assessment of forage availability to inform landscape management decisions such as prescribed burning, water source improvements, and herbivore population culling.