Precision mapping tracks woody plant spread across Great Plains grasslands

Summary

A small portion of the study area, zoomed in to show detail: (A) aerial imagery from NAIP RGB (red–green–blue; naked eye view); (B) visual of values in most important NAIP input for model training; (C) visual of values in most important NEON input for model training; (D–F) visuals of RF-classified models for all three images.Credit: Remote Sensing (2025). DOI: 10.3390/rs17132224 Hikers on the Konza Prairie may look up this summer and see something unusual in the air. K-State researchers are employing aerial data in their mission to understand and manage the rapid spread of woody plants across the Great Plains. Known as woody encroachment, the transformation of open grasslands into shrub and tree-dominated landscapes is impacting biodiversity, livestock forage, water resources and even wildfire risk. "Woody encroachment is a pattern that is happening in grasslands all around the world, where areas that used to be grasses, wildflowers and other herbaceous species are seeing a rapid and large increase in shrubs and trees," said Zak Ratajczak, assistant professor of biology at K-State. "That's not to say that all of these changes are negative, but in a lot of these grassy ecosystems, shrubs and trees move in and change things drastically." Remote sensing meets machine learning A machine-learning produced aerial of a prairie shows the canopy height of plants, blue representing low canopy, green showing taller plants and yellow showing the tallest. Published in the open-access journal Remote Sensing, a study led by K-State master's students Brynn Noble and Ratajczak offers a cost-effective, open-access approach to detecting woody encroachment across landscapes as small as six-by-six feet. The system combines aerial imagery from federal programs with ground-based data collected by K-State researchers. Zak Ratajczak and his lab get a closer look at one of the planes that collects the data used by their lab. Credit: Zak Ratajczak, Kansas State University "We're at the point ...