WPE02 Shrub stem data to quantify woody encroachment in Konza watersheds from 2020, 2022, and 2023

Woody plant encroachment (WPE) is one of the most widespread and acute threats affecting grasslands worldwide. Nature-based solutions to reversing WPE in mesic grasslands have proven largely ineffective, with decades of frequent prescribed fire failing to reverse WPE in some instances. One solution is to conduct more extreme fires compared to traditional prescribed fire. However, most tests of this idea have occurred at small scales, a mismatch with the need for landscape-scale land management. We considered two catchments, each with long-term destocking of grazers to increase fuel loads, one which accidentally burned under dry windy conditions that produced an extreme fire, while one burned under prescribed fire conditions. The extreme fire caused a sharp decline in woody cover without corresponding negative externalities such as decreases in grass cover or biodiversity. However, after three years, the woody community completely recoverd with a 23% increase in woody cover from the first to third year post-fire. The prescribed fire catchment saw minor decreases in woody plant dominance that rebounded quickly to pre-fire values. Our results suggest that reversing encroachment will likely require a long-term approach, along with applying a combination of pressures that reduce woody abundance and promote fuel loads to intensify fire.