Reevaluating the role of woody plants in rangelands: Implications for soil carbon and hydrological dynamics in rangelands.

Agriculture producers and land managers often view woody plants in rangelands negatively, resulting in their removal, due to negative impacts that invasive woody plants cause. However, woody plants can positively influence many ecosystem services. Most studies examining the impact of woody plants have focused on species such as mesquite (Prosopis spp) and juniper (Juniperus spp), with little attention to other species. We examined the effect of eight woody plant species on soil organic carbon, total nitrogen, field capacity, and water infiltration to understand the impact of different woody plants on rangeland ecosystem functions. We sampled under each species of woody plant and open grass areas across three different rangelands in North America during 2024. We analyzed our data using linear/generalized linear models and model selection. We determined that, except for average field capacity, the presence of a woody plant in rangelands significantly increases soil organic carbon, total nitrogen, and water infiltration. After accounting for variation in soil texture, water infiltration was approximately seven times higher under woody plants than grass. The effects of soil organic carbon, total nitrogen and water infiltration were variable among species. Our data show that woody plants play an important role in carbon storage and hydrologic functioning in rangelands. Management decisions should acknowledge the ecological benefits provided by woody species and consider the potential consequences of their removal. The implementation of removal of some species may be warranted in some situations, but our data does not support the elimination of all woody plants in rangelands.