Pressures

Healthy grasslands are naturally open landscapes with few trees or other woody plants. While species like juniper, eastern redcedar, and mesquite occur naturally and provide cultural and environmental benefits, their tendency to spread was historically kept in check by fire.

While trees and shrubs can provide shelter for livestock and people, their encroachment into grasslands has led to significant loss in forage for cattle, with economic consequences for ranchers. The conversion of grasslands into woodlands and shrublands also contributes to habitat loss for wildlife. For example, many grassland birds avoid woody areas because they attract predators like snakes, ground squirrels, and perching raptors.

Historically, cultural burning and lightning-caused fires shaped grassland ecosystems, creating a mosaic of vegetation through varying frequencies and intensities. These fires, along with grazing patterns of animals like bison and elk, influenced nutrient cycling and plant growth, contributing to the dynamic nature of these landscapes. 

Fire suppression interrupts this natural cycle and allows trees, woody shrubs, and invasive species to outcompete native grasses and wildflowers. Without regular fire, soils lose nutrients, plant productivity declines, and the risk of high intensity wildfires increases as fuels accumulate.

Changes in historical fire and grazing patterns have contributed to the proliferation of non-native and invasive plant species like cheatgrass and smooth brome and the loss of native grasses and other plants. Many of these species outcompete desirable forage species, are often of lower nutritional value for grazing animals, and increase fire risk.

Grasslands need grazers to thrive; sustainable management is essential to maintain healthy habitat and rangelands. The number of domestic livestock and the  timing, intensity, and duration of their grazing can negatively impact plant health and create opportunities for less desirable plant species to take hold. These imbalances can lead to increased costs for producers and contribute to issues like soil erosion and higher amounts of sediment in nearby waterways, decreasing water quality.