While grasslands are among the most heavily converted ecosystems and have the least protection, woody plant encroachment is the biggest ongoing threat within the PLJV region. Woody plants, such as honey mesquite and eastern redcedar, continue to invade large intact grasslands — fragmenting habitat and worsening grassland bird declines.
The amount of woody plant cover at which grassland birds begin to decline can be astonishingly low, often at less than 1% cover.
Woody plants — like juniper and mesquite species — have always been a feature of grasslands and woodland savannas in the plains, but they were kept in check naturally by frequent fires. Without the regular use of fire, areas that were once prairies are quickly becoming shrublands, and even woodlands, which changes the quality of habitat for grassland dependent birds.
Each bird species has very specific habitat preferences. For example, Cassin’s Sparrows, the most frequently detected breeding sparrow in the PLJV region, favor areas with a small amount of native shrub cover, whereas Horned Larks would rather have open ground and short grasses. The encroaching woody plants also provide more perches and, therefore, more opportunities for raptors and other birds of prey to hunt smaller grassland species.
The amount of woody plant cover at which grassland birds begin to decline can be astonishingly low, often at less than 1% cover. Fortunately, grassland birds are resilient and benefit from grassland management. Farm Bill conservation programs, such as the Conservation Reserve Program (CRP), provide large contributions to grassland conservation every year. Removing invasive woody plants and other efforts to control encroachment are also important grassland management strategies.
Tackling a problem as substantial as woody plant encroachment across the central and southern grasslands of the Great Plains involves close collaboration among many partners. PLJV is currently working with a number of large partnerships that are addressing this issue including JV8 Central Grasslands Conservation Initiative, NRCS Great Plains Grasslands Initiative, Working Lands for Wildlife Great Plains Woodland Expansion Framework, National Fish and Wildlife Foundation Southern Plains Grassland Program, and the Central Grasslands Roadmap.