Practices combining fire and grazing in the Central U.S. reduce woody encroachment and accommodate grassland and shrubland birds

woody encroachment, ecotone, shrubland birds, grassland birds, fire, grazing, fire-grazing interaction, patch-burn grazing

Capozzelli, Jane F. ; Spyreas, Greg, ; ,Benson, Thomas ; Miller ; James R.

关键词: woody encroachment, ecotone, shrubland birds, grassland birds, fire, grazing, fire-grazing interaction, patch-burn grazing;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/104868/CAPOZZELLI-THESIS-2019.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Temperate grasslands and shrublands are critically endangered ecosystems receiving almost no protection, as nearly 50% of their global area has been lost and less than 5% has been set aside in reserves. To further complicate matters, in many instances these are alternate states of the same system, so conserving one may be at the expense of the other. Woody encroachment is one of the greatest contemporary threats to grasslands, but reversing encroachment necessarily reduces shrublands. A parallel conundrum arises with avian biodiversity, as both grassland and shrubland birds are in steep decline. Yet conservation strategies usually prioritize improving habitat for grassland birds, and rarely consider shrubland birds. Is it possible to employ management practices that benefit both guilds? To address this challenge, I compared three regimes involving fire and grazing in terms of their impacts on woody encroachment in grasslands in the Central U.S., and the extent to which these practices support grassland and shrubland birds in ecotones. Fire in combination with grazing controlled woody encroachment more than fire alone, and low amounts of woody cover in ecotones increased the abundance or occupancy of grassland and shrubland avian species. Overall, the ability of fire-and-grazing regimes to reduce woody encroachment and accommodate birds in both guilds suggests that managing for grasslands and shrublands need not be mutually exclusive in all instances.