Goat-grazing for invasive plant control

two photographs side by side of white goats eating buckthorn stems in the woods
Goats munching on woody species

 

Background

Managing invasive plants is expensive and labor-intensive. The high cost of conventional tactics like mowing and herbicide application has led managers to look to less traditional methods of control such as use of browsing goats.

Goat management has surged in popularity, but proof that it works in the long-term is lacking. This project evaluated the lasting benefits of goat defoliation for buckthorn management and determined if feeding poses harm to the native plant ecosystem.

Another area of concern with goat management involves the deadly snail- or slug-borne parasite, Parastronguloides tenuis. Goats who eat an infected snail or slug while grazing can suffer a number of neurological symptoms ranging from paralysis to death. Some universities have recommended the use of grazing geese for snail and slug control, and this project tested that method for the first time on a goat grazing system.

Research questions

  • How effective is goat browsing for long-term invasive species control?
  • What are the effects, if any, of goat browsing on native plant diversity?
  • Does goose grazing lower risk of the P. tenuis parasite in goat herds?

Outcomes

Targeted grazing by goats has some benefits for the control of invasive R. cathartica and the enhancement of native plant communities. However, goats provide only temporary suppression of R. cathartica abundance and the invasive shrub rebounds after grazing ends. In some cases of the study, native plant diversity reached higher levels following grazing treatments.

Consumption by goats kills the seed of R. cathartica, and other invasive plants with larger seeds, indicating that goats are unlikely to exacerbate invasions by spreading them to new areas.

While P. tenuis transmission to goats remains a concern during invasive plant management, co-grazing goats with waterfowl may mitigate this seasonal disease risk. Waterfowl did not negatively affect overall gastropod abundance or diversity.

Publications

News and media

Research team

Tiffany Wolf | principal investigator

Daniel Larkin | co-principal investigator

Katie Marchetto | post-doctoral associate

Sara Nelson | field technician and Masters student

 

Collaborating organizations

Goat Dispatch

University of Tennessee