Invasive species are increasingly taking over our natural landscapes. These invasive plants can disrupt the delicate balance of the existing ecosystem by outcompeting our native bunch type grasses for space and resources and choking out existing vegetation on our grasslands. Over the years, Sericea Lespedeza, encroached into open grassy habitat, fences, drainage draws, and lake/river shorelines on U.S. Army Corps of Engineers lands. These invasive species have been removed in the past, with limited success.
Sericea Lespedeza is a very aggressive, drought hardy, perennial plant. Originally native to Asia, it was introduced as a forage crop in the United States in the 1930’s and has completely overtaken native habitat since. The best way to control this invasive plant is to prevent the seed production and try to control it before it flowers and disburses the seeds.
While much research has been done documenting invasive species, not much research has been completed on effective control methods. Control methods for invasive plant species range extensively and can include: chemical control by use of herbicides, mechanical control through prescribed burning or mowing of affected areas, or biological controls by the introduction of a species that preys upon the invasive species in some way. This is where are four legged friends with a great appetite come in to play.
USACE Tulsa District, is trying something different to reduce the use of chemical applications at the project level. The invasive plant species management practice, using goats as a biological control, is on the move at Fall River Lake and John Redmond Reservoir in Kansas. “The current landscape at these areas will allow for the existing Sericea Lespedeza and grasslands to be maintained by goats with minimal landscape damage and no chemicals being applied” says Christopher Wright, contract specialist for the Tulsa District.
A contract was awarded to have the goats browse a designated area to assist in the invasive species removal. The majority of the Sericea Lespedeza was maintained up to a level the goats would normally browse. The current grass is being browsed to a height of approximately half the present height including the flower of the plants prior to going to seed heads. Grass height is being closely observed by the goat manager to ensure consistent management of the browsing area.
“The contract was awarded to utilize goats to assist with invasive species management to reduce the use of chemical application methods.” Says Eugene Goff, Operations Project Manager for the Kansas area.
So why goats? Goats possess a unique characteristic that separates them from almost all other types of livestock. They would rather eat brush and weeds than grass because they are browsers. They can also control the invasive weeds without disturbing the soil. Using goats to control invasive plant species is preferable to other biological control methods, such as insect releases, since the movement and spread of captive livestock can be more easily controlled and does not present the risk of a secondary invasion, and let’s face it, who wouldn’t mind watching these cute guys working.
Getting to see the progress that has been made in just three weeks is highly impressive. You can look at the fenced in area and see where the goats have already been through, it looks like it was just mowed down compared to sections where they have not browsed yet.
Currently there are goats browsing at both Fall River and John Redmond projects. The current timeline is to have goats working for 30 calendar days within designated areas for weed reduction. The results will be evaluated once the contract period is completed. “The way forward will be looked at for future contract options, to have a base bid with option years to use goats for expanded/enhanced invasive species management practice within the Kansas Area of the Tulsa District.” Says Eugene Goff.