George says, "Weeds taste yummy."

Nature's Weed Eaters

Lambs grazing weeds and grass	Wooly Weed Wackers Sheep (and goats) have long been used for weed control. Their use has increased in recent years because of the need for biological control agents in environmentally sensitive areas. Sheep mostly graze forbs (flowering plants) while goats prefer shrubs.
Controlling Noxious Weeds Sheep (and goats) are currently being used throughout the Great Plains and Intermountain regions to control noxious and invasive weeds. Many of these weeds could not be controlled by means of chemical, mechanical or cultural practices due to the high cost associated with these control methods or their relative ineffectiveness. One such weed is leafy spurge (Euphorbia esula), a Eurasian weed which has consumed millions of acres and is so competitive that it quickly crowds out all other plants to form a monoculture.	Leafy Spurge Euphorbia esula Photo Source: ARS Image Gallery
Weeds, Weeds, and More Weeds Another weed, which has impacted many areas throughout the West, is Spotted Knapweed (Centaureamaculosa). This weed invades native ranges and threatens even pristine areas such as our national parks. Sheep readily graze knapweed and are being looked at as another tool to fight this aggressive invader. Sheep will readily consume kudzu (Pueraria montana), a vine that completely replaces all vegetation where it grows in the Southeast. Larkspur (Delphinium sp.) is a weed that is poisonous to cattle. Because sheep can tolerate up to 3 to 4 times more larkspur than cattle, they can be used to help control the weed in cattle pastures.	Sheep grazing larkspur Photo Source: ARS Image Gallery
Sheep grazing can help to prevent wildfires. Photo Source: ARS Image Gallery	Reducing the Threat of Wildfires Sheep (and goats) are being used in many places to reduce the threat of wildfire in areas where wildlands interface with urban communities. This method of reducing wildfire is called creating a “fuelbreak.” The goal is to reduce the amount of fuel, reduce vegetation height, and create an effective firebreak.
Improving Rangeland Numerous studies have shown how sheep (and goats), used under prescribed conditions, can help increase the plant biodiversity on western ranges. Since sheep prefer to graze and bed on upland areas away from wet lowlands, they are easier to manage in grazing areas where critical riparian and watershed issues are a concern. When sheep are grazed in the same areas for several years, the level of perennial grasses within the plant community tends to increase which has been shown to increase water infiltration and decrease erosion.	Range Flock in Idaho Photo Source: ARS Image Gallery
Pronghorn Antelope Photo Source: ARS Image Gallery	Improving Wildlife Habitat Prescribed sheep grazing has been shown to enhance wildlife habitat in a variety of ways. By allowing sheep to graze different areas at specific times of the year, the quality and quantity of certain critical vegetation types can be enhanced.
Enhancing Tree Plantations Sheep producers in Canada are now being paid up to $35 per sheep to graze newly planted tree plantations. This method of prescribed grazing increases the viability of the new tree seedlings by reducing the competition of grasses, forbs and weedy species for water, soil nutrients and sunlight. Similarly, power companies are “hiring” sheep (and goat) herds to keep areas under power lines in forested areas grazed, thus reducing the chance that an errant spark from the lines might start a wildfire and destroy the power line and surrounding forest.	Sheep grazing under powerlines Photo Link: Grazing Power Project Public Service of New Hampshire
Many of the hefted sheep are rare breeds, like this Swaledale. Photo by Hilary Wilson Courtesy of Explore Cumbria	"Hefted" Sheep The extensive grazing of hefted sheep on the commonland of Britain is a unique phenomenon in Europe, enabling livestock to be kept in unfenced areas without constant shepherding. Each hefted flock has its own territory and is self-confining to that area, a heft. Extended areas are divided into numerous hefts, with each flock knowing its own area and returning to it after lambing, veterinary treatment or other husbandry requirements. Hefted sheep are integral to maintaining the unique and "wild" or semi-natural environment of which they form part. Unfortunately, the numbers of hefted sheep were reduced drastically by the British government during the 2001 foot-and-mouth disease outbreak

. . New Words . . Prescribed Grazing - the controlled harvest of vegetation with grazing animals, managed with the intent to achieve a specific objective. Fuel break - a wide strip or block of land on which the native vegetation has been permanently modified so that fires burning into it can be more readily extinguished. Forbs - perennial herbs with broader leaves than grasses. Hefted - a hefted flock is one which by instinct remains on the same area. Shrubs - woody plants less than 7 meters in height. Usually have multiple trunks or stems. Weed - any plant growing out of place. A plant that crowds out cultivated plants or other desired species. Noxious weeds - undesirable plants that infest either land or water resources and cause physical and economic damage. Perennial - a plant that lives from year to year and typically involves many reproductive cycles. By definition, for three seasons or more. Monoculture - a large group of a single species of a plant. Biodiversity - The variety of life in all its forms, levels and combinations. Includes ecosystem diversity, species diversity, and genetic diversity. Riparian - pertaining to the banks of a river or other body of fresh water.
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