The Problem
Whats the big deal about Leafy Spurge?
Leafy spurge (Euphorbia esula) is an invasive exotic weed that infests more than five million acres of land in 35 states and the prairie provinces of Canada. It causes significant problems by invading grazing lands for cattle and horses, reducing rangeland productivity and plant diversity, degrading wildlife habitat, displacing sensitive species and drastically reducing land values.
A native of Eurasia, where it is controlled by natural enemies, leafy spurge readily adapts to a variety of situations. It infests, and if not aggressively managed, can dominate landscapes ranging from open prairie and hillsides to riparian areas and lowlands. The deep-rooted and prolific perennial has doubled in acreage every 10 years since the early 1900s, and is expanding beyond its foothold in the western United States.
With a head start of more than 100 years before control efforts were initiated, (see Spurge Timeline) leafy spurge is a tenacious opponent that cannot be eliminated or managed by any single entity or control tool. A collaborative, integrated, area-wide approach is essential to solving this costly weed problem.
Yellowstone National Park, the world’s first national park, is a national and worldwide treasure susceptible to extensive damage caused by leafy spurge. This invasive species currently infests the Park and all counties surrounding it. Numerous species of rare and sometimes endangered plants and animals are in danger of being impacted further by continued reintroductions of leafy spurge from infestations located outside the Park. Collaboration between all land managers and concerned citizens groups in and around the Park, as proposed in this project, will centralize infestation data and future treatment efforts, bringing much needed consolidation to the large task of preventing and treating a serious weed on a wide landscape scale across multiple borders.
The Costs
The economic impact of leafy spurge is staggering.
Infestations in the Dakotas, Montana and Wyoming alone are
estimated to cost agricultural producers and taxpayers $144
million a year in production losses, control expenses and other
impacts to the economy. Every AUM (Animal Unit Month: the amount
of grazing required to sustain a cow/calf pair, or six sheep,
for one month) lost to leafy spurge infestations costs $167 in
lost economic activity. Leafy spurge has literally forced some
ranchers out of business.
Its impact, however, cannot be measured in dollars alone. Leafy
spurge crowds out native vegetation, resulting in a monoculture
that reduces biodiversity and threatens both abundant and
sensitive species. The invasion of exotic weed species in
national parks, wildlife refuges and other lands set aside for
wildlife and recreation has, in fact, reached epidemic
proportions. In addition, the most commonly used control tool –
herbicides – often have adverse environmental consequences.
In short, leafy spurge is an economic and environmental
catastrophe for ranchers, land managers and taxpayers in the
U.S. and Canada.