Livestock’s Role in Spreading Weeds and Pinion-Juniper

Mike Hudak interviews Retired USDA researcher Steve Monsen about livestock grazing’s impact to weed and Pinion-Juniper spread in the western United States:

Retired USDA researcher Steve Monsen explains how overgrazing by cattle and sheep throughout the Great Basin, beginning in the mid-19th century and continuing to the present day, has initiated a cascade of environmental changes that have disrupted vegetational communities and extremified their fire regimes, resulting in the replacement of native vegetation with weeds that are noxious, toxic, or nutritionally deficient for wildlife as well as livestock.



  1. Kevin Jamison Avatar
    Kevin Jamison

    Poor guy. It must have been very frustrating to see all this going on. Historic, current and ongoing rape and exploitation of the public lands for the benefit of a very few and not to be able politically to do anything about it. I’m sorry his education and professional life was for naught. Powerful interests tend to chrush the spirit of those who tell the truth, especially when the public does not want to hear that the Marlboro Man is a fraud.

  2. Larry Thorngren Avatar

    I drove along the Payette river here in Idaho from Banks to the Stanley Basin last week and the Skeleton Weed was so thick above Garden Valley that it was crowding out the Cheat Grass. If this weed is not checked, there won’t be any elk winter range left along that stretch of the Payette River. I am sure that it already causing a decrease in elk numbers.

  3. Woody Avatar

    In 1999 I went on my first trip to SE Arizona primarily for birding. I was amazed at the abundance of native vegatation on Fort Hauchuca and the lack of nearly all grasses and forbes once crossing the cattle guards leaving the area into that grazed by livestock for 100+ years.

    In 1991 +/- while returning from the High Desert Conference at Malhuer Field Station, Oregon and listening to George Wuerthner I was sorry I didn’t have a camera, there was a cow stretching her neck out under the fence of her allotment trying to snag a whisp of grass with her tongue; nothing was left inside worthy of cattle fodder.

    Recently I came across a note to myself in my book the “Manual of Higher Plants in Oregon” by Morgan Peck, 1941:

    “The changes in the vegetation brought about directly or indirectly through human agencey are immense. These comprise first, the introduction of foreign species; second, deforestation by lumbering operations and forest fires; and third, excessive pasturing of domestic animals. Throughout most of the cultivated sections of the state the native species have been very largely displaced by foreigners. The species of the latter are very numerous and many are excessively abundant. Even where there is relatively very little agriculture, these invaders are often dominent; thus the most abundant plant of the whole Eastern Oregon Area is Bromus tectorum, an Old-World weedy grass.

    Over pasturing by cattle and more particularly be sheep has greatly changed the aspect of the vegetation over large areas. Short-sighted and unwise management of the grazing lands of the National Forests, extending these even over the “Primitive Areas,” has had and is still having a disastrous affect upon the native vegatation.

    Unfortunately most of the private lumbering operations have been of a sort to quite annihilate the forests and render nateral reforestation a very slow and uncertain process, while forest fires have been equally destructive. It is to be hoped that wherever possible means may be found to preserve many of the rarer plant species of the state before these agencies have completed their extermination.”

    And that was written 70 years ago!