Western Watersheds Project

Livestock, Degraded Ecosystems and Biodiversity

Key to Notes on PowerPoint Slide Presentation

Slide Number



Photo of 150+ year-old cottonwoods in San Rafael Swell, Utah.  Shows complete loss of riparian system that existed when these trees established prior to livestock grazing.



West, N.E. 1992. Biodiversity of Rangelands.  J. Range Mgt 46:2-13

Here we see that biodiversity has several components.  The species-specific maintenance of genetic diversity that allows for adaptation to environmental change, which requires adequate numbers to avoid extinction.  Species diversity is generally considered the numbers of species in an area, but must include consideration of population numbers in order to sustain a population.   For example, if insufficient numbers to provide genetic diversity or reproduce, then extinction could occur.  Community or ecosystem diversity includes the range of structural components in a habitat or ecosystem that allows species to flourish as well as their arrangement that provides the necessary habitat features for survival and growth.  Landscape diversity considers the variety of ecosystems, habitats and their structural features that occur across the land along with the ability of population migration to occur, i.e. connectedness (lack of fragmentation).  It also considers the resilience of the ecosystem to withstand disturbance.



Sagebrush, aspen and riparian habitats were chosen for illustrating the concepts of diversity and the impacts of livestock because of the reasons given.  They are keystone habitats in the arid west.  While riparian areas only occupy a small portion of the land, they are important to nearly all species of wildlife for water and to numerous species for food and shelter.  Similarly, aspen habitats are extremely productive and important to high numbers of species.  Sagebrush habitats are widespread across the west.  All these habitats have suffered extreme degradation by livestock, water developments, dams and diversions.



This and the next two slides provide visual comparisons of sagebrush, aspen and riparian area with and without livestock grazing.   The noticeable difference in this slide of sagebrush in northern Utah and SE Idaho is the lack of any herbaceous vegetation (grass and flowering plants, or forbs) in the grazed sagebrush habitat compared to the ungrazed.  This loss of productivity means little food for many species of wildlife that should occur here.  It also means a loss of a major structural component that provides habitat.



Here we see the same loss of herbaceous vegetation and understory structure in grazed aspen.  In addition, there is no effective regeneration because livestock eat all the small aspen that try to grow each year.  Thus, no recruitment and eventual loss of the stand.  The opposite is true of the ungrazed aspen.  Aspen clones have been aged to over 12,000 years with some suspecting much longer lifespans.



The differences here are numerous.  The grazed riparian zone lacks any vegetation to stabilize the stream banks against erosion and provide cover for fish.  It also lack streamside shrubs and trees to provide litter, woody debris and shade as well as habitat for birds and mammals.  Finally, the sediment from eroding streambanks and the grazed watershed choke the stream bottom with silt, destroying habitat for invertebrates and spawning fish.  Cutthroat trout used to occupy the grazed stream, now they are gone.  The ungrazed stream still contains cutthroat trout.



These are terms that are important in understanding how livestock alter habitat.  Essentially, a niche is that arrangement of habitat structure and nutrients that allow a particular species to survive.  Structure is the house in which organisms live and is species-dependent as to its necessary components (niche).



These relate to the previous photos and are self-explanatory.  With livestock, these are some of the components that are either reduced or completely lost.  They constitute essential components of habitat and ecosystems.



Little herbaceous vegetation, loss of young aspen, no streambank vegetation, banks trampled and destroyed, stream bottom completely sediment-filled and stream flow reduced from loss of watershed function.  This is Cold Creek, Idaho still grazed by cattle.




Just the opposite.  Healthy aspen in a healthy ungrazed aspen area.  Stream is not shown in the photos, but is in later photos.  This is along Paris Creek, Idaho in an area ungrazed for 9 years.



Also along Paris Creek, Idaho.  Shows a new generation of 9 year-old aspen that began growing the first year cattle were excluded.  Three old aspen on the verge of dying at that time are still there, recovering and have made it 9 years.



These figures come from work by Forest Service Research Scientists Dale Bartos and Robert Campbell and Charles Kay who is a research scientist at Utah State University.  They are cited to reveal the extent of loss of aspen in the west as illustrated from the Forest Service’s own assessment, the loss of herbaceous production and water due to livestock.  Kay is cited because his work has shown conclusively that it is livestock that are the principal factor leading to aspen decline in the west.



Bartos, Dale L.  and Robert B. Campbell, Jr.  1998b.  Decline of quaking aspen in the interior west-examples from Utah.  Rangelands 20(1):17-24.


Bartos, Dale L. and Robert B. Campbell, Jr.  1998a.  Water depletion and other ecosystem values forfeited when conifer forests displace aspen communities.  Proceedings AWRA Specialty Conference, Rangeland Management and Water Resources.  American Water Resources Association, Herndon, Virginia


Kay, Charles E.  2001.  The condition and trend of aspen communities on BLM administered lands in central Nevada – with recommendations for management.  Final Report to Battle Mountain Field Office, Bureau of Land Management.


USDA.  1996.  Intermountain Regional Assessment Properly Functioning Condition.  Region IV Forest Service.16p.



No herbaceous vegetation, dead cow.  One of many dead cows seen in this area.  Of course the barren soil is eroding and silting in streams lower in the watershed.



Here, cattle have beaten the sagebrush and eaten all the grasses to the ground, leaving no habitat for sage grouse or other sagebrush obligate species.  The grasses that are present are a non-native, bulbous bluegrass that was seeded for cattle.  Constant grazing by livestock has eliminated native grasses and flowers.



Here is an ungrazed sagebrush habitat near Paris, Idaho.  It contains all the attributes missing in the grazed sagebrush and supports a year-round population of sage grouse, elk, deer, rabbits and the associated riparian and forested areas contain moose year-round.



Ungrazed for about 70 years, this photos shows that sagebrush habitats have potential for nearly 100% vegetative cover and that production doesn’t decline if livestock don’t graze it as agency and ranching advocates assert.



Carter, John G., Brandon Chard and Julie Chard.  2000.  Analysis of ground cover in forest openings in the Bear Hodges Analysis Area - Little Bear Sheep Allotment, North Rich Cattle Allotment.  Wasatch-Cache National Forest, Utah.  Report of Willow Creek Ecology.  Mendon, Utah. 

Carter, John G. and Brandon Chard.  2001.  An assessment of upland and riparian condition for Rich County, Utah BLM lands.  Report of Western Watersheds Project.  Mendon, Utah.


Carter, John G., Brandon Chard and Julie Chard.  2002.  Assessment of Habitat Conditions in the Bear River Range, Caribou National Forest, Idaho.  Western Watersheds Project Report.

USDA.  2002a (in press).  Big Sagebrush:  A Sea Fragmented into Lakes, Puddles dn Ponds.  General Technical Report RMRS-GTR-___.  Dr. Bruce Welch, Author.



West, Neil E.  1983.  Western intermountain sagebrush steppe.  In:  Temperate Deserts and Semi-Deserts.  Elsevier Scientific Publishing Company, Amsterdam.



From Carter et al, 2000.  Shows result of decades of grazing in sagebrush habitat in northern Utah.  Ground cover of herbaceous vegetation, litter and cryptogamic crust reduced.  Accompanying that reduction and resulting also from loss of topsoil by erosion is the reduction in total Nitrogen in the upper soil horizon.  Thus, long-term productivity is impaired by lowered nutrient status as well as organic carbon from plant material (not shown).




Grazed tributary of Cold Creek near Oakley, Idaho on State Lands.  Shows complete loss of riparian trees, shrubs and bank covering grasses and sedges.   Stream completely trampled and dysfunctional from watershed erosion from adjacent barren slopes and eroding banks.



Similar area in Curlew National Grassland.  Complete elimination of trees and shrubs other than sagebrush which has invaded the former riparian zone.  High sediment load and loss of inhabitable stream substrate.



Paris Creek, Idaho ungrazed for 9 years.  Trees, shrubs, grasses, flowering plants all present providing shelter for fish, birds and mammals.  Also providing leaves and woody debris for stream organisms, which form the basis of the food chain.  Elimination of these elements results in elimination of whole groups of organisms.



Good illustration of never-grazed wilderness stream in the Wind River Range, Wyoming.   Note clean gravel substrate without silt, grasses lining stream bank, woody debris in stream, shading as well as solar insolation for in-stream primary production.



From Belsky, A.J., A. Matzke and S. Uselman.  1999.  Survey of livestock influences on stream and riparian ecosystems in the western United States.  J. Soil and Water Conservation 54(1):419-431


Here are listed the basic components lost from thousands of miles of streams in the West.  Many streams are polluted by livestock resulting in loss of function.  For example high inputs of organic waste (manure) from cattle coupled with eroding soil result in the rocky substrate being buried and those organisms such as larval fish and invertebrates that rely on interstitial space within that substrate are eliminated due to loss of oxygen as well as available space.  Loss of habitat structure means those organisms associated with those particular habitats are also lost.  The same can be said of the loss of vegetation as well as the accompanying loss of organic inputs that certain groups of invertebrates require.



From:  U.S. DOI.  1993.  Riparian Area Management Process for Assessing Proper Functioning Condition.  U.S. Dept of Interior, BLM. TR-1737-9.


This shows the path of a degraded stream and riparian zone from total elimination of vegetation and stream channel integrity to a fully natural stream at bottom.  Many streams are placed in the “Bare Ground”, or lowest successional state by livestock.  Few streams are in the Potential Natural Community state shown at the bottom.




Here we see the effects of loss of habitat or vegetational attributes on stream invertebrate functional groups.  These are groups that depend on certain modes of living.  For example, shredders feed on vegetation, fallen leaves or wood.  Loss of riparian vegetation can eliminate this group which is composed of numerous species.  Whole groups of “clean water” indicating organisms such as stone flies, may flies and some caddis flies are included in the groups of shredders, collectors and scrapers – all of which rely on clean, not silt-bearing water as well as vegetation.



Armour, Carl, Don Duff and Wayne Elmore.  1994.  The effects of livestock grazing on western riparian and stream ecosystems.  American Fisheries Society Position Statement.  Fisheries 19(9):9-12.


USDA.  1996.  Intermountain Regional Assessment Properly Functioning Condition.  Region IV Forest Service.16p


Schulz, Terri Tucker and Wayne C. Leininger.  1990.  Differences in riparian vegetation structure between grazed areas and exclosures.  Journal of Range Management 43(4):295-299.


Here we see a quantification of the loss of streams as well as productivity in grazed vs. ungrazed riparian zones.



Adapted from:  Primack, Richard.  1993.  Essentials of Conservation Biology.




Self explanatory



This calculation was based on data from U.S. Department of Agriculture Statistics for numbers of livestock grazed on National Forest and BLM lands.  It does not consider State Lands or Private Lands grazed.




Adapted from Holechek, Jerry L., Rex D. Pieper and Carlton H. Herbel.  2001.  Range Management, Principles and Practices.  Prentice – Hall.


Here is presented a calculation of the potential loss in deer equivalents based on forage consumption.  Given that deer consume grasses in spring, flowering plants in summer and shrubs in winter, it is not necessary that all these vegetation types be consumed by livestock, only that a critical spring, summer or winter component is consumed.  Loss of any of the critical period forage bases can result in loss of reproductive ability, fawn mortality or death of adults due to poor condition entering and during winter.  The same is true of sage grouse or any other bird or mammal species that rely on vegetation and vegetative structure.



Self explanatory



Self explanatory and illustrated by following example from Oakley, Idaho and Range Science literature.



Galt, Dee, Francisco Molinar, Joe Navarro, Jamus Joseph and Jerry Holechek.  2000.  Grazing capacity and stocking rate.  Rangelands, December 2000.


This data shows how closely plant production follows annual precipitation in arid lands of the West.



This precipitation record from Oakley, Idaho shows the variation in precipitation over 80 years.  It also shows the drought threshold as defined by the Society for Range Management that defines drought as a year in which precipitation falls below 75% of the annual average.  Implications for plant production and livestock management are that plants are highly susceptible to grazing impacts during dry and drought years and that stocking rates of livestock must be reduced or the land not grazed during these years, otherwise productivity in following years will be reduced.  Long-term grazing in the West at constant numbers over a century as here in Idaho has resulted in the loss of ecosystem productivity described in the earlier examples.



Here is a simulation of a theoretical population of animals that shows how their numbers vary with plant production which also reflects precipitation.  It shows that populations go thru cycles with peaks and dips, but generally don’t go extinct.



But with livestock lowering the productivity of the land, these same dynamics occurring with less resources results in a higher risk of extinction (population crosses red line).



Self Explanatory