Targeted Livestock Grazing Won’t Preclude Large Wildfires

Senators Steve Daines of Montana and Diane Feinstein of California have once again introduced legislation, the “Emergency Wildfire and Public Safety Act of 2020” that is based upon misguided assumptions that fuel reductions will preclude the large blazes occurring as the West.

Never mind that climate change is the driving force in all these fires as was recently documented in a paper (Jones et al 2020). Though the bulk of the legislation is aimed at increasing the logging of our public lands, there is also a provision for targeted livestock grazing as a panacea for wildfire.

The legislation will reduce the public review process of these logging and grazing proposals through the use of categorical exclusions. Categorical exclusions permit agencies to bypass most environmental analysis and public scrutiny.

COLLATERAL DAMAGE OF LIVESTOCK GRAZING

The basic idea behind targeted grazing is that livestock will consume grass and other vegetation and thereby reduce the spread of wildfire. There is some rationale to the idea—less fuel under “normal” fire weather conditions can influence fire behavior.

However, almost all large fires—the fires that this legislation is designed to halt–occurs during extreme fire weather conditions (Keyser A. and Westerling, A, 2017). These conditions which include drought, low humidity, high temperatures and high winds overrides the normal influence of fuels.

Furthermore, grazing to the degree where fuels are significantly reduced has collateral damage that is frequently ignored.

There are many studies that document that grazing exclusion leads to ecosystem recovery and health (Dobkin, D.S., A. C. Rich, and W. H. Pyle, 1998; Beschta, R.L., D. L. Donahue, A. DellaSala et al., 2012; Cheng, J. et al. 2011).

A recent meta-analysis found livestock was a major factor in global biodiversity losses (Filazzola, A. et al. 2020).

The idea that heavy grazing can improve ecosystems has been disputed by many studies (Carter, J. et al., 2014)

Severe grazing imposes multiple ecological impacts on the landscape (Fleischner 1992; Wuerthner and Matteson 2002; Wilcove 1998; Freilich et al 2003; Flather, C.H. L.A. Joyce and C.A. Bloomgarden, 1994).

Grazing to the point where fuel reductions will be effective in slowing or halting fires requires cropping vegetation to the level of a manicured golf course.

In achieving such fuel reductions, hiding cover for small mammals, reptiles, and birds is reduced. Forage and pollen for insects is removed. Forage that would otherwise feed native herbivores from ground squirrels to elk is removed. Soils are compacted. Weeds are spread (Belsky, A.J., and J. L. Gelbard, 2000)

The banks along streams are broken down (Kauffman B. and W. C. Krueger. 1984, Belsky, J.A., A. Matzke, and S. Uselman, 1999). Biocrusts (which cover the soil between bunchgrasses and reduces erosion) are destroyed. Water is polluted by livestock feces (Wuerthner and Matteson 2002).

The mere presence of domestic livestock can socially displace native ungulates like elk and deer (Steward, K. 2002, Clegg, Kenneth. 1994).

A further impact of livestock production in the arid West is the consumption of water for irrigation and its impacts on aquatic ecosystems. Irrigated agriculture for livestock forage production is the biggest consumer of water in California as well as much of the West (Reisner, Mark, and Sarah Bates. 1990; Hanson, Brian. 2020). The consumption of water for irrigated forage production is a major factor in the decline of native fish around the West (Minchkley, W.L., and J.E. Deacon. 1991; Richter, B.D. et al., 2020).

Trampling by livestock negatively impacts native mollusks (Freist, Terrence.J. 2002, Denmead, Lisa H., et al., 2015}.

Livestock grazing is also responsible for the killing of native predators (Treves, A. et al., 2019)

Heavy livestock grazing can compact soils (Warren, S.D. et al., 1986) and negatively influence soil carbon stores (Belsky, Joy, and Dana M. Blumenthal. 1997; Bird, S.B. et al. 2002; Fang Fei, Chang Rui-ying, Tang Hai-ping, 2014;  Dingpeng Xionga, Peili Shia, Xianzhou Zhanga, Chris B. Zou. 2016; Ingram L.J. et al., 2008). Grazing contributes to soil carbon losses (Klumpp, K., Fontaine, S., Attard, E., Le Roux, X., Gleixner, G. and Soussana, J.-F., 2009; McSherry, M., and Mark Richie. 2013.).

It is worth noting that much of the terrain under public lands management never had significant grazing pressure from large herbivores like bison (Mack and Thompson 1982, Bailey, James A., 2016) and are often harmed by heavy grazing. For instance, it can take a native grass like bluebunch wheatgrass up to 10 years to recover fully from severe grazing pressure (Anderson, L. 1991).

Despite claims by Allan Savory and others that livestock grazing can reduce greenhouse emissions and sequester carbon (Savory, A., 2013), most researchers conclude that domestic livestock emissions are one of the major factors driving climate change (Myers, Bruce, 2014) which is creating the extreme fire weather conditions driving wildfires.

The United Nations Food and Agriculture Organization concluded that livestock contributed to 18% of global greenhouse gas emissions (FAO, Livestock’s Long Shadow. Environmental Issues and Options (Rome, Italy: Food and Agriculture Organization of the United Nations, 2006), while other studies put livestock contribution to global GHG emissions even higher (Goodland, R Anhang, J, 2009: Ripple, W. et al., 2014). Advocating livestock grazing to preclude wildfires is counterproductive in the long run since it only exacerbates the climatic conditions that favors large fires.

These are only a few of the ecological impacts that result from the severe grazing necessary to significantly alter fire behavior. And we will see later, even this kind of severe grazing usually will not stop a wind-driven fire occurring during extreme fire weather.

LIVESTOCK CONTRIBUTION TO CHEATGRASS SPREAD

Alternatively, and far more critical these days, livestock grazing is one of the major factors in the spread of cheatgrass, an annual exotic, that is extremely flammable (Williamson, Matt. A. et al. 2019, Belsky, A.J. and J. L. Gelbard, 2000).

Therefore, cheatgrass has increased fire frequency in sagebrush ecosystems, causing complete type conversion of sagebrush steppe in many areas (Reisner, Michael D. et al. 2013, Condon Lea and David Pyke. 2018).

The factors that favor cheatgrass spread, including livestock grazing (Bradley BA, Curtis CA, Fusco EJ, Abatzoglou JT, Balch JK, Dadashi S, Tuanmu M-N. 2017). Selective grazing of preferred perennial grasses reduces their competitive abilities, permitting cheatgrass colonization. Besides, biological soil crusts (BSC) found in the interspaces between bunchgrasses inhibits cheatgrass establishment. Cattle trample these BSC (Root, Miller, and Rosentreter.2019).

Maintaining healthy stands of perennial grasses has been shown to inhibit cheatgrass spread (Strand et al. 2017).

Although grazing is often trumpeted as a means of reducing fuels (Bailey, Derek W., et al. 2019) and thus wildfire, especially by “targeted” grazing and fuel reductions. (Diamond, Joel, Christopher A. Call, and Nora Devoe 2009). The claims must be scrutinized closely.

For instance, a study done in Arizona concluded (with modeling) that light utilization (26%) in treated sites, the BehavePlus fire model predicted that herding and supplement reduced fire rate of spread by more than 60% in grass communities and by more than 50% in grass/shrub communities (R.A. Bruegger et al. 2016).

However, the authors go one to conclude: “Although it is a promising tool for altering fire behavior, targeted grazing will be most effective in grass communities under moderate weather conditions.” The weather factors are significant because nearly all massive wildfires burn under “extreme fire weather conditions.” Under such conditions, targeted grazing, as well as fuel breaks, fail to contain or stop fires (Bruegger et al., 2016)

Another study that looked at fuel breaks created by targeted grazing and other measures like bulldozing native vegetation cautioned that the “cure might be worse than the disease” since the destruction of soil biological crusts and loss of native grasses that occur with targeted grazing, bulldozing. Other fuel reductions create the disturbance habitat that favors the spread of cheatgrass (Shinneman et al 2018).

The authors cautioned: “these projects could also add thousands of kilometers of new fuel breaks to the region over the next decade or two, directly altering hundreds of thousands of hectares through habitat conversion, and indirectly affecting sagebrush plant and animal communities through the creation of new edge effects and habitat fragmentation” (Shinneman et al. 2018).

None of the studies that promote grazing to reduce fuels considers the unavoidable ecological impacts that accompany grazing. These include water pollution, soil compaction, trampling of biological soil crusts, the spread of weeds (as with cheatgrass), the social displacement of wildlife (like elk), and the loss of forage wildlife and insects, and costs.

While targeted grazing and the ecological impacts that result might be acceptable for small areas, say to reduce vegetation around a home or some other limited area, it is not effective or acceptable on a landscape scale. As such, it cannot aid in reducing large wildfires.

Furthermore, the probability that any area “treated” by targeted grazing and other fuel reductions will encounter a blaze when fuel removal is effective is extremely small (Rhodes and Baker 2008). Thus, targeted grazing and further fuel reductions, which have their own set of impacts, occur now, potentially reducing a fire that may or may not come in the future.

REFERENCE:

 

Anderson, Loren. 1991. Bluebunch wheatgrass defoliation effects and vigor recovery. BLM State Office, TECHNICAL BULLETIN 91-2

Bailey, Derek W., et al., 2019. Synthesis Paper: Targeted Livestock Grazing: Prescription for Healthy Rangelands, Rangeland Ecology & Management

Bailey, James A., 2016. Historic Distribution and Abundance of Bison in the Rocky Mountains of the United States. Intermountain Journal of Sciences, Vol. X, No. X, 201X

Beschta, R.L., D. L. Donahue, A. DellaSala et al., 2012 .“Adapting to climate change on western public lands: addressing the ecological effects of domestic, wild, and feral ungulates,” Environmental Management, vol. 51, no. 2, pp. 474–491, 2012.

Belsky, Joy A. et al., 1993. Overcompensation by or red herring? Evolutionary Ecology, 1993, 7, 109-121

Belsky, Joy, and Dana M. Blumenthal. 1997. Effects of Livestock Grazing on Stand Dynamics and Soils in Upland Forests of the Interior West Conservation Biology, Pages 315-327 Volume 11, No. 2, April 1997

Belsky, A.J., and J. L. Gelbard, 2000. Livestock Grazing and Weed Invasions in the Arid West, Oregon Natural Desert Association, Bend, Ore, USA, 2000.

Belsky, J.A., A. Matzke, and S. Uselman, 1999.  “Survey of livestock influences on stream and riparian ecosystems in the western United States,” Journal of Soil and Water Conservation, vol. 54, no. 1, pp. 419–431, 1999

Bird, S.B. et al. 2002 Spatial heterogeneity of aggregate stability and soil carbon in semi-arid rangelands. Environmental Pollution 116 pages 445-455

Bradley BA, Curtis CA, Fusco EJ, Abatzoglou JT, Balch JK, Dadashi S, Tuanmu M-N. 2017. Cheatgrass (Bromus tectorum) distribution in the intermountain Western United States and its relationship to fire frequency, seasonality, and ignitions. Biological Invasions. https://dx.doi.org/10.1007/s10530-017-1641-8

Bruegger, Retta A. et al. (2016). Targeted Grazing in Southern Arizona: Using Cattle to Reduce Fine Fuel Loads Rangeland Ecology & Management Volume 69, Issue 1, January 2016, Pages 43-51

Carter, J. et al., 2014. Holistic Management: Misinformation on the Science of Grazed Ecosystems.  International Journal of Biodiversity Volume 2014, Article ID 163431, 10 pages

Cheng, J. et al. 2011. Cumulative effects of 20-year exclusion of livestock grazing on above and below-ground biomass of typical steppe communities in arid areas of the Loess Plateau, China. Plant Soil Environ. 57, 2011 (1): 40–44

Clegg, Kenneth. 1994. Density and Feeding Habits of Elk and Deer in Relation to Livestock Disturbance Master of Science Utah State University.

Condon Lea and David Pyke. 2018.  Fire and Grazing Influence Site Resistance to Bromus tectorum Through Their Effects on Shrub, Bunchgrass and Biocrust Communities in the Great Basin (USA) https://link.springer.com/article/10.1007/s10021-018-0230-8

Denmead, Lisa H., et al., 2015. Experimental evidence that even minor livestock trampling has severe effects on land snail communities in forest remnants. Journal of Applied Ecology 2015, 52, 161–1

Diamond, Joel, Christopher A. Call, and Nora Devoe. 2009. Effects of targeted cattle grazing on fire behavior of cheatgrass-dominated rangeland in the northern Great Basin, USA International Journal of Wildland Fire 2009, 18, 944–950

Dingpeng Xionga, Peili Shia, Xianzhou Zhanga, Chris B. Zou. 2016. Effects of grazing exclusion on carbon sequestration and plant diversity in grasslands of China—A meta-analysis. Ecological Engineering 94 (2016) 647–655

Dobkin, D.S., A. C. Rich and W. H. Pyle, 1998. “Habitat and avifaunal recovery from livestock grazing in riparian meadow system of the northwestern Great Basin,” Conservation Biology, vol. 12, no. 1, pp. 209–221, 1998

Fang Fei, Chang Rui-ying1, Tang Hai-ping. 2014. Effects of Grazing on Carbon Sequestration in Temperate Grassland, Inner Mongolia of North China  Vegetos- An International Journal of Plant Research Volume: 27, Issue : 3 pgs. 126-134.

FAO, Livestock’s Long Shadow. Environmental Issues and Options (Rome, Italy: Food and Agriculture Organization of the United Nations, 2006).

Filazzola, A. et al. 2020. The effects of livestock grazing on biodiversity are multitrophic: a meta-analysis Ecology Letters, (2020) 23: 1298–1309.

Flather, C.H. L.A. Joyce and C.A. Bloomgarden. 1994.Species Endangerment Patterns in the United States. USDA Forest Service General Technical Report RM-241. Rocky Mountain Research Station, Fort Collins, CO.

Fleischner, Thomas. 1994. Ecological Costs of Livestock Grazing on Western North America. Conservation Biology 8, no. 3629-644.

Freilich et al., 2003. Ecological Effects of Ranching: A Six-Point Critique. August 2003 / Vol. 53 No. 8 • BioScience 759

Freist, Terrence.J. 2002. Native Snails: Indicators of Ecosystem Health. Welfare Ranching: The Subsidized Destruction of the American West.

Goodland, R Anhang, J (2009) Livestock and Climate Change: What if the key actors in climate change were pigs, chickens, and cows? World Watch, November/December 2009. Worldwatch Institute, Washington, DC, USA. Pp. 10–19. Available at: http://www.worldwatch.org/files/pdf/Livestock%20and%20Climate%20Change.pdf

Hanson, Brian. 2020. Irrigation of Agricultural Crops in California. Department of Land, Air and Water Resources University of California, Davis brhanson@ucdavis.edu

Jones et al. 2020  Climate Change Increases the Risk of Wildfires. ScienceBrief

Ingram L.J. et al., 2008. Grazing impacts on soil carbon and microbial communities in a mixed-grass ecosystem. Soil Sci. Soc. Am. J. 72:939-948

Kauffman B. and W. C. Krueger. 1984. Livestock Impacts on Riparian Ecosystems and Streamside Management Implications: A Review JOURNAL OF RANGE MANAGEMENT 37(5), September 1984

Keyser A. and  Westerling Anthony, 2017, Climate drives inter-annual variability in probability of high severity fire occurrence in the western United States Environmental Research Letters, Volume 12, Number 6

Klumpp, K., Fontaine, S., Attard, E., Le Roux, X., Gleixner, G. and Soussana, J.-F. (2009), Grazing triggers soil carbon loss by altering plant roots and their control on soil microbial community. Journal of Ecology, 97: 876–885. DOI: 10.1111/j.1365-2745.2009.01549.

Mack Richard N. and John N. Thompson. 1982. Evolution of the Steppe with few large, hoofed mammals.  The American Naturalist. Vol 19. No. 6.

McSherry, M., and Mark Richie. 2013. Effects of grazing on grassland soil carbon: a global review. Global Change Biology (2013) 19, 1347–1357, DOI: 10.1111/gcb.12144

Minchkley, W.L., and J.E. Deacon. 1991. Battle Against Extinction: Native Fish Management in the West. U of Arizona Press

Myers, Bruce. 2014. Livestock’s Hoof Print-the Challenge of Regulating Global Warming Emissions. Environmental Law Institute, Policy Brief 8.

Reisner, Mark, and Sarah Bates. 1990. Overlapped Oasis: Reform or Revolution for Western Water. Island Press, Washington DC.

Reisner, Michael D. et al., 2013.  Conditions favouring Bromus tectorum dominance of endangered sagebrush steppe ecosystems. Journal of Applied Ecology 2013

Rhodes Jonathan J. and William L. Baker. 2008. Fire Probability, Fuel Treatment Effectiveness and Ecological Tradeoffs in Western U.S. Public Forests The Open Forest Science Journal, 2008, 1, 1-7

Richter, B.D. et al., 2020. Water scarcity and fish imperilment driven by beef production. Nature Sustainability. https://doi.org/10.1038/s41893-020-0483-z

Ripple, W. et al., 2014. Ruminants, Climate Change, and Climate Policy. Nature Climate Change Vol. 3 www.nature.com/natureclimatechange

Root, Heather et al., 2019. Grazing disturbance promotes exotic annual grasses by degrading soil biocrust communities. Ecological Applications, 0(0), 2019, e02016

Savory, A., 2013. How to fight desertification and reverse climate change. https://www.ted.com/talks/allan_savory_how_to_fight_desertification_and_reverse_climate_change/transcript?language=en

Shinneman, Douglas J., Cameron L. Aldridge, Peter S. Coates, Matthew J. Germino, David S. Pilliod, and Nicole M. Vaillant. 2018. A Conservation Paradox in the Great Basin—Altering Sagebrush Landscapes with Fuel Breaks to Reduce Habitat Loss from Wildfire. Open-File Report 2018-1034

Stewart, Kelly, et al., 2002. Temporospatiall distribution of elk, mule deer, and cattle. Resource partitioning and competitive displacement. Journal of Mammalogy, 83(1):229–244, 2002

Strand, E. et al., 2017. Do perennial bunchgrasses competitively exclude Bromus tectorum in post-fire rehabilitation across spatial scales? Fire Science JFSP PROJECT ID: 15-2-01-22

Treves, A. et al., 2019. Predator Control Needs a Standard of Unbiased Randomized Experiments With Cross-Over Design. Front. Ecol. Evol., 12 December 2019 | https://doi.org/10.3389/fevo.2019.00462

Warren, S.D. et al., 1986.  The Influence of Livestock Trampling under Intensive Rotation Grazing on Soil Hydrologic Characteristics. JOURNAL OF RANGE MANAGEMENT 39(6). November 1966

Wilcove, David, et al. 1998. Quantifying Threats to Imperiled Species in the United States. Bioscience 607-613.

Williamson, Matt. A. et al., 2019. Fire, livestock grazing, topography, and precipitation affect occurrence and prevalence of cheatgrass (Bromus tectorum) in the central Great Basin, USA Biol Invasions https://doi.org/10.1007/s10530-019-02120-8(0123456789().,-vols() 0123458697().,-volV)

Wuerthner, George, and Mollie Matteson. 2002. Welfare Ranching: The Subsidized Destruction of the West. Island Press. Washington DC.