Grazing Leads to Greener Pastures
by Craig Madsen, Healing Hooves
Travis Bruner recently published an article on The Wildlife News website claiming that “Grazing Leads to Blazing,” blaming cattle for the severity of this year’s fire season. He makes several common errors in reaching this conclusion.
The tool of grazing can have a beneficial or negative impact on plant communities depending on how well it is managed. It is true that poor management of livestock has resulted in significant changes in the plant community on western rangeland. There are areas throughout the West where overgrazing has resulted in the loss of native bunchgrasses and the invasion of annual grasses such as cheatgrass, but we need to understand what overgrazing really is. Overgrazing occurs when the plant is grazed a second time before it has time to recover from the first grazing. It is the level of management that determines whether or not the tool of grazing has a beneficial or negative impact on the ecosystem, not the simple presence of livestock.
As Aldo Leopold so eloquently stated, we must restore balance with the ““creative use of the same tools that have heretofore destroyed it – axe, plow, cow, fire, and gun.”
Several studies have shown the beneficial use of the tool of grazing. Planned grazing has been used to reduce the amount of annual grasses on rangelands, as shown in the publication “Grazing Invasive Annual Grasses: The Green Brown Guide,” a publication by USDA ARS. Another study conducted on the Great Basin Experimental Range in Southeastern Oregon showed that moderate grazing of sagebrush plant communities with livestock increased the ability of the native plant community to tolerate fire and thus prevent cheatgrass from increasing (“Grazing History influences the response of Sagebrush Plant Communities to Fire, Davies, Svejcar, and Bates”). This study reported in areas where livestock were excluded for more than 50 years after a burn, cheatgrass production went from less than 10 lbs/acre to close to 300 lbs/acre. In the moderately grazed sites, cheatgrass production went from less than 10lbs/acre to about 30 lbs/acre. The significant increase in cheatgrass production in the ungrazed area could lead to more frequent fires. Proper grazing in that context appears to protect the habitat of sage-grouse and other wildlife that are dependent on sagebrush communities.
In both studies it is the proper application of the tool of grazing and animal impact that had the beneficial impact. Animal impact includes all activities of the grazing animal including depositing dung and urine and trampling of vegetation. Due to complexity of the ecosystem and the number of variables to consider in the application of the tool of grazing/animal impact, it takes careful planning and monitoring to get the beneficial results.
There are two key points to keep in mind. First, many plant communities, especially in areas where moisture is poorly distributed through out the year, depend on grazing and animal impact to maintain a healthy plant community. Second, timing is a critical factor in the proper management of livestock. Eliminating grazing from public lands or using artificial timetables for movement and stocking ignore these two points.
In drier environments the biological activity necessary to break down plant material at the soil surface is limited to times when moisture is available. The grazing animal carries the moist environment needed to break down plant material within its digestive system. In these dry environments grazing and animal impact helps to maintain the vigor of the plants by cycling the nutrients through dung and urine, removing plant material that prevents sunlight from reaching the base of the plant where the new growth is starting, and trampling plant material on the ground which provides soil cover. The plant material on the soil surface reduces the erosive impact of rain drops, allowing for more water to be absorbed versus running off as well as covering the soil to reduce evaporation. Trampling the plant material places it in contact with the ground where microorganisms can break it down and create organic matter, continuing the nutrient cycling process.
Grazing Herbivores Cycle Nutrients
The role of timing is key factor in the use of the tool of grazing. Timing can be looked at in three ways: (1) the time of year the area is grazed, (2) length of time the animals stays at a specific location, and (3) the length of time before the animals return to a specific location. The correct timing of grazing is influenced by the context of each situation.
For example, assume we have a common situation where the predominant vegetation is annual grasses with a remnant population of native grasses, and our objective is increasing the native grass component. For this very simple grazing plan, our focus will be on preventing the annual grasses from producing seed and limiting livestock utilization on the native bunchgrasses. The time of year to graze will be when the annual grasses are green and the native bunchgrasses are dormant (brown). At this time of year the livestock are going to prefer the green annual grasses. The length of time on the site will be based on when the annual grasses are fully utilized while maintaining the desired stubble height on the dormant native grasses. When to return? The time to return depends on two main factors: regrowth on the annual grasses and whether or not growth has started on the native bunchgrasses. If soil moisture enabled regrowth on the annual grasses but the native bunchgrasses are still dormant, then a second grazing is allowed. If the native bunchgrasses are growing and growth is above the stubble height created by previous grazing, then grazing will be delayed until the native grasses have completed their growth cycle, after seed set. For more information on reducing annual grasses by grazing see the publication “Grazing Invasive Annual Grasses: The Green Brown Guide.”
Mr. Bruner calls for the “passive restoration of the landscape”. I am assuming he means applying the tool of “rest” to the landscape. We may not think of resting the land as a tool but it is a decision and resting the land has an impact.
The tool of rest is a powerful tool. In moist environments you see an opening in the trees quickly reclaimed by the forest. In drier environments where moisture is not well distributed throughout the year, short term rest can result in native plants recovering from past overgrazing. Long-term rest in these dry environments can have the opposite results. In some situations you see native bunchgrasses dying, increased bare ground and as a result increased erosion. Allan Savory talks about this situation in his TED talk showing pictures of national parks in the Western United States where livestock have been excluded for over 70 years, native plants are dying, and erosion is increasing (http://www.ted.com/talks/allan_savory_how_to_green_the_world_s_deserts_and_reverse_climate_change?language=en)
Note the un-grazed area to the left of the fence. The right side was grazed six weeks before. There is significant green re-growth on the grazed side. The decadent un-grazed side creates more dry fuel for fire.
The tools of grazing, animal impact and rest all have impacts on the land. The impact is dependent on how the tools are applied and the type of environment the where the tools are being used. As with any tool the effect is dependent on how the tool is applied. The tools of grazing and animal impact have been used to reduce annual grasses on rangeland, improve wildlife habitat and increase the absorption of rain. These tools must be applied in a manner that deals with the complexity of the area being managed. Holistic Planned Grazing™ is one method of dealing with the complexity of the ecosystem as well as the context being managed. It planning system that places the right livestock in the right place at the right time for the right reason to meet the landscape objectives. For more information about Holistic Planned Grazing see the following link http://savory.global/assets/docs/evidence-papers/The_Science_and_Methodolgy_of_Holistic_Planned_Grazing.pdf
