Extension by Rachel MealorWritten by Rachel Mealor
Racheal Mealor, UW Extension Range Specialist
Rangeland science and management has evolved in the development of management strategies that are sustainable for our arid landscapes. This has impacted the way livestock are managed and ecological services are valued. We have witnessed and implemented numerous strategies to maintain healthy vegetative communities while considering livestock production. However, managing our landscapes for multiple species at one time can be complex and at times contradictory. Take for example, a grassland bird species, the mountain plover, Charadrium montanus. Mountain plover’s nesting habitats usually consist of areas with vegetation that is level to the ground (prostrate) along with high amounts of bare soil. Mountain plovers are cryptically colored, so they blend in and look like bare soil when viewed from above and frequently stay motionless when an avian predator is present. Long-standing range management practices tell us bare soil is an undesirable characteristic for long term rangeland health. So, how does one deal with such a paradox?
A recent study in a short grass steppe community in northeastern Colorado characterized various types of disturbances in relation to suitable habitat for breeding mountain plovers. Breeding mountain plovers were primarily located on black-tailed prairie dog colonies or areas that had been burned during the previous dormant season. Vegetation surrounding plover nests and foraging sites were primarily patches of vegetation low in stature, or those plants less than four centimeters tall, interspersed with greater than 35 percent bare soil. Mountain plover nesting habitat was examined in relation to the following disturbances: prescribed fire, grazing by black-tailed prairie dogs and cattle grazing. Sites with bare ground created by prescribed fire or black-tailed prairie dog colonies were favored by these grassland birds. Yet, intensive grazing at twice the recommended stocking rate during spring (March to May) or summer (May to Oct) for six years did not produce enough bare ground desired by mountain plovers. Therefore, intensive cattle grazing did not substitute for fire or prairie dog grazing in terms of how vegetation structure was affected for mountain plover habitat. The disturbances considered in this study can be manipulated and used as tools to reach management goals. If providing habitat for breeding mountain plovers is a management goal, grazing as a tool may not suffice. Managing for prairie dog colonies or using prescribed burning could be considerations to add to the management toolbox in order to reach the goal of increasing habitat for a desired wildlife species.
Wildlife habitat continues to be an important consideration for many landowners throughout Wyoming. Whether that be providing habitat for a species of concern or maintaining wildlife populations for a hunting enterprise, understanding habitat needs can be crucial to the sustainability of an operation. This again exemplifies the need for an overall management plan that includes clear goals and objectives for the property.
Understanding the resource that is being managed will allow landowners or managers to match the resource with the most suitable animal to more efficiently, effectively and responsibly utilize the land. For example, the emphasis in the study mentioned above was to determine the situation resulting in the most suitable habitat for mountain plover in regards to prescribed fire, grazing by black-tailed prairie dogs and grazing by large herbivores, including cattle. It is interesting to point out the characteristics of the site in which the research was being conducted (the resource). In terms of plant productivity, cover, and species composition, the short grass steppe is among the most resistant grasslands worldwide to grazing by large herbivores (Milchunas et al. 2008).
So, within this community, it was determined that even intense cattle grazing could not match the amount of bare soil that was found on prairie dog colonies and burns. Looking closer at the resource, short grass steppe is dominated by warm-season grasses, mostly blue grama and buffalograss, which have adaptations to aridity and intensive herbivory. These grasses have a prostrate canopy, minimal stem investment, a large amount of biomass belowground (stolons), and rapid growth results after defoliation and small pulses of precipitation (Milchunas et al. 2008).
So, now that we have identified the resource, how about the consumers? Due to the mouth structure of cattle, they only graze short grasses to a little less than half an inch above crown height, allowing regrowth to occur. Much differently, however, is how a prairie dog would use this same resource. Prairie dogs remove plant leaves more often and, in contrast to the mouths of cattle, these little critters can graze closer to the crown level. As expected, these circumstances combined with defoliation occurring year-round will result in a loss of vegetation dominance and an increase in bare soil on colonies. Therefore, it is not hard to believe that prescribed burning and prairie dog colonies are effective ways to maintain habitat for mountain plover in short grass steppe. Grazing on the contrary would not provide the same situation or reach the same goal. Knowledge of the differences on how each disturbance would affect the resource could determine the success or failure of individual goals.
I think many would agree that there are times when management goals seem complex. It can seem hard to imagine how they will all be incorporated into an overall management plan. Having a good understanding of all the available tools that can be used to meet these goals can help assist with such complexity. As shown in the highlighted study, the use of grazing alone will not result in ideal mountain plover nesting habitat. This illustrates the need to recognize the strengths and limitations of each tool and consider combining certain tools to provide the desired result. This, in my opinion, is why there is the saying that range management is more than just a science, but also an art.