Reasons Given by Managers for Setting and
Adjusting Appropriate Management Levels
The committee recognized that, by and large, AMLs for individual HMAs had been set before the publication of the handbook in June 2010 and that little time had passed for adjustments to be made between the publication and when the committee’s survey questions (Appendix D) were distributed to 40 HMAs in January 2012. The committee wanted to gain an understanding of how AMLs had been established and adjusted before publication of the handbook. The 40 HMAs in the survey were the same as those sampled for population-estimate and survey-method information (Appendix E, Table E-3).
Survey respondents reported considerable variation at the HMA level in the approaches used for assessment and monitoring on HMAs. Establishment of HMAs generally occurred through consultation with state departments of fish and game for habitat and wildlife assessment, as called for in the legislation; use of state or regional BLM standards for rangeland (or public land) health as the “Standards for Land Health” stipulated as a goal in the handbook (BLM, 2010, p. 59); and reliance on the number of horses and cattle on the range at the time of HMA establishment to determine a goal for population levels, and in some cases to establish a ratio of number of horses to number of cattle as a framework for adjusting numbers.
The committee asked BLM managers who had been surveyed how they allocated forage among horses, cattle, and wildlife. Only a few fully addressed the question, and their responses were diverse. Use at the time of AML establishment was the most common answer, along with use of the original numbers at the time of the establishment of the HMA, the number specified in accordance with a resource management plan, the outcome of a land-use planning process, or a combination of the three. For example, in one HMA, the allocation between free-ranging horses and livestock was based on the original AMLs in the resource management plan, maintaining the original ratio of forage use for livestock and horses so that livestock and horses were reduced at the same rate. In this HMA, forage allocations were not increased because all the areas were stocked at or above carrying capacity. In another state, managers reported that in consultation with their department of fish and wildlife, the biologists at BLM made forage allocations to the native and exotic ungulates. Often, the forage allocated for existing livestock grazing privileges in an HMA was subtracted from total forage availability to determine the amount available to wildlife and horses.
Participating districts reported that measures of range condition and trend, upland utilization (amount of forage grazed, also termed “actual use” away from water), noxious weeds, and other types of rangeland and vegetation monitoring were considered relevant to adjusting and setting AMLs. One district used “negatively impacted vegetation functionality” as part of the justification to adjust an AML. Such considerations were frequent among reasons listed by managers for resetting or reaffirming AMLs. No data were provided on the metrics used to make the decisions, although some managers referred to other reports and multiple-use directives that were used in arriving at decisions. Monitoring of range and animal conditions; threatened, endangered, and sensitive species; and habitat was also conducted as part of setting, maintaining, or adjusting AMLs according to the survey. Most respondents to the committee’s survey reported that rangeland-monitoring studies (upland utilization, upland and riparian trend, and noxious-weeds monitoring) were being used to assess and evaluate forage availability in HMAs.a
On one HMA in another state, the AML was set after an intensive 5-year monitoring program. Data that were used included actual use, range condition and trends, utilization, precipitation, range sites, observations, and frequency of concentration areas for free-ranging horses. To change the AML again, the district
provide a process for adjusting AMLs, it may need to be revised or amended so that AML adjustments can be made.
In the committee’s view, the setting of an AML within a NEPA planning process when allocating resources among uses is in concert with the recognition that tradeoffs and values are parts of management decisions. The NEPA process provides for public comment and review and increases public participation in environmental decisions although the relationship is consultative rather than collaborative, tends to be bureaucratic, and