Rangeland Inventory, Monitoring, and Evaluation
Susan Muir (New Mexico State University)
Mitchel P. McClaran (University of Arizona)
16 September 1997 (Draft for Review)
Rangeland inventory and rangeland monitoring are the processes of describing and evaluating the resources at a rangeland site.
a. Rangeland inventory is information collected to document and describe the existing resource status within a management unit. Features included depend on the purpose of the inventory, but in rangeland situations are likely to entail vegetation types, range sites, range condition, carrying capacity, soil types, utilization patterns, topography, streams, habitat assessments for wildlife, and improvements such as roads, watering points, and fences.
b. Rangeland monitoring is conducted to record changes in resource status, usually to assess the response to a management program at a site. Such changes can only be detected by a series of measurements spanning time. Data collected from a range inventory provides a valuable baseline against which to compare responses, but monitoring can rarely be conducted at the same level of detail as the information provided by an inventory. Instead, monitoring is usually based on observations of key areas and key vegetation attributes carefully selected to meet the objectives of the program. For example, species composition could be measured in a riparian area to determine the impact of a certain grazing system, changes in mesquite (Prosopis spp.) density could be used to assess the effectiveness of herbicide control, or ground cover could be chosen to monitor the impact of tourism at a popular site in a National Park.
Inventory and monitoring have always been central themes of rangeland management, as tools to assist in making wise decisions according to the productive potential of the land resource, such as, carrying capacity, utilization levels, grazing systems, and range improvements. Today under the philosophy of multiple use and increased legislative demands, however, inventory and monitoring programs serve a greater variety of interests and groups. For example, Artz (1984, p. 600) enumerated the following objectives of inventory and monitoring programs.
- To develop high quality land use plans.
- To allocate resources to uses and users.
- To assess current conditions and to monitor conditions in the future for measurement of progress towards goals.
- To assess impacts of proposed land use actions.
- To assess capability or potential of resource production under various levels of management.
- To establish a common basis of measurement between various land types and ownerships.
- To assist in defending decisions in hearings and court actions.
- To satisfy legal requirements.
These objectives must be implemented at different time scales and levels of detail, depending on the purpose and end-user of the resource information. For example, local land managers (e.g., ranchers, stewards of local natural public reserves), need detailed site information to plan and evaluate specific projects, such as erosion control, reseeding programs, the management of invasive plants, or the regulation of wildlife populations. Conversely, regional and national administrators are increasingly obliged by legal mandates to use inventory and monitoring information for a variety of assignments, from district land use plans to large-scale national inventories reporting on current resource status, which rely on data collected at more general or summarized levels.
When planning an inventory or monitoring program, the objectives must be balanced against the availability of resources, including time, money, and skilled personnel. In combination, these criteria will influence inventory and monitoring strategies, sampling designs, which vegetation attributes are collected, and evaluation of the final data from ecological and management perspectives.
In this chapter, you will find the following sections:
- General Principles of Inventory and Monitoring
- Sampling Concepts
- Vegetation Attributes
- Rangeland Evaluation
- Management Applications
References and Further Reading
Artz, J.L. 1984. The environment of rangeland inventory 1980. In: National Research Council/National Academy of Sciences. Developing strategies for rangeland management. Westview Press. pp 593-605.
Bonham, C.D. 1989. Measurements for terrestrial vegetation. John Wiley Sons, New York, NY. p 265.
Holechek, J.L., Pieper, R.D., and C.H. Herbel. 1995. Range management principles and practices. Prentice Hall, Englewood Cliffs, NJ. 2nd ed. pp 159-176.
National Research Council. 1994. Rangeland health: New methods to classify, inventory and monitor rangelands. National Academy Press. pp 134-157.
Pearson, H.A., and J.W. Thomas. 1984. Adequacy of inventory data for management interpretations. In: National Research Council/National Academy of Sciences. Developing strategies for rangeland management. Westview Press. pp 745-763.
Smith, E.L. 1984. Use of inventory and monitoring data for range management purposes. In: National Research Council/National Academy of Sciences. Developing strategies for rangeland management. Westview Press. pp 809-842.
West, N.E., McDaniel, K., Smith, E.L., and S. Leonard. 1994. Monitoring and interpreting ecological integrity on arid and semi-arid lands of the western United States. Range Improvement Task Force, Las Cruces, NM. pp 1-15.