We are regularly asked to explain the difference between “Carrying Capacity” and “Limits of Acceptable Change”. This series of posts is intended to review these planning systems and to provide a more in-depth view of LAC and its implementation.

The growing awareness that designation of protected areas does not ensure their preservation has stimulated an enormous level of discussion globally in recent years. Rights of indigenous people, off-site induced impacts and management of recreational uses have broadened the arena of both scientific and public debate beyond the biology of these areas.

While the biophysical characteristics of many protected areas remain the fundamental rationale for their initial designation, it has become quite clear that the values for which these areas were initially protected can be threatened by unmanaged or poorly managed recreational use.

The Limits of Acceptable Change (LAC) planning system was initially designed to address visitor management issues in the U.S. National Wilderness Preservation System and was a product of the spreading realisation that “Carrying Capacity” failed in achieving its objectives. While there are many reasons why the carrying capacity paradigm failed, the most fundamental was that it impelled managers toward the wrong question: “How many is too many?” Carrying capacity is intrinsically a quantitative term, yet, research was showing that many problems of recreational use were a function not so much of numbers of people, but their behaviour.

LAC, on the other hand, dealt with a significantly different question: “What resource and social conditions are appropriate (or acceptable), and how do we attain those conditions?” This question represented a substantially different approach to thinking about recreational use questions, yet was actually more closely aligned with the principal job of recreation managers –protecting the values for which an area was established – than the carrying capacity paradigm.

Thus, Limits of Acceptable Change as a planning system was viewed as a way for managers to confront and resolve the complex issues of managing visitors to not only provide for the experiences they seek, but to deal with the problems of their social and biophysical impacts.

The LAC system is, in effect, built upon eleven principles that have emerged from research on visitor impacts and growing public interest to be involved in protected area decision-making.

While these principles had not entirely been formally and explicitly articulated when the LAC process was developed, they are now unmistakably recognised as fundamental components of any systematic planning system for natural area protection and management. In the section, that follows each principle will be briefly discussed.

Concepts and Principles

Principle 1: Appropriate management depends upon objectives

A clear and consistent theme expressed throughout the literature of visitor management in protected areas has been the need for explicitly stated objectives. Objectives provide definitive statements of the products or outcomes of recreation or protected area management. Objectives, either as formal statements of legislative or administrative policy or as explicit assertions in a management plan identify the appropriateness of management actions and indicate acceptable resource and social conditions.

Formally stated objectives allow protected area managers to determine how successful management actions may have been in resolving problems.

Unfortunately, writing good objectives is not easy; while people tend to agree about general values and concepts, specific and explicit objectives are likely to evoke considerable disagreement about what is to be accomplished or produced at a recreation site. It should be noted that the process of establishing objectives is an intrinsically political one, and therefore methods that include interaction with those affected will help develop objectives upon which a consensus can be developed.

Principle 2: Diversity in resource and social conditions in protected areas is inevitable and may be desirable

Resource and social conditions within any relatively large protected area are not likely to be uniform. Impacts, use levels, and expectations of appropriate conditions tend to vary. Topography, vegetation and access influence use densities and level of impact. Visitor use is frequently unevenly distributed. This diversity of conditions is inevitable, and sometimes desirable. For example, in large terrestrial protected areas, it generally would not be desirable to have developments spread evenly across the area, leaving no place untouched. The interior areas of protected areas often display fewer human-induced impacts than the periphery. Managers can identify this diversity and then make decisions on its desirability, thus separating technical decisions from judgmental ones. Finally, it has been argued that managing for diversity explicitly through some type of zoning process is more likely to lead to preservation of protected area values than existing implicit or de facto zoning.

Principle 3: Management is directed at influencing human-induced change

Many protected areas have been established to protect not only unique and valuable natural features and conditions, but natural processes as well. Management is generally oriented toward limiting and managing human-induced changes in these. It is human-induced changes that we find most disturbing in protected areas. Such human-induced changes may lead to conditions that visitors or managers may feel are unacceptable or inappropriate. Management then concerns itself with determining what actions will be effective in influencing the amount, type and location of these changes in addition to determining how much change is acceptable.

Principle 4: Impacts on resource and social conditions are inevitable consequences of human use

A variety of research has shown that relatively small amounts of recreational use lead to disproportionately large biophysical impacts. Thus, allowing any level of recreation in a protected area means that some level of impact will occur. The principal question that managers must ask is “how much impact is acceptable in this area?” Once this question has been addressed, managers must then deal with the appropriateness of various techniques or actions to manage to this level of impact. In a similar way, social impacts often occur with relatively small amounts of use. For example, a few people behaving in a rowdy manner may impact another visitor’s experience far more than many people being more quiet. This principal extends to types of visitors as well. A hiker may be more sensitive to encountering a single quad bike  than a large number of hikers.

Principle 5: Impacts may be temporally or spatially discontinuous

Impacts from visitor use or management activities may occur offsite and may not be visible until later. For example, a management strategy eliminating camping around a lake may simply transfer impacts to other, potentially, more sensitive areas. Inefficient water treatment may result in pollution of water downstream from the outlet. And, impacts, such as dying vegetation, may not be visible until long after recreationists leave the site. Such tendencies make understanding and managing impacts significantly more difficult, demand substantial knowledge about use/impact relationships at different scales, and require managers to carefully design appropriate monitoring strategies.

Principle 6: Many variables influence the Use/Impact Relationship

While the level of recreational use is an important consideration in managing protected areas, a variety of other variables affect the use/impact relationship. For example, it has long been known that behaviour of recreationists influences the amount of impact they cause. In marine settings, treading water with flippers may stir up sand that may impact coral. Other variables include travel method, group size, season of use, and a variety of soil and vegetation characteristics. Similarly, there may be coral settings that are more or less sensitive to recreational use. What this principle means is that the standard errors around lines depicting use/impact relationships will be extremely large because of these other factors and that attempts to control human-induced impacts solely through use limits or carrying capacities may fail. Education and information programs and regulations aimed at changing visitor behaviour may be more effective.

Principle 7: Many management problems are not use density dependent

Management problems that relate to the number of people using an area tend to be those that have relatively simple technological solutions, such as sewage, water supply and parking. Even for some of these, however, the intensity of the problem may not be linearly related to amount of use. For example, per capita consumption of water for sewage disposal may be reduced by using toilets with low water requirements. The lack of a precise linear relationship between use and biophysical impact implies that management problems are not density dependent.

Similar conclusions can be made with respect to social conditions. For many visitors to remote areas of national protected areas, solitude is not a significant or salient motivation. Thus, controlling use levels to optimise opportunities for solitude would be inappropriate.

Principle 8: Limiting use is only one of many management options

One of the problems with the carrying capacity approach is its emphasis on controlling or limiting the number of visitors as a key to limiting impacts (Stankey and McCool 1991).

Because carrying capacity carries with it the question “how many is too many?”, it tends to view imposition of use limits as an end in itself. A use limit policy is only one of a number of potential management actions that are available to address visitor impacts, yet is one of the most intrusive actions that managers could deploy. Use limit policies have historically carried with them a host of additional problems, such as choosing appropriate allocation and rationing techniques. These techniques have been among the most controversial actions protected area managers have ever taken.

Principle 9: Monitoring is essential to professional management

Monitoring, in an informal sense, has historically been a component of the protected area manager’s job. However, monitoring has generally been conducted informally, with little systematic planning and implementation. Monitoring is defined as the period and systematic measurement of key indicators of biophysical and social conditions. It performs two major functions in the LAC process. First, it allows managers to maintain a formal record of resource and social conditions over time. In serving this function, data points can inform managers of changes in these conditions rather than relying solely on informal perceptions of changes that might have occurred. This is particularly important in situations where managers change frequently or where effects are slow to develop. Second, it helps assess the effectiveness of management actions. Thus, monitoring helps managers understand, in a relatively objective way, if the action addressed the problem.

Principle 10: The decision-making process should separate technical decisions from value judgments

Many decisions confronting protected area managers are simply technical in nature, such as the number of toilets in a campground, the location of a trail, or the design of a visitor centre.

However, many others, including decisions to limit use (and how), reflect judgments about values – such as objectives for an area, spacing between campsites, types of facilities, or the kind of recreation opportunities to be provided. It is important in decision-making that these means/ends decisions not get confused. Decision processes should separate questions of “what is” from “what should be”. For example, identifying the range of diversity in resource or social conditions that exists within a protected area is a different task from determining the preferred range of diversity. Existing conditions may influence preferred conditions, but the two tasks should be kept separate.

Principle 11: Consensus among affected groups about proposed actions is needed for successful implementation of Protected Area Management Strategies

Managing visitor impacts in national protected areas occurs within a context of increasing public concern about both environmental quality and participation in government decision-making. Increasing conflict over natural resources indicates that successful decisions – ones that can be implemented – require not only a systematic and technical problem solving process but also one that incorporates public participation as well. Within the highly charged social and political contexts that protected area management frequently occur, technical planning processes tend to create more in the way of disagreement than agreement because proposed actions may adversely affect some well-defined value expressed by a group within the public.

While the LAC system does not specifically require public participation, the lessons from  experience suggest that the legal power to plan is separated from the power to implement. Individual interest groups have “veto” power over proposed actions. Planning is political and must proceed specifically with this acknowledgment. Thus, a consensus (“grudging agreement”) is needed for a protected area agency to implement.

With acknowledgement to the following sources:

McCool, S.F. 1994. Planning for sustainable nature dependent tourism development: The limits of acceptable change system. Tourism Recreation Research 19(2): 51-55.

Stankey, G.H., and S.F. McCool. 1991. Recreation use limits: The wildland manager’s continuing dilemma. Western Wildlands 16(4): 2-7.

Eagles, Paul F.J., McCool, Stephen F. and Haynes, Christopher D.A. (2002). Sustainable Tourism in Protected Areas: Guidelines for Planning and Management. IUCN Gland, Switzerland and Cambridge, UK. xv + 183pp.

The next post in this series will deal with the four major components of the LAC planning System and the nine distinct steps of the planning process.

Contact Lorton Consulting about for professional input on recreational planning in protected areas, Limits of Acceptable Change and the use of indicators for monitoring recreational impacts — we would be more than willing to advise you.