Subject: Limits of Acceptable Change (LAC)
Author: John Shores, Sustainable Development Consultant

Summary: Limits of Acceptable Change (LAC) is a system for applying adaptive management to the problem of assessing and monitoring cause and effect on ecosystems. LAC provides a straightforward method for managing the impacts of tourism on biodiversity.

Limits of Acceptable Change (LAC) is a well-developed system for guiding the principles of adaptive management to the problems we have been discussing related to the impacts of tourism on ecosystems and biodiversity. I view LAC as the next evolutionary step after Carrying Capacity (as I recall, Carrying Capacity was developed first in the field of animal husbandry and later was applied to wildlife management). Carrying Capacity approaches to managing tourism and visitor impacts tended to take a worst-case-scenario approach to tourists. We perhaps cynically assumed that all tourists were equally bad or destructive for a fragile environment, and we restricted access by setting a carrying capacity (a maximum number of these generic tourists) for the landscape or seascape in question.

LAC recognizes that all tourists are not equal. A minimum-impact trekker does not have the same impact as an off-road 4WD recreationist. So we set thresholds (Limits) for the amount of change a given ecosystem or habitat can absorb (Acceptable Change). Then we adapt our management of the ecosystems and the tourist impacts to try to stay within those limits.

A separate LAC scheme does have to be defined for each ecosystem / habitat / landscape being considered, so there is a significant amount of work involved in setting up the system. Although this may sound like it requires a lot of scientific research, in practice the hardest part usually is getting the stakeholders to agree on the limits.

There is a considerable body of literature (mostly in English) dealing with limits of acceptable change and carrying capacity, with a significant amount addressing tourism and visitor issues specifically.

John Shores / Consultant / San Jose, California, USA