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Social-Ecological Systems Meta-Analysis Database: Theory

CAR principles for conservation area design

Variable relationship:

Comprehensive, Adequate, and Representative (CAR) are three key principles from the conservation planning literature that broadly determine what it is that a protected area (Policy Instrument) should protect. The goal of the CAR principles (PA CAR principles) is to find a system of protected areas that comprehensively captures viable representatives of all biodiversity features. The CAR principles serve to inform the design of a resilient protected areas that reflects available data and knowledge of the biodiversity of the region. Sometimes they are referred to as CARE principles, with E standing for efficient (i.e., minimum cost). This theory predict that positive environmental outcomes (Commons Condition Trend) follow from satisfying these principles in PAs.

Scientific Field
Component Type(s)


VariableRoleRole ExplanationValue
Policy instrumentProximate independent variableUses networks of protected areas as the policy instrumentProtected area
PA CAR principlesProximate independent variableComprehensive: refers to an aim to capture the full range of biodiversity (both typical and atypical) within a PA, taking into consideration biodiversity composition, structure and function and evolutionary processes. A reserve system is most comprehensive if it contains examples of as many elements of biodiversity as possible (Possingham et al. 2005). Adequate: refers to a PA/network’s ability to play a role in the long term protection of biodiversity within a given bioregion – it builds on the comprehensiveness principle – but with the goal not to just capture biodiversity, but to promote its persistence (long-term viability) Representative: requires PAs to capture biodiversity that is representative of their surroundings (i.e. protection covers the range of variation in that chosen species and/or habitat). The selection of such areas should also take into consideration any communities/species that are rare, endangered or unique.Yes
Commons condition trendFinal outcomeThe outcome of a well-designed system of protected areas is expected to be the preservation and recovery of species and biodiversity.Remained the same or Improved

Related Theories

TheoryRelationshipCharacterizing Variables
Local livelihood and protected areasrelated
Ecological effectiveness of MPAsrelated
Centralized conservationrelated

Related Studies


Possingham, Hugh, K. A. Wilson, and T. J. Regan. 2005. The roles of spatial heterogeneity and ecological processes in conservation planning. In Ecosystem Function in Heterogeneous Landscapes, edited by G. Lovett, C. Jones, M. Turner and K. Weathers. New York: Springer