The enlisting of such areas is part of a strategy being used toward the conservation of the world's natural environment and biodiversity. The IUCN has developed the protected area management categories system to define, record, and classify the wide variety of specific aims and concerns when categorising protected areas and their objectives.
A strict nature reserve (IUCN Category Ia) is an area which is protected from all but light human use in order to preserve the geological and geomorphical features of the region and its biodiversity. These areas are often home to dense native ecosystems that are restricted from all human disturbance outside of scientific study, environmental monitoring and education. Because these areas are so strictly protected, they provide ideal pristine environments by which external human influence can be measured.
In some cases strict nature reserves are of spiritual significance for surrounding communities, and the areas are also protected for this reason. The people engaged in the practice of their faith within the region have the right to continue to do so, providing it aligns with the area's conservation and management objectives.
Human impacts on strict nature reserves are increasingly difficult to guard against as climate and air pollution and newly emerging diseases threaten to penetrate the boundaries of protected areas. If perpetual intervention is required to maintain these strict guidelines, the area will often fall into category IV or V.