The concept of Conservation Unit (CU) has evolved since its advent in the United States in 1872. At first it referred to the goal of preservation of scenic attributes and potential for the development of leisure activities. It gradually began to incorporate notions of preservation of historic heritage, protected natural area and, in the mid-twentieth century, to comprise the idea of biodiversity conservation.
At present, according to SNUC – Sistema Nacional de Unidades de Conservação da Natureza (National System of Nature Conservation Units), the creation of CUs aims at preserving biodiversity in characteristic environments, besides protecting headwaters and other water sources, rare or endangered species and natural monuments. These spaces allow the development of environmental education activities, scientific research, leisure, and maintenance and reproduction of the gene bank of wildlife.
CUs may be classified in two big groups according to the form of use of natural resources:
Full Protection Units – Ecological Station, Biological Reserve, National Park, Natural Monument and Wildlife Refuge;
Sustainable Use Units – Environmental Protection Area, Area of Relevant Ecological Interest, National Forest, Extractive Reserve, Fauna Reserve, Sustainable Development Reserve and Private Reserve of Natural Heritage.
Rio Grande do Sul is regarded as a pioneer in dealing with environmental issues since the 1950s, and at present it counts with 113 conservation units, including areas established by law and still not implemented. Out of these, 12 are federal areas, 26 are state ones, 51 are municipal ones (including areas of multiple uses and urban parks), and 24 are Private Reserves of Natural Heritage (PRNHs).
Source: IBAMA; SEMA/FEPAM and FZB.Note: Three municipal CUs were included in the period 2000-2010 without the date of creation: Antônio Prado Municipal Park; Guaporé Fauna Forest Reserve and Novo Hamburgo Municipal Park.