The United Nations organization responsible for sustainable development has named 13 new international sites as areas to try alternative approaches to environmentally sensitive economic growth.

The United Nations Educational, Scientific and Cultural Organization (UNESCO) said the new designations include areas in Ethiopia and Zimbabwe for the first time and raises the number of biosphere reserves worldwide to 534 sites.

"Biosphere reserves … serve as places to test different approaches to integrated management of terrestrial, freshwater, coastal and marine resources and biodiversity," the UN agency said in a press release. The sites are found among 109 countries.

Of the new reserves, Mexico received three designations while Ethiopia and Nicaragua got two each.

The UNESCO program was launched in the mid-1970s in an effort to help countries, especially those economically disadvantaged, develop without crippling their environments.

For example, the Yayu region, in the western part of Ethiopia, is a huge area that produces spices, wood and honey among other natural resources. Sustainable development will focus on the coffee crop, UNESCO said.

Canada currently has 15 sites under the biosphere program, including Riding Mountain in Manitoba, the Niagara Escarpment in Ontario and the Clayoquot Sound area of British Columbia.