Environment and Sustainability in Urban Areas

Urban growth and the migration of populations from rural environments to cities is a global trend. According to the United Nations, in 1950, only 30% of people in the world lived in cities. This number rose to 50% in 2007 and forecasts indicate that between 2010 and 2030, 60% of the world's population will have left rural areas and migrated towards urban areas (TRZYNA, 2014).

In Brazil, these data are even more significant. In 1980, around 68% of the Brazilian population lived in cities and, in 2010, this number rose to 85% (IBGE, 2014), an even higher percentage than that observed in the world average. This entire increase in the number of populations living in cities often occurs without adequate urban planning, which impacts the organization of territorial space, overloads environmental resources, affecting the environment and people's quality of life.

Thus, they are increasingly notorious:

- the scarcity of natural resources (including water);

- environmental degradation;

- climate change (with rising sea levels, higher temperatures, variation in rainfall and floods, droughts, storms and more frequent and severe heat waves);

- demographic and social changes associated with urbanization and population growth (increase in wealth and absolute number of poor people)

As cities grow, the pressure on the remaining native vegetation also increases. This growth situation directly impacts natural areas, including terrestrial protected areas. Given this scenario, the conservation of urban forests and other natural areas gains even more importance, as they provide ecosystem services, which are fundamental to sustaining human health and well-being and promoting environmental quality in cities and their surroundings ( NOWAK AND WALTON, 2005).

Some local interventions can contribute to maintaining or increasing biodiversity and quality of life in urban environments:
- restoration of existing habitats in cities;

- enrichment or gradual reintroduction of plants and animals (increasing the complexity of ecosystems and the services they provide);
- planting native species in parks, squares, streets, domestic gardens, vertical gardens and rooftops, as well as other areas, which diversifies the environment that supports mammals, birds, reptiles, amphibians, bees and other insects;
- creation of small wetlands, such as lakes or depressions, which helps provide a variety of ecosystem services.

(Secretariat of the Convention on Biological Diversity-2012).