Seite - 366 - in Biodiversity and Health in the Face of Climate Change

366 16.2.1 Ecosystem Benefits and  Services Protected areas and other natural ecosystems, such as wetlands and forested areas, including those within and adjacent to cities, can provide positive health benefits and services (Dudley et  al. 2010; Townsend et  al. 2015). Conserving or restoring forests can, for example, reduce the risk of malaria and certain other diseases. Watersheds retaining natural vegetation, particularly forests, provide cleaner water than more degraded watersheds. Protected areas can maintain dryland vegetation, stabilising soil, preventing desertification and dust storms, and reducing the sus- pended solids in air that create major respiratory problems (WCPA 2015). Marine protected areas and healthy wetlands boost fish stocks, contributing to food security and adequate protein for coastal and subsistence communities (Halpern 2003). Access to clean water is an essential pre-requisite for public health, and espe- cially important in densely populated cities. Poor planning, inefficient use, popula- tion growth and increasing demands for water all mean that the provision of adequate, safe supplies of water remains a major source of concern. One in five people in the developing world live without a reliable water supply and two billion city dwellers do not have adequate sanitation. Lack of clean water increases infant mortality and the prevalence of water-borne diseases, reducing productivity, strain- ing health services, and causing millions of deaths every year (WHO 2005; Stolton and Dudley 2010; WCPA 2015). Furthermore, water shortages undermine agricul- tural productivity and food security, while excess water, as a result of storms and floods, creates not just immediate social and economic impacts but is often followed by disease and epidemics (Dudley et  al. 2010). Protection of natural habitats helps regulate against flooding and other weather-related events and sustains the avail- ability of high-quality water for health, social and economic development. Functioning natural ecosystems within well-managed watersheds and protected areas provide efficient and cost-effective ways of supplying clean water (see Box 16.1). One-third of the world’s largest 100 cities, including Jakarta, Dar es Salaam, New  York, Melbourne and Sydney, rely on forest-protected areas for a substantial part of their domestic water supply (Dudley and Stolton 2003). High-altitude, tropi- cal montane vegetation provides clean water supplies to major cities in Latin America. Protected areas in Colombia, for example, cover about 10% of the country and provide 50% of Colombians with water. In the capital, Bogotá, eight million people get 80% of their water from the paramos vegetation protected in the Chingaza National Park (WCPA 2012). Recognising the importance of this natural function, the mayors of the surrounding municipalities are supporting restoration of natural habitats within the Park. Protected wetlands can also provide critically important water supplies and pro- tection from flooding for many urban populations. The 89,000 hectare Lagoas de Cufada Natural Park in southern Guinea-Bissau was created to protect the largest freshwater reserve of the country. In a region where rainfall has been reducing, this Ramsar site plays a crucial role in supplying water for the city of Buba, as well as K. MacKinnon et al.