To be labelled a wetland, an area must be soaked with water for at least some portion of the year, however some wetlands may even be dry for part of the year. Included in wetlands are swamps, marshes and bogs. The role of wetlands is a varied one. Some of their functions include: a collection facility for flood waters, filtering and cleaning water, habitat for a multitude of plants and animals, fishing areas, recreation and of course providing picturesque scenes!
One of the largest wetland areas is the Pantanal, covering over 75,000 square miles in Brazil, Bolivia and Paraguay. The Pantanal boasts up to 12 sub-regional ecosystems, each with its own distinctive identity and characteristics. Because of this, it is identified as being a very precious resource for Brazil. There are estimations of more than 10,000 animal species found in the Pantanal, and more than 3,500 plant species.
Threats to existence of wetlands are mostly felt from humans. According to the World Wildlife Foundation, “Half of the world’s wetlands have disappeared since 1900.” In addition to industrial threats, invasive species, pollution, climate change, and dams are serving to decrease wetlands. There have been many efforts to balance the needs of populations with saving the vital wetland areas. Thus, The Ramsar Convention was signed in 1971. Under the convention, participating countries agree to identify wise use of wetlands, designate and effectively manage appropriate wetlands for the “Ramsar List”, and cooperate with other countries on shared wetlands and species. The country with the highest number of wetlands sights on the Ramsar List is the United Kingdom, with 170. There are currently 168 contracting parties, including the United States.
Sources:
http://en.wikipedia.org/wiki/Wetland#Balancing_wetland_conservation_with_the_needs_of_people
http://en.wikipedia.org/wiki/Ramsar_Convention
http://water.epa.gov/type/wetlands/index.cfm
http://www.defenders.org/wetlands/basic-facts
https://www.worldwildlife.org/habitats/wetlands
http://wwf.panda.org/about_our_earth/about_freshwater/intro/majorwetlands/
http://www.brazil.org.za/pantanal.html
http://wwf.panda.org/about_our_earth/about_freshwater/intro/threats/