About this site
Providing tropical forest news, statistics, photos, and information, rainforests.mongabay.com is the world's most popular rainforest site. [more]
Weekly Newsletter
Mongabay will never distribute your email address or send spam.
Share
Waterways off the Rio Negro in Brazil. (Courtesy of NASA)
Chapter 6:
RAINFOREST WATERS
Tropical rainforests have some of the largest rivers in the world, like the Amazon, Madeira, Mekong, Negro, Orinoco,
and Zaire (Congo), because of the tremendous amount of precipitation their watersheds receive. These mega-rivers
are fed by countless smaller tributaries, streams, and creeks. For example, the Amazon alone has some 1,100 tributaries,
17 of which are over 1,000 miles long. Although large tropical rivers are fairly uniform in appearance and water
composition, their tributaries vary greatly. Many tropical rivers and streams have extreme high and low water levels
that occur at different parts of the year.
In addition to rivers, rainforests have conventional, free-standing lakes and so-called oxbow lakes, formed when
a river changes course. These lakes are home to species adapted to the quiet, stagnant conditions.
Tropical waters, whether they be giant rivers, streams, or oxbow lakes, are almost as rich in animal species as
the rainforests that surround them. But they, too, are increasingly threatened by human activities, including
pollution, siltation resulting from deforestation, hydroelectric projects, and over-harvesting of resident species.
Review questions:
Why are some of the world's largest rivers found in tropical regions?
Ecological benefits of REDD boosted by inclusion of private landowners, potentially harmed by plantations
(11/17/2009) Reducing Emissions from Deforestation and Degradation [REDD] programs that include landowners will conserve more habitat and ensure greater ecosystem services function than programs that focus solely on protected areas, report researchers from the Woods Hole Research Center (WHRC), the Instituto de Pesquisa Ambiental da Amazônia (IPAM), and the Universidade Federal de Minas Gerais (UFMG).
Forgotten species: Madagascar's water-loving mammal, the aquatic tenrec
(11/12/2009) There are many adjectives one could attach to the aquatic tenrec: rare, mysterious, elusive, one-of-a-kind, even adorable, though one tries to stray from such value-laden titles since it excludes so many other non-adorable inhabitants of the animal kingdom. This small and, yes, cute insectivore, also known as the web-footed tenrec, lives in Eastern Madagascar where at night it spends the majority of its time swimming and diving in fast-moving streams for insects and tadpoles. It sleeps during the day in small streamside burrows. To date that is about the extent of our knowledge of this species.
Will Brazil's blackout drive a new push for more rainforest dams?
(11/12/2009) The power outage that affected nearly a third of Brazil's population Tuesday could be used by development interests to justify a renewed push for hydroelectric dams in the Amazon rainforest.
Amazonian natives say they will defend tribal lands from Hunt Oil with "their lives"
(10/25/2009) Indigenous natives in the Amazon are headed to the town of Salvacion in Peru with a plan to forcibly remove the Texas-based Hunt Oil company from their land as early as today. Peruvian police forces, numbering in the hundreds, are said to be waiting in the town. The crisis has risen over an area known as Lot 76, or the Amarakaeri Communal Reserve. The 400,000 hectare reserve was created in 2002 to protect the flora and fauna of the area, as well as to safeguard watersheds of particular importance to indigenous groups in the region.
