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?
[print version | spanish | french | portuguese
| chinese | japanese]
Continued: Rainforest rivers
This article was written by Rhett A. Butler [bibliographic citation for this page] and was last updated on the most recent date listed in the column on the right side.
Other pages in this section:
|
|
| |
CONTENTS
Other languages
WEEKLY NEWSLETTER
INTERACT
|
Recent news
Brazilian mining company connected to Belo Monte dam voted worst corporation
(01/31/2012) The world's second largest mining company, Vale, has been given the dubious honor of being voted the world's most awful corporation in terms of human rights abuses and environmental destruction by the Public Eye Awards. Vale received over 25,000 votes online, likely prompted in part by its stake in the hugely controversial Brazilian mega-dam, Belo Monte, which is being constructed on the Xingu River. An expert panel gave a second award to British bank Barclay's for speculation on food prices, which the experts stated was worsening hunger worldwide.
Saving the world's biggest river otter
(01/30/2012) Charismatic, vocal, unpredictable, domestic, and playful are all adjectives that aptly describe the giant river otter (Pteronura brasiliensis), one of the Amazon's most spectacular big mammals. As its name suggest, this otter is the longest member of the weasel family: from tip of the nose to tail's end the otter can measure 6 feet (1.8 meters) long. Living in closely-knit family groups, sporting a complex range of behavior, and displaying almost human-like capricious moods, the giant river otter has captured a number of researchers and conservationists' hearts, including Dutch conservationist Jessica Groenendijk.
Brazil begins preliminary damming of Xingu River as protests continue
(01/19/2012) Damming of the Xingu River has begun in Brazil to make way for the eventual construction of the hugely controversial, Belo Monte dam. The Norte Energia (NESA) consortium has begun building coffer dams across the Xingu, which will dry out parts of the river before permanent damming, reports the NGO International Rivers. Indigenous tribes, who have long opposed the dam plans on their ancestral river, conducted a peaceful protest that interrupted construction for a couple hours.
Deforestation, climate change threaten the ecological resilience of the Amazon rainforest
(01/19/2012) The combination of deforestation, forest degradation, and the effects of climate change are weakening the resilience of the Amazon rainforest ecosystem, potentially leading to loss of carbon storage and changes in rainfall patterns and river discharge, finds a comprehensive review published in the journal Nature.
-small.150.jpg)
Picture of the day: nearly-extinct turtle released into the wild in Cambodia
(01/18/2012) Only around 200 southern river terrapins (Batagur affinis) survive in the wild, but today at least the species got some good news. A female terrapin was released back into the Sre Ambel River with much fanfare after being caught by a local fishermen in Cambodia.
More rainforest news
|
|
|
