Igarapé Cajari, Rio Caurés tributary, Brazil

Environment

Environment

Affected by human activity

Affected by human activity

Agriculture

Agriculture

Surrounding area

Rio Negro is the second largest river in South America with many river tributaries that eventually end up with smaller forest streams. One of these forest streams is Igarapé Cajari, which is a tributary of Rio Caurés .

Underwater landscape

In Amazonia, during the rainy season with a heavy rainfall water level rises and eventually it’s flooded into the surrounding forest area. In this time, fish migrates into the submerged forest where abundant food sources are found, and the breeding begins.

We know, any forests represent as a major source of plankton and other natural foods. With the water level rises, this turns into a necessary area for young fish, as well as for adult ones. With the amount of fallen leaves, which acts as a source of infusoria, is ideal of baby fishes. Other than providing natural food for fish, forests provide them with the shelter from predators and create the shadow above water, thereby preventing overheating and even excessive drying during the dry season.

The soil is sandy and with almost no mineral content. A large amount of leaf litter forms a dense carpet, along with the roots of the flooded forest and branches. Water carries a large amount of detritus. Detritus contains decomposing organic matter, including animal remains, plant residues, waste products, and bacteria and other microorganisms associated with them.

During the rainy season (starts September 6 and lasts for 8.7 months, ending around May 29) the water is considerably colder and temperature is about 23 °C, water pH is about 6ph. During the dry season (starts around May 29 and lasts for 3.2 months, ending around September 6), the water level is reduced and warmer, the temperature of water is around 28-30 °C. Due to the low water level and the large amount of leaves and branches, the water contains a large concentration of tannins, which adds a dark color like “Tea color” and the water pH is low and is about 3.5-4ph.

List of fishes:

• Paracheirodon axelrodi
• Iguanodectes adujai
• Hemigrammus bellottii
• Hyphessobrycon paepkei
• Hyphessobrycon jackrobertsi
• Apistogramma mendezi
• Nannostomus eques
• Nannostomus trifasciatus
• Nannostomus digrammus
• Carnegiella strigata
• Petitella bleheri
• Dicrossus filamentosus
• Crenicichla notophthalmus
• Mesonauta festivus
• Fluviphylax zonatus

List of plants: At the location of the biotope I have mentioned there are no water plants, except the forest flooded plants.

Threats to ecology

Now a days there are 2 threats of natural habitat of this Amazon rainforest biotope:

1. Deforestation of Amazonia
2. The logging of the Amazon rainforest

“Lungs of the World” i.e. Amazon rainforest is already gone more than 20 % and much more is severely threatened as the destruction continues. If the trees and plants are destroyed, that means the area around where the rainforest sits – a region that depends on water from the Amazon for up to 70 percent of its economic activity – is likely to dry out. It is estimated that the Amazon alone is vanishing at a rate of 20,000 square miles a year.

Vivid beauty that comes with great diversity in plants and animals, rainforests also play a practical role in keeping our planet healthy. By absorbing carbon dioxide and releasing the oxygen that we depend on for our survival. The absorption of this CO2 also helps to stabilize the Earth’s climate.

Riparian zone

Trees near the aquatic habitat

Many -