The Amazon ecosystem

The Amazon forest is the purest form of Tropical Rainforest. It contains an overwhelming biodiversity and is the slowest growing tropical forest in the world.

Fluvial system

The hydrographic system is the largest in the world. The physical-chemical composition of the water in its rivers and Igarape’s (streams) help us classify this giant system into three main types:

  • Clear rivers with black waters;
  • Turbid rivers with white waters;
  • Clear rivers with light, almost colorless waters.

Varzea and Igapo

The Varzea is a flat, periodically flooded terrain alongside the white water rivers and it is far more fertile than the Igapo, which borders the black waters. This Varzea of the Amazon river, which can be as much as 60 miles wide, consists of a group of islands, lakes, canals, side streams, etc. which is exposed to flooding according to the water level. The decomposition of submerged organic matter, which is speeded up by the high temperature and by the action of bacteria and fungi, helps to fertilize the soil of these flood plains.

The Igapo form the banks of the black rivers, also inundated during the periods of flood. They have low fertility and little productivity in terms of aquatic and surrounding fauna, in spite of a large variety of species. The trees growing in the Igapo are resistant to flooding.

Seasons in the Amazon

Rainy season

The rainy season normally runs from January till June, March and April are the wettest months. In most cases, bursts of rain are followed by sunny periods with temperatures that can go up to 86 F.

The period following the rainy season is considered as ‘springtime’ in the region. The swollen rivers have reached their maximum level. Huge tracts of forests are entirely or partially swamped by this mass of water. Nights in the region are considered cool and fresh all year round, due to the presence of the nearby rivers.

Dry season

From August onward, daytime temperatures gradually rise due to the diminishing rainfall and the lowering of the level in the rivers. Temperatures in November may reach 110 F. The nights however, remain cool. December generally is known as the transition period towards the approaching raining season.

Fishing season

The receding waters later in the year gradually concentrate the fish within the riverbeds as the temporarily inundated areas fall dry. This leads to spectacular situations, specially in the Amazon river region, where the sportfishing fanatic can have peculiar and spectacular experiences. The preferred period for fishing is from August to December.