Tropical Rainforests Ecology

What is a rainforest? In ecological terms- “ multi-storied closed, broad-leafed vegetation with a continuous tree canopy of variable height and with characteristic diversity of species and life forms”. Home to over 50% of all species on Earth

Location

Forest Climate Global heat and water pumps Rainforests are dark, - they absorb heat. Above a rainforest the air is cooler so it is more likely to rain. Inside rainforest, below canopy, humidity stays high. The forests stay wet and evaporate vast quantities of water through their foliage and into the air above, forming clouds. Some falls again as rain in the tropics but often clouds are carried great distances to fall as rain in the mid latitudes

Climate Compared Manaos(Brazil)London (England)

The Forest Structure Notes:

Adaptations

Fertile & Fragile Soil in r/forests very thin - trees have shallow roots Depends on rapid recycling of nutrients Removal of trees devastates this nutrient cycle

Rainforest Nutrient Cycle Abundant trees Numerous fallen leaves Rapid decay to form humus Nutrients added to soil Rich soil Rich tree growth

Rainforest Nutrient Cycle Trees removed No leaves falling No decaying leaves to form humus Remaining Nutrients leached from soil Soil deteriorates V.difficult for new trees to recover

Deforestation - the destruction of rainforests Forest Fires and Deforestation in Mato Grosso, Brazil

The Amazon River Basin

Clear-cutting –Starting point for other activities - logging, mining, agriculture, roads, settlements –mongobaymongobay

Causes of Deforestation Agriculture Clearing forest for cattle ranching, plantations (palm oil) or crops - eg. soybeans

Causes of Deforestation Logging Removal of trees for valuable hardwoods (e.g. mahogany, teak) Often illegal or uncontrolled

Causes of Deforestation Mineral Extraction(Mining) Mining trucks, equipment, open pits and roads at the Rio Huaypetue gold mine in southeastern Peru Location: Southeastern Peru; from Cuzco to Boca Manu mongobay

Rates of Deforestation in South America % loss per year

Rates of Deforestation Worldwide Hectares per year

What else is causing loss of rainforest? Look up the following websites and see what you can find. es.htmhttp:// es.htm mlhttp:// ml feature4.shtmlhttp:// feature4.shtml