Amazon Rainforest Case Study.

• Hot Enviroment - Codajas, State of Amazonas, Brazil.

• Average rainfall is high (over 2000mm per year) with frequent, high-intensity rainfall.

• Distribution of precipitation is relatively even throughout the rainforest however there are occasional spells of short drier priods in some parts.

• Plant interception is high due to high amount of canopy with intercepted rainfall accounting for 25% of evaporation.

• Warm humid conditions make the amazon rainforest ideal for plant growth.

• High rates of photosynthesis due to large, continous diversity and distribution of vegetation here.

• This takes out atmospheric carbon supplies for photosynthesis but decomposition of plants also releases it.

• Trees and plant absorb water from soil via interception and theen release it through the leaf stoma via evapotranspiration.

• High vegetation density in the forest means this process is sped up because of the humid conditiosn making it ideal forp lant growth which therefore provide high moisture in the rainforest - this is a loop of positive feedback between vegetatio ngrowth and atmospheric humiditiy.

• High amounts of photosynthesis and NPP because of the high biodiversity which could make the amazon a carbon source but this maybe balanced out by lots of vegetation taking up carbon dioxide for photosynthesis therefore acting as a carbon sink.

Evapotranspiration:

• High rates of evapotranspiration from high temperatures, abundant moisture and dense vegetation.

• Strong evapotranspiration-precipitation loop sustains high rainfall totals.

• Half of incoming rainfall is usually returned to atmosphere with most evaporation being intercepted moisture from leaf stoma.

• MOisture lost by transpiration is intercepted from soil via plant roots.

Atmosphere:

• The absolute humidity in the atmosphere is high due to high temperature which leads to adiabatic expansion of air due to high rates of evapotranspiration.

Goundwater/soil:

• Abundant rainfall leads to increase filteration and therefore increased groundwater flow meaning high ground storage in aquifers and soils.

Run-off:

• Rapid run-off due to abundant rainfall, intensive events and well-drained soils. Inpermeable grounds due to crystalline rock. 

• Overland flow may occur when rainfall exceeds infiltration capacity of ground therefore increase risk of flooding.

• During seasonal distribution, run-off may peak every other month of the year.

Geology: 

• Impermeable catchment areas have minimal water storage capacities leading to rapid run-off due to minimal channel storage.

• Permeable/porous rocks such as limestone/sandstone store rainwater from infiltration, increasing groundwater storage and decreasing run-off/throughflow/overland flow.
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• Large parts of the 

Relief:

• Most of the amazon basin comprises of extensive wetlands.

• Areas of gentle relief water moves across surface via overland flow or horizontally through the soil via throughflow into streams and rivers.

• Widespread innudation across extensive floodplains occurs annual storing water for several months and slwing its movement into rivers.

Temperature:

• High temperatures throughout year generate high evapotranspiration rates.

• Strong convection causes high atmospheric humidity and development of thunderstorm clouds as well as intense precipication. 
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• Water cycles between the land surface, canopy and atmosphere by transfers/flows such as evapotranspiration and precipitation.

Water cycle:

• 1970-2013 the annual area deforested average around 17,500km^2.

• 1/5 of primary forest is deforested albeit this has slowed down recently,

• The channel storage in the amazon catchment basin reach its peak in April 2014 when flooding occured.

• There was a reduction in precipitation, interception, groundwater storage and accerelated run-off and overlad flow.

Nutrient/carbon cycle:

• Primary forest biomas represents 60% of carbon storage in the amazon rainforest.

• Most is found in the soil as humus (organic material) or roots.

• Deforestation exhausts carbon stores.

• Reduced canopy results in less carbon storage.

• This depletion results in reduced transfer of carbon from soil to atmosphere.

• Legislation of large primary vegetation expanses currently unaffected by commercial developement. (enacted by the brazilian government of 1998).

• Projects to reforest deforested/degraded areas by subsistence farming, cattle ranching, logging and mining.

• Improving agricultural techniques make cultivation pernament (e.g. diversitication of crop harvests).