Earth's Life Support System pt 2- amazon rainforest Flashcards
What’s our case study of a tropical rainforest?
The Amazon rainforest
What’s the climate like in a tropical rainforest?
High average annual temperatures of 25-30 degrees.
Low seasonal variation in that temperature.
High average rainfall (no dry season)
What’s the average annual temperatures in a tropical rainforest?
25-30 degrees
What’s the average rainfall in a tropical rainforest?
2000mm
Why are there high average temperatures in a tropical rainforest?
As the sun shines directly over head with the concentration of the sun’s rays.
What type of rainfall is found in a tropical rainforest?
mainly convectional rainfall and precipitation all year round, due to intertropical convergence zone or low pressure belts dominating.
What does the intertropical convergence zone do?
It causes low pressure and rainfall all year round in the amazon rainforest. As it moves south to the tropic of Capricorn it may cause a smaller drier season in equatorial areas in the northern hemisphere.
What are the two different air masses for the intertropical convergence zone?
tropical maritime air mass
tropical continental air mass
What’s the tropical maritime air mass?
In tropical latitudes this air mass is hot to very hot, with high relative humidity, bringing unstable weather.
Where can the tropical maritime air mass be found?
Originates in the Atlantic ocean
What’s the tropical continental air mass?
In tropical latitudes this air mass is hot to very hot, with relatively low humidity, bringing stable weather.
Where can the Tropical continental air mass be found?
Originates in the Sahara desert.
What happens when the two air masses for the intertropical convergence zone meet?
moist air is forced upward, which causes water vapour to condense as the air cools and rises. This results in a band of heavy precipitation around the globe.
What are the flows in the amazon rainforest for the water cycle?
Precipitation
Evaporation
Run-off/ overland flow
What are the stores in the amazon rainforest for the water cycle?
Soils/ groundwater
Vegetation
Atmosphere
Precipitation in amazon rainforest water cycle:
High average of around 2000mm of rain per year. - 10% of that is intercepted by trees.
Convectional rainfall
Evaporation in amazon rainforest water cycle:
High evapotranspiration due to high temperatures, rainfall and dense vegetation.
50% of the incoming rain is returned to the atmosphere by evapotranspiration.
Run-off/overland flow in amazon rainforest water cycle:
Rapid run-off due to high rainfall.
River discharge peaks on one or two months per year.
Atmosphere in amazon rainforest water cycle:
High temperature means large amounts of moisture stored in the atmosphere, therefore high absolute humidity.
Vegetation in amazon rainforest water cycle:
Rainforest trees absorb and store water from the soil and release it by transpiration.
Soil/ groundwater in amazon rainforest water cycle:
Deep tropical soils/ high rainfall means large storage of water in soils or aquifers.
Where does the losses of water in the Amazon rainforest basin come from?
river flows out to the Atlantic ocean, and the export of water vapour to the atmosphere.
Where does the inward flux of moisture to the water system come from in the Amazon rainforest basin?
moisture from the Atlantic Ocean.
What percentage of carbon in land is stored in biomass in the Amazon rainforest?
40-50%
How much carbon is in the Amazonia?
14-40kg of carbon per km squared
How much biomass is in the amazon rainforest?
400-700 tonnes/ha
What does the Net Primary Productivity mean?
The amount of energy fixed (taken from the sun) that’s available for new plant growth.
What is the term for the amount of energy fixed (taken from the sun) that’s available for new plant growth?
Net Primary Productivity
What is the NPP in the Amazon rainforest?
2500g per m squared per yr
What is Net Primary Productivity measured in?
grams per metres squared per year.
How much carbon is stored in the soil of the Amazon rainforest?
between 90-200 tonnes/ha
What are examples of soil carbon?
fungi, microbes and decaying organic matter -> BIOTIC FACTORS
Minerals -> ABIOTIC
How much carbon does the Amazon rainforest absorb?
2.4 billion tonnes per year.
What type of soil does the rainforest have?
poor nutrient levels.
What are the key characteristics of the Amazon rainforest carbon cycle?
Rapid carbon exchange between the atmosphere, biosphere and soil.
Rapid and high levels of carbon fixing through photosynthesis.
Warm, humid conditions, so rapid decomposition and quick release of CO2.
What does rapid exchange enable in the carbon cycle for the Amazon rainforest?
enables the nutrient poor soils to support a diverse biome with high biomass.
What are the physical factors affecting the flows and stores in the water cycle for the Amazon rainforest?
Geology
Relief
Temperature
How does the geology affect the stores and flows in the Amazon rainforest?
In areas of the rainforest with permeable underlying geology, there is greater storage of rainwater and slow run-off.
Other areas of the rainforest have crystalline impermeable rock with minimal storage capacity and so high levels of run-off.
How does the relief affect the stores and flows in the Amazon rainforest?
Large parts of the Amazon basin are lowland areas so water will flow to streams and rivers as either overland flow or through flow.
What’s an example of rock that’s permeable in the Amazon rainforest?
Limestone
What’s an example of rock that’s impermeable in the Amazon rainforest?
granite
How does the temperature affect the stores and flows in the Amazon rainforest?
MORE WATER IS INVOLVED AS A RESULT
High rates of evapotranspiration due to the warmer temperature.
Strong convection resulting in high atmospheric humidity.
What are the physical factors affecting the flows and stores in the carbon cycle for the Amazon rainforest?
Climate- growing conditions
Biomass
Climate- decomposition rates
Geology
How does the climate-growing conditions affect the stores and flows in the Amazon rainforest?
Hot humid conditions with high rainfall and intense sunlight means high NPP due to high levels of photosynthesis.
How does the biomass affect the stores and flows in the Amazon rainforest?
Trees in the Amazonia are the principal carbon store; 100 billion tonnes are locked up here.
60% of carbon is stored in the above ground biomass, with the rest in the soil.
How does the climate- decomposition rates affect the stores and flows in the Amazon rainforest?
Decomposition is rapid due to hot, humid conditions.
Soil organisms decompose organic matter releasing nutrients, taken up b y trees and return CO2 to the atmosphere.
How does the Geology affect the stores and flows in the Amazon rainforest?
Much of the Amazonian basin consist of igneous and metamorphic rocks.
Close to the Andes limestone outcrops are found which is a significant carbon store for the slow carbon cycle.
