WATER AND CARBON CYCLES - THE AMAZON RAINFOREST

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WATER AND CARBON CYCLES - THE AMAZON RAINFOREST

EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -17 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation

Question 1: Atmospheric moisture,

Precipitation, Interception storage,

• Evapotranspiration, back to atmospheric moisture.
• Stem flow
• Drip flow

Surface storage water in puddies,

• Water in plant tissue, evapotranspiration (as above).
• Evaporation from soil, back to atmospheric moisture.
• Soil water, evaporation from soil.

Answer:

Describe the Amazon water cycle.

Question 2: The low air pressure belt between the equator and Hadley Cell, and warm air converges at the Inter Tropical Convergence Zone (ITCZ), causing air mass to rise, cool and condense (evapotranspiration), forming clouds and therefore rain over the rainforest.

Answer:

Describe the global atmospheric circulation system.

Question 3: - 1/5 of world's biomass of carbon (stores 80-120b tons).

• Forest size changed over time by shrinking & extending (covers 5.5m km2, 300 billion of

world's trees).

• Carbon sequestration has increased the productivity of rainforests.
• The net uptake of forests has changed by half, due to increased CO2, meaning trees die faster.
• Average rainfall 3,000mm, however 75% total rainfall is intercepted by dense canopy layer and

then transferred to ground via stemflow. This is used by plants or is infiltrated through soil or flows overland into nearby channels. Evapotranspiration occurs to the remaining 25%.

• Average temperature 28 degrees celsius, very humid climate (high humidity levels and

unstable weather causes heavy rain most days).

Answer:

General Facts Question 4: - National Government set a target of "One Billion Trees for the Amazon" from 2008-2030 in Para, Brazil.

• Protect the land from unsustainable logging and agricultural practices that have blighted parts

of the Amazon.Why: To replenish part of Amazon rainforest as 90% Para's land has been deforested.Consolidate image of Para as guardian and restorer of Amazon. Protect 1000's of wildlife species, e.g Jaguars and colourful Macaws.How: Plant 1b trees on deforested land by 2013 and reduce global levels of greenhouse gases by 5% until 2030. Restore legal and environmental reserves in Para. Develop new economic model for more sustainable practices.

Answer:

Afforestation Question 5: Forests play a crucial role in maintaining the global carbon budget, absorbing 2.4b metric tons of carbon/year (Amazon absorbs 1/4 of total).Wood is around 50% carbon, therefore rainforests act as a major carbon sink, and in return emit oxygen. Described as "lungs of the earth".

Answer:

How do rainforests mitigate the effects of global warming?

Question 6: Over past 2 decades trees have been dying at an increasing rate and the rate of tree growth has remained flat. As a result, the average hectare of Amazon rainforest gains less than

• ton of biomass/year. This is due to the paradoxical effect of the higher concentration of CO2 in

air, encouraging tree growth, causing them to die faster (positive feedback mechanism). Faster growing trees invest less energy in defences against disease and produce less dense wood, therefore they are more susceptible to sickness or falling down. If sustained over a long time, increases in tree mortality could lead to degradation of the forest. Amazon's role as a global carbon sink is shrinking, we can't rely on trees to solve the whole carbon problem, deeper cuts in emissions will be required to stabilise our climate.

Answer:

Why is the Amazon rainforest losing its ability to soak up CO2?

Question 7: - Increased surface run-off causes a high risk of flooding.

• Removal of trees through slash and burn reduces porosity of soil, resulting in faster rainfall

drainage, erosion and silting of rivers and lakes.

• Spracken et al 2012 found further deforestation in Amazon, could result in 20% decline in

regional rainfall, as air blowing from rainforest contains less moisture.

Answer:

What are the impacts of deforestation on the tropical rainforest water cycle?

FLOODING

Question 8: - United Nations Educational, Scientific and Cultural Organisation (UNESCO), established 1980 in state of Amazonas.

• World Heritage Site and Biosphere reserve covering an area of around 2m hectares.

Why: To promote heritage, beauty and rich biodiversity to the public, encouraging protection of the rainforest.How: Creating tourist attractions: ? Itaubal trail ? Rapids of Carabinani and Jaú river ? Petroglyphs ? historical site of Airão

Answer:

Jaú National Park

Question 9: - South America

• Equator in Southern Hemisphere
• Passes through multiple different countries

Answer:

Location

Question 10: Water:

• Causes plants to decompose, imputing carbon into the soil which increases growth spurt of

trees. The growth stimulation feeds them through the system much faster meaning they die younger.

• Recycling of water system within tropical rainforest.
• High precipitation, leads to a unique ecosystem.
• Fast decomposition leads to a faster uptake of nutrients from the soil.

Carbon:

• Increases growth spurt of trees; the growth stimulation feeds them through the system much

faster meaning they die younger.

• Sequestering of increased CO2 concentrations in the atmosphere, results in increasing above

ground biomass by 0.3-0.5% and increases productivity.

• The increase in CO2 increases photosynthesis and therefore plant growth.
• The rainforest acts as a major carbon sink, deforestation has decreased the CO2 uptake.

Answer:

How do the water & carbon cycle and the rainforest influence each other?Question 11: - As is that the transpiration is reduced the atmosphere becomes less humid.

• Transpiration will rapidly decrease.
• Less trees causes rainfall to be transferred straight to forest floor encouraging surface flow as

the soil becomes dry and baked (exposed to the sun).

• Reduced evapotranspiration from cleared areas mean air is less moist, causing a reduction in

cloud cover.

• Removal of trees through slash and burn, facilitates sudden evaporation of water that was

previously retained in forest canopy.

Answer:

What are the impacts of deforestation on the tropical rainforest water cycle? EVAPOTRANSPIRATION

Question 12: CO2 from atmosphere,

Trees absorb carbon via photosynthesis,

• Leaf litter
• Root cell respiration and death
• Runoff
• CO2 released through respiration by plants/animals and decomposers, back into atmosphere.

Answer:

Describe the carbon cycle in the Amazon rainforest.