How do water and carbon cycles operate in contrasting locations? Flashcards
What type of run-off is associated with high rainfall in the Amazon?
Rapid run-off
Related to high rainfall, intensive rainfall events, and well-drained soils.
What is the average net primary productivity (NPP) of the Amazon rainforest?
2500 grams/m2 per year
How much carbon does the Amazon rainforest absorb annually?
2.4 billion tonnes
What is the average biomass of the Amazon rainforest?
400-700 tonnes/ha
What role do rainforest trees play in the water cycle?
Absorbing and storing water from the soil and releasing it through transpiration
What are the effects of geology on the flood hydrograph in the Amazon Basin?
- Impermeable catchments result in rapid run-off
- Permeable rocks store rainwater and slow run-off
What is the significance of high temperatures in the Amazon rainforest?
Generate high rates of evapotranspiration and lead to intense precipitation
What is the relationship between deforestation and water storage in the Amazon?
Deforestation reduces water storage in forest trees and soils
True or False: Deforestation increases evapotranspiration.
False
Fewer trees mean less evapotranspiration and therefore less precipitation.
What is the impact of converting rainforest to grassland on run-off?
Increases run-off by a factor of 27
What percentage of rainforest carbon is stored in the above-ground biomass?
60%
Fill in the blank: The Amazon rainforest is a major global reservoir of stored _______.
Carbon
What strategies are being implemented to manage tropical rainforests sustainably?
- Protection through legislation of primary forest
- Reforestation projects
- Improving agricultural techniques
What is the goal of the Parica project in Rondonia?
Develop a 1000 km2 commercial timber plantation on deforested land
How does deforestation affect the carbon cycle?
Exhausts carbon biomass store and reduces inputs of organic material to the soil
What nutrients are primarily stored in rainforest trees?
- Calcium
- Potassium
- Magnesium
How much of the primary forest in Amazonia was destroyed or degraded since 1970?
Almost one-fifth
What was the effect of the April 2014 floods on the Madeira River?
- Record levels of 19.68 m above normal
- 60 people died
- 68,000 families evacuated
What are the main stores of carbon in the Amazon rainforest?
- Above ground biomass (trees)
- Below ground (roots and soil organic matter)
What is the main reason for the reduction of rainfall in regions affected by deforestation?
Disruption of the regional water cycle
What type of rocks dominate the geology of the Amazon Basin?
Ancient igneous and metamorphic rocks
What is the role of tree nurseries in deforestation mitigation?
Tree nurseries provide seedlings for sustainable timber production and reforestation efforts.
What are the benefits of the monoculture project mentioned?
- Sustainable timber production
- Carbon sequestration
- Reduction of CO2 emissions from deforestation
- Re-establishment of water and carbon cycles
- Reduction of runoff and nutrient loss from soil.
Who are the Suruf people?
The Suruf people are an indigenous group in Rondonia participating in rainforest protection and reforestation efforts.
What is the aim of the scheme that the Suruf people participate in?
To protect primary rainforest on tribal lands from illegal logging and reforest degraded areas.
In what year did the Suruf join the UN’s REDD scheme?
2009
What does the REDD scheme provide to the Suruf people?
Payment for protecting the rainforest and abandoning logging.
What are carbon credits?
Permits that allow companies to emit a certain amount of CO2, which can be purchased from those who have reduced their emissions.
What was significant about Natura’s purchase of carbon credits from the Suruf?
It was the first carbon credit sale by indigenous people in Amazonia.
What has been the main cause of deforestation in Amazonia?
Farming.
What is a response to improve agricultural sustainability?
Diversification through rotational cropping and integrating livestock with arable operations.
What are dark soils?
Human-engineered soils made from charcoal, waste, and human manure that retain fertility long-term.
What climatic conditions characterize the Alaskan tundra?
Mean temperatures below -15 °C and a negative heat balance for eight or nine months of the year.
What is permafrost?
Permanently frozen ground found in the Alaskan tundra.
What are the main features of the water cycle in the Alaskan tundra?
- Low annual precipitation (less than 100 mm)
- Low temperatures reducing absolute humidity
- Limited transpiration
- Low rates of evaporation
- Limited groundwater and soil moisture stores
- Accumulation of snow and ice during winter.
True or False: The biodiversity in the Alaskan tundra is high.
False.
Fill in the blank: The growing season in the Alaskan tundra lasts about _______.
three months.
What happens to river flow in spring and early summer in the Alaskan tundra?
A sharp increase in river flow occurs due to melting snow and ice.
What is the discharge range of the Yukon River from winter to summer?
- Minimum discharge: 340 cumecs in winter
- Maximum discharge: 24,600 cumecs in summer.
What is the primary reason for the presence of extensive wetlands in the Alaskan tundra during summer?
The presence of permafrost, which impedes drainage
Alaska has over 3 million lakes and extensive wetlands that lie in valleys, deltas, and along the coast.
How much carbon is estimated to be contained in the permafrost globally?
1600 GT of carbon
The permafrost acts as a vast carbon sink.
What is the net primary productivity (NPP) of the Alaskan tundra?
Less than 200 grams/m2/year
How does the carbon flux in the tundra change seasonally?
Concentrated in the summer months when the active layer thaws
What types of plants rapidly grow in the Alaskan tundra during the summer?
Sedges, crowberry, and moss
True or False: CO2 and CH4 emissions are limited to the summer in the tundra.
False
Emissions can occur even in winter due to pockets of unfrozen soil and water in the permafrost.
What has raised concerns about permafrost in Alaska becoming a carbon source?
Global warming and its effects on carbon emissions
What factor limits plant growth in the Alaskan tundra?
Low temperatures and the unavailability of liquid water for most of the year
What is the estimated range of carbon emissions from North Slope permafrost?
7 to 40 million tonnes/year for CO2 and 24,000 to 114,000 tonnes/year for CH4
Fill in the blank: The North Slope of Alaska accounts for less than ______ percent of the USA’s domestic oil production today.
4
List three impacts of oil and gas exploitation on the water and carbon cycles in Alaska.
- Melting of permafrost
- Increased runoff and flooding
- Disruption of drainage networks
What is the primary purpose of management strategies employed on the North Slope?
To protect the permafrost and minimize disruption to the water and carbon cycles
What percentage of precipitation in the Amazon rainforest is recycled by evapotranspiration?
Between 50 and 60 percent.
What is the average annual rainfall in the Amazon rainforest?
More than 2000 mm.
What is a characteristic of the climate in the Amazon rainforest?
High average temperatures between 25°C and 30°C with small seasonal variation.
How much carbon is estimated to be transferred annually from chemical weathering?
0.3 billion tonnes.
What is the significance of the limestone surface lowering observed at Norber Brow?
It indicates the effectiveness of chemical weathering processes over 13,000 years.
Fill in the blank: The process of photosynthesis can be summarized by the equation _______.
6CO2 + 6H2O -> C6H12O6 + 6O2
True or False: Respiration absorbs CO2 and emits oxygen.
False. Respiration absorbs oxygen and releases CO2.
What are the two main processes involved in carbon exchanges?
- Photosynthesis * Respiration
What role does fire play in forest ecosystems?
It frees carbon and nutrients, opens up the forest canopy, and increases biodiversity.
What factors affect the rate of decomposition?
- Climatic conditions * Temperature * Humidity
What is the significance of phytoplankton in the ocean’s carbon cycle?
They fix carbon through photosynthesis and contribute to the biological pump.
What are the main factors that sustain high rainfall totals in the Amazon rainforest?
High temperatures, abundant moisture, and dense vegetation
Strong evapotranspiration-precipitation feedback loops sustain high rainfall totals.
What percentage of incoming rainfall is returned to the atmosphere by evapotranspiration?
Around half
Most evaporation is from intercepted moisture from leaf surfaces.
What is the primary source of moisture lost in transpiration?
Soil via tree roots.
