The amazon Flashcards
Key facts about the amazon
The world’s largest tropical rainforest and covers 40% of south American landmass
hot, wet climate–>vegetation is dense
Home to up to 1million plant species
500 species of mammals
2000 species of fish
Covers 9 countries
5,500,000km^2 of forest cover
What are the causes of deforestation
cattle ranching
small-scale agriculture
fires
logging
More about cattle ranching
vast areas of land are cleared to create pastureland for grazing cattle
leading cause of deforestation is beef consumption
greatest rates of deforestation are near slaughter houses
more about small-scale agriculture
requires the forest to be “slashed and burned” to clear the ground for crops and grazing
More on logging
This can create inroads towards deeper reaches of the forest, to make a path for further destruction as roads are make it easier for heavy equipment to get through
What is the climate of the amazon
warm all year round (22-34C)
relative humidity is 88% in the rainy season
77% humidity in the dry seasons
Rainfall at least 2,000mm and in some areas 10,290mm of rain each year
What are the attempts to limit human impacts on the amazon
selective logging
replanting
environmental law
protection
Description of selective logging
only the older trees are cut down
if only a few trees are taken from each area then the forest structure is kept
–>the canopy is still there and the soil isnt exposed
–>the rainforest is able to regenerate
–>reducing the impact on the water and carbon cycle
description of replanting
new trees are plants to replace the old ones
It is important that the same species of tree is replanted as the ones cut down so the biodiversity is maintained for the future
An example of replanting in the amazon
in Peru a project replanted 115 acres of forest between 2016-2019
description of environmental law
laws that ban the use of wood from forests that are not managed sustainably
laws that ban excessive logging
laws that control land use
What is an example of environmental law used to protect the amazon
the brazilian forest code says that landowners have to keep 50%-80% of their land as forest
Description of protection within the amazon
Many countries have set up national parks and nature reserves to protect rainforests
Within the parks and reserves logging is monitored and prevented
What is an example of protection in the amazon
The central amazon conservation complex in brasil was set up in 2003 to protect biodiversity in 50000km^2
while allowing local people to use the forest in a sustainable way
Why is the water cycle important to the amazon
The water cycle causes the amazon to be wet
There’s a lot of evaporation over the Atlantic ocean and the wet air is blown towards the amazon-contributing to the high rainfall
Warm temperatures mean that evaporation is high in the forest increasing precipitation
The rainforest has a dense canopy-meaning interception is high. As a result less water flows into the river and does so slowly
The amazon is populated with species that are adapted to high humidity and frequent rainfall
Why is the carbon cycle important to the amazon
The amazon is a carbon sink
the increasing co2 concentration in the atmosphere has led to increased productivity as the forest is able to access more co2 for photosynthesis-the amount of biomass is increasing
As a result the amount of co2 sequestered by the amazon has increased, making it an even more important carbon store
However, even though trees are growing more quickly they are dying younger
Therefore we may be unable to rely on the amazon as a carbon sink for much longer
Effects of deforestation on the water cycle
There is no tree canopy to intercept rainfall, so more water reaches the soil surface. The soil becomes saturated and instead the water moves to rivers as surface runoff, increasing flood risk
Deforestation reduces rate of evapotranspiration-less water vapour reaches the atmosphere, fewer clouds form and rainfall is reduced. Increasing risk of drought
How does deforestation effect the carbon cycle
Without roots to hold the soil together, heavy rain washes away nutrient rich top layer soil, transferring carbon stored in the soil to the hydrosphere
Deforestation means that there is less leaf litter, so humus isnt formed. The soil cannot support much new growth, limiting the amount of carbon that is absorbed
Trees remove co2 and store it, so fewer tress enhances the greenhouse effect and global warming.
When did the amazon suffer severe droughts
2005
2010
2015-16
How has climate change affected the water and carbon cycle as well as the amazon
Increasing temperatures leads to decreasing rainfall leading to droughts
Plants and animals are adapted to moist conditions so many species will die in dry weather. Frequent or long periods of drought could lead to extinction. Droughts may lead to forest fires, releasing co2
Scientists predict that a 4C temperature rise could kil85% of the amazon rainforest. Leading to co2 release due to decomposition, less co2 being taken through photosynthesis.
What is the Amazon Basin and why is it significant?
The Amazon Basin is the world’s largest rainforest, covering 670 million hectares. It is home to 300 billion trees and 15,000 species, storing one-fifth of all carbon in the planet’s biomass.
How does the Amazon contribute to the carbon cycle?
The Amazon stores carbon in its biomass and acts as a carbon sink. In 2019, it absorbed about 600 million tonnes of CO₂ per year, but this is much less than the estimated two billion tonnes in the 1990s.
How does increased atmospheric CO₂ affect the Amazon?
It initially stimulates tree growth, but over time leads to faster tree aging and higher tree mortality rates.
What is the impact of rainfall in the Amazon Basin?
Average rainfall is 2,300 mm annually, with some areas exceeding 6,000 mm. Up to half never reaches the ground, as it is intercepted by the canopy and re-evaporated.
What were the deforestation rates in the Amazon between 2000 and 2007?
The Brazilian Amazon was deforested at a rate of 19,368 km² per year, destroying an area larger than Greece.
How does deforestation affect climate and soil?
Reduces soil humidity and increases temperature.
Enhances water evaporation and decreases rainfall.
Releases stored carbon into the atmosphere.
How has climate change affected the Amazon’s temperature?
Since the mid-1970s, temperatures have increased by 0.26°C per decade, with projections of a 2–3°C rise by 2050.
How does vegetation change impact the Amazon?
Rising temperatures and droughts cause species decline. A 3°C increase could destroy 75% of the forest within a century.
How do soil changes occur due to deforestation?
Amazonian soils store 4–9 kg of carbon per m².
Deforestation releases 30–60% of this carbon into the atmosphere.
Heavy rainfall erodes the topsoil.
What are the effects of river changes in the Amazon?
Reduced river discharge.
Increased silt, disrupting transport.
Flash flooding.
Loss of freshwater ecosystems and drinking water.
How does warming water temperature affect the Amazon’s rivers?
Kills temperature-dependent species.
Alters biodiversity.
Reduces oxygen levels, harming eggs and larvae.
What are some mitigation strategies for Amazonian deforestation?
National parks and forest reserves.
Biofuel production from sugarcane.
Reforestation using planted forests.
Enrichment of degraded forests with native species
