Ecosystems flashcards

Question 1

Evaluate a local scale management strategy, outlining what issue they are trying to tackle/help with, how they work, how effective they have been.

Answer 1

✔ The Biological Reserve in Monteverde now covers over 10,500 hectares, this
ensures wider habitat range for the animals within this ecosystem. It has extremely diverse flora
and fauna (over 100 species of mammals, 2,500 plant species).
✔ It ensures that new infrastructure (new roads, sewers, water pipes, electricity lines)
benefit the locals as well as the tourists.
✔ 80 new businesses have opened in Monteverde since 1970s. Ecotourism aims to create local employment while conserving the natural
environment: There are 400 full-time and 140 part-time jobs directly related to
tourism.This is great for the economy and can allow Costa Rica to put their money elsewhere

X People have migrated into the area looking for jobs. This is placing pressure on
the local infrastructure such as dirt roads.
X Atmosphere has negatively changed away from traditional local community to
a busy tourist centre.
X Tourists are demanding more and more facilities and greater luxury. These
facilities can use more electricity, although the majority of Costa Rica’s energy is
produced from renewable sources.

Question 2

What Impacts are humans having on a named tropical rainforest?

Answer 2

People have migrated into The Cloud Forest looking for jobs. This is placing pressure on the local infrastructure such as dirt roads.
Atmosphere has negatively changed away from traditional local community to a busy tourist centre.
Tourists are demanding more and more facilities and greater luxury. These facilities can use more electricity, although the majority of Costa Rica’s energy is produced from renewable sources.
Wood/paper products - Humans are deforesting forests for logging to collect wood for creating furniture and timber for house building + wood pulp for paper.
The cloud forest is also impacted by climate change - more forest fires.

Question 3

Explain the distribution of tropical rainforests (8 marks)
Low Pressure
Heat + light
ITCZ (equator)

Answer 3

Role of ITCZ in the rainforest?
Firstly, the majority of the tropical rainforests are found within the Intertropical Convergence Zone, an area near the equator where trade winds converge. This area experiences consistently low pressure due to the convergence of warm, moist air. This low-pressure system gives ideal conditions for the formation of clouds, as the warm, moist air rises at the ITCZ, it cools and condenses, forming dense cloud formations. These clouds act as reservoirs of moisture, leading to frequent and copious rainfall in the surrounding regions. The abundance of rainfall and the continuous uplift of moist air and subsequent condensation generate substantial precipitation levels vital for the perpetuation of the flora and fauna in tropical rainforests, therefore contributing significantly to the unique and thriving ecosystems found within rainforests.

Role of insolation in the rainforest?
Secondly the equatorial regions receive high insolation throughout the year due to the angle of the earth (23.5°) relative to the sun, this has a marked impact upon the insolation in different places and at different times of the year. The suns very concentrated rays lead to higher temperatures. These elevated temperatures create a warm and stable climate that is essential for sustaining the lush and diverse vegetation found in tropical rainforests. The warmth provided by the high insolation leads to photosynthesis, allowing plants to thrive and flourish all year-round. Therefore due to the continual warmth and abundance of sunlight enables a high rate of plant growth, fostering the incredible biodiversity and dense foliage that characterise tropical rainforests.

Role of nearby oceans?
Thirdly, tropical rainforests being found nearby oceans, such as those in Borneo and Indonesia, plays a pivotal role in sustaining these ecosystems. The presence of oceans nearby facilitates a consistent source of moisture through evaporation and the transportation of humid air masses inland. As prevailing winds carry moist air from the oceans towards the land, this air contributes significantly to the humid conditions essential for rainforest ecosystems. Additionally, nearby oceans help maintain relatively stable temperatures within these regions, preventing extreme fluctuations that could otherwise disrupt the delicate balance of rainforest ecosystems. Therefore, the oceanic influence contributes to the regulation of climatic conditions, fostering an environment possible for the growth and sustenance of the diverse vegetation and wildlife characteristic of tropical rainforests in these coastal areas.

Question 4

What are the main causes of deforestation?

Answer 4

Natural disasters - hurricanes, forest fires, flooding -
Wood/paper products - logging to collect wood for creating furniture and timber for house building + wood pulp for paper.
Clearing of TRF for animal agriculture (farmland) eg: cattle farming, soy, sugar cane and palm oil.
Climate Change: this can exacerbate risk of wildfires as the lack of available water leads to trees dying and becoming very dry
Urban expansion removal of trees for urban development such as road building land change to residential (house building)
Mining: iron ore, gold - clear the land for mining access, settlements for labourers, roads.

Question 5

What is an Ecosystem?

Answer 5

The interdependence of climate, water, soil, plants and animals

Question 6

Using the statements below explain in a few sentences the characteristics of the Tropical rainforest soil profile.
- Decomposition rates are higher in warm and wet climates
- Weathering rates are higher in warm and wet climates
- Nutrients levels in the soil are low

Answer 6

The combination of high temperatures and intense rainfall accelerates decomposition rates, breaking down organic matter rapidly. This contributes to a thick organic layer at the surface. Additionally, the warm and wet conditions enhance chemical weathering in particular, leading to the development of a highly weathered, leached, and nutrient-poor soil profile. The nutrients released through decomposition and weathering are often swiftly taken up by vegetation, leaving the soil with low nutrient levels. Despite the lush vegetation above, the soil profile in tropical rainforests tends to be relatively shallow and nutrient-depleted, emphasising the rapid nutrient cycling and tight nutrient recycling within the ecosystem.

Question 7

For the nutrient cycle explain how biotic and abiotic components of an ecosystem are dependent on one another (4)

Answer 7

• Flora are dependant on warm climate for photosynthesis
• Decomposers are dependant on soil for a habitat
• Many flora are dependant on animals for seed dispersion and fertilisation
• Some animals are dependant on plants for food
• Animals are dependant on climate for warmth
• Flora are dependant on the litter/soil for nutrition

Question 8

For food chains, explain how biotic and abiotic components of an ecosystem (TRF) are dependent on one another (4)
Talk about:
- Producers
- Decomposers
- Consumers
- Biotic and Abiotic components

Answer 8

• Producers (biotic) are dependant on abiotic factors such as sunlight, to provide photosynthesis for growth.
• Some fauna are dependant on the plants for food - therefore growth.
• Decomposers are dependant on the dead leaves (litter) to respire and reproduce.
• Flora and Fauna depend on the availability of water in the environment. Plants, through transpiration, release water vapor into the atmosphere, affecting local humidity levels. Herbivores and carnivores, in turn, obtain water directly or indirectly from their food sources and the environment.
• Biotic Component: Organisms need suitable habitats for feeding, breeding, and shelter. Vegetation provides habitats for a variety of species.
• Abiotic Component: Soil composition, topography, and physical features of the environment contribute to the structure of habitats.
  Interdependence: The structure of habitats, influenced by abiotic factors, determines the availability of resources and shelters for biotic components. For example, trees may provide nesting sites for birds, and burrows in the soil may serve as shelters for small mammals.

Question 9

Describe where hot and cold deserts are found

Answer 9

Deserts: Deserts are particularly dry environments. Cold deserts can be found at a wider range of latitudes (usually around 75c). Hot deserts such as the sahara form between the hadley and ferrel cells at around 25-40 degrees from the equator. Deserts are found between the ferrel and hadley cells because these are predominantly high pressure areas. This is where air descends from high altitudes and is particularly dry having already used up all its moisture over lower latitudes closer to the equator. This explains why on average we see less than 100 cm of rainfall in the deserts biomes.
The temperatures of deserts range between -5 and 30c and an average of 0-70cm of annual rainfall. Deserts are predominantly found within North Africa with some deserts in Australia, California (West coast of USA) and some deserts found in Central Asia. Hot deserts are mainly found around the tropics. Cold deserts are found in Greenland, the North of Canada and in Antarctica.

Question 10

Describe the location of TRF:
(3 separate points. Must give regions, latitude, specific countries.)

Answer 10

Tropical Rainforests are commonly found in South America, South East Asia and parts of Africa. Tropical rainforests are found surrounding the equator and up to about 25 degrees North and South. They are found within the hadley cells. The region with the largest area of rainforest is in South and Central America, the majority of which is the Amazon rainforest. Another example is in SouthEast Asia, for example Indonesia.

Question 11

Explain why we get high levels of convectional rainfall in the rainforest: use the terms: ITCZ, low air pressure, concentrated solar radiation, rapidly rising air, high humidity, evaporation, condensation.

Answer 11

Tropical rainforests get high levels of convectional rainfall because they are found within the Hadley Cells and within the ITCZ. Convectional rainfall is frequent here because the sun’s rays are most concentrated at the equator so this leads to rapid heating of the earth surface, this heats up the air above it leading it to rapidly rise. We also have high levels of evapotranspiration due to the concentrated rays which creates moist air, as it rises, it cools and condenses to form cumulonimbus clouds leading to high levels of precipitation when the air becomes oversaturated.

Question 12

Describe the climate of a tropical rainforest

Answer 12

Very wet with over 2,000 mm of rainfall per year.
Very warm with an average daily temperature of 28°C. The temperature never drops below 20°C and rarely exceeds 35°C.
The atmosphere is hot and humid.
The climate is consistent all year round. There are no seasons.

Question 13

Explain how water is cycled in the rainforest

Answer 13

As the rainforest heats up during the morning, the water evaporates into the atmosphere and condensates forming cumulonimbus clouds

Precipitation occurs in the rainforest, leading to water either directly hitting the ground (infiltration), or being intercepted by leaves or by stemflow (flowing down the stem).
This is called convectional rainfall. 25.6% of water is lost through pores in leaves and then evaporated by heat in a process known as evapotranspiration.

The roots absorb some moisture, but the canopy intercepts most of the rainfall; 48.5% of the water evaporates from the canopy layer.
Transpiration allows the water to go back from the leaves into the atmosphere. Warm moist air rises; the water will cool and condense forming rain clouds again (the cycle continues).

Question 14

Explain how the nutrient cycle works in the rainforest

Answer 14

The forest floor is hot and damp (perfect conditions) which enables dead leaves to decompose quickly. This explains the small circle for leaf litter. Due to the vast amount of vegetation, the nutrients leave the soil very quickly. This decomposition can occur within three to four months in the rainforest.
As organic material (such as leaves) decays and is recycled so quickly by the nutrient-hungry plants and trees, few nutrients ever reach the soil. The circle for the soil is even smaller than that for the litter. This is why many trees have their roots close to the surface or even above the surface of the ground; they are poised to take advantage of any nutrients available
The greatest store of nutrients is in the biomass - the living plants and animals.

Question 15

Most of the Rainforest’s nutrients is stored in the biomass. Using the following bullet points explain why this is the case – have a think about rates of decomposition and productivity rates.
- Extremely intense rainfall
- Warm temperatures

Answer 15

Intense rainfall in rainforests can lead to leaching, where water percolates through the soil, carrying away nutrients. This leaching process can result in nutrients being washed out of the soil and into water bodies. Intense rainfall can also lead to rapid decomposition of organic matter on the forest floor. Decomposition releases nutrients into the soil, but the high precipitation rates may wash away these nutrients before plants can take them up. As a result, plants have adapted to retain nutrients within their biomass as a strategy for nutrient conservation.
Warm temperatures increase the rate of enzymes in decomposers such as bacteria, fungi, and other microorganisms. This accelerates the decomposition of organic matter, releasing nutrients into the soil. However, the warm conditions also increase the likelihood of nutrient leaching. Therefore, plants store nutrients in their biomass to ensure they have a steady supply for growth and development. The rapid growth of vegetation requires a continuous supply of nutrients. Storing nutrients in the biomass allows plants to maintain high productivity even during periods of nutrient scarcity in the soil.

Question 15

Compare the landscape of both the Arctic circle and Antarctic landscapes. (mountains, amount of sea ice, thickness of glacial ice, landmass size)

Answer 15

Within the arctic circle in areas such as Greenland and Siberia large areas are made up of permafrost. When the top few centimetres of this ground thaws in the summer it produces a landscape with many depressions which fill with lakes. The top few centimetres of permafrost will melt revealing Marshland and boggy land. This is different to Antarctica where the vast majority is covered with ice sheets throughout. The Arctic is very mountainous, an example is Thor Peak reaching the highest of 5,495 ft. Antarctica is also very mountainous; the Transantarctic mountains stretch for 3500 km across the continent. There is vegetation present underneath the ice in the Arctic whereas in Antarctica not much vegetation is present as it is more rocky. Although Greenland’s ice sheet is the 2nd thickest - Antarctica’s ice sheet is by far the thickest and largest.

Question 15

Describe a polar biome’s climate and explain why this is the case.
Refer to:
- (high pressure and low temperatures for evaporation)
- (high latitude and diluted solar radiation due to curvature of the earth)
- (albedo effect)

Answer 15

polar biomes have low levels of precipitation because they are located in high pressure zones leading to minimal rainfall, the temperatures are so low that very little evaporation takes place. (high pressure and low temperatures for evaporation)

The polar biome has very cold temperatures (reaching below -50c occasionally) because the latitude is so high that the sun’s rays are diluted due to the curvature of the earth. (high latitude and diluted solar radiation due to curvature of the earth)

Ice and snow-covered areas have high albedo, and an ice-covered Arctic reflects solar radiation which otherwise would be absorbed by the oceans and cause the Earth’s surface to heat up. The proportion of the Earth’s surface that is covered by snow and ice has a great deal to say for how much of the incoming solar radiation is reflected or absorbed. (albedo effect)

Question 16

Describe the distribution of the polar biome.

Answer 16

Our polar biomes are found at high latitudes 66.5 to 90c North and South of the equator. Our tundra parts of the Polar biome are found mostly in the Northern hemisphere. For example in Siberia, Greenland and Northern Canada.

Question 17

Suggest why we might consider Antarctica a desert

Answer 17

Antarctica is a desert because it is so dry - with an average annual precipitation of just 166 mm along the coastal regions, and even less when moving further.
High pressure disallows clouds to form easily.
So cold there’s very little evaporation - except in summer where small amounts can occur, particularly in low latitude areas. Little variation of wildlife, harsh climates, little vegetation.

Question 18

Explain the interdependence of climate, soil, water, plants, animals and human activity in either the Antarctic or the Arctic
polar region.

Answer 18

Cold, dry climates (abiotic) can lead to less biodiversity (biotic) in the Arctic and Antarctica

Ocean currents (abiotic) bring up large amounts of nutrient rich water with algae (biotic), which is the main food for fish such as krill and cod leading to an increase of population which then supports the whole food chain.

The cold temps (abiotic) particularly in the winter allow the extension of ice which is essential for polar bears (biotic) because it provides them a base to hunt from. This is important as they get very tired swimming long distances.

Question 19

What would happen to the ecosystem if ocean warming kills arctic autotrophs?

Answer 19

When the autotrophs such as the ice algae die out due to ocean warming, this has a direct impact on the primary consumers (zooplankton) because there isn’t enough food, this will reduce the availability of food for secondary consumers such as phytoplankton etc. and this continues until we see the collapse. This is due to the fact that the polar ecosystem is incredibly fragile, as there are very few autotrophs in the food web. One of them is based solely on dead organisms which only exist if there are living organisms. The extreme temperatures and conditions mean only fauna and flora that have adapted to this climate can exist - any disruption to the food web can lead to rapid decline.

Question 20

Explore a range of impacts of human activity on either the Antarctic or the Arctic ecosystems, such as scientific
research, indigenous people, tourism, fishing, whaling and mineral exploitation.

Answer 20

Krill fishing - Antarctica water holds 550 million tons of krill. They sustain a huge number of species such as penguins and humpback whales. If you remove a main primary consumer there are not many alternatives leading to a quick collapse. South Korea, Norway, China, Ukraine and Chile go to the Antarctic from December - July. The Antarctic charter (over 20 countries) will only use Antarctica for scientific purposes. The quota system is not sustainable however. Humpback whales were caught in the nets as they were following the krill that got caught. The Krill oil market will rise by more than 900 million dollars by 2026. This is one of the biggest threats in the future because the demand will increase - possibly allowing the food web to collapse. This is being exacerbated by climate change making even more of a risk

Tourism - Since the early 1990s tourism in Antarctica has grown continually. Between 1992 and 2020, the number of tourists arriving increased ten-fold, rising to 75,000 in the 2019-20 season and again to 104,897 in the 2022-23 season. Antarctic travel has a high carbon footprint. Tourist activities can also cause damage at visitor sites and along travel routes, and disturb wildlife. For example, research has shown that tourist activities are causing penguin species to change their reproductive and social behaviours. Animals are not as used to human interaction as much as other animals in rural/city areas.

Overall the impacts are predominantly negative, the most significant negative is melting ice from human forced global warming. In the Arctic sea ice is melting at a rate of over 12% a decade. This boasts a range of issues, firstly, a reduction in ice leads to a reduction in the albedo effect thus only increase temperatures in the area, alongside rising sea level. Additionally melting ice means animals such as polar bears have reduced platforms to hunt off of, leading to increasing threat to their survival. Therefore due to the multitude of impacts, melting ice through global warming is the most significant impact caused by human forced global warming.

An increasing threat to the polar biome is tourism introducing ‘alien’ species to a fragile environment. For example, in Antarctica, tourists have brought species such as flies and algae over on clothing and in bags. This can have a devastating impact on indigenous species, as alien species can either kill off or spread diseases to indigenous ones which have not had time to adapt to competition. The growth in tourism in the polar biome is an increasing negative impact of human activity.

However, one of the few positive impacts of human activity is scientific research. In Antarctica, long term scientific research into rates of glacial ice such as melt rates has been essential in providing evidence towards scientific arguments on the need for action on climate change. Therefore not all human activity is negative and scientific research is important in protecting the polar biome.

Question 21

Explain a case study you have researched (Union Glacier) to examine one small-scale example of sustainable management in either the Antarctic or the Arctic such as sustainable tourism, conservation and whaling.

Answer 21

Minimising impacts and examples of being sustainable
✔ Guest are encouraged to use a minimum amount of water when showering.
✔ Human waste is transported away from camp and guest are given pee bottles.
✔ Tents are naturally heated by 24hr sunlight during the Antarctic summer.
✔ Equipment is powered by solar energy to reduce the use of fossil fuels.
✔ Strict controls on preventing species outside of the Antarctic ecosystem from
entering.

Negative impacts and examples of not being sustainable
X Rescue operations to anyone injured or in danger would be greatly restricted.
X There’s risk of few individuals committing environmental misconduct and
damage.
X Tourist still have to travel huge distances to the base, meaning tourists would
have a large carbon footprint for visiting.
X Increasing demands for tourism in Antarctic may pose environmental problems
to the fragile ecosystem in the future.
X Visiting is hugely expensive and therefore only the wealthy are able to share and
appreciate the unique Antarctic environment.

Question 22

Assess the impact of human activities on the polar biome (8)

Answer 22

Overall the impacts are predominantly negative, the most significant negative is melting ice from human forced global warming. In the Arctic sea ice is melting at a rate of over 12% a decade. This boasts a range of issues, firstly, a reduction in ice leads to a reduction in the albedo effect thus only increase temperatures in the area, alongside rising sea level. Additionally melting ice means animals such as polar bears have reduced platforms to hunt off of, leading to increasing threat to their survival. Therefore due to the multitude of impacts, melting ice through global warming is the most significant impact caused by human forced global warming.

An increasing threat to the polar biome is tourism introducing ‘alien’ species to a fragile environment. For example, in Antarctica, tourists have brought species such as flies and algae over on clothing and in bags. This can have a devastating impact on indigenous species, as alien species can either kill off or spread diseases to indigenous ones which have not had time to adapt to competition. The growth in tourism in the polar biome is an increasing negative impact of human activity.

However, one of the few positive impacts of human activity is scientific research. In Antarctica, long term scientific research into rates of glacial ice such as melt rates has been essential in providing evidence towards scientific arguments on the need for action on climate change. Therefore not all human activity is negative and scientific research is important in protecting the polar biome.

Question 23

Examine one global example of sustainable management in either the Antarctic or the Arctic by
investigating global actions such as the Antarctic Treaty.

Answer 23

Has the Antarctic Treaty been successful?

✔ The Antarctic Treaty establishes
freedom of scientific investigation and bans military activity on that continent. It does not recognise territorial disputes between different countries. Under the Treaty, countries have enjoyed peaceful cooperation with no conflict. The absence of military activities helps to preserve the unique and fragile environment of Antarctica. Without the threat of military presence, there is less risk of environmental degradation from activities such as pollution, habitat destruction, or resource exploitation.
✔ The Antarctic treaty is a model for possibly protecting other environments such as
the Arctic.
✔ Today 52 countries have signed the treaty to demonstrate their commitment to retaining this vast untouched wilderness for the benefit of all human kind. Therefore the large number of countries that have signed the treaty shows its effectiveness in sustainable management.
X There are pressures from an increase in tourism and demand for precious mineral
resources. This could be a source of conflict in the future.
X Countries such as the UK, Chile and Norway still have not given up their claim for
parts of Antarctic territory. This could also cause conflict in the future