Ecosystems

Question 1

What is an ecosystem?

Answer 1

All the biotic parts and abiotic parts of an area.

Question 2

What is a producer?

Answer 2

An organism using sunlight to produce food.

Question 3

What is a consumer?

Answer 3

An organism getting its energy from eating other organism.

Question 4

What is a decomposer?

Answer 4

An organism that gets its energy from breaking down dead material.

Question 5

Example:
Describe the Epping Forest.

Answer 5

-The Epping forest is found in London.
-It is deciduous, with a large variety of native trees such as oak, elm, ash and beech.
-It has a lower shrub layer of holly and hazel above a layer of grasses, bracken, fern and flowering species.
-117 species of moss and lichen grow here.
-There are 9 amphibian and reptile species.
-There are 58 bird species.
-700 fungi species have been found.

Question 6

What are the seven major types of ecosystem, and what are their characteristics?

Answer 6

Tundra: Very cold winters, brief summers, little rainfall. Hardly any trees, with mosses, grasses and low shrubs for vegetation. Permafrost.

Grassland: Savannah: dry and wet season, although low rainfall. Mainly grasses and some trees. Temperate: more varied temperature, less rainfall. No trees, just grasses.

Boreal Forest (taiga): Cold, dry winters, mild moist summers. Trees are coniferous.

Temperate Deciduous Forest: Warm summers and mild winters with rainfall all year round. Deciduous trees.

Tropical Rainforest: Hot and wet all year round. Lush forest with dense canopies.

Polar: Very cold, icy and dry. Not much grows at all. Remains dark for several months each year.

Hot Desert: Little rainfall. Very hot during the day and very cold at night. Sparse shrubs and cacti.

Question 7

Describe the climate of the tropical rainforest.

Answer 7

The climate is the same all year round. It is hot and rainy all year round: 20-28ºc with 2000mm rainfall yearly.

Question 8

Describe the people of the tropical rainforest.

Answer 8

There are many indigenous people who have adapted to life in the rainforest, hunting, gathering and growing crops.

Question 9

Describe the soil of the tropical rainforest.

Answer 9

The soil isn’t very fertile as heavy rain washes nutrients away. There is a thin layer of decayed leaf fall with decay fast in warm moist conditions, but competition for these nutrients is great.

Question 10

What are the different layers of the tropical rainforest?

Answer 10

Shrub layer, undercanopy, main canopy, emergent trees.

Question 11

Give five examples of plant adaptions in the rainforest.

Answer 11

Emergent trees have adapted to grow very tall to reach the sunlight which is in such high competition. They have evolved wide strong butress roots in order to support their height.

Plants have thick, waxy leaves with pointed drip tips to channel off rainwater so it doesn’t damage the plant.

Epiphytes attach to trees, so they are risen up high with them, allowing them to reach the sunlight.

Plants only drop leaves gradually throughout the year, so they can keep growing all year round.

Some carnivorous plants have adapted to catch prey, such as the pitcher plant. This is important, as the soil is low in nutrients.

Many trees have smooth, thin bark as there’s no need to protect the trunk from cold temperatures, and the smooth surface helps allow water to run off it.

Question 12

Give five examples of animal adaptions in the rainforest.

Answer 12

Spider monkeys have adapted prehensile tails which allow them to traverse the dense canopies with the equivalent of a fifth limb.

Sloths have evolved to have highly camouflaged fur, meaning they don’t have to waste energy escaping predators, because the predators won’t see them.

Jaguars have developed sharp claws that allow them to climb small trees to sneak up on prey. This is useful as the rainforest is full of trees.

The draco lizard has expanding ribs that allow it to glide, meaning it can travel tree to tree without crossing the forest floor, risking predators.

Poison dart frogs have evolved brightly coloured skin to warn off predators, which secretes poison, discouraging them from being eaten.

Question 13

Case study:
How big is the Amazon Rainforest?

Answer 13

8 million km²

Question 14

Case study:
How much of the Amazon was deforested between 2001 and 2012?

Answer 14

18 million hectares

Question 15

Why is the Amazon being deforested?

Answer 15

-Commercial farming (65-70% cattle, 5-10% other)
-Subsistence farming (20-25%)
-Commercial logging (2-3%)
-Other causes (1-2%): Mineral extraction, energy development, population growth, road building.

Question 16

Case study:
What are the impacts of deforestation in the Amazon?

Answer 16

• Climate change: the Amazon stores 140 billion tonnes of carbon. 75% of Brazil’s emissions are from deforestation.
• Soil erosion: Brazil loses 100 tonnes of topsoil per hectare each year. This leads to future landslides and flooding. Soil fertility is reduced, as nutrients are washed away more easily.
• Economic development: In March 2018, Brazil exported almost $600 million of beef. Brazil is also the world’s second largest exporter of soy beans. The mining industry creates jobs, one Peruvian company employing 8000 people. Local rubber tappers have lost their livelihoods.

Question 17

How can the rainforest be managed sustainably?

Answer 17

Selective logging is where only the oldest trees are felled, and most trees remain, such as helicopter logging.

Replanting is planting new trees to replace the old ones that were cut down.

Ecotourism minimises damage to the environment and benefits local people. Only a small number of visitors are allowed in an area at a time. This provides an income for local people, meaning they won’t have to earn money through logging, as well as raising awareness and giving an incentive to conserve the rainforest.

Education raises awareness of the impacts of deforestation and encourages people to be sustainable.

Conservation of areas of rainforests allows them to be protected.

Reducing debt in lower income countries can be traded for conserving the rainforest, and means the country doesn’t have to make this money to repay it through logging.

International hardwood agreements promote sustainably sourced hardwoods which richer countries may buy for furniture, meaning they won’t have to be sourced through unsustainable logging.

Question 18

What is the climate like in polar and tundra environments?

Answer 18

Polar areas can reach -90ºc, but winters tend to be around -40ºc. Tundras reach a maximum of 10ºc in warm months and drop to -50ºc in winter. Precipitation is low – less than 100mm a year in polar areas and less than 380mm in tundras. The seasons are well defined by cold summers and freezing winters.

Question 19

What is the soil like in cold environments?

Answer 19

Ice sheets cover polar areas, so no soil is exposed. Tundra soil is thick, acidic and not very fertile. Beneath the soil is a layer of permafrost, containing trapped greenhouse gasses.

Question 20

What plants live in cold environments?

Answer 20

Polar areas have very few plants, only lichens and mosses on rocks, and some grasses at the coast. Tundras as well as this have some hardy shrubs, and potentially in warmer areas, a few short trees.

Question 21

What animals live in cold environments?

Answer 21

There are relatively few species in cold environment ecosystems. Polar bears, penguins and seals are found in polar areas, with lemmings, wolves and reindeer in tundra areas.

Question 22

What people live in cold environments?

Answer 22

The tundra is home to indigenous people, as well as oil and gas workers in larger towns.

Question 23

Describe plant adaptations to cold environments.

Answer 23

Most plants become dormant to survive the cold, dark winters.

Plants are low-growing and round-shaped to provide protection from the wind.

Most plants have shallow roots because of the layer of permafrost beneath the soil layer.

Leaves are generally small to limit the amount of moisture lost through transpiration.

The warmer, wetter summer is very short, so plants have a growing season of just 50-60 days.

Many plants reproduce using underground runners or bulbs to cope with the cold.

Question 24

How have animals adapted to live in cold environments?

Answer 24

Animals like seals are well-insulated with blubber to reduce the energy required to keep them warm.

Some animals hibernate, such as Arctic ground squirrels, which hibernate for 7-8 months each year and can survive even if their body temperature drops below freezing.

Animals have adapted to survive on the limited food available, such as reindeer on lichen.

Many birds migrate to warmer areas, like Arctic terns flying to the southern hemisphere in winter.

Many animals grow white winter coats to camouflage from predators, such as Arctic foxes.

Question 25

Case study: Alaska
What opportunities for development are there in Alaska?

Answer 25

The oil and gas industry: most oil comes from Prudhoe Bay, which is linked to Valdez by the Trans-Alaska pipeline.

Mineral resources: materials such as gold, silver, iron and copper are all mined in Alaska, particularly in the Tintina gold belt. In 2015, $154 of gold was exported from Alaska.

Fishing: in 2016, Alaska’s fishing industry had a value of $1.7 billion, and employed 30,000 fishermen.

Tourism: tourists are attracted to Alaska’s scenic and wilderness areas, with around 2 million tourists visiting yearly, bringing in almost $2.5 billion and employing 39,000.

Question 26

Case study: Alaska
What are the challenges for development in Alaska?

Answer 26

Alaska’s population is small in relation to its area, and most live on the south-eastern coastline.

It is extremely cold: Prudhoe Bay’s mean annual temperature was -9ºc, making it dangerously cold for workers.

Northern parts of Alaska are quite inaccessible, with the lack of infrastructure for travel making these northern areas difficult to access.

Buildings and infrastructure: providing buildings that cope with the permafrost is expensive. Resource value has encouraged people to overcome this, however, with the Trans-Alaska pipeline being built on stilts to not melt the permafrost.

There is a risk of harming wildlife: Caribou have very strict migration patterns, and disrupting these would threaten the species. Also, the oil industry could severely damage wildlife is there was a spill. The Exxon Valdez oil spill in Alaska, 1989 spilled 11 million gallons of oil into the environmentally sensitive area, killing 250,000 seabirds, 2,800 sea otters and 22 orca.