GCSE Edexcel Geography A - Ecosystems(3)

What is an ecosystem?

A series of interconnections linking plants and animals with the non-living environment in a particular area.

What is a biome?

A large-scale ecosystem that encompasses various ecosystems.

Where are tropical forests located?

In a latitudinal belt along the Equator, extending from 10°N to 10°S.

What are the three main tropical forest areas?

Amazon Basin in South America, Congo Basin in Central Africa, and Indonesian archipelago in Southeast Asia.

What is the average monthly temperature in tropical forests?

27-30°C all year.

What is the total annual precipitation in tropical forests?

Greater than 2,000 mm.

What type of vegetation is found in tropical forests?

Dense evergreen rainforest vegetation with four layers: emergent, canopy, under canopy, and shrub.

What animals are commonly found in tropical forests?

Sloths and howler monkeys, which eat fruit and leaves.

Where are tropical grasslands located?

In a latitudinal belt from 10°-20°N and 10°-20°S, mainly in Africa.

What is the average monthly temperature in tropical grasslands?

30°C in the wet season and 25°C in the dry season.

What is the total annual precipitation in tropical grasslands?

500-1,000 mm, with rains falling in a 6-8 month wet season.

What type of vegetation is found in tropical grasslands?

Mainly grasses that grow rapidly in the wet season and die back in the dry season.

What animals are found in tropical grasslands?

Herds of zebra, wildebeest, and giraffes.

Where are deserts located?

Along the Tropic of Cancer and Capricorn, extending from 20°-30°N and 20°-30°S.

What is the average monthly temperature in deserts?

30°-40°C, but nighttime temperatures can fall below 0°C.

What is the total annual precipitation in deserts?

Less than 250 mm, often unreliable.

What type of vegetation is found in deserts?

Sparse vegetation, including plants like prickly pear cactus that store water.

What animals are adapted to desert environments?

Camels, which store water in their humps, and nocturnal gerbils.

Where are temperate grasslands located?

In a latitudinal belt from 30°-45°N and 30°-45°S, mainly in the interior of continents.

What is the average monthly temperature in temperate grasslands?

20°C in warm summer and -5°C in cold winter.

What is the total annual precipitation in temperate grasslands?

500-800 mm, mostly in summer months.

What type of vegetation is found in temperate grasslands?

Mainly grasses, with few trees or shrubs.

What animals are commonly found in temperate grasslands?

Buffalo and wild horses.

Where are temperate forests located?

In a latitudinal belt from 45°-55°N and 45°-55°S, mainly on the edges of continents.

What is the average monthly temperature in temperate forests?

20°C in warm summer and 5°C in cool winter.

What is the total annual precipitation in temperate forests?

1,000 mm, with rain throughout the year.

What type of vegetation is found in temperate forests?

Deciduous broadleaved trees, such as oak, that shed leaves in winter.

What animals are found in temperate forests?

Deer, rabbits, and squirrels.

Where are boreal forests located?

In a latitudinal belt from 55°-65°N, mainly in northern Canada and Siberia.

What is the average monthly temperature in boreal forests?

15°C in summer and -10°C in winter.

What is the total annual precipitation in boreal forests?

500 mm, with some falling as snow in winter.

What type of vegetation is found in boreal forests?

Evergreen coniferous trees, such as fir and pine.

What animals are found in boreal forests?

Red foxes and black bears.

Where are tundra grasslands located?

In a latitudinal belt from 65°-75°N, mainly in northern Canada and northern Siberia.

What is the average monthly temperature in tundra grasslands?

15°C in summer and down to -30°C in winter.

What is the total annual precipitation in tundra grasslands?

150-250 mm, usually as snow.

What type of vegetation is found in tundra grasslands?

Lichens, mosses, and grasses, with a few stunted trees in sheltered areas.

What animals are found in tundra grasslands?

Reindeer, wolves, and arctic hares.

What is the most important factor influencing the distribution of biomes?

Climate, particularly rainfall and temperature.

What is the role of rainfall in determining biome types?

It determines whether an area will be forest, grassland, or desert.

What is the significance of soils in ecosystems?

Soils influence ecosystem distribution and can affect vegetation types.

How does altitude affect ecosystems?

Temperature decreases with altitude, influencing the type of vegetation and ecosystem present.

What is the environmental lapse rate?

The rate at which temperature decreases by about 1°C per 1,000 m of altitude.

What is a rainshadow effect?

It produces grassland or desert ecosystems, such as temperate grassland in the lee of the Rockies and the Atacama Desert in the lee of the Andes.

What is the biosphere?

The part of Earth and atmosphere in which living organisms exist or that is capable of supporting life.

What are some vital natural resources found in the biosphere?

Food, medicine, building materials, and fuel.

What types of food did hunter-gatherers collect?

Fruits, berries, grains, nuts, and hunted animals and fish.

What traditional medicines are derived from the biosphere?

Herbs, minerals, and animal parts, such as willow bark tea for fever and ginger for rheumatism.

What are common building materials sourced from the biosphere?

Wood, stone, straw, clay, slate, and dung.

What fuels are traditionally used from the biosphere?

Wood, coal, wind, water, and animal power.

What are renewable resources?

Resources that can be naturally reproduced within a human lifetime, such as wood and water.

What is sustainable use of renewable resources?

Exploiting resources no faster than they are being replaced.

What are non-renewable resources?

Resources that cannot be reproduced naturally within a human lifetime, such as fossil fuels.

How can non-renewable resources be sustainably exploited?

By utilizing them as efficiently as possible to maximize stock for future generations.

What impact has rapid population growth had on the biosphere?

It has increased demand for resources from the biosphere.

What was the effect of the Industrial Revolution on resource output?

It dramatically multiplied the output of manufactured goods produced for commercial sale.

How has energy demand affected forests?

Increased demand for woodfuel and charcoal has led to deforestation.

What role does water play in agriculture and industry?

It is used for irrigation, as a raw material, and for cooling or washing machinery.

What are terrestrial ecosystems?

Ecosystems found on land.

What characterizes moorland ecosystems?

Heavy rainfall, shrub vegetation like heather, and acidic peaty soils.

What defines heath ecosystems?

Dry, acidic, sandy soils with shrub vegetation like bell heather and gorse.

What is the primary type of woodland in the UK?

Temperate forest, characterized by broadleaved deciduous trees like oak and ash.

What are wetlands and where are they commonly found?

Ecosystems near estuaries and river mouths, characterized by grass and herb vegetation.

What are marine ecosystems?

Ecosystems found in the sea, including estuaries, lagoons, and coral reefs.

What is the significance of UK ports?

They transport 90% of UK imports and exports, generating £5 billion for the economy.

What is the impact of overfishing in the UK?

Unsustainable rates of fish extraction have led to reduced fish stocks and ecosystem degradation.

What is eutrophication?

The process where nutrient-rich conditions lead to algae blooms, which deoxygenate water and kill other organisms.

What are biotic components of an ecosystem?

Living organisms found in an area.

What are abiotic components of an ecosystem?

Non-living parts of the environment.

What characterizes tropical forests?

High temperatures, high rainfall, and high biodiversity, located along the Equator.

What type of soil is found in tropical rainforests?

Deep, red-colored latosols, which are rich in organic matter.

What climatic conditions contribute to the formation of latosols?

A hot, wet climate that promotes deep chemical weathering and rapid decay of organic matter.

What is the primary reason for the red color of latosols?

Oxidation of iron minerals in hot, wet conditions.

How does high rainfall affect tropical rainforest soils?

High rainfall washes nutrients quickly out of the soil, making latosols nutrient-poor and often saturated.

What is absolute humidity?

The actual quantity of water vapor in a given amount of air, measured in grams per cubic meter (g/m³).

What is relative humidity?

A measure of how close air is to saturation with water vapor, expressed as a percentage.

What are the four layers of trees in a tropical rainforest?

Canopy, emergents, undercanopy, and shrub layer.

What adaptations do tall trees in tropical rainforests have?

Buttress roots for support and drip tips on leaves to shed water and prevent moss growth.

What is the role of epiphytes in tropical rainforests?

Epiphytes grow on branches of canopy trees to access sunlight, as the forest floor receives little light.

What is a food chain?

A unidirectional transfer of energy through a series of organisms, with each species at a different trophic level.

What are the first and second trophic levels in a food chain?

First trophic level is producers (plants), and the second is herbivores (primary consumers).

What is the difference between a food chain and a food web?

A food web is a complex system of interconnected food chains with multiple species at each feeding level.

What role do decomposers play in the ecosystem?

Decomposers break down dead organic matter, recycling nutrients back into the soil.

What is Gersmehl's model?

A simplified summary of nutrient exchanges in an ecosystem, showing three nutrient stores: biomass, litter, and soil.

What are the main adaptations of animals in tropical rainforests?

Strong limbs for swinging, modified wings for maneuvering, and camouflage for avoiding predators.

How does climate change affect tropical rainforests according to the IPCC 2013 Report?

It predicts increased intensity of Hadley Cell circulation, leading to higher precipitation in some areas and reduced rainfall in others.

What is shifting cultivation?

A traditional agricultural practice where small areas of forest are cleared for crops, allowing the forest to recover after a few years.

What is biodiversity, and why is it high in tropical rainforests?

Biodiversity refers to the variety of species in an ecosystem, which is high in tropical rainforests due to ideal growing conditions and intense competition.

What are the characteristics of the canopy layer in tropical rainforests?

The canopy layer consists of tall trees (up to 30 m) that receive abundant sunlight and support diverse life forms.

What is the significance of surface roots in tropical rainforest trees?

Surface roots help trees extract nutrients from the litter layer, compensating for the nutrient-poor latosols.

What adaptations do hummingbirds have for feeding in tropical rainforests?

Hummingbirds have modified wings for hovering and specialized beaks for extracting nectar from specific flowers.

What is the role of the top carnivore in a tropical rainforest food chain?

The top carnivore is the final consumer that has no natural predators and can influence the population of other species.

How do trees in tropical rainforests manage water on their leaves?

Trees have drip tips on leaves to shed excess water and prevent moss growth, which can inhibit photosynthesis.

What is leaching in the context of tropical rainforest soils?

Leaching is the process by which nutrients are washed out of the soil due to high rainfall, leading to nutrient depletion.

What are the two simplified layers of stratification in a rainforest?

Canopy and shrub layer.

How do trees adapt to the dry season in a rainforest?

They shed leaves, allowing sunlight to reach the ground for grasses and shrubs to grow when rains return.

What role do forest fires play in rainforest ecosystems?

They reduce tree cover, leaving only species adapted to burning, such as those with fire-resistant bark.

How does evapotranspiration in coastal forests affect rainfall in continental interiors?

It recycles much of the rain, impacting rainfall patterns and forest structure.

What is the impact of climate change on energy and nutrient flows in rainforests?

Lower rainfall leads to reduced photosynthesis, smaller biomass, and simpler food chains.

What happens to the litter store during the dry season in rainforests?

It temporarily increases in size due to slow decay, but decays rapidly when wet.