GCSE Geography (Edexcel B): People & the Biosphere

What are biomes?

They are large-scale, global ecosystems

What does and ecosystem include?

An ecosystem includes all living and non-living things in an area

What determines what biome an area has?

They are determined by the climate in an area

What are the features of a tropical rainforest climate?

No definite seasons, always hot (20-28 degrees), 12 hour days all year and rain every afternoon (2000mm per annum)

Why does the TRF have similar temperatures and day lengths all year round?

It is based near the equator so the sun is almost directly above it all year.

What are some TRF plant characteristics?

Most trees are evergreen (don't lose their leaves in a specific season) to take advantage of the year round growing season.

Plants grow fast and are adapted to take in maximum light.

What are some TRF animal characteristics?

Lots of species because of the wide variation of vegetation which provides food and habitats.

Lots of insects and birds.

What are some TRF soil characteristics?

Plants leaves that drop all year round decompose, this provides a constant supply of nutrients in the soil, these nutrients are cycled quickly.

What are the features of a Temperate Forest climate?

They have 4 distinct seasons, warm summers and cool winters.

High amounts of rainfall (1500mm per annum) and it occurs year round.

Days are shorter in winter and longer in summer, hours of sun vary through the year.

What are some Temperate Forest plant characteristics?

The mild, wet climate supports less plant species than TRF but more than Boreal Forests.

Forests usually have broad leaved trees that drop leaves in autumn, shrubs and undergrowth

What are some Temperate Forest animal characteristics?

The climate and range of plants provides food and habitats for mammals, birds and insects

What are some Temperate Forest soil characteristics?

Plants lose leaves in autumn and leaf litter decomposes quickly in the moist, mild climate.

The soils are thick an quite nutrient rich.

What are the features of a Boreal Forest climate?

short cool winters (10 degrees) and long cold winters (-20 degrees)

low precipitation (less than 500mm), most of this is snow

A lot of daylight during summer but almost none during winter. Clear skies so during day there's lots of sunlight

What are some Boreal Forest plant characteristics?

Most trees are evergreen so they can always take advantage of the small amounts of light, coniferous trees and mosses are common

What are some Boreal Forest animal characteristics?

Relatively few animal species, some examples are wolves, elk, eagles and black bears

What are some Boreal Forest soil characteristics?

The cool dry climate means the that needles from trees decompose slowly.

The soil is thin, acidic and nutrient poor, in some areas the ground is frozen for most of the year.

What are some features of the Tropical Grassland climate?

Little rainfall (800-900mm per annum), with distinct wet and dry seasons. Temperatures are highest before wet season (35 degrees) and lowest (15 degrees) just after.

Usually near the equator so sun all year round.

What are some Tropical Grassland plant, animal and soil characteristics?

Consists mostly of grass, scrub and small plants, with a few scattered trees.

They are home to lots of insects and larger animals like lions and elephants.

Grass died back during dry season which forms a thin nutrient rich soil but these nutrients are washed out during the wet season.

What are some Temperate Grassland plant, animal and soil characteristics?

Have a lot of grasses and small plants but have very few trees and less animals than tropical grasslands.

High summer temperatures mean that decomposition is fast which leads to thick and nutrient rich soil.

What are some features of Temperate Grassland climate?

They have hot summers (40 degrees), cold winter (-40 degrees) and up to 500mm of rain per year in early summer/late spring.

They are further down from the equator so light varies around the year.

What are the features of a Desert climate?

Very low rainfall (less than 250mm per annum), sometimes it only rains once or twice every 2-3 years.

Hot deserts might be up to 45 degrees in the day but below 0 at night.

Hot deserts get more daylight in summer than winter, because there is little cloud cover there is lots of sun every day.

What are some Desert plant characteristics?

Very little plant growth due to the small amount fo rainfall

What are some Desert animal characteristics?

Relatively few species, those that do live there are adapted to the harsh climate such as lizards, snakes and insects

What are some Desert soil characteristics?

Sparse vegetation means little leaf litter, the dryness makes decomposition slow.

Soil is mostly thin and nutrient poor.

What are the features of a Tundra climate?

Low temperatures, 5-10 degrees in summer,-30 in winter. Low precipitation (less than 250mm)

Usually found at very high latitudes which results in almost continuous daylight in summer but little to none in winter.

What are some Tundra plant characteristics?

The cold and lack of light makes it extremely hard to grow plants so it is usually just grass, moss and low shrubs.

What are some Tundra animal characteristics?

The cold and lack of vegetation means that few animals live here, lots of birds, some mosquitoes and arctic species reside here.

Some animals migrate south for winter.

What are some Tundra soil characteristics?

Sparse vegetation leads to little leaf litter and slow decomposition. The soil is thin and nutrient poor, there is also a permafrost layer below the soil which stops water drainage.

What local factors affect biome distribution on a smaller scale?

Altitude, Rock type, Soil type and Drainage

How does Altitude affect biomes on a smaller scale?

Higher altitudes are colder, so fewer plants grow there which limits plant species. This also leads to thin or non-existent soils.

How does Rock Type affect biomes on a smaller scale?

Type of rock affects how nutrient rich the soil is as different rocks have different minerals so when they are weathered different qualities form.

How does Soil Type affect biomes on a smaller scale?

More nutrient rich soils can support more plants, acidity and drainage also affects types of plants that can grow.

How does Drainage affect biomes on a smaller scale?

If drainage is poor then only plants adapted to wet conditions can grow there.

What is a biotic component of a biome?

This is the living part of a biome like plants and animals

What is an abiotic component of a biome?

This is the non living part of a biome like water and soil

What is an example of biotic and abiotic components interacting?

Water availability affects how plants can grow, it also affects soil quality which affects plant growth. Plants also release moisture into the atmosphere for further rainfall.

What resources does the biosphere provide?

Food, Medicine, Fuel and Building Materials

How does the biosphere provide Food?

Many indigenous people get their food directly from plants and animals, some forage, some hunt and some grow their own.

How does the biosphere provide Medicine?

Lots of plants have medicinal properties and are used to cure illnesses

How does the biosphere provide Fuel?

Indigenous people rely on plants and animals for fuel for cooking and keeping warm.

For example wood, moss, dried grass, dried animal dung or animal fat.

How does the biosphere provide Building Materials?

Trees are often used to build houses and sap can be used for waterproofing and as glue. Straw is good for roofs and insulation, plant fibres can be used to make rope.

How do humans exploit the biosphere for Energy?

Demand for energy increases as the population increases because people have more electronic devices.

Large areas of forest are cut down to clear land for crops that make biofuel or coal mines or power stations.

Some areas of the TSR have been flooded by hydroelectric dams.

Drilling for oil and gas in the Tundra leads to melting of the permafrost

How do humans exploit the biosphere for Water?

As the population rises more people use water for washing, drinking and irrigating farmland.

Water resources can be over exploited easily especially in arid areas, this leads to plants and animals have not enough water to survive.

How do humans exploit the biosphere for Minerals?

Minerals are used in building, electronics and scientific instruments so demand is increasing.

Mines in the TSR are responsible for deforestation and contamination of water sources

Open pit mines remove large ares of land surface.

How does the biosphere help control the proportion of different gases in the atmosphere?

Plants take in CO2 and give out Oxygen during photosynthesis

Animals take in Oxygen then give out CO2 when they breathe.

Why is balancing gasses important?

increased CO2 levels lead to global warming, cause acidic oceans (which affects aquatic creatures) and not enough means the earth would be too cold to support life.

Why is the biosphere important for keeping soil healthy?

Plant roots and animals spread nutrients through the silt maintain soil fertility and structure.

The roots of vegetation hold the soil together.

Vegetation intercepts rainfall which prevents leaching

What is leaching?

Leaching is where nutrients in soil are washed downwards out of reach of plants.

How does the biosphere regulate the water cycle?

Water is taken up by plants so less reaches rivers, this helps prevent flooding and soil erosion.

Plants also store water and release it into the atmosphere slowly which reduces risk of drought and flooding.