Topic 3: Ecosystems, biodiversity and management Edexcel a

3.1. Large-scale Ecosystems What do I need to know? a. Distributions and characteristics of the world’s large-scale ecosystems (tropical, temperate and boreal forests, tropical and temperate grasslands, deserts and tundra). b. The role of climate and local factors (soils and altitude) in influencing the distribution of different large-scale ecosystems. Large-scale ecosystems are found in different parts of the world and are important

LO: To define the term biosphere and locate examples of biomes. What is the biosphere? LO: To define the term biosphere and locate examples of biomes.

A very large ecosystem that covers large parts of the Earth. BIOME: A very large ecosystem that covers large parts of the Earth. ECOSYSTEM: A community of animals and plants that interact with each other and their physical environment. Together, these biomes make up our BIOSPHERE.

Distribution of Biomes Describe how the distribution of biomes changes as latitude increases (as you go away from the equator).

Distribution of Biomes Describe how the distribution of biomes changes as latitude increases (as you go away from the equator).

Distribution of Biomes TASK: Practice your map skills by completing your own map to show the distribution of the biomes.

TROPICAL RAINFORESTS

TROPICAL SAVANNA

DESERT

CHAPARRAL - vegetation consisting chiefly of tangled shrubs and thorny bushes.

TEMPERATE DECIDUOUS FOREST

CONIFEROUS FOREST

TUNDRA (ARCTIC & ALPINE)

What are biomes like? Task: Complete your table about the characteristics of different biomes using the information around the room.

Non living things Living things Abiotic Biotic Living things

So let’s test what you have learnt so far Which biome does the UK fit into? Which biome has the highest level of productivity? Why do you think this is? Define the following key terms Ecosystem Biome Deciduous Tundra Biotic Abiotic Now identify which biomes are missing from the list.

Factors Affecting the Location of Biomes What do plants need to survive? The climate helps determine what plants and animals can grow in a biome. Plants require sunlight, water and carbon dioxide for photosynthesis. LO To understand the Global and local factors which influence biomes

Factors affecting biomes Precipitation (rain, sleet, snow, hail) Temperature How hot or cold is it? Does it rain often?

What factors affect the distribution of biomes? Temperature With the aid of a diagram, explain how the latitude of the earth affects the location of biomes. Sun Solar ray Solar ray Earth

Precipitation Explain why there are different levels of precipitation around the world. Warm, moist air rises Cooler, dry air falls

For example, the UK is not all covered in deciduous woodland..! The world map does not show the variations that occur at a local level. For example, the UK is not all covered in deciduous woodland..!

Local factors: Above the tree line, colder temperatures limit forest growth Savannah grassland An area where rainforest thins out Mangrove forest replaces true rainforest in areas where seawater regularly floods Poorly drained land close to rivers is occupied by swampland

Local factors: Temperatures fall by about ½ a ⁰C for every 100m above sea level. This means tough grasses replace trees on higher mountain slopes.

Local factors: Areas further away from the sea receive drier winds This is because they lose their moisture quickly, resulting in less rainfall. We call these rain shadows.

Construct and complete a table like the one below: There are many factors that influence each biome. Discuss and write down the kinds of factors that could affect the vegetation and wildlife. Construct and complete a table like the one below: PHYSICAL FACTORS HUMAN FACTORS

how did you get on? PHYSICAL FACTORS Temperature Amount of Precipitation Hours of sunlight Drainage – is the soil too wet? Too dry? How can this influence the vegetation Altitude Distance inland Geology HUMAN FACTORS Deforestation Urbanisation Water extraction Pollution Talk through why each one can have an influence – page 43 of the textbook is really helpful for this

Exam Practice Question Study the diagram. Describe how local factors affect growth of rainforest (4 marks) 10 mins

PEER MARK Basic answers 0-1 mark Are incomplete and describe one or two of the factors shown such as altitude Good answers 2 marks Use the full range of factors and identify 4 places where rainforest is prevented from growing by local factors Excellent answers 3-4 marks Distinguish between places where rainforest cannot grow at all (such as mountain tops) and places where it is changed but in a changed form such as the edges of savannah)

Quick recap… What is a biome? Give an example… What is an ecosystem? What is the biosphere? Why is temperature important in determining where a biome is located? Why is precipitation important in determining where a biome is located? What does biotic mean? What does abiotic mean?