Biomes and the Biosphere Flashcards
What is a biome?
A global size ecosystem categorised by similar environmental characteristics such as climate, vegetation type and soil
What do biomes occur in?
Latitudinal belts
- This means they’re present across the world at similar latitudes
Why do latitudinal patterns occur in biomes?
Because climate in these regions is similar due to atmospheric circulation
Why are there some variations in biome location?
Other influences:
- Ocean currents
- Winds
- Land-sea temperature differences
Where is the Tundra located?
Far North
- Canada, Northern Russia, coastal Greenland
What are the characteristics of tundra?
- Harsh winters and very short summers
- Treeless, as it is too cold and not damp
- Very low precipitation levels
- Short growing season, and soil lacks nutrients
- Most animals are migratory
Where is the taiga located?
North America
Russia
Scandinavia
What are taiga characteristics?
- Coniferous forest
- Evergreen trees
- Around 50cm of rainfall / year
- Long growing season
- Contains small animals and migrating birds
- May also contain wolves, bear and moose
Where is temperate deciduous forest located?
Eastern USA
Europe- including Uk
Eastern Australia
What are the characteristics of temperate deciduous forest?
- Broad leaf trees that shed their leaves
- Oak, maple and beech trees are common
- Hot summers and cold winters
- Moderate precipitation
- Animals include deer, bear and small animals
Where is temperate grassland located?
Central Europe and Asia
Central USA
Central Australia
What are the characteristics of temperate grassland?
- Dominant vegetation is grass, due to periodic fires and low precipitation
- Animals include prairie dog and bison
- Hot summers, cold winters
Where is desert located?
Northern Africa
Australia
Eastern USA
Middle East
What are the characteristics of desert?
- Extremely low precipitation
- Temperature fluctuates between night and day
- Limited plant growth and soil is poor in nutrients- mainly cacti
- Small, often nocturnal animals
Where are tropical rainforests located?
Close to the equator
South America
South-East Asia
What are the characteristics of tropical rainforest?
- Species rich
- Warm moist climate
- Very high precipitation
- Very quick nutrient cycle
- Animals include many insects, reptiles and amphibians
Where is savanna located?
India
Central Africa
Central South America
What are the characteristics of Savanna?
- Little temperature variation throughout year
- Seasonal precipitation, with dry and wet periods
- Dry seasons characterised by wildfires
- Often used for animal grazing
- Hoofed animals and herds are common as well as lions and leopards
Where is Mediterranean/ Chaparral located?
South of the Equator-
South Africa
Western Australia
What factors affect the distribution and characteristics of biomes?
Climate factors-
Precipitation
Temperature
Sunlight exposure
How does precipitation affect biomes?
- Forest biomes are found in low pressure areas, because they’re rainy, which supports tree growth
- Grasslands and deserts are found in areas of high pressures as there isn’t enough rain to support forests
How does temperature affect biomes?
- The equator is more warm, which causes plants to be very productive, creating tropical rainforest biomes
- At high latitudes, the temperatures are lower because sunlight is less intense, limiting plant growth
What local factors affect biome distribution?
Altitude
Rock and soil type
Drainage
What is altitude?
The height of the land
What effects does altitude have on temperature and height?
- Temperature gets colder with increasing altitude- for every 1000m change in height temps can decrease by 6.5
- Precipitation usually increases with height
What is altitudinal zonation?
The pattern we see on hills and mountains where the ecosystem changes with increasing elevation
How can rock and soil type affect biomes?
- When rocks are broken down in weathering, chemicals and nutrients are released into the soil
- This can affect soil pH and fertility
What does the bedrock of an area affect?
- It influences soil composition and grain size (such as if its a sandy or clay soil)
- This affects things such as permeability, vulnerability to erosion and drainage
What is drainage?
- How fast water enters and leaves soil
What can drainage impact?
- Well drained soils wont retain excess water
- Poorly drained soils can become boggy and waterlogged
- Species are adapted to live in these areas, such as willow trees in boggy areas
What is drainage influenced by? (Local factors)
Topography and relief
- some areas may receive more water due to the shape of the land
Soil type
- more permeable soils (sandy) drain well whilst porous soils (clay) retain it
Amount of vegetation
- Trees and plants intercept and store water
Precipitation and temperature
- More precipitation leads to wetter soils and higher temperatures lead to more evaporation
What is a biotic component?
Living organisms, such as plants (flora) and animals (fauna)
What is an abiotic component?
Non-living environmental factors which influence an ecosystem
- Climate
- Light exposure
- Soil type
- Water availability
Interaction of water in a biome?
- Breaks up rocks through weathering, releasing chemicals into soil
- Chemicals are taken up by plants and used as nutrients to help grow
- They are then passed onto animals when they eat the plants
- Finally, put back into soil when animals die and decay
What is the biosphere?
Living layer of Earth between the atmosphere and the lithosphere where all plants and animals are found
What are goods that the biosphere produces?
Physical materials-
- Food and water (meat, berries, nuts)
- Energy sources (fossil fuels, timber)
- Materials (metal, rock, wood)
What services happen in the biosphere?
Processes in the biosphere that support life
- Atmosphere regulation
- Soil formation and nutrient cycling
- The hydrological cycle
Example of indigenous population and where they live?
- The Efe people
- Native to the Ituri Tropical Rainforest in the Congo Basin
How do the Efe people use the biosphere?
- Hunt and gather food
- Use rainforest materials to build homes, make fire, and produce medicine
- Use wood from the rainforest for fires
- Hunt the giant forest hog and sell its meat to other people in the region
- Hunt monkey and antelope for food
What impact have human activities had on the biosphere?
- Exploiting goods and services at an unsustainable rate
- The biosphere cant recover and regenerate
- Humans are exploiting it for energy, mineral resources and water
How is energy affecting biosphere?
- Biosphere contains fossil fuels that are being extracted at an unsustainable rate to meet demands
- It takes millions of years to produce coal, oil and gas
- Extraction causes lasting environmental damage (mines)
- Fossil fuel combustion releases greenhouse gases into the atmosphere
How is water demand affecting the biosphere?
- Water resources are being depleted, affecting the hydrological cycle
- Groundwater stores, aquifers, are being depleted faster than they can replenish
How is demand for mineral resources affecting the biosphere?
- Some minerals can take billions of years to form and are now being depleted at a very high rate due to commercial demand
What are the uses for mineral resources?
Consumer goods
- Makeup, jewelry, phones, televisons
Construction of buildings and infrastructure
Many medicines are derived from minerals
Some fertilisers are made of minerals
How does the biosphere regulate the environment?
- Maintains greenhouse gases, keeping the planet warm enough to live on
- Regulates CO2 and O2 levels through photosynthesis
- Regulates CO2 and methane levels through carbon sequestration- carbon is stored in soils, rocks, ice, permafrost and the sea
What is carbon sequestration?
The long-term capture and storage of carbon dioxide from the atmosphere
How does the biosphere maintain soil health?
- Nutrient cycling
- Healthy soils are needed for plant growth
How does the biosphere regulate water through the hydrological cycle?
- Trees intercept, absorb and transpire water, putting water vapour back in the atmosphere that can then fall as precipitation
What is the hydrological cycle?
- How water is transferred throughout the world from different sources into different states
Why is there a growing demand for resources?
- Growing population
- World is getting richer
- Urbanisation is increasing
- Increasing industrialisation in poorer regions
What did Thomas Malthus say?
- Malthusianism
- Population will increase exponentially but resources will only increase linearly
- The population will eventually run out of food and resources
- Population will then decrease due to deaths and low birth rates
- Population will also decrease due to Positive and Preventative checks
What were Malthus’ Positive checks?
Disease, war famine
- A disaster that significantly reduces a population by increasing deaths
What were Malthus’ Preventative checks?
A cultural choice to not have children, as you wont be able to support them
Lowering the birth rate
What did Ester Boserup say?
- Boserupian Theory
- No matter how large the population grows, the population will always discover new ways to sustain food supplies
How would food supplies be sustained according to Boserup?
- New agricultural technologies
- Systems to ensure food security
What is eutrophication?
The growth of algae in a body of water due to excess nutrients
This leads to depletion of oxygen in an aquatic ecosystem
Vegetation in tundra:
Grasses, lichens and dwarf shrubs
No trees
Vegetation in taiga:
Coniferous trees (e.g pine)
Vegetation in temperate forests:
Deciduous trees (e.g oak)
Vegetation in temperate grassland:
Short or tall grasses
Few trees
Vegetation in Mediterranean:
Evergreen and Deciduous trees
Shrubs
Vegetation in hot desert:
A few cacti and succulents
Vegetation in tropical rainforest:
Evergreen trees growing all year round
Vegetation in tropical grassland:
Grass with some trees (e.g acacia)
