Biomes (7) Flashcards
Climate of TRFs?
-Same climate all year round - no definite seasons
-Hot (20-28C) - near the equator
-Same day length, plenty of sunshine - near the equator
-Very high rainfall (2000mm) - rains nearly every day
Characteristics of TRFs
Plants:
-Most trees are evergreen - take advantage of continuous growing season
-Grow quickly and adapted to maximise intake of light
Animals:
-Dense vegetation provide lots of habitats - many species
Soil:
-Plants grow quickly and shed leaves all year round
-Decompose quickly, constant supply of nutrients
Climate of Temperate Forests
-4 distinct seasons (warm summers, cool winters)
-Rainfall is high
-Days are shorter in winter, longer in summer (varying sunshine levels)
Characteristics of Temperate Forests
Plants:
-Forests made up of broad-leaved plants that drop leaves in autumn eg. shrubs
Animals:
-Mild climate and range of plants provides food and habitats for mammals
Soil:
-Plants lose leaves in autumn - leaf litter decomposes quickly (nutrient-rich soil)
Climate of Boreal Forests (Taiga)
-Short summers and long winters - cold winter temperatures (>-20C)
-Low precipitation - mostly snow (>500mm)
-Lots of daylight during the summer, but hardly anything in winter
Characteristics of Boreal Forests (Taiga)
Plants:
-Most trees are evergreen. Coniferous trees eg. pine, fir are common
Animals:
-Relatively few animal species
-Less food available + relatively little time to adapt to climate
Soil:
-Cool, dry climate means needles decompose slowly - nutrient-poor soils
-Frozen ground, acidic soils
Climate of Deserts
-Rainfall is very low (>250mm) - once every 2 or 3 years
-Hot desert temperatures range from very hot in the day (40C) -> cold at night (>0C)
-More daylight during summer than winter - many hours
Characteristics of Deserts
Plants:
-Plant growth is sparse due to a lack of rainfall
-Few plant species - cacti, thornbushes
Animals:
-Relatively few species - have to be adapted
-Scorpions, snakes, insects, lizards
Soil:
-Sparse vegetation means that there is little leaf litter - slow decomposition
-Nutrient-poor soils
Climate of the Tundra
-Low temperatures (around -30C) in the winter
-Low precipitation - mostly snow (>250mm)
-High latitudes - near continuous daylight in summer, no daylight in the winter
Characteristics of the Tundra
Plants:
-Cold climate + lack of light makes it hard for plants to grow, hardly any trees
-Mosses, grasses, shrubs
Animals:
-Very few species - cold climate, lack of vegetation
-Arctic hares, arctic foxes, mosquitoes, birds
Soil:
-Sparse vegetation - little leaf litter- cold, dry climate leads to slow decomposition
-Nutrient-poor soils
-Large layer of PERMAFROST (stops water from draining away)
Climate of Tropical Grassland
-Low rainfall (800-900mm)
-Distinct wet and dry seasons
-Near the equator - warm (15-35C) and get lots of sunshine
Characteristics of Tropical Grassland
-Mostly grass and small plants, few trees
-Home to lots of insects eg. grasshoppers, beetles, termites and larger animals eg. lions, elephants, giraffes, zebras, antelope
-Grass dies during the dry season , forming nutrient-rich soil, but nutrients are washed out during wet season
Climate of Temperate Grassland
-Hot summers (40C) and cold winters (-40C)
-Low precipitation (250-500mm)
-Furthest from equator - light varies throughout the year
What 4 factors is Biome distribution affected by?
Altitude
Rock type
Soil type
Drainage
How is Biome distribution affected by Altitude?
-Higher altitudes are colder, therefore fewer plants grow there, limits animal species
-Not much organic matter, so soils are thin and nutrient-poor
How is Biome distribution affected by Soil type?
-Nutrient-rich soils can support plants
-Acidity of soils affects which plants can grow eg. conifers grow in acidic peat soils
How is Biome distribution affected by Rock type?
-Some rock types are easily weathered to form soils
-Different rock types contain different minerals, affecting the nutrients of the soil
-Some rocks are permeable and others are impermeable (water flow)
How is Biome distribution affected by Drainage?
-Poor drainage systems can lead to waterlogged soils - plants adapted to wet conditions grow
-Very wet areas may be home to aquatic organisms
How do Biotic and Abiotic components of Biomes interact?
1) Water availability affects the plants that grow
2) The type and density of vegetation that grows affects the soil that forms - affecting the next vegetation that grows
3) Some organisms cause biological weathering - when rocks are broken into smaller pieces by living things eg. tree roots
What 4 important resources does the Biosphere provide?
Food
Medecine
Building materials
Fuel
Describe ‘food’ in terms of resources from the Biosphere
-Many indigenous people get their food directly from plants/animals
-Some forage for fruit, vegetables and nuts or hunt for animals and fish
Describe ‘medicine’ in resources of the Biosphere
-Lots of plants eg. Aloe have medicinal properties used to make drugs for humans
-Used to keep people healthy
Describe ‘building materials’ in resources of the Biosphere
-Trees and other plants are often used for building materials to make furniture
-Plant fibres can be used to make rope
Describe ‘fuel’ in resources of the Biosphere
-Indigenous people rely on plants and animals for fuel for cooking and keeping warm
-Wood, dried grass etc. is burnt as fuel
-Some areas eg. Tundra - with little plants - use blubber from animals such as seals
How do Humans exploit the Biosphere? (Energy)
Energy:
-Demand increases as population increases - people have more energy intensive devices
-Large areas of forest are cleared for plantations of biofuels or mines
-Some areas were cleared for HEP - flooding the land
-Drilling in the Tundra leads to pipelines melting the permafrost
How do Humans exploit the Biosphere? (Water)
Water:
-Demand increases as population increases - used in washing, farming etc.
-Resources such as rivers, lakes, aquifers (underground water stores) can be over-exploited
-Plants and animals no longer have enough water to survive
How do Humans exploit the Biosphere? (Minerals)
-Minerals such as gold and iron are used in electrical appliances and building
-Often extracted by mining
-Deforestation occurs because of mining, toxic chemicals are released into environments - killing wildlife
Other factors increasing Demand for resources?
Increasing Wealth
Urbanisation
Industrialisation
How does Increasing Wealth affect Demand for resources?
-Economic development means people get wealthier
-They have more disposable income to spend on food, cars, fridges, televisions
-More people can afford appliances such as showers, dishwashers
How does Urbanisation affect Demand for resources?
-Growth of proportion of a population living in urban areas
-Cities are more energy-intensive than rural areas (more neon lights for example)
-Food and water have to be transported over longer distances to meet rising demand
How does Industrialisation affect Demand for resources?
-Shift from primary to secondary industry production
-Manufacturing goods such as cars, chemicals and electrical appliances uses lots of energy
-Uses lots of water as well
What was Thomas Malthus’ theory?
If the population rises by too much, resources will eventually run out (too many people)
-Killed by famine, war, hunger, illness until the population returned to a stable number
What was Ester Boserup’s theory?
As population increases, so can the amount of resources available
-Could make technological advances
-Could develop new resources through innovation and scientists
What does the Biosphere help to do?
Regulate gases in the atmosphere, keeps soil healthy and regulates the water cycle
Why is maintaining the balance of gases in the atmosphere important?
- most living organisms need oxygen to survive
- increased levels of CO2 make oceans acidic and leads to global warming
As the world’s population rises, more people require more ______?
Resources
As population increases, so does demand
How does the Biosphere regulate the Water Cycle?
Water is taken up by plants, so less reaches rivers, preventing flooding and soil erosion
Plants store water and release it slowly. Large areas of forest can help prevent drought in areas far away
How does the Biosphere keep Soil healthy?
- Plant roots and animals spread nutrients through the soil, maintaining fertility, allowing plants to grow
- Roots of vegetation keeps the soil binded together. Without them, soil could be easily eroded
- Vegetation intercepts rainfall before reaching the ground, preventing leaching
