Ecosystems Flashcards
What is the earths climate driven by?
The Suns energy
What does temperature decrease with?
It decreases with latitude. The equator receives the most heat from the sun because the sun is directly overhead and therefore it’s rays are most intense here. Further away from the equator the temperature decreases
What does the high surface temperatures at the equator all year round power?
It powers a convection cell of rising air. As this air rises it cools, the moisture it contains condenses and a lot of rain falls.
Turn to page 128 in the text book and study the map
Go
What are the characteristics of the tropical rainforest?
Hot all year (27-30 degrees)
Wet all year (average annual precipitation 2000-3000 mm)
A huge variety of broad leaved plants. Trees dominate, with other plants come ring for light
Found near the equator
What are the characteristics of tropical grasslands?
Hot all year (25-35 degrees)
500-1000 mm of rainfall a year but always with a dry season
Tall grasses with scattered, drought-adapted trees and shrubs
Found either side of the equator on edges of tropical rainforests
What are the characteristics of deserts?
Very hot all year (above 30 degrees)
Very low rainfall (less than 259 mm annual average)
Plants have water-storing features, spines instead of leaves and extensive root systems
Hot, dry deserts found near the Tropic of Cancer and the Tropic of Capricorn, cold deserts found near the Arctic
What are the characteristics of temperate grasslands?
Hot in summer (25 degrees), very cold in winter (as low as -40 degrees)
500-900 mm of rainfall a year, most in late spring and summer
Grasslands with very few trees or shrubs
Found in the middle latitudes of interior continents
What are the characteristics of the temperate forest?
Warm summers (around 18 degrees),cool winters (around 5 degrees)
Precipitation all year round (1000mm)
Deciduous trees, which drop their leaves in Autumn
Found in the eastern half of North America, the middle Europe, Asia and southern Australasia
What are the characteristics of a boreal forest?
Warm summers (16-30 degrees), very cold winters (below 0)
Low precipitation (less than 500 mm) mainly in summer
Coniferous trees with needles instead of leaves to survive cold and reduce water loss.
They stretch over Erasia and North America, near the top of the world
What are the characteristics of tundra?
Temperatures below 0 for most of the year, only reaching 10 degrees in the summer
Low precipitation (often less than 250 mm)
Very few plants can live here, mostly lichens and mosses. Trees are rare and stunted (short height)
Located north at the top of the world
What are the characteristics of mountains?
10-15 degrees in the summer and below 0 in the winter
300 mm on annual rainfall
200 species, small ground over plants, so they don’t get blown over in the breeze
Found all over the world usually about 10,000 feet high
What are the characteristics of of the Mediterranean?
Between 10-40 degrees
380-1000 mm on rainfall
Most plants have small, hard leaves that hold moisture such as cacti
The cooled air falls over the tropics of cancer and Capricorn, which creates high pressure zones of clear skies. As the air falls it warms, what does this mean?
This means that temperatures are high but precipitation is low here
What does the tilt of the Earth on its axis create?
Seasons, theses often have different precipitation patterns,nth equator is least affected by this so has similar precipitation all year round
The inter-tropical convergence zone shifts northwards in June, following the overhead sun, to bring a wet season to the tropical grasslands of the northern hemisphere. Why are these grasslands dry in winter?
Because the inter-tropical convergence zone has moved to the Southern Hemisphere
In the interior of the worlds continents, summer temperatures are much higher and winter temperatures much lower that in locations near the coast, where the sea moderates temperature extremes. What biomes are affected by this?
Temperate grasslands and deserts
High mountains force air to rise and cool as it passes over them, what does this mean?
This means that precipitation is high in the mountains. When the air has passed o ear the mountains it has lost its moisture. This is called the rain shadow affect
How does altitude affect of large-scale ecosystems?
Because temperature drops by 1 degree for every 100 metres gain in height, high mountains in the tropics can have cold temperature ecosystems
How do soils affect ecosystems?
The characteristics of an ecosystem can change when the underlying geology or relief produces different types of soil or soil conditions. The vegetation in a poorly drained, swampy area will be different from that of a well-drained area
What is the biosphere?
It’s a vital system that provides us with some of our most essential resources such as: food, medicines, building materials and sources of fuel
What have modern technology done to the biosphere?
It has reduced our day to day dependence on the biosphere but has led to an increase in the exploitation of the biosphere.
What does the huge demand for water (for rapidly growing cities for industry and agriculture) mean for the biosphere?
It means that parts of the biosphere are deprived of water.
Biofuels are a valuable alternative to fossil fuels because they provide renewable energy. However What is the problem with this?
Commercial production of biofuels means that huge areas of land are devoted to biofuel crops instead of food crops. Forest land has also been cleared for biofuel crops instead of food crops. This makes vital resources from the biosphere (food and fuel) more expensive for local people and impacts of biodiversity.
Mineral resources are not part of the biosphere
But an increasing demand has an impact on the biosphere
What food can we get from the biosphere?
Natural vegetation can be replaced with rice and wheat, there is a sustainable harvesting of fruits, berries and nuts, and fish and meat
What medicines can we get from the biosphere?
The periwinkle plant is used to treat leukaemia and Hodgkin’s disease, the aloe plant has soothing properties and aloe Vera is used in many cosmetics, poppies are a the source of the painkiller morphine
What are the fuel resources from the biosphere?
Animal dung is dried and burned as fuel, wood from trees and shrubs, and biofuels convert plant products to fuel a range of different processes eg bioethanol made by fermenting crops like sugar cane
What building material can be got from the biosphere?
Timber, essential for construction comes from trees, and animal dung can be mixed with clay and straw to make bricks, and straw the dry stalks of cereal plant is used for roofing and insulation.
What is the nutrient cycle?
It’s the transfer of nutrients between the living and non-living parts of an ecosystem
What did a scientist called Philip Gersmehl do?
He used a model based on nutrient cycles to explain differences between ecosystems. Gersmehls model said that all ecosystems have the same three basic compartments: soil, litter and biomass. Each store is a store for nutrients. Nutrients are transferred between the stores. The size of these stores is different in different ecosystems, as is the amount of nutrient transferred between stores.
What is a model?
It’s a scientific theory that allows complete systems to be understood more easily.
What are the living parts of an ecosystem called?
Biotic components (bio means life). Nutrients allow the biotic components to survive and grow, but nutrients are not biotic components.
What are the parts of an ecosystem that are not living but essential to life called?
Abiotic components, eg water, light temperature, atmosphere and soil.
Biotic and abiotic factors are interdependent, what does this mean?
They are closely connected and interlinked.
Describe the stages of the nutrient cycle
As plants and animals die, their tissue falls into the litter store.
As living tissue decomposes, nutrients are transferred to the soil store.
Some nutrients are lost from litter by surface sun off.
Plants take nutrients from the soil, soil loses nutrients by leaching, but gains nutrients from weathering of rock beneath it.
What are the three basic compartments in an ecosystem?
Soil, litter and biomass
Go to page 131
And look at the diagram
Go to page 132
And look at the map
Describe the woodland ecosystem in the UK?
Of the UK land area, 12% is woodland, 5% is ancient forest; 80% is less than 100 years old. In England this is mostly deciduous. Scotland and Wales have many monoculture non-native plantations.
Describe the moorland ecosystem in the UK?
Distribution: upland areas that are too high to be used for crops.
Characteristics: rough grassland and peat bogs; low growing plants.
Distinctive plants and animals: heather often dominates, rare birds eg the ring ouzel. Moorland is managed for grouse shooting.
Describe the wetlands ecosystem in the UK
Distribution: scattered across the UK in lowland locations; about 95,000 ha in all.
Characteristics: some heaths are dry and sandy, others are marshy.
Distinctive plants and animals: has species rarely found anywhere else eg marsh gentian and sundews, ladybird spider, land lizard.
Describe marine ecosystems
Marine ecosystems around the UK together make up an area that is three and a half times as big as the whole of the UKs land area. Marine ecosystems can be divided into inshore and offshore.
Describe inshore habitats in a marine ecosystem
Inshore habitats are those close to the shore and coastal margins. These are very important for recreation and tourism in particular.
What are offshore ecosystems in marine ecosystems?
Offshore ecosystems are found away from the shoreline and are important for commercial fishing and energy production. They have a vital role in the buffering of global warming.
Name the varied marine ecosystems
Estuaries, lagoons, salt marshes, seaweed beds, deep sea beds, beaches, coral reefs, oyster beds, seafarers beds, sea caves
Describe how marine ecosystems provide tourism
250 million people visit the UKs coats, supporting 200,000 jobs in coastal tourism, which brings about £3 billion into the UK’s economy.
Describe how marine ecosystems providing fishing is a benefit
The UK fishing fleet is the seventh largest in the EU with around 6400 fishing boats. 12,000 people work on the fleet and 14,000 more work in fish processing.
Describe how marine ecosystems providing energy: oil is a benefit
The UK has oil reserves of around 24 billion barrels in the North Sea (off the east coast of the UK), enough for another 30’years of production. The industry employs 450,000 people.
Describe how marine ecosystems providing energy: offshore wind farms is a benefit
The London array in the Thames estuary, 20km from the Kent coast, is the world’s biggest wind farm, with 175 turbines
What are the ways human activity damages marine ecosystems?
Eutrophication, which is caused by fertilisers used on farmland being washed into the sea; it may also be caused when the sea is used to break down and detoxify sewage.
The construction of deep-water ports and navigation channels, essential for global trade.
Economic development of the coastline, which often removes coastal ecosystems such as salt marsh.
The construction of large wind farms interferes with bird migration routes and the noise they make may disturb animals that rely on sound, such as Dolphins
How does overfishing damage the UKs marine ecosystem?
Although the UK has many thousands of small boats in its fishing fleet, one-half of the UK catch each year is made by just 4% of the fleet which is made up of very large vessels that are extremely efficient at catching fish. In 2011 there was a collapse in cod stocks in some UK marine areas. The removal of an important species such as cod has a big effect on the whole ecosystem.
What are the characteristics of a tropical rainforest?
Although rainforest trees are deciduous, different species lose their leaves at different times (only for a few weeks) so the forest always looks green.
Trees grow very tall between 30-40M, but they have shallow roots.
Stratification ( the five separate layers in TRF: emergent, canopy, understorey, shrub layer, forest floor)
Soil is low on nutrients even though there is rich and abundant life
Describe stratification
The rainforest has different layers. The tree canopy is one layer. Above that is the emergent layer - very tall trees that grow another 10M above the canopy. Below the canopy, where there is less light, is the understorey: shorter trees of around 20M, their air is still there and the humidity is very high. Below that is the shrub layer. Only around 3% of light reaches the layer through the canopies above. The final layer is the dark forest floor.
Describe the biotic characteristics of TRF in terms of the nutrient cycle.
The nutrient cycle is key to understanding TRF ecosystem, the biggest stores is biomass (b) which is all the biotic factors in TRF. When leaves fall or branches drop into the litter store (L), they decompose very quickly. As soon as the nutrients are released into the soil (S), the plants on the TRF Hoover them up. The trees have shallow roots because the only fertile part of TRF soils is a very thin nutrient layer at the surface. The nutrient cycle returns nutrients to the biomass stores very quickly.
Another biotic factor is human activity. Humans play an important role in May TRF ecosystems. People hunt animals for food, spread the seeds of rainforest plants through the fruits, nuts and seeds that they eat, and affect the ecosystem through their use of fire.
Describe the abiotic factors of the TRF
The warm temperatures and moist conditions are perfect for chemical weathering of the bedrock, which released minerals into the soil. However, TRF soils are often 30 or 40M deep so these nutrients do not reach the upper layers. The constant rainfall means that a lot of water travels down through TRF soils. As it trickles through the soil, the water takes nutrients and mineral salts with it.
What do food webs show?
They show the interactions between species in an ecosystem
Turn to page 134 and 135
And look at the diagrams