Ecosystems Flashcards
biome
large-scale ecosystem
ecosystem
a community of living things (plants and animals) working together with the non-living environment
what are the biomes
hot desert
tropical rainforest
temperate deciduous forest
tundra
taiga (boreal coniferous forest)
tropical grassland (savannah)
hot desert climate
temperature between 30°C and 35°C, less than 250mm of rain a year
tropical rainforest climate
hot all year (23-30°C), very high rainfall (>2000mm a year)
savannah/grassland climate
warm all year (25-30°C), 1000mm annual rainfall but only in 6 months
tundra climate
cold winters, cool summers, precipitation falls mainly as snow
taiga climate
cold and dry, short summers, long winters, temperature: -10 to 15°C, 500mm rainfall a year
temperate deciduous forest climate
warm summers, mild winters, >0°C in winter, 20-25°C in summer, 500-1500mm rainfall per year
tundra plants and animals
plants with shallow roots e.g. arctic poppy, animals e.g. polar bear
taiga plants and animals
evergreen trees e.g. pine, plants with shallow roots, animals e.g. red fox, black bear
TDF/TDW plants and animals
deciduous trees that lose leaves in autumn/winter e.g. oak, birch, vegetation is in four layers, animals e.g. deer, squirrel, hedgehog
TRF plants and animals
high biodiversity of species, vegetation in 4 layers, animals e.g. toucan, sloth
grassland plants and animals
tall grasses e.g. elephant grass in wet season, animals e.g. meerkat, zebra, lion
hot desert plants and animals
short prickly shrubs e.g. fishhook barrel cactus, animals e.g. camel
how the biosphere provides resources for people
food
medicine
fuel
building materials
photosynthesis
recreation
biosphere importance: food
global demand for seafood destined for human consumption is 143.8 million tonnes per year
protein for humans (meat)
natural vegetation can be replaced by crops e.g. wheat/rice
sustainable harvests - fruit, berries, nuts
biosphere importance: medicine
poppies (morphine)
aloe vera plant
vitamin c found in oranges
lichens stop blood loss from cuts
periwinkle to treat leukaemia
biosphere importance: fuel
animal dung dried and burned
trees and shrubs
fermenting crops like sugar cane produce bioethanol
we use 82.4 million barrels of oil per day
biosphere importance: building materials
timber sector generates $600 billion each year
timber/paper/straw/buildings
biosphere importance: photosynthesis
20% of the oxygen we rely on comes from the tropical rainforest. 80% comes from oceans. if it gets warmer, it is less effective
trees act as a carbon sink
trees and plants provide oxygen and take in carbon dioxide from photosynthesis
biosphere importance: recreation
tourism»economic income
how are human activities degrading marine ecosystems in the UK
- the development of coastlines can lead to destruction of plant and wildlife habitats e.g. salt marshes
- climate change allows new species to move into new areas, which may alter the food web and biodiversity
- overfishing of fish species (like cod in the North Sea) impacts the wider ecosystem and damages the food chain
- fertilisers used by famers can lead to eutrophication from chemicals reaching the sea
why does the TRF have a very high biodiversity?
rainforests offer optimum conditions for plant growth, which then supports very high animal biodiversity
there are a variety of layers in the TRF which provides many different habitats
causes of deforestation in the TRF
agriculture
population pressure
resource extraction
causes of deforestation in the TRF: agriculture
palm oil plantations - in demand as ingredient in foods and cosmetics, and as biofuel
cattle ranching - needs vast areas of land; biggest cause of deforestation in the Amazon
subsistence agriculture - land cleared to grow crops quickly loses its nutrients, so farmers clear more
causes of deforestation in the TRF: resource extraction
mining - rising demand and rising prices for minerals in rainforest (e.g. Carajas iron ore mine, Brazil)
road building - to transport resources like iron ore and timber; often built without proper controls
illegal logging - high demand for timber in the Western world
causes of deforestation in the TRF: population pressure
rapid population growth - rising demand for housing and agriculture. Madagascan population 4 million in 1950; 20.7 million in 2010
statistic about deforestation in TRF
7.3 million hectares of rainforest are cleared each year: the equivalent of 36 football pitches of forest every minute.
political and economic factors that have contributed to the sustainable management of the TRF
- government policies/governance
- commodity value
- ecotourism
- reduced-impact + selective logging
factors contributing to the sustainable management of the TRF: governance
- National Forests belong to the state, but government can grant timber companies concessions to manage certain areas.
- 31 National Forests covering 16 million hectares - an area larger than England
- Biodiversity survey must be carried out before logging, to establish which areas need protection.
factors contributing to the sustainable management of the TRF: commodity value
- In parts of the Amazon (e.g. Paragominas) timber firms are realising that undamaged forest is a commercial asset and can yield sustainable income.
- ‘Sustainable management’ or ‘reduced-impact logging’ (RIL) can be more profitable than ‘clear all’ methods of timber extraction.
- RIL is up to 12% cheaper than conventional logging.
factors contributing to the sustainable management of the TRF: ecotourism
- provides local people, that rely on subsistence farming, a reliable income and better quality of life
- includes entrance fees for tourists for more money for rainforest conservation, profits for education projects to promote conservation
- activities to raise awareness encourage conservation
- tourists visit in small groups so harm to environment is limited
factors contributing to the sustainable management of the TRF: reduced-impact logging
- Selected mature trees cut down
- ‘Seed’ trees are left to help quicker regrowth
- Direction of falling trees calculated to reduce damage to other trees
- Less fragmentation and quicker regeneration
nutrient cycle/Gersmehl Model
how nutrients transfer between 3 stores: biomass, (leaf) litter and soil
biomass definition
the mass of living biological organisms, including microorganisms, plants or animals
characteristics of TRF Gersmehl model
- biomass circle is very large
- soil circle is small
- leaf litter circle is very very small
- decomposition arrow is very large
- absorption by plants arrow is quite large
- leaching output arrow is very large
- precipitation input arrow is very large
TRF Gersmehl model: Why is the biomass circle very large?
There is a lot of living vegetation in the rainforest. Lots of energy is stored here. The hot, wet conditions are ideal for growing plants
TRF Gersmehl model: Why is the soil circle small?
- The soil in the rainforest is not very fertile (doesn’t have many nutrients) Little energy is stored there.
- The many trees absorb most of the nutrients, leaving few
in the soil.
TRF Gersmehl model: Why is the leaf litter circle very very small?
- There aren’t many dead or decaying leaves on the forest floor. Not much energy is stored there.
- There are no seasons in the rainforest, so there is no autumn when the leaves fall off. Instead, a few leaves die and fall constantly.
TRF Gersmehl model: Why is the decomposition arrow very large?
There is a lot of decomposition. Hot damp conditions mean that any dead leaves rot quickly.
TRF Gersmehl model: Why is the absorption by plants arrow quite large?
Plants take in a lot of nutrients very quickly. There are so many trees that any nutrients which are available are absorbed very quickly.
TRF Gersmehl model: Why is the leaching output arrow very large?
It rains a lot in the TRF. The rainwater dissolves the nutrients and washes them out of the soil.
TRF Gersmehl model: Why is the precipitation input arrow very large?
The TRF has high rainfall
characteristics of TDW Gersmehl model
Why do deciduous woodlands (TDW) have moderate biodiversity?
TDW have fewer types of species compared to TRF because:
- lower food production levels in the winter
- smaller size ecosystem than TRF, so less space for plant and animal species
- higher latitude»_space; lower temperature and fewer sunlight hours: not as efficient for photosynthesis or food production for animals
Some characteristics support biodiversity
- TDW have rainfall all year with 4 distinct seasons which leads to different adaptations by species
- the ecosystem’s 4 layers create a range of wildlife habitats
