Geography- Ecosystems and TRFs Flashcards
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What does abiotic and biotic mean?
Biotic means something is made up of living things.
Abiotic means something is made up of non living things.
Example:
Foxes and mushrooms are Biotic
Rivers and nutrients are Abiotic
What is a keystone species?
A species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.
It helps to define an entire ecosystem.
Information on UK beaver introduction
Castoreum from anal area, meat and fur caused beavers to be hunted.
They went extinct in the 16th century.
Beavers create new wet land habitats for other species which improves biodiversity and act as carbon sinks by storing CO2
Beavers can reduce flooding with their dams.
Eco tourism - people want to see beavers in the wild.
5-8% of the world is covered in wetlands and 25%of carbon is stored in them.
Flooding increases downstream if they build near cities or farms.
They can prevent fish migration and navigation in boats with their dams.
Beavers chop down larger than average trees which may hurt the environment.
Information on Yellowstone National park case study
Yellowstone is located in Northern, central USA.
The park lost wolves due to extermination by humans and were gone for 70 years.
The whole park became overgrazed and new growth was hard.
They were reintroduced.
The number of elks halved which reduced grazing.
Coyotes, with the new competition had their numbers fall.
There were increased numbers of Beavers, aspen, foxes, birds of prey, rodents, magpies and more.
Aspen and trees regrew because of less grazing pressure.
River banks were stabilised due to increased trees meaning that there was less erosion.
Beavers flooded areas promoting new growth.
How can an ecosystem be restored?
Many species have been hunted to extinction for sport or for something they produce like fur. This can cause an increase in other animals which devastates environments (interdependence is imbalanced).
The reintroduction of these species can help rebalance the ecosystem.
What things may affect an ecosystem?(5)
Tourism - Tourists may pollute the area or cause foot erosion. Companies may chop down trees or harm the environment to get money from these tourists with attractions.
Agriculture - Agricultural fertilisers can lead to eutrophication - nitrates increase, algae grows, oxygen depletes. Over farming can deplete soil of nutrients.
Fishing - Over fishing can lead to extinction of species. People may also litter there because fishing takes a long time.
Extreme weather - Droughts, Hurricanes and tornadoes can significantly impact ecosystems. Heavy rainfall may lead to leaching and runoff which may prevent flora growth.
Deforestation - Increases soil erosion, lowers nutrients in soil. Destroys habitats. Releases carbon into atmosphere.
What is a global ecosystem/ biome?
Very large ecological areas on the earth’s surface of biomes, with fauna and flora (animals and plants) adapting to their environment.
Examples:
Tropical rainforest, Desert, temperate forest.
What is runoff
Runoff occurs when there is more water than land can absorb. This may leach the land of nutrients or remove litter from the ground.
What is leaching?
Leaching is the removal of materials in solution or suspension downwards as water moves vertically through the soil body by force of gravity.
It removes the nutrients meaning plants may not survive
What is the nutrient cycle?
Plants(biomass) absorb nutrients from the soil. When the plants die, they form a layer of vegetation known as litter. This is decomposed and nutrients are released back into the soil. Leaching takes some nutrients away, rock weathering adds nutrients back.
What are the different parts of the food chain?
Producers convert energy from the environment into glucose. These are typically plants.
Consumers get energy produced from the sugars made by the producers. These are typically herbivores/ Omnivores on the first level.
Next level consumers get energy from other consumers by eating them. These are all predators and are top of the food chain.
What is the food chain and food web? How are they different?
A food chain shows the flow energy from one living organism to another.
A food web consists of interlocking food chains and can be easily damaged by physical and/or human factors.
A food chain shows how different organisms interact and eat on a small scale whereas a food web is made up of many more organisms on a larger scale because it is made up of multiple food chains.
What is an ecosystem?
An ecosystem is a biological community of interacting organisms and their environment.
What is humus and how is it produced?
Humus is nutrient rich and is found in soil. It is created when decomposers decompose leaves and remove the nutrients. It is typically found on the surface or top layers of soil.
Information about Epping forest Case study
Epping Forest is a site of special scientific interest (SSS).
Located North East of London.
It has a large number of native tree species including oak, elm, ash, and beech.
studies have found 700 species of fungi - decomposers.
It is 6000 acres and used to be larger.
It has been managed for over 1000 years.
It is a hunting resort.
It is an example of a small-scale ecosystem in the UK and is a deciduous forest.
It has producers and consumers such as mosses, herbs, beetles, worms, mice, small birds, foxes and owls.
What does interdependence mean?
The dependence of different organisms on each other
All organisms in an ecosystem depend on each other. If the population of one organism falls then this can affect the rest of the ecosystem.
Example:
grass -> rabbit -> fox
Foxes die
Nothing eating rabbit so they grow in numbers
They eat all the grass and they starve
What are the different parts of a rainforest?(4)
Shrub layer/Forest floor - It is where decomposition takes place. Because of dark and moist conditions, plants and animals decompose quickly. Fungi feed on decaying matter. Few plants except small trees and shrubs grow here due to limited light.
Under canopy - The under canopy is relatively dark due to the canopy. The air is still and it would take you time to feel the rain because the canopy blocks most of it.
Canopy - 80% of the sunlight is absorbed by the canopy. Holds 70% of the species. Most of the rainfall is captured by the canopy.
Emergents - The emergent layer has insects and birds that are crucial for pollination. These trees can be 120 feet tall and 16 feet wide. Temperate and climate fluctuations are common.
General facts about rainforests(5)
50% of the earths plans and animal species live in tropical rainforests.
25% of the ingredients in cancer-fighting drugs come from the rainforest.
20% of the worlds oxygen comes from rainforests and they are known as the lungs of the world.
Every second a football pitch sized area of rainforest is cut down.
The rainforest produces 50% of its own rainfall.
What is latisol and where does the rainforest get nutrients?
Soil in tropical rainforest is called Latisol. It is rich in iron and aluminium and is red in colour. It is infertile. This is due to heavy rainfall leaching the nutrients out of the soil.
Most nutrients are found at the surface where dead leaves decompose.
Many trees and plants have shallow roots to absorb the nutrients.
This means that if these nutrients are washed away, the rainforest won’t have any nutrients left.
What are adaptations?
Adaptations occur when a species evolves to best suit its environment
What is biodiversity?
Biodiversity is the variety of plant and animal life in the world or in a particular habitat a high lever of which is usually considered to be important or desirable.
What is species richness and species evenness?
Species richness is how many species there are.
Species evenness is how equal the species are.
Biodiversity is measured with a combination of these factors.
Why is palm oil harmful to rainforests?
Palm oil comes from Indonesia and Malaysia from Palm trees.
Palm oil is produced in plantations in rainforests.
Large areas of trees containing orangutan are cut down for these plantations.
150,000 orangutans or half of the island population died due to palm oil and poaching.
It also reduces biodiversity and is a driving factor for increased deforestation.
Palm oil can be made sustainably if you meet the criteria of the RSPO. These criteria include no areas of high biodiversity, primary forests, fragile ecosystems or areas which are needed by locals can be cut down.
What are the causes of deforestation?
Cattle ranching Arable/commercial farming Subsistence farming Mineral extraction Logging Selective logging Infrastructure/roads Population pressure Hydroelectric power
