B8 Ecology In Action Flashcards
Ecosystems
The interaction of a community of organisms with the non living parts of their environment
Self supporting
Has all the requirements for living organisms to grow and survive are present
Need an external energy resource (the sun)
Interdependence
Relying on other species for survival
Natural ecosystem
Oceans
Lakes
Puddles
Rainforest
Artificial ecosystem
Fish farms
Zoo
Planted forests
Biodiversity
The range of different plant and animal species living in an ecosystem
Producers, consumers and decomposers
Population
Total number of one species living in an ecosystem
Community
All the plants and animals living in an ecosystem
Habitat
Where an organism lives in the ecosystem is its habitat
High biodiversity is important because
Wide variation of food sources reducing the dependence of a species on a particular food source
Provides Food, water, medicine, atmosphere and water
Abiotic factors
Physical (non living) conditions that affect the distribution of an organism like: Temperature Light intensity Oxygen and carbon dioxide levels Moisture levels pH and mineral content for plants Wind intensity and direction
Biotic factors
Living organisms affecting other populations in their ecosystem like: Food availability New pathogen New predators Competition between species
Looking at changes
the number and type of organism can gradually change across a habitat
Can be easily seen on the sea shore, where there are distinct zones of organisms due to changing tides
How does the distribution of species change
Little grazing= few plants to out compete others
Grazing increases= more plants grow as dominant plants are controlled by animals so weaker plants can grow
Only specially adapted plants can resist the effect of intensive grazing and survive
A stable community
Where the biotic and abiotic factors are in balance so that the population sizes remain fairly constant
Food chain
Energy Producer Primary consumer Secondary consumer Tertiary consumer
Parasitism
One organism lives of the host
If a parasite kills their host they die too
Population cycles
The number of predators (population) follows the size of the preys population
Trophic levels
Describes the feeding position in food chains Level 1 producers Level 2 herbivores Level 3 carnivores Level 4 carnivores (apex predators)
Extracellular digestion
Decomposers Break down dead plant and animal matter
They secrete enzymes onto food to digest it
The digested food molecules then diffuse into the microorganism
Happens outside the cell
Using pyramids
Has producers at the bottom and works up to consumers
It shows how much is required of each Trophic level for the species to gain enough energy
Biomass pyramids
Show the amount of energy in a trophic level more accurately than pyramids of number
Problems with biomass pyramids
Organisms need to be collected and killed to measure dry mass
It is difficult to catch and weigh the organisms
Biomass varies. A tree in the summer has more biomass than it does in the winter
Some organisms are omnivores and feed at more than one trophies level
How is biomass lost
Some plant material, which can not be digested, leaves as the body faeces
Some animal material can not be digested eg. Bones, horns, teeth etc.
Biomass eaten by animals is also used in respiration to release energy, and leaves the animal as carbon dioxide and water
Biomass lost in animals
Herbivores need to eat more as plants take longer to digest
Whereas carnivores eat less meat as it is easier to digest
Animals use lots of glucose and lose CO2 and water to surroundings in respiration
More movement means more biomass used
Biomass is used to regulate body temperature
Energy transfers
Energy transferred between organisms is about 10% at each tropic level
Plants compete for:
Light
Space
Water
Mineral ions
Animals compete for:
Food
Water
Mates
Territory
The more resources
The more successful the species is to survive
A less successful species may
Do nothing and become extinct
Stay in it’s habitat but adopt new survival strategies
Move to another area looking for resources
Interspecific competition
Competition between different species
Intraspecific competition
Competition within one species
May result in territorial behaviour
More significant than interspecific competition
RP: measure the population size of a common species in a habitat
Random sampling with repetition
The number of daisies in trampled and Untrampled land
Use a quadrat and a tape measure
Why are adaptations important?
Help allow them to survive and be successful within their habitat
Camouflage
Blending in with surroundings so that prey or predators can not be seen
Behavioural adaptations in hot temperatures
Active during cooler mornings
Move to shady areas to keep cool
Remain in burrows as temperatures are more stable
Behavioural adaptations in cold temperatures
Hibernate over the winter when food is scare
Metabolic rate is lowered to reduce the need for food
Migrate to warmer countries where there is more food
Adaptations of Plants in hot temperatures
Reduced surface area
Storing water in their tissues
Adaptations of plants in cold temperatures
Growing closer to the ground
Having smaller leaves
Extremophiles
Organisms that can survive in extreme environments such as:
Very high/low temperatures
High slay concentrations in water
High pressures
Adaptations of plants in drier conditions
Reduced surface area
Storing water
Extensive root systems that are wide or deep
Adaptations of cacti
Spine like leaves to reduce surface area Fleshy stem Extensive shallow roots Thick waterproof cuticle Round shape resolute surface area to volume ratio
Epiphytes
Grow in rain forest and grow above the ground
They grow on other plants allowing leaves to absorb sunlight through trees
Having roots that’s absorb rain and moisture from humidity and minerals from leaf litter
Having upturned leaves to store water
The water cycle
Evaporation- water is heated by the suns energy and water vapour is carried up in conventional currents
Condensation- water vapour rises, cools and condenses back into water droplets that form clouds
Precipitation- water droplets in clouds get bigger and heavier, they fall as rain, snow or sleet
Transpiration- water vapour is realised into the air through stomata in leaves
The water cycle is important because it circulates water that:
Maintains habitats
Maintains internal fluids and transport systems
Is needed for chemical reactions
Is a reactant in photosynthesis
Factors that speed up decay
Plenty of microbes
Warmth
Plenty of oxygen
Some moisture
Carbon
In fossil fuels and carbonate rocks
Dissolved in rivers, lakes and oceans
Small amount in the air CO2
Used to make carbohydrates, proteins, fats and DNA that form new biomass which is eaten by consumers
Carbon cycle
Fossil fuels are burned
Carbon dioxide is released
Plants take in carbon dioxide from the air through photosynthesis
The plants die they decompose and become aquatic biomass and limestone
Carbon stores
Shells contain carbonates
They die and fall to the sea floor
Over millions of years they compress to form limestone
Carbon dioxide reacts with rain to form carbonic acid. This acid train erodes limestone and releases carbon dioxide
Can be held in carbon sinks and then released in huge amounts during volcanic eruptions and forest fires
Biogas
Produced in marshes, septic tanks and sewers
Cheap fuel source for cooking, heating, electricity, and fuel for vehicles
Gases contained in biogas
Methane (50-75%)
Carbon dioxide (15-45%)
Water vapour
Small amounts of other gases
RP: investigating the effect of temperature on the rate of decay of fresh milk by measuring pH change
Milk and sodium carbonate are added to water
A lipase (enzyme) is added
Use a pipette of 10cm3
Heat solutions to different temperatures
Use a phenolphthalein indicator ( pink in solutions of pH 10)
Changes indicator from pink to colourless
The lower the temperature of the solution the quicker the pH level falls
Environmental changes can be
Natural- caused by season changes or geographic location
Caused by humans
Season changes impact
Low temps and food shortages cause some animals to migrate, hibernate or have a dormant stage
Hot seasons may cause drought, rainy seasons may cause flooding
Hot temperatures reduce the available oxygen in water
Geographic changes impacts
Land bridges sinking and stopping animals from moving between continents
Global warming causes mountainous regions to become warmer, mountain species are having to compete with lowland species whose habitats are extending upwards
Seas are becoming more acidic and warmer so Shells of calcareous organisms are dissolving and becoming thinner
Erosion by rivers and tides may gradually destroy habitats
Environmental change by humans
Burning fossil fuels causes global warming. Higher sea temperatures are associated with lower dissolved oxygen levels
Intensive farming causes desert regions
Dredging sea beds for building has endangered some marine ecosystems
Impact of rising sea temperatures
Global warming means that sea temperatures are getting too higher which is bleaching corals
Algae living in them can not survive
20% of coral reefs have been destroyed in 50 years
Human propulsion growth means we use more land for
Farming
Building
Quarrying
Dumping waste
Eutrophication
When water containing lots of fertilisers or sewage goes into a river. These minerals increase the growth of algae. This prevents sunlight from reaching species in the water
The plants and algae die.
Bacteria repute as they breakdown dead plants and use up oxygen in the water
Other organisms in the water die due to the lack of oxygen
deforestation is happening to:
Provide land for cattle and rice fields
Grow crops eg. Plan oil and sugar cane to make biofuels. They are sometimes grown at the expense of food crops
Peat
When decomposes can not break down plant material in acidic conditions with little oxygen
Is a store of carbon
Can be used as a fuel or as cheap compost for gardeners
The mass destruction of trees has:
Increased the release of carbon dioxide into the atmosphere ( due to burning and the respiration of microorganisms that are decaying the remaining plant material)
Reduce the rate that CO2 is removed from the atmosphere (by photosynthesis)
Reduced biodiversity; some of the lost plants and animals may have been more useful in the future
Increased methane in the atmosphere because cleared land is used to grow rice in swamp like fields
There is a massive conflict between:
The need for deforestation to increase land available for food production
The use of leaf as cheap compost to increase food production
The need to conserve forests and pear lands as habitats for biodiversity
The need to reduce carbon dioxide emissions from using pear as a fuel and from burning fossil fuels
Global warming
The average global temperature of the earth and its atmosphere is increasing
What causes global warming
Increasing atmospheric levels of carbon dioxide and methane
Why have CO2 and methane levels increased so much over the last 150 years?
Power plants burning fossil fuels
Petrol is used as fuel in vehicles
Rice crops and cattle farming are increasing
Deforestation and destruction of peatlands are increasing
Wasted
Waste substances like: sewage, smoke, toxic gases, herbicides, pesticides, fertilisers, lead, paper, cardboard and plastic products can kill plants and animals, reducing biodiversity
Effects of acid rain
Damages leave and roots of plants
Washes mineral ions out of soil causing mineral deficiencies in plants
Washes aluminium ions from soil into lakes which affect gills in fish so they die
Acidifies waterways so aquatic organisms can not survive
Can travel in air, acid rain produced in uk effects trees and fjords in Norway
Indicator species
Organisms are sensitive to abiotic factors. If the conditions change the distribution of organisms can also change. So some organisms are used to measure environmental change
Pollution levels are also directly measured using
Probes attached to computers to measure precise conditions eg. pH, temperature, oxygen and CO2 levels
Special tests to indicate levels of different chemicals such as nitrates
Measures to protect ecosystems
Introducing breeding programs for endangered species
The protection and regeneration of rare habitats
Re introducing field margins and hedgerows on farmland where mono cultures are grown.
Hedgerows are a habitat for many wild species
Reducing deforestation and replanting trees
Recycling instead of dumping
Cloning plant species
Conservation programs are introduced
Moral responsibility to protect endangered species
More plant species can be identified for medicines
Minimise damage to food chains and webs
Protect future food supplies
Protecting rare habitats have many challenges
Ensuring long term funding
Having qualified scientists who understand the issues
Animal and plants do not recognise boundaries
Many organisms and governments may be involved, working locally, nationally and internationally
Lack of policing of protected areas
Food security
When all people have access to consistent supplies of safe and nutritious food to meet their needs for an active healthy lifestyle. Food must be available,affordable and useable
Factors that affect food insecurity
Increasing birth rate Changing diets in developing countries New pests and pathogen's affect farming Environmental changes Cost of agricultural inputs Conflicts and war
Modern farming methods
Use machines and chemicals to produce larger yields
Use fertilisers
Insect excises and fungicides to kill pests and herbicides to kill weeds
Growing plants in greenhouses
Using hydroponics
Factory farming and fish farming
Hydroponics advantages
Mineral supply controlled and recycled
Cheaper as no pollution risk to waterways
System is covered so control conditions and disease is improved
Sustainable fisheries created by
Fishing quotas to conserve stocks at sustainable levels
Control size of net to ensure that young fish mature and breed
Efficiency of intensive farming is increased by
Killing weeds to reduce competition with crops
Fewer animal pests to eat crops or cause disease in livestock
Feeding animals high protein foods to increase growth
Restricting movement so biomass isn’t lost and energy can be used for growth
Controlling temperatures reduces energy that animal uses to maintain a constant body temperature
Mass production of animals for food causes suffering through
Close confinement increases risk of disease
Lack of movement
Nature of the pens and cages
Poor transportation or slaughtering techniques
Biotechnology
Used in living organisms to make a product to improve the quality of life such as
GM crops
Human insulin
Mycoprotien ( a protein rich food)
GM crops can be
Resistant to insect attack or to herbicides
Produce larger yields
Provide more food or more nutritious food
They are overall more efficient
Fusarium
A fungus used to make a protein rich, low fat food called mycoprotein
It grows and reproduces rapidly on glucose syrup in aerobic conditions
It can double its biomass every 5 hours
It is almost tasteless and a range of textures and flavourings can be added to it
Fermenters have
Constant oxygen supplies of fusarium to respire
Water jackets to remove heat produced during respiration
pH and temperature probes to monitor conditions and allow adjustments to be made quickly
Stirrers to spread heat, oxygen and syrup evenly through the vats and keep the fungus in suspension
