B7 - Ecology Flashcards
What is ecology about?
Organisms and the environment that they live in, and how the two interact
Give the definitions of these words:
a) Habitat
b) Population
c) Community
d) Ecosystem
a) The place where an organism lives
b) ALL the organisms of one species living in a habitat
c) the populations of different species living in a habitat
d) The interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of their environment
Give some biotic and abiotic factors
BIOTIC - trees, plants, insects, animals, humans
ABIOTIC - soil (pH), sun, air, light, temperature
What do animals and plants compete for?
Resources to survive -
Plants need light & space 7 water & mineral ions/ nutrients from the soil
Animals need space (territory) & food & water & mates
In a community, each species depends on other species for things such as food, shelter, pollination and seed dispersal - what is this called?
Interdependence
Give some stable communities, and what this means.
In some communities, all the species and environmental factors are in balance so that the population sizes are roughly constant. Examples are tropical rainforests, ancient oak woodlands, possible deserts
Say if these factors are biotic or abiotic:
a) Carbon dioxide & oxygen level
b) New pathogens
c) Soil pH and mineral content
d) Wind intensity and direction
e) New predators
f) Moisture level
g) Availability of food
h) Competition
i) Light intensity & temperature
a) Abiotic
b) biotic
c) Abiotic
d) Abiotic
e) Biotic
f) Abiotic
g) Biotic
h) Biotic
i) Abiotic
What could a decrease in light intensity on plants cause?
Same as a decrease in CO2 and temperature could - decrease the rate of photosynthesis in a plant, affecting plant growth and cause a decrease in the population size
What would a decrease in mineral content of the soil cause?
Nutrient deficiencies, affecting plant growth and decreasing the population size
What could a new predator cause?
A decrease in the prey population
Give some stable communities, and what this means.
In some communities, all the species and environmental factors are in balance so that the population sizes are roughly constant. Examples are tropical rainforests, ancient oak woodlands, possible deserts
What does structural adaptation mean?
Featires of an organism’s body structure - such as shape or colour. (Arctic foxes with white fur to camouflage, whales with a thick layer of blubber to deal with cold)
What could a decrease in light intensity on plants cause?
Same as a decrease in CO2 and temperature could - decrease the rate of photosynthesis in a plant, affecting plant growth and cause a decrease in the population size
What would a decrease in mineral content of the soil cause?
Nutrient deficiencies, affecting plant growth and decreasing the population size
What could a new predator cause?
A decrease in the prey population
IN A FOOD CHAINS, WHAT DO THE ARROWS REPRESENT??????
Where the energy goes - the arrows go UP to the PREDATOR because they are the BEST
What do food chains:
a) show?
b) start with?
c) continue?
a) What’s eaten by what in an ecosystem
b) a producer - they make their own food using energy from the sun
c) Producers eaten by primary consumers.
Primary consumers eaten by secondary consumers.
Secondary consumers eaten by tertiary consumers
Often, a peak in the prey population will cause what shortly after? (in a stable community)
A peak in the predator population. Then they go down again.
PREDATOR-PREY CYCLES are always out of phase with each other, as it takes a while for one population to respond to changes in another population.
What is the population of any species limited by?
The amount of food available
Quadrats are used for what?
To study the distribution of small organisms
Environmental factors affects what?
Where an organism is found
Often, a peak in the prey population will cause what shortly after? (in a stable community)
A peak in the predator population. Then they go down again
Give a definition of distribution
The distribution of an organism is where an organism is found
How can you make the quadrats random?
By dividing the area into a grid and use a random number generator to pick co-ordinates
Environmental factors affects what?
Where an organism is found
Give the steps to use quadrats
1) Place a 1m squared quadrat on the ground at a random point in the first sample area (By dividing the area into a grid and use a random number generator to pick co-ordinates)
2) Count all the organisms of ONE SPECIES within the quadrat
3) Repeat those steps as many times as possible to make the results more reproducible
4) Work out the mean number of organisms per quadrat in the first sample area
5) Repeat steps 1-4 in the second sample area
6) Compare the 2 means. E.g. you might find 2 daisies per m squared in the shade, and 22 daisies per m squared in the open field
How do you calculate the mean number of organisms per quadrat in one sample area?
Number of quadrats
Give the use of a transect
Used to study the distribution of organisms along a line
REPRODUCIBLE
REPRODUCIBLE
What’s the method for using a transect?
1) Mark a line in the area you want to study using a tape measure
2) Collect the data alon g the line. You can do this by
a) counting the organisms you want that touch the line or
b) randomly pacing quadrats along the line/ the book says placing them next to each other or along the line at equal intervals
How do you calculate the percentage cover of a quadrat?
(It’ll give you a chart)
1) Count the number of squares covered by the organism
2) Make this into a percentage
Rearrange this for the water cycle:
1) Some of this water is absorbed by the soil and taken up by the pant roots. This provides fresh water to plants for stuff like photosynthesis. Some of the water becomes part of the plants’ tissues and is passed along animals in the food chain
2) Water that doesn’t get absorbed by the soil will run off into streams and rivers
3) Water also evaporates from plants- this is transpiration
4) Like plants, animals need water for chemical reactions in their bodies. Animals return water to the soil and atmosphere through excretion (e.g. sweating, urination and breathing out)
5) Energy from the sun makes the water evaporate from the land and sea, making water vapour
6) From here, the water then drains back into the sea, before it evaporates all over again
7) The warm water vapour is carried upwards (as warm air rises). When it gets higher up it cools and condensates to form clouds
8) Water falls from the clouds as precipitation (usually rain, but snow and hail too) onto land, providing fresh water for plants and animals
5) Energy from the sun makes the water evaporate from the land and sea, making water vapour
3) Water also evaporates from plants- this is transpiration
7) The warm water vapour is carried upwards (as warm air rises). When it gets higher up it cools and condensates to form clouds
8) Water falls from the clouds as precipitation (usually rain, but snow and hail too) onto land, providing fresh water for plants and animals
1) Some of this water is absorbed by the soil and taken up by the pant roots. This provides fresh water to plants for stuff like photosynthesis. Some of the water becomes part of the plants’ tissues and is passed along animals in the food chain
4) Like plants, animals need water for chemical reactions in their bodies. Animals return water to the soil and atmosphere through excretion (e.g. sweating, urination and breathing out)
2) Water that doesn’t get absorbed by the soil will run off into streams and rivers
6) From here, the water then drains back into the sea, before it evaporates all over again
Summarise the water cycle
EVAPORATION + TRANSPIRATION - WATER VAPOUR UP
CONDENSATION - CLOUDS
PRECIPITATION - RAIN & SNOW & HAIL
DRAINS BACK TO SEA FROM RIVERS - CYCLES!
How are elements cycled back to the start of the food chain?
By decay
FIll the blanks:
Living things are made of materials from the world around them. E.g. ______ turn elements like ______, oxygen, ________ and nitrogen from the soil and air into complex _________ (_____________, proteins and fats). that make up living organisms. These get passed up the ____ _____. These materials are _______ to the environment in _____ ________, when the organism dies and decays
Plants Carbon Hydrogen Compounds Carbohydrates Food chain Returned Waste products
Why do materials decay?
Because thy’re being broken down by microorganisms
What factors speed up decay?
Warm, moist, aerobic (high oxygen) conditions, because microorganisms are more active in this environment
What does decay do for plants?
It puts the stuff plants need to grow back into the soil to be reused
In stable community, what is the carbon cycle like?
It too is balanced - the materials taken out of the soil and used by the plants etc. are balanced by those put back into the soil. IT IS A CONSTANT CYCLE
What parts of the carbon cycle contribute to the CO2 in the air? What uses it?
Burning fossil fuels & products made by plants and animals (picture of T-shirt), plant respiration, animal respiration, CO2 released from decay.
Photosynthesis uses it
What are fossil fuels made from?
Decayed plant and animal matter (from millions of years ago)
Give the definition of biodiversity
The variety of different species of organisms on Earth, or within an ecosystem. HIGH biodiversity is important
What are the main reasons for the sudden and high rise of the world population?
Modern medicine and farming methods, reducing the number of people dying from disease and hunger
What are the 2 main problems we are causing on the Earth with population growth?
Increasing demands on our environment
Producing more waste
Talk about the waste we create reducing biodiversity in:
a) Water
b) Land
c) Air
a) Sewage and toxic chemicals from industry can pollute lakes & rivers & seas, affecting the plants and animals relying on them for survival (including humans). And the chemicals used on land (e.g. fertilisers, pesticides and herbicides) can be washed into the water
b) We use toxic chemicals for farming (pesticides and herbicides). We also bury nuclear waste underground, and we dump a lot of household waste in landfill sites
c) Smoke and acidic gases released into the atmosphere can pollute the air e.g sulfur dioxide causing acid rain
Acid rain is what?
Sulfur dioxide
What is the temperature of the Earth a balance of?
A balance between trhe energy it gets from ten sun and the energy it radiates back into space
What do gases in the atmosphere act like?
An insulating layer - they absorb most of the energy that would normally be radiated out into space, and re-radiate it in all directions (including back towards Earth). This increases the temperature of the planet
What are the main 2 greenhouse gases?
Methane and Carbon Dioxide (water vapour too, but that isn’t rising as much)
Talk about these 4 consequences of global warming:
1) Higher temperatures cause seawater…
2) The distribution of many wild animals and plant species may change as temperature increases…
3) There could be changes in migration patterns…
4) Biodiversity could be reduced…
1) to expand & Ice to melt, causing the sea to rise, resulting in low lying land to be flooded and so a loss of habitat
2) and the amount of rainfall in different areas. Some species may become more widely distributed (e.g. species needing warmer temperatures may spread further as the conditions they thrive in exist n a wider area, and vice versa for cold species)
3) Some birds may migrate further north, as more northern areas are getting warmer
4) if some species are unable to survive in the climate change, so become extinct
Give some uses that humans have for land
Building, quarrying, farming, dumping waste - this gives less land for other organisms
Give 2 reasos for deforestation
To clear land for farming (cattle or rice crops etc.) to provide more food
To grow crops from which biofuels based on ethanol can be produced
|What are the 3 main problems that deforestation can cause?
1) LESS CARBON DIOXIDE TAKEN IN - amount of CO2 taken in through photosynthesis by trees is reduced, and trees lock up some carbon they absorb, which can remove it from the atmosphere for 100s of years. Less trees = less locked up
2) MORE CARBON DIOXIDE IN THE ATMOSPHERE - Carbon in wood doesn’t contribute to atmospheric pollution until burning). Microorganisms feeding on decaying wood release CO2 too as a waste of respiration
3) LESS BIODIVERSITY - Reducing forest habitats puts animals there in danger of becoming extinct without a home, biodiversity is reduced
What are peat bogs?
Bogs are areas of land that are acidic and waterlogged. Plants that live in bogs don’t fully decay when they die as there isn’t enough oxygen. The partly-rotted plants gradually build up to form a peat
Why does destroying peat bogs cause more CO2 to enter the atmosphere?
As carbon from the partially rotted plants that form the peat is stored in the peat instead of released into the atmosphere - what happens when they’re destroyed
What happens when peat is drained?
It comes into contact with air and some microorganisms start to decompose it. When these microorganisms respire, they use oxygen and release CO2 - contributing to global warming
Name some programs/ their aims to protect ecosystems & biodiversity
Breeding programs - prevent endangered species from becoming extinct
Programmes to protect & regenerate rare habitats like mangroves, heathland and coral reefs
Programmes to reintroduce hedgerows and field margins around fields on farms where only a single type of crop is grown, providing a better habitat as wild flowers and grasses are left to grow
Programmes to reduce deforestation set up by governments
Programmes encouraging people to recycle & reuse stuff instead of using landfills - more space for ecosystems
How do breeding programmes work?
Animals are bred in captivity to make sure the species survives. individuals can sometimes be released into the wild to boost or re-establish a population
What conflicting measures can affect how biodiversity is maintained?
MONEY ugh
Local people - unemployment for lumberjacks for example
Foxes and locusts are seen as pests by farmers for example, and are killed to protect crops, affecting the food chain and biodiversity
Need of land
