Please enable JavaScript.
Coggle requires JavaScript to display documents.
Topic 7 Ecology By Bethan Poole (7.3 Biodiversity and the effect of human…
Topic 7 Ecology
By Bethan Poole
7.1 Adaptations, Interdependences and Competition
7.1.2 Abiotic Factors
Non-living factors
They are
Soil pH and mineral content
Wind intensity and direction
Moisture levers
Carbon dioxide levels for plants
Temperature
Oxygen levels for aquatic animals
Light intensity
7.1.3 Biotic Factors
Living factors
They are
New predators arriving
New pathogens
One species out competing another
Availability of food
7.1.1 Communities
Interdependence
when another organism relies on another for certain resources
Within a community, each species depends on another for food, shelter, pollination, seed dispersal etc. -one species removed affects the whole community
Stable community
When organisms in the community are well adapted to the conditions in the community
Ecosystem
Interaction of a community of living organisms with non-living parts of their environment
To survive and reproduce organisms require a supply of materials form their surroundings and from other living organisms there
Animals compete for
Territory
Mates
Food
Plants compete for
Nutrients
Water
Light
Space
7.1.4 Adaptations
Organisms have adaptations to enable them to survive in their nature habitat
Can be structural behavioural or functional
Organisms living in environments with extreme temperature, pressure or salt concentration are called
extremophiles
e.g.
bacteria living in deep sea vents
7.2 Organisation of an ecosystem
7.2.2 How materials are cycled
The Carbon Cycle
Returns carbon from organisms to the atmosphere as CO2 to be used by plants in photosynthesis
The Water Cycle
Provides fresh water for the plants and animals on land before draining into the seas- continually evaporated and precipitated
7.2.3 Decomposition (biology only)
Detritus feeders (maggot and worms) start the process
Decomposers (bacteria and fungus) finish it off
Conditions needed
Temperature
Moisture
Oxygen
These organisms are essential to maintain the cycle of life and maintain other resources
Gardeners and farmers try and provide the optimum conditions for pride decay of waste biological material- compost produced as a natural fertiliser
Anaerobic Digester
Produces methane gas
Biogas genertors can be used to produce methane gas as a fuel
7.2.1 Levels of organisation
Photosynthetic organisms are the producers of biomass for life on earth
Feeding relationships within a community can be represented by a food chain- all begin with a producer (green plant or algae) which synthesises molecules
Producer
Primary consumer
Secondary consumer
Tertiary consumer
Quadrat smapling
Sampling technique used to estimate plant population numbers, in a uniform area thats too large to collect
The more you place the more accurate
Placement must be random
estimate plant population= mean number of plants per quadrat X area of field
Transect lines
Sampling technique used to compare distribution across an area
Mean
total of all numbers divided by how many numbers there are
Median
middle value- numbers increasing in size order
Mode
most common value
7.2.4 Impact of environmental change (biology only)
Environmental Changes
Affect distribution of species in an ecosystem
They include
Composition of atmospheric gases
Lichens don't grow where there is an increase in sulphur dioxide
Water
Animals may migrate due to the availability of water
Temperature
Bird migration patterns change due to average temperature
7.3 Biodiversity and the effect of human interaction on ecosystems
7.3.3 Land use
Reduction of land for animals and plants
Building
Quarrying
Growing sugar cane
Dumping waste
Peut bogs
Destruction of peut bogs increases CO2 in the atmosphere-
Reduces habitat and biodiversity
7.3.4 Deforestation
Large scale deforestation in tropical areas has occurred to
Provide land for cattle and rice fields
Grow crops for biofuel
7.3.2 Waste management
More waste from human activity is produced due to the growing population and increase in the standard of living
Pollution can occur from the waste
In water
Sewage
Oxygen levels decrease causing fish to die
Fertiliser
Increased numbers of plants in water- block sunlight- everything else dies
Toxic chemicals
Bioaccumulation
In air
Smoke
Acidic gases
On land
Landfill
Toxic chemicals
7.3.5 Global warming
A gradual increase in the temperature of the Earth
Caused by changes in various gases (including carbon dioxide and methane), caused by pollution and deforestation
There are a number of biological causes
Loss of habitat, when low-lying areas are flooded by rising sea levels
Changes to the distribution of species in areas where temperature or rainfall has changed
Changes to the migration patterns of animals
7.3.1 Biodiversity
The variety of all the different species of organisms on earth, or within an ecosystem
Great biodiversity ensures an ecosystems stability by reducing dependence on one species for:
Food
Shelter
The maintenance of the physical environment
Many human activities are reducing biodiversity
only recently have measures been taken to try and stop this reduction
7.3.6 Maintaining biodiversity
Programmes put in place to increase biodiversity
reintroduction of field margins and hedgerows in agricultural areas where farmers grow only one type of crop
reduction of deforestation and carbon dioxide emissions by some governments
protection and regeneration of rare habitats
recycling resources rather than dumping waste in landfill sites
breeding programmes for endangered species
7.5 Food Production
(Biology Only)
7.5.2 Farming techniques
Efficiency of food production can be improving by restricting energy transfer from food animals to the environment
Can be done by:
Limiting movement
Controlling temperature
Feeding animals high protein foods to increase growth
e.g.
Caged animals
Pros
Ration food
Medical Checks
Protects them
Take up less space
Human safety
Energy used to grow
Can still communicate
Cons
Normally, rest before giving birth
Can't move
Concrete ground- faeces
Stressed- noisy
Multiple births, babies taken away
Not social/mental illness
Not ethical
7.5.3 Sustainable fisheries
Fish stocks in the ocean are declining
Methods to help fish stocks recover
Fishing technique
Quotas- time- boat size
Banned zone
Smaller fish get thrown back
7.5.1 Factors affecting food security
Food security is having enough food to feed a population
Factors include
Droughts and floods (rainfall)
Cost of agricultural inputs
Conflict- affects availability of water and food
Pests and pathogens- kill crops
Changing diets in developed countries
Increasing birth rates in some countries
Sustainable methods must be found to feed everyone on earth
7.5.4 Role of biotechnology
Mycroprotein
Grown in
fermenters
- conditions carefully controlled
the fungus
Fusarium
is useful for producing
mycoprotein
Mycoprotein is
Protein-rich
low in fat
High in fibre
Suitable for vegetarians
Fungus grown on glucose syrup in aerobic conditions, then harvested and purified
Allows microorganisms to be grown in large quantities for food
E.g. Quorn
Genetically Modified Crops
Resistance to pests
Resistance to frost
Herbicide resistance
Addition of nutrients
Disease resistance
Longer shelf-life
7.4 Trophic Levels in an ecosystem
(Biology Only)
7.4.1 Trophic levels
Can be represented by numbers
Level 1
- Producers- Plants and algae
Level 2
- Primary consumer- Herbivores eat plants and algae
Level 3
- Secondary Consumers- Carnivores that eat herbivores
Level 4
- Tertiary Consumers- Carnivores that eat other carnivores
Decomposer break down dead plants and animal matter by secreting enzymes into the environment- small soluble molecules then diffuse into the microorganism
7.4.3 Transfer of biomass
Loss of energy caused by
Energy used in bodily functions
Whole animals not eaten
Faeces are released
Producers mainly plants and algae- transfer about 1% of the incident energy from light for photosynthesis
7.4.2 Pyramids of biomass
Always looks like a pyramid
e.g.
Represents the relative amount of biomass in each level of the food chain- Trophic level 1 is at the bottom
