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population & sustainability 6.3.2 - Coggle Diagram
population & sustainability 6.3.2
strategists
https://docs.google.com/document/d/1WbowmBh8o47yZH14eTiwsAS8Sodh1cFxcBkeYK0HGZQ/edit
Species that obey this trend are called ‘K species’ those who don’t are called ‘R species’
E.g.s of ‘R species’:
Bacteria
Rabbits
Insects
factors effecting population growth
Natality: birth rate
Immigration: individuals moving into the area
Emigration: individuals moving out of the area
Mortality: death rate
https://docs.google.com/document/d/1wmtS327cj-Hoa8jlMfxiyPlkK9Qhakn95-ZaVo9tJns/edit
Lag phase:
Few individuals
Time to acclimatise to habitat
There reproduction rate is low
Therefore growth is slow
Exponential growth phase (log phase):
Acclimatised to habitat
High rate of reproduction
Lots of resources
Food
Water
Space
Shelter
Stationary phase:
Population has reached carrying capacity
Where population equilibrium is achieved, i.e. mortality rate = natality rate
Carrying capacity:
where the population has reached its limit in terms of space & resources
large scale timber management
Clear felling:
removing of all the trees in an aa including roots (often done by slash & burn)
Selective cutting:
cutting done specific trees (often only the large, desirable, profitable trees are felled, leaving young trees to mature)
Advantage:
Introduces spaces in the forest between trees, reducing the risk of disease spreading between trees
small scale timber management
Coppicing:
When a deciduous tree is cut it regrows from its base
Rotational coppicing:
dividing an area being managed into sections and copping them 1 at a time, letting the others grow in between
Benefits:
Allows for habitats
Prevent trees obscuring sunlight reaching forest floor
Supports biodiversity of ground level plants - means more bugs
Less machinery used
Becomes a renewable material resource
Shorter growth time than growing whole new tree
Leaving roots in place prevents soil errosion
Pollarding:
similar to coppicing, except each tree is cut higher up compared to coppicing
Advantage:
Avoids new shoots being eastern by deer or other animals
sustainability
= using renewable resources in such a way that it will never run out
Conservation:
active preservation of ecosystem, habitats, species, etc… through human interaction or management, to enhance, protect or restore it
Preservation:
passive preservation of ecosystems, habitats, species, etc… (e.g. limiting human contact) through banning human interference so ecosystems are kept in original state
predator prey relationships
When a predator feeds on just one type of prey, there is an interdependence between the predator and prey populations. This means changes in one population affects the other.
The Canadian lynx and the snowshoe hare have an interdependent relationship.
Their numbers are dependant on each other and fluctuate according to each other, e.g. more predation = less prey, leading to less predator then more prey and so on…
https://docs.google.com/document/d/1D8rlkaUCahmL0k-WeZBZG8fyZ8x-QFrz_3u-A45ynvg/edit
competition
Intraspecific competition
: competition between individuals of the same species
When there is a large population there is more competition causing a decrease in population, which leads to less competition leading to increases in population, and so on…
Interspecific competition
: competition between 2 or more different species
Experiment run by Gause to demonstrate interspecific competition:
Competitive exclusion principle:
When there is more overlap between niches of 2 species there is more intense competition
If they have the same niche, 1 would outcompete the other & it would die out / become extinct
This is cause 1 species is better adapted & uses the resources more effectively
https://docs.google.com/document/d/1EAahVSCa1RGfCPB2ott8svSCXg7DjDNAt10neyrHaBs/edit
factors limiting population growth
Human interference
Disease
Competition
Space
Soil pH
Sunlight
O2
sustainable mangement - peat bogs
Peat:
partially decayed plant matter. Peat contains lots of stored carbon and can hold 20 times its own weight in water. It decomposes very slowly.
Peat bogs:
a type of wetland (very wet area of land) that contains a high amount of peat. They are very acidic and contain low levels of nutrients.
Peat bog destruction
Peat bogs are formed over 1000s of years
Peat is made from dead plants that haven’t decomposed
Hasn’t decomposed because peat bogs have very acidic environment & low O2 levels, meaning decomposers don’t thrive
Peat can be burnt as fuel. This releases CO2 into the atmosphere
Peat is put onto gardens as compost will decay & the microbes will release CO2 in respiration. Peat free composts should be encouraged
Preservation:
Ban human activity - e.g. entry, removal for compost or fuel
Conservation:
Prevent the drainage of water - want to keep it water logged
Remove young trees (saplings) - trees absorb massive amounts of water
Controlled grazing - ensures diverse wetlands surface for habitats
sustainable fishing solutions
International Measures to Promote Conservation of Fish:
Bans – good, where respected
Total allowable catches (TACs) and quotas – each state receives quota reflecting dependence on fishing
Technical conservation (TC) – aim to make fishing more selective, eg minimum landing sizes, specific mesh sizes, separator devices
Net mesh size - use larger net mesh size to ensure you re only catching larger, mature fish & younger fish can survive to go onto breed and maintain population
Bans on drag nets - trawl on sea floor catching all, even unwanted & destroys coral & seagrass
Increase size and number of protected areas
Limited on fishing times to prevent fishing during breeding seasons
Fish farms - protect an area of water & breed fish in there, can monitor disease, prevent loss of wold species
Excess feed and faeces drop from the farms into wider ocean, and can cause eutrophication & agal bloom
https://docs.google.com/document/d/10N8GLAGy1DrU_b6CT2ZPiEHTx0aPW9tZvIagd0_TgpE/edit
