Populations And Sustainability (Paper 2) Flashcards
Why does the size of a population vary
The effect of
abiotic factors ( temperature in surroundings)
Biotic factors (intraspecific and interspecific competition and predication)
What is interspecific competition
When individuals of different species compete with each other for the same resources
Intraspecific competition
When individuals of the same species compete with each other for the same resources
Carrying capacity of an environment
The maximum stable population size of a species that it can support
Negative feedback effect on predators and prey
As the prey population increases there is more food for predators so the predator population grows. As the predator population increases more prey is eaten so the prey population then begins to fall. This means there is less food available for predators, causing the predator population to decrease and allow the prey population to increase once more.
Limiting factors to population size of a species increasing
Abiotic-
The amount of shelter in an ecosystem limits the population size of a species when there’s only enough shelter for a certain number of individuals .
Biotic-
Interspecific competition limits the population size of a species because the amount of resources available to a species is reduced.
What is conservation
The protection and management of ecosystems
Importance of conservation
Economic:
Ecosystems provide resources that Humans need like rainforests contain species that provide things like drugs clothes and food. as well as trade of these items at a local to international scale
Social:
Bring people joy due to aesthetic looking and provides activities such as bird watching and walking.
Ethical:
It’s because it is the right thing to do do and to prevent other organisms becoming extinct for future generations due to moral responsibility
Ecological:
Conserving species and habitats can help prevent climate change. E.g. when trees are burnt they release CO2 as well as stopping them absorbing CO2. (double effect) also if trees are destroyed the habitat it’s creates are destroyed and therefore there is a nock on effect for the species that live in the trees…
Preservation
Is the protection of ecosystems so that they are kept as they are
How can temperate woodlands can be managed in a sustainable way to ensure it meets needs now and in the future
- tress are cleared in strips so that the woodland grows back more quickly in smaller areas between bits if existing woodlands
- the cleared strips arnt too large or exposed or soil erosions occur and then plants wouldn’t be able to grow
- timber can be harvested by coppicing ( cutting down part of trees to allow them to regrow)
- plant new native species and non native species together as they prefer that due to the long established ecosystems of plants fungi and animals to help the new species thrive in the area.
- plant trees attached to posts to provide support and prevent grazing of animals to allow them mature
- plant trees at a slight distance so that they don’t compete for the exact same resources
How to manage the ecosystem of the ocean so it’s useful now and in the future
- having fishing quoats to limit the amount of certain fish species that fisherman are allowed to catch and kill. They are set by scientists and inforced by the Common Fisheries Policy’s
(Problem is that fish can often be thrown back into the sea in random places so that it doesn’t count against quota )
Mesh sizes
Government sets limits for the mesh size to reduce the number of unwanted and discarded fish that are accidentally caught. E.g. Shrip caught along Cod. Unwanted fish can travel through wholes, including young fish.
(However multiple nets that meat requirements can technically be used together defeating the point)
How ecosystems can be managed to balance conflict between conservation and preservation and human needs
Maasai Mara
- national reserve in Kenya. Large area of Savannah which is home to wildebeest cheetahs and lions ect
- Maasai people traditionally earn a living form livestock
- conservation trusts are working with them to help people to make money from ecotourism rather than farming and if farming using sustainable practices.
Terai Arc
- forest and grasslands on the border between Nepal and India.
- plants and species like Bengal tiger and Asian Elephant
- forests are being distoyed to make way for more housing and other development which also increases conflict between animals and humans
- WWF workong with local people to balance this by providing solar cookers and biogas generators and mint hedges
Peat bogs
- areas of wet peat in UK
- peat bogs stores water and CO2 and home to lots of animals and plants such as sphagum moss
- farmer use the land for there animals to graze like sheep
- government programs like the Environmental Stewardship Scheme give farmers money to use the peat bogs sustainably e.g. reducing number of livestock on land.
Human activities effect on environmentally sensitive ecosystems and ways to control these effects
Galapagos Islands
- small group of islands in the Pacific Oceans
- many species don’t live anywhere else
- Species of Giant Tortoise was hunted to extinction for food
- non native animals were introduced that eat native species such as non native dogs that eat each young giant Tortoises.
- non native plants were introduced that compete with native plants such as Quinine trees are taller than some native plants due to them blocking light to native plants
Control this by eradication programs and Quinine tress controles by herbicides. As well as introducing rules to visitors like not bring any new species.
Antarctica:
- protected by Antarctica Treaty and is now a nature reserve
- huge whale overfishing
- huge seal hunting issue
- pollution problem due to dumpted sewage and shipping accidents
- commercial whaling andseal hunting is banded which has allowed there number to increase
- finishing is allowed but limits are set
- all food wate bar from sewage must be taken away by ship, ships have to use thick oil to prevent such catastrophic spills.
Lake District/ Snowdonia
- over walked causing errorion of paths, causing off roading and a loss of soil from hillsides causing issue for wildlife and pH shift.
- water pollution issues due to the use of phosphate fertilises used in farms which cause algal blooms
- conservation charities attempt to keep up and maintain paths as well as blocking some up for regrowth.
- education on sticking to the paths
- improving sewage treatment in area by supplying grants to local farmer to improve practices
