Populations And Sustainability Flashcards
What is a limiting factor in terms of population growth?
Environmental resource or constraint that limits population growth
Give an example of a limiting factor of population growth
Food availability
What are the 3 main stages of a population growth curve? Explain them
Phase 1. Slow growth
Small group of individuals reproducing but birthrate > death rate so population grows
Phase 2. Rapid growth
Breeding individuals increases and no constraints act to limit population increase
Phase 3. Stable state
Further growth is prevented by external constraints, population fluctuates but is relatively stable birth rate = death rate
What is phase 3 of the population growth curve known as?
Carrying capacity of a population
List 4 abiotic limiting factors affecting population growth
- Light
- PH
- Water availability/ oxygen availability
- Humidity
List 3 biotic limiting factors affecting population growth
- Predators
- Disease
- Competition
What is the definition of carrying capacity?
The maximum population size that an environment can support
Define Immigration
Immigration is the movement of individual organisms INTO a particular area that INCREASES population size
What is an example of a organism that Immigrate
Christmas islands red crabs move from forest to shore to reproduce
Define Emigration
The movement of individual organisms AWAY from a particular area DECREASES population size
Give an example of Emigration
The Norway lemming emigrates away from areas of high population density of poor habitat
What is a density independent factor ?
Factors that have an effects on the whole population regardless of its size
What are the 4 density independent factors?
Earthquakes, fires, volcanic eruptions and storms
Is competition abiotic or biotic limiting factor?
BIOTIC - it is an interaction of living organisms
What is interspecific competition?
Competition between different species
What is intraspecific competition?
Competition between members of the same species
When does interspecific competition occur?
Interspecific competition occurs when two of more different species of organism compete for the same resource
What is the competitive exclusion principle?
When in interspecific competition, the species that use the resource more effectively will eliminate the other species
Give an example of interspecific competition
Red and grey squirrels - grey squirrels have a larger range of diet
When does intraspecific competition occur?
When members of the same species are competing for the same resource
What does the availability of resources determine in intraspecific competition?
The size of the population
What does intraspecific competition result in for species?
Fluctuations in the number of organisms in the population
Describe the 3 stages of the intraspecific competition graph
Stage 1 - increase
Resource is plentiful and all organism have enough to serve and reproduce
Stage 2 - decrease
As the population has decreased there are more individuals to share the resource so it is limited and not enough for everyone to survive
Stage 3 - increase
Less competition in smaller population so more organism survive and reproduce (cycle)
What time of competition is predation?
Interspecific as it operates between two different species
Describe and explain the 4 stages of predator-prey relationship graph
Stage 1 - increase in prey population provide more food for predators (after a short delay) predator population increase
Stage 2 - increased predator population causes a fall in prey population so death > birth rate of prey
Stage 3 - reduced prey population no longer supports increased predator population so decrease in predator population
Stage 4 - reduced predator numbers result in less prey being killed so they reproduce and survive
Cycle repeats again
Is the predator prey graph representative of in the wild?
NO other factors such as food availability for prey, other predators or seasonal changes will also have an impact on
What is the definition of conservation?
Maintenance of biodiversity through human action or management
Conservation involves the management of ecosystems so natural resources can be used without running out, what is this called?
Sustainable development
Give an example of conservation
The forest stewardship council ensures that their tumbler supply is sustainable
What is reclamation conservation?
Th process f restoring ecosystems that have been damaged or destroyed
What is the definition of preservation?
The protection of an area by restriction of banning human interference so an ecosystem is kept in its original state
What sites are often preservation sites? And what isn’t allowed here
Archaeologiclly paleontological and ecological sites
No visitation is allowed
What are examples of preserved habitats?
Nature reserves and marine conservation
What is the economic importance of conservation? Give an example
To continue providing resources that humans need to survive
E.g rainforest supply medicinal drugs
What is the social importance of conservation? Give an example
Many people enjoy the natural beauty of wild ecosystems
E.g birdwatching, cycling, walking
What is the ethical importance of conservation?
All organisms have a right to to exist as well as play a role in their ecosystem
We also have a moral responsibility for future generations
What has occurred due to exploitation of environmental resources due to human demand?
Destruction of ecosystem, reduction in biodiversity and depletion of resources
What is a sustainable resource?
Renewable resource that is being economically exploited in such a way that it will not diminish or run out of
What are the 5 aims of sustainability?
- Preserve environment
- Ensure resources are available for future generations
- Allow humans in all societies to live comfortably
- Enable LICs to develop through natural resources
- Creates a balance in consumption of resources between HICs and LICs
What technique is used for sustainable small scale timber production?
Coppicing is used
What is coppicing?
Tree trunk is cut close to the ground and new shoots form from the surface and mature
What is rotational coppicing?
When a woodland is divided into sections and trees are only cut in a particular section until all have been coppicing
What is pollarding?
Same technique as coppicing but trunk is cut higher up so deer and other animals cannot eat the new shoots
How do companies ensure that large scale timber production is sustainable?
- Selective cutting only the largest trees
- Replace trees through replanting
- Plant trees apart to reduce competition
- Manage pests and pathogens
- Ensure that areas of forest remain for indigenous people
What technique is used for large scale timber production?
Felling - trees are destroyed and will not regrow
What is a major disadvantage of felling?
Habitats are destroyed and soil minerals are reduced susceptible to erosion
What has lead to overfishing?
Increased population
What has overfishing caused?
Depletion of fish populations that can no longer regenerate
What has been done to overcome overfishing?
International agreements about the number of fish that can be caught - known as fishing quotas
What 3 techniques have also been used alongside quotas - to stop overfishing?
- Nets with different mesh sizes so immature fish can escape
- Commercial and recreation fishing restriction to certain times of year to allow breeding seasons undisrupted
- Fish farming to maintain supply
Where is the Masai Mara National Reserve (MMNR)?
Located in southern Kenya
When was the MMNR established as a wildlife sanctuary?
1961
Describe the MMNR ecosystem
The ecosystem is mainly savannah with the Mara river running through which is surrounded by fertile grasslands and woodland
Lots of wild animals: buffalo, elephants, leopards, lions, rhinos
Previously landscape was dominated but acacia trees
Why were acacia trees removed by the government?
They were habitat to the fly carrier of sleeping sickness bug
What other factors have reduced the presence of acacia trees in MMNR?
Elephants, fire and cattle grazing
How was grazing traditionally done by the Masai Mara?
Tribes would frequently move based on climates and existence of tsetse flies - allowing vegetation time to recover when farmers moved
How is grazing controlled now in the MMNR? And what is the impact of this on the environment?
Grazing is limited to the areas on the edge of the reserve as local tribes are prevented form entering
This means that large herds graze the areas on the outskirts of the savannah so more vegetation is removed and soil erosions increases
Cultivation has increased in the Masai Mara region in recent years, what are the consequences of this?
Grassland is converted into crop land so natural vegetation is removed and soil nutrient are used up and not replenished
This results in the reliance on synthetic fertilisers for effective crop growth
What is ecotourism?
Tourism aimed toward natural environments to support conservation efforts and observe wildlife
It is a form of sustainable development rescuing impact of tourism on the environment
What are the 3 key principles of ecotourism?
- Ensure that tourism does not exploit natural environment or local communities
- Consult local communities
- Ensure infrastructure benefits locals not just tourists
What are the negative impacts of ecotourism?
Repeated use of hiking trails or mechanised transport may contribute to soil erosion
How does the MMNR play a role in conservation of endangered species?
The black rhino is critically endangered and lives in the MMNR
Stopping illegal poaching by employing park rangers and equipment to defer poachers
Name 3 research projects occurring in the Masai Mara region
- Michigan university studying behaviour of hyenas
- Cheetah project which monitors cheetah population and impact of human activity
- Mare predator project which monitors lion populations in the region
What are some mechanisms in place to allow human activity to occur in balance with wildlife?
- Fences around crop to prevent elephants trampling
- Legal hunting to cull excess animals
- Increase in built environments as population increases
Where is the Terai region?
Located in Nepal along the border with India
Describe the ecosystem of the Terai
Fertile land which is the main agricultural site of the region
Hot and humid in summer months of is composted of fertile soil
Extreme biodiversity lots of subtropical plants
Why has the Terai area been cleared? And what are the consequences of this?
For agriculture and timber production
The consequences mean the effects of monsoon flooding have increased causing severe disruption to communities
What is the aim of sustainable forest management in Nepal?
Provide a livelihood for locals, conserve the forest and provide income for the state
How is sustainable forestry in Nepal being managed?
Local community forestry groups which set their own rules and regulations and price of produce
What has been the successes for community forestry groups?
Soil quality has improved, biodiversity has been secured, increase in price of produce means more economic beenfit to region
What are the management strategies used by the Terai to maintain sustainable land use?
- Cropping crops that can survive in a range of soil and environment
- Improved irrigation systems
- Growth of nitrogen fixing crops such as pulses and legumes to enhance fertility of soil
What are environmentally sensitive ecosystems?
Regions that are less resistant to environmental change
What 5 techniques are used to maintain environmentally sensitive areas?
- Limiting areas to tourists
- Controlling movement of livestock
- Introducing anti poaching measure
- Replants of forests and native plants
- Limitation of hunting
What is a peat bog?
Region of wet, spongy ground that contains decomposing vegetation
What does undisturbed peatland act as?
A carbon sink - meaning it stores carbon dioxide
Once dried, what is a use of peat?
Peat can be used as fuel - it releases thermal energy and carbon dioxide
Why is preserving peat bogs important to climate change?
Maintaining peat bogs will prevent the release of green house gas carbon dioxide into the atmosphere
What is a commercial use of peat?
In commercial soil for farmers and gardeners
It has moisture retaining qualities and stops excess water killing roots
When does peat form?
When plant material is inhibited from fully decaying by acidic and anaerobic conditions
What kind of peat bogs are a threatened habitat? How much have they declined in 100 years?
Lowland peat bogs - have diminished over 90% in 100 years
What is it essential that lowland raised peat bogs are conserved?
To maintain biodiversity, flood management, erosion and carbon storage
What has caused decline in peat bogs?
Afforestation, peat extraction and agriculture
What is needed to conserve lowland bogs?
Maintain or restore appropriate water levels
List 3 steps taken to conserve areas of lowland bog
- Ensure bog surface is undisturbed and as wet as possible
- Removal of seedling trees from that area
(Transpiration means they will remove lots of water from the area) - Controlled grazing to maintain biodiversity
Where is the Galapagos island?
Located in the Pacific Ocean, west of Ecuador
Who used the Galapagos to develop the theory of evolution by natural selection?
Darwin
What animals live in the Galapagos?
Majority of land animals are reptiles
Only species of land mammal is the Galapagos rice rat
Galapagos giant tortoise
Flightless cormorant - small wings better for fishing underwater
Marine iguana who has advantageous mutation to swim effectively
What plans are present in each region of the Galapagos [3]
- Coastal zone containing salt tolerant plants (mangrove)
- Arid zone contains drought tolerant plants (cacti)
- Humid zone contains dense cloud forest (lots of mosses)
What disturbed the fragile Galapagos environment in the 19th century?
The Whaling trade - domestic animals roaming loose, trees used for fire wood and the burning of whale fat
When was the Galapagos nation park established?
1959
What 4 measure have been taken to protect the Galapagos?
- Park rangers
- Limitations to human access
- Control of migration to and from the islands
- Controls of movement of introduced animals
What do animals living in the Antarctic rely on to insulate themselves from the cold?
Thick layers of blubber - penguins, whales and seals
What is the only warm-blooded animal remaining in the Antarctic during the winter?
Emperor penguin
What plants grow in the Antarctic?
Plants can only grow in ice - free regions
Theses tend to be lichens and moss
What impact has human activity had to Antarctica?
- Global warming
- Hunting of whales and seals is depleting populations
- Soil contamination around research stations
- Waste being disposed into the ocean
What is the Antarctic treaty and what does it contain?
1961 treats to protect to Antarctic continent
- protection of environment
- conversation of plants and animals
- management of tourism
- international agreement
Where is snowdonia and what is its landscape?
Snowdonia is located in north-western wales and contains the highest mountain range in England and wales
What wildlife is present in snowdonia?
A wide range of birds are present
What plants are present In snowdonia?
Woodland of oak, elm, snowdonia lily and arctic alpines
What are the purposes of the snowdonia national park created in 1951? [2]
- Conserve and enhance national beauty and wildlife
- Enhance economic and social wellbeing of communities within the park
What is the dinorwig power station? What impact does this have?
Hydroelectric power station built to meet demands or energy requirement
It was building inside a cave to minimise effect on environment
