POPULATION AND SUSTAINABILITY Flashcards
What are the 3 phases of a population growth curve?
Phase 1 - slow growth
Phase 2 - rapid growth
Phase 3 - stable state - birth rates and death rates are approx same
What is the definition of limiting factors
Limiting factors prevent further growth of a population
What’s the difference between abiotic and biotic factors
Abiotic are non living factors like temperature light humidity
Biotic factors are living factors like predators disease and competition
What does carrying capacity mean
The max population an environment can support
What are the 2 types of migration
Immigration - movement into an area
Emigration - movement away from an area
What are density independent factors
Factors that have an affect on whole population regardless of its size like volcanoes
What does it mean is an ecosystem is environmentally sensitive
It is less resistant to change so needs management techniques to preserve it
What types of management techniques are used on environmentally sensitive ecosystems
Limit areas tourists can visit
Control movement of live stock
Introduce anti poaching measures
Limit hunting through quotas
What are some environmentally sensitive ecosystems
Galápagos Islands
Snow Donia national park
Antarctica
Lake District
What animals live on the Galápagos Islands
Mostly reptiles
1 mammal - rice rat
What are the 3 regions in the Galápagos Islands
Coastal zone - salt tolerant species
Arid zone - drought tolerant species
Humid zone - dense cloud forest
How did the whaling trade disrupt the Galápagos Islands
Whalers disrupted the ecosystem by allowing domestic animals to roam loose
They chopped forest for fires to render down whale fat and ate giant tortoises that could be kept on the long sea voyages
Why was the Galápagos national park established
To protect the living and non living parts of the ecosystem
Introduced park rangers
Limited human access to particular islands
Controlled migration
Strict control over movement of introduced animals like pigs
What animals are present in Antarctica
Whales
Seals
Penguins
They all have thick layers of blubber to insulate them
How have human activities affected Antarctica’s ecosystem
Plant wide impacts such as global warming and ozone depletion
Hunting of whales and seals has depleted stocks
Soil contamination - in scientific areas
Discharging of waste in the sea
Why was the Antarctica treaty established
To protect the unique nature of the Antarctic continent
Allows scientific cooperation between nations
Protection of Antarctic environment
Conservation of animals and plants
Management of protected areas
Management of tourism
What animals are present in snow donia
Rich diversity of habitats with a range of birds and over 40 species of land mammals
Also a diverse range of plant species
Why was the snow donia national park created and Lake District national park
To conserve the biodiversity in the area and its natural beauty
Promote opportunities for the understanding of the paths special qualities
Ema chance economic and social well being
What are peat bogs
Wet spongy ground that contains decomposing vegetation
What can peat be used for
Once peat dries it can be used as a fuel by releasing thermal energy
By burning it - it releases c02 into the atmosphere
Why is preservation of peat bogs important
It takes many thousands of years for peat bogs to form
It’s important to preserve these as they prevent further climate change
Why do farmers use peat
To mix with soil and increases soils acidity
Peat has moisture retaining properties
How does peat form
When plant material is inhibited from fully decaying by being in acidic and anaerobic conditions
What do peat bogs support and provide
Support a wide range of insects by having a lack of disturbance that makes it also ideal for birds to nest
It has an abundance of insects as it provides food for many species
Support a wide range of insects by having a lack of disturbance that makes it also ideal for birds to nest
It has an abundance of insects as it provides food for many species
Afforestation
Peat extraction
Agricultural intensification
Which have all contributed to drying out bogs
What is the key feature of maintaining low land bogs
To maintain and restore water levels
How do people maintain ans reserve water levels in low land peat bogs to conserve them
Ensure peat is undisturbed and as wet as possible
Removal of seedling trees from the area because trees have a high water requirement
Use controlled grazing to maintain the biodiversity of the peatland
What is the terai region of Nepal
It is an area of extreme biodiversity
It’s forests are depended on by millions for their livelihoods
What has happened to the forests and what has this caused
Large areas of forest have been cleared for agriculture or to sell timber
This removal has increased the effects of monsoon flooding and caused severe disruption to communities downstream
Why is sustainable forest management needed in Nepal
Forests provide a livelihood for local people
Sustainable management = ensure conservation of forests + provide Nepali state with income for general development
How do locals groups manage the forests sustainability
They have developed their own operational plants and set harvesting rules rates and prices for products
They also have determined how Income is distributed
Also created several small community forestry groups
What successes have arisen from the community forestry groups
Improvement in conserving forested regions
Improved soil and water managements
Increase in forestry products so greater economic input
Secure biodiversity
What management strategies for sustainable land use have been developed to prevent damage to the ecosystem
Promote production of fruit and veg in hills and mountains
Improve irrigation facilities to enhance crop production
Improve fertilisation techniques to enhance crop yields
What are the main features of the Masai Mara
It has a Savannah ecosystem
The regions close to the river are rich grasslands and woodlands
The regions further from the river are open plains with scattered shrubs
It has famous zebra and wildebeest migrations
What are the types of farming that takes place in the Masai Mara
Grazing and cultivation
How is grazing done in the Masai Mara
It was traditionally done by the local tribes for livestock grazing
It’s now limited to areas on the edge of the reserve and tribes are prevented from entering the park
How has cultivation changed in the Masai Mara and what takes place
It has increased in the recent years
Grassland has been converted to crop land
Natural vegetation has been removed
Nutrients in the soil have been used up
This has led to a reliance on fertilisers for effective crop growth
What does the Masai Mara rely on for economic input
Tourism
Ecotourism
What is ecotourism
Tourism directed towards natural environments to support conservation efforts
It ensures tourism doesn’t exploit the natural environment
It makes people consult and engage with local communities on planned developments and ensures infrastructure improvements benefit local people
How has scientific research projects helped conservation in the Masai Mara
They have established a balance between human abs animal populations as they are incompatible with one another
What is a sustainable resource
A renewable resource that is being economically exploited in such a way that it won’t run out
Why do we use sustainable resources
To preserve environments
To ensure resources are available for future generations
To enable less economically developed countries to develop
What are the ways used for sustainable management of forests
What are the ways used for sustainable management of forests
How do we produce sustainable timber on a small scale
Use coppicing
What is coppicing
Tree trunk is cut close to the ground
Then new shoots will form from the cut surface and mature
The new nature shoots are eventually cut and in their place more are produced
What is rotational coppicing
Woodland is divided into sections and trees are only cut in a particular section until all have been coppiced
Then coppicing is begun in a new area and the process continues until you reach the trees that were first coppiced
Why do we use coppicing for sustainable timber production on small scales
It maintains biodiversity
The trees never grow enough to block out the light
What is pollarding
A similar technique to coppicing but trees are cut higher up so deer abs other animals cannot eat the new shoots
What is used in large scale timber production
Felling large areas of forest
Felled trees are destroyed and will not grow again
How do we ensure felling is sustainable
Practice selective cutting - only the largest trees are cut
Replace trees via replanting - this ensures biodiversity is maintained
Plants trees at optimal distances apart - this reduces competition
What disadvantages does felling have
It destroys habitats
It reduces the minerals in the soil
How has fishing been made sustainable
There has been an international agreement made about the number of fish that can be caught
- fishing quotas - limit number of certain fish that are allowed to be caught in particular area
Nets have different mesh sizes
Recreational fishing is only allowed at only certain times of the year
What is the definition of conservation
The maintenance of biodiversity through human action or management
Manages ecosystems so that natural resources can be used without running out
What does reclamation mean in conservation
The restoration of destroyed ecosystems
What is the definition of preservation
Protection of an area by restricting or banning human interference
The ecosystem is kept to its original state
What are the 3 main things why it is important to conserve places
Economic
Social
Ethical
Why is conservation important in economic reasons
Provide resources that humans need to survive and produce an income
Why is conservation important in social reasons
Enjoy natural beauty of wild ecosystems as well as using them for beneficial health resources
Why is conservation important in ethical reasons
All organisms have a right to exist and most play an important role in their ecosystem
What happens in stage 1 and 2 in predator prey relationships that are shown on a graph
Stage 1 - an increase in prey provides more food for predators so predators increase
Stage 2 - as predators increase more prey is eaten so there is a decrease in prey
What happens in stage 3 and 4 of predator prey relationships
When the prey decreases, intraspecific competition increases and the predator population decreases
In the final stage, as the predator population decreases, more prey can survive and reproduce so prey population increase
What are the two types of competition
Interspecific - competition between different species
Intraspecific - competition between members of the same species
What is the competitive exclusion theory
In interspecific competition the species that uses the resources more effectively will eliminate the other
What does competition between same species usually depend on
The availability of the resource
The greater the availability the more of the population that can be supported
K selection
Offspring have a high prob of survival
Heavy parental care and nurturing
Larger organisms
Much lower reproductive rate
Young are altricial, longer lifespans and have overlapping generations
R selection
Produce many low effort organisms
Species grow rapidly
Found in less competitive and low quality environments
Young are precocial
High of mortality so start reproducing earlier
Non overlapping generations, shorter lifespans
Boom and bust (cyclical)
Draw, label, and annotate with explanations, a generalised growth curve for natural populations.
- Phase 1/ lag phase/ slow growth - Small numbers of individuals that are initially present reproduce increasing the total population. Birth rate> death rate.
- Phase 2/ exponential phase/ rapid growth- Number of breeding individuals increases, the total population multiplies exponentially. No constraints. birth rate»death rate.
- Phase 3/ stationary phase/ stable state- further population growth is prevented by external constraints. Population size fluctuates, but overall its size remains relatively stable. Birth rates= death rates. Slight changes- fluctuations in limiting factors e.g prey
Give 3 examples of limiting factors for population size and explain how each affects population size.
- Competition between the organisms for resources
- Build-up of the toxic by-products of metabolism
- Disease
Define Density dependent factors
- Any factor limiting the size of a population whose effect is dependent on the number of individuals in the population.
- For example, disease will have a greater effect in limiting the growth of a large population, since overcrowding facilitates its spread.
- Other examples- competition, predation, grazing
