24 - Population and Sustainability Flashcards
What are 4 examples of environmentally sensitive ecosystems?
- Antarctica 2. Snowdonia 3. Lake District 4. Galapagos Islands
What is a population?
All the organisms of one species in a habitat
What is interspecific competition?
Competition for resources between different species
What is intraspecific competition?
Competition for resources between members of the same species
What pattern can intraspecific competition follow and what does this mean?
Can be cyclic, so greater resources mean a larger population
What 2 things can interspecific competition affect?
- Distribution 2. Population of both species (both will usually decrease)
What is carrying capacity?
The maximum stable population size of a species that an ecosystem can support
What is population density?
Number of individuals per unit area of a chosen habitat
What are the 4 most basic factors which affect population density?
- Birth rate 2. Death rate 3. Immigration rate to habitat 4. Emigration rate from habitat
What 2 types of factors can affect population size?
- Density dependent 2. Density independent
What are 3 examples of density dependent factors which affect population size?
- Predation 2. Disease 3. Competition
What are 2 examples of density independent factors which affect population size?
Climate or catastrophe
What type of feedback are predation cycles an example of?
Negative feedback
What are the 5 phases of a population growth curve?
- Lag phase 2. Log phase 3. Stationary phase 4. Stable phase 5. Death phase
What happens during the lag phase of a population growth curve?
Population growth begins slowly from a few individuals
What happens during the log phase of a population growth curve?
Exponential growth in ideal conditions
During what phase of a population growth curve is maximum growth rate reached?
Log phase
What happens during the stationary phase of a population growth curve?
Growth rate begins to slow as factors become limiting
What happens during the stable phase of a population growth curve?
Population stable
During what stage of a population growth curve is carrying capacity reached?
Stable phase
What normally prevents populations from undergoing uncontrolled exponential growth?
Limiting factors
What happens during the death phase of a population growth curve?
The population crashes and the process of the curve restarts
What causes the death phase of a population growth curve?
A sudden change in the environment which lowers carrying capacity
What is a limiting factor?
An environmental resource or constraint which limits population growth
What is the competitive exclusion principle?
No two species can occupy the same niche in the same habitat at the same time, so the species which uses resources more efficiently will ultimately eliminate the other
What happens when two species are competing for the same food source but one is better adapted than the other?
The less well adapted one is outcompeted
What is predation?
An interaction in which one organism kills another for food
What are the 3 stages of the effects of intraspecific competition on population size?
- When a resource is plentiful in a habitat, all organisms have enough to survive and reproduce, causing a rise in population size 2. Increased population means more organisms have to share available resources. As resources are now limited, the population decreases in size 3. Less competition exists due to smaller population, so growth occurs again
What type of competition is almost all predation?
Interspecific
What can happen if a predator or prey species does not evolve?
They could go extinct
Do all predator-prey relationships show the same pattern?
In general yes
What are the stages of a predator-prey relationship?
- Increase in prey population causes more food for predators, so predator population rises 2. Increased predator population eats more prey, so prey population decreases 3. Reduced prey population can no longer support predator population, so it falls 4. Reduced predator population causes prey population to increase as less are killed
Why are predator-prey relationships rarely as simple as the model?
There are other biotic and abiotic factors to consider
What is conservation?
The protection and management of an ecosystem so that natural resources can be used before running out
What is preservation?
The protection of ecosystems so that they are kept exactly as they are
What type of process is conservation and why?
A dynamic one, as it needs constant adaptation to changes within the ecosystem
What is reclamation?
Restoring ecosystems which have been damaged or destroyed
What is preservation commonly used to preserve?
Sensitive resources and species
What are 3 examples of commonly preserved ecosystems?
- Marine conservation zones 2. Nature reserves 3. Newly discovered caves
What 2 things are maintained in conservation?
Habitats and genetic diversity within a species
What are 4 classes of reasons for the importance of maintaining biodiversity?
- Economic 2. Ecological 3. Ethical 4. Social
What are 5 techniques used as part of conservation?
- Managing land 2. Taking steps to encourage new habitats 3. Removing animals to captivity 4. Growing plants in cultivation 5. Reclamation
What is a technique humans can use to encourage new habitats?
Controlled habitats
Is anything removed from a preserved area?
No
What are 3 threats to biodiversity?
- Habitat loss 2. Introduced species 3. Overexploitation
What are 3 reasons wild populations may be overexploited by humans?
- For food 2. For sport 3. For commerce
What are 3 reasons habitats may be disrupted by humans?
- Intensive agricultural practices 2. Increased pollution 3. Building
What is a sustainable resource?
Renewable resource that is being economically exploited in such a way that it will not diminish or run out.
What are 5 methods used for conservation?
- National parks 2. Green belts (areas of green land) 3. SSSIs (Sites of Special Scientific Interest) 4. Legal protection 5. Ex Situ conservation
What is sustainable management of the environment necessary for?
Conservation of natural resources for future generations
What are the 5 aims of sustainability?
- Preserve the environment 2. Ensure resources are available for future generations 3. Allow humans in all societies to live comfortably 4. Enable LEDCs to develop through exploiting their natural resources 5. Create even balance in consumption of resources between LEDCs (less economically developed countries) and MEDCs (more economically developed countries)
What technique is used to produce sustainable timber on a small scale?
Coppicing
What is coppicing?
Cutting tree trunks near the ground, which allows new shoots to form from the cut stumps and mature, before these shoots too are cut.
What is a use of the shoots from coppicing?
Fencing
What type of coppicing is used in most managed woodlands?
Rotational coppicing
How does rotational coppicing maintain biodiversity?
The trees never grow enough to block out the light, so succession cannot take place
What is rotational coppicing?
Only certain sections of a forest are coppiced at a time in a cyclical fashion, so once you get back to the original section new shoots have appeared
What is the difference between coppicing and pollarding?
In pollarding the trunk is cut higher up
What is an advantage of pollarding over coppicing?
Deer and other animals cannot eat the shoots
What are 3 disadvantages of large-scale timber production?
- Habitats are destroyed 2. Soil minerals are reduced 3. Bare soil left is susceptible to erosion
What 5 techniques to companies use to do sustainable large-scale timber production?
- Selective cutting of only the largest trees 2. Managing pests and pathogens to maximise yields 3. Ensure areas of forest remain for indigenous people 4. Plant trees an optimum distance apart to reduce competition and maximise yield per tree 5. Replace trees through replanting rather than wait for natural regeneration
What are 4 examples of techniques used to guarantee sustainable fishing?
- Use of catch quotas 2. Use of nets with different mesh sizes 3. Allowing fishing only at certain times of the year 4. Introducing fish farming to reduce loss of wild species
What 2 things are balanced in the Masai Mara nature reserve?
Need for conservation and needs of humans
What country is the Masai Mara nature reserve in?
Kenya
What type of ecosystem is the Masai Mara primarily?
Savannah
What divides the Masai Mara?
The Mara river
What plant which once dominated the Masai Mara has been largely cleared over the last 50 years?
Acacia bush
Why was the Acacia cleared so aggressively in the Masai Mara?
It provided a habitat for the tsetse fly, which causes sleeping sickness
What 4 things have reduced Acacia coverage in the Masai Mara?
- Elephants 2. Cattle 3. Fires 4. Efforts by the government
What have local tribes traditionally used the Masai Mara for?
Livestock grazing
What traditional farming method did the local tribes in the Masai Mara?
Semi-nomadic farming
What 2 things traditionally caused tribes to move in the Masai Mara?
- Tsetse flies 2. Climate variation
What was an advantage of the Masai Mara tribes’ traditional semi-nomadic farming?
Allowed vegetation to recover from animal grazing
How is grazing now limited in the Masai Mara?
Limited to the edge of the park as tribes are not allowed in
What are some disadvantages of the new grazing practices in the Masai Mara?
More trees removed for fuel, larger herds graze grasslands, risk of soil erosion increases with reduced vegetation
How has cultivation changed in the Masai Mara recently?
It has increased
What 2 negative things have happened as a result of increased cultivation in the Masai Mara?
- Nutrients in soil used up 2. Reliance on fertiliser developed over time due to lack of soil nutrients
What provides most of the economic input of the Masai Mara?
Tourism
What is ecotourism?
Tourism directed towards natural environments, to support conservation and observe wildlife
What does ecotourism reduce?
The impact of tourism on natural habitats
What are the 3 key principles of ecotourism?
- Ensure that tourism does not exploit the natural environment or local communities 2. Consult and engage with local communities on planned improvements 3. Ensure that infrastructure improvements benefit local people as well as visitors
Why can ecotourism have a negative impact on the environment?
Tourist movements such as repeated use of hiking trails, or use of mechanised transport, may contribute to soil erosion or other habitat changes
What species were protected by conservation and preservation efforts in the Masai Mara?
Black Rhinos
What caused people to be lured into Rhino poaching in the Masai Mara?
The large amounts of money on offer combined with their poverty
What caused a large decline in the Black Rhino population of the Masai Mara?
Illegal poaching
What are currently being undertaken in the Masai Mara?
Scientific research project
What are 4 examples of balancing the needs of humans and wildlife in the Masai Mara?
- Elephants can threaten cultivation and eat crops so land can be fenced, but as this can affect migration it must be done in moderation 2. Legal hunting used to cull excess animals, but with constant monitoring of numbers 3. As livestock is threatened by migratory wildlife the needs of both must be managed 4. Expanding human population means more home and land for livestock needed, so must be managed as not to reduce wildlife density
What and where is the Terai region?
A rich agricultural region of Southern Nepal
Why are natural resources at risk of being overused in the Terai?
High population density and prevalence of agriculture
What are there large areas of in the Terai region?
Thick forests
What is the soil like in the Terai region?
Very fertile
Why have large areas of the Terai forests been cleared and what for?
Agriculture or to sell the timber, largely as a result of poverty and corruption
What is the Terai climate like?
Hot and humid in summer
How biodiverse is the Terai region?
Very biodiverse
What problem in the Terai region has been exacerbated by deforestation?
Flooding during the monsoon season
Why would the near complete loss of forest in the Terai be devastating for the local population as well as wildlife?
They rely on the forests for tourist income and timber for construction and fuel
What 2 examples of sustainability can be seen in the Terai region?
- Sustainable forestry 2. Sustainable agriculture
What 2 groups have helped sustainable forestry in the Terai region?
- Nepali government 2. Local worker cooperatives
What have been 6 successes of sustainable forestry in the Terai region?
- Significant improvement in forest conservation 2. Improved soil and water management 3. Increase in retail price of forestry products 4. Securing biodiversity of forested areas 5. Sustainable wood fuel sources 6. Employment and income generation through forest protection
What have been 6 sustainable agriculture techniques used in the Terai region?
- Growth of nitrogen fixing plants to improve soil fertility 2. Growing resistant crops 3. Improved irrigation 4. Promoting production of fruits and vegetables in lesser used mountains to lower intensification 5. Multiple cropping 6. Improved fertilisation techniques
What is a peat bog?
A region of wet, spongy ground that contains decomposing vegetation
What can undisturbed peatland act as?
A carbon sink
Why is preserving peat bogs important in fighting climate change?
Dried peat, when burned, releases carbon dioxide, and new peat bogs take thousands of years to form and become a carbon sink
What else is peat commercially extracted for apart from to be used as fuel?
For use in gardening
How do peat bogs form?
When plant material is inhibited from decomposing properly by acidic and anaerobic conditions
How are plants which thrive on peat bogs adapted?
To live in wet conditions with few nutrients
What 4 things will continued peat bog preservation contribute to?
- Maintained biodiversity 2. Erosion control 3. Carbon storage 4. Flood management
What 3 activities have historically destroyed peat bogs?
- Planting of forests 2. Peat extraction 3. Agricultural intensification
What 3 methods are used to preserve lowland UK peat bogs?
- Ensuring peat and vegetation of bog surface is as undisturbed as possible, such as by using ditches to block off drainage 2. Removing seedling trees 3. Using controlled grazing
What currently threatens the remaining UK peat bogs?
Continuing intensive land usage
What are environmentally sensitive ecosystems?
Ones which are less resistant to change than others
What are 5 techniques used to protect environmentally sensitive ecosystems?
- Limiting areas tourists can visit 2. Controlling livestock movement 3. Introducing anti-poaching measures 4. Replanting of forests and native plants 5. Limiting hunting through quotas and seasonal bans
Why are the Galapagos Islands of special interest?
They have never been connected to the mainland, so any plants or animals will have had to have travelled thousands of miles
What are most land animals on the Galapagos Islands?
Reptiles
How did reptiles arrive on the Galapagos Islands?
On floating rafts
What are the 3 distinct regions of the Galapagos?
- Humid 2. Coastal 3. Arid
What caused damage to the ecosystem of the Galapagos Islands from the 19th century onward?
Whalers and their pet goats (which may have outcompeted the giant tortoises)
What 4 measures have been taken to protect the ecosystem of the Galapagos Islands?
- Introduction of park rangers 2. Limiting human access to certain islands, or parts of islands 3. Controlling migration to and from islands 4. Strict controls over movement of introduced animals such as pigs
What 3 things did whalers do to damage the Galapagos Islands?
- Cut down forests to render whale fat 2. Removed tens of thousands of giant tortoises 3. Allowed domestic pets to run wild
What is the climate like in Antarctica?
Very cold and nearly the whole spot is covered in ice
What do all vertebrates living in Antarctica rely on?
A layer of blubber to keep them warm
Do any plants grow in Antarctica?
Yes, but only in the small ice-free regions
What are 5 provisions of the 1961 Antarctic Treaty?
- Scientific cooperation between nations 2. Protection of Antarctic environment 3. Conservation of plants and animals 4. Management of tourism 5. Designation & management of protected areas
What are 4 effects of humans on Antarctica?
- Soil contamination 2. Planet-wide effects caused by global warming and the hole in the ozone layer 3. Pollution caused by discharge of waste into the sea 4. Hunting of whales, seals and fish has depleted their stocks
What was created in 1951 to protect the biodiversity of Snowdonia?
Snowdonia national park
What is an example of the needs of humans and animals being met in Snowdonia?
Large pumped storage hydroelectric power station being located inside a mountain to minimise effects on wildlife
What is an example of active management in the Lake District National Park?
Replanting native tree species
What is the purpose of the Lake District National Park Authority?
Conserving the region while allowing access for millions of tourists a year
What are the 3 key purposes of the Snowdonia National Park Authority?
- Conserve and enhance natural beauty, wildlife and cultural heritage of area 2. Promote opportunities for understanding and enjoyment of special qualities of park 3. Enhance economic and social wellbeing of communities within park
