24 - populations and sustainability

Question 1

What are limiting factors?

Answer 1

They prevent further growth of a population and in some cases, cause it to decline. Can be split into biotic [living factors e.g. predation and disease] and abiotic factors[ non living e.g. temperature and water availability]

Question 2

What is carrying capacity?

Answer 2

The maximum population size that an environment can support. Although individual years can show slight increases or decreases in pop size, it remains stable as the no. of births and deaths are approximately equal.

Question 3

what is the difference between immigration and emigration?

Answer 3

Immigration- the movement of individual organisms into a particular area increases population size
Emigration- movement of individual organisms away from a particular area decreases population size.

Question 4

What are density independent factors?

Answer 4

Factors that have an effect on the whole population regardless of it’s size. These dramatically change population size. e.g. earthquakes, fires, volcanic eruptions and storms. In some cases, these factors can remove whole populations of a species from a region.

Question 5

What are the two types of competition?

Answer 5

Interspecific- competition between different species
Intraspecific - competition between members of the same species

Question 6

How does interspecific competition lead to lead to outcompetition?

Answer 6

If two species are competing for the same food sources but one is better adapted, the less well adapted one is likely to be outcompeted. If the conditions remain the same, the less well adapted species will decline in number until it can no longer exist in the habitat alongside the better adapted species.

Question 7

What is the competitive exclusion principle?

Answer 7

Where two species are competing for limited resources, the one that uses the resources more effectively will ultimately eliminate the other.

Question 8

How do red and grey squirrels show interspecific competition?

Answer 8

When grey squirrels were introduced, their population increased quickly and resulted in the native red squirrel disappearing from many areas. This was because the grey squirrel can eat a wider range of food than the red squirrel and as it is larger it can store more fat. This increases its chances of survival and therefore its ability to reproduce, thus increasing its population. An increase in the population of grey squirrels further reduces the food supply for red squirrels, reducing their ability to survive and reproduce.

Question 9

What is intraspecific competition?

Answer 9

Occurs when members of the same species compete for the same resources. The availability of the resource determines the population size- the greater the availability, the larger the population that can be supported. This results in fluctuations in the number of organisms present in a particular population over time.

Question 10

Explain the cycle of intraspecific competition.

Answer 10

Stage 1- when resources are plentiful in a habitat e.g. food or space, all organisms have enough of the resources to survive and reproduce. This results in an increase in population size.
Stage 2- As a result of the increased population, there are many more individuals that share the food or available space. Resources are now limited, so the pop will decrease in size.
stage 3 - less competition exists as the smaller population means less organisms are competing for the same resources. This means more organisms survive and reproduce, resulting in pop growt.

Question 11

Explain the pattern of a graph showing predator- prey relationships.

Answer 11

1. Increase in prey pop = more food for predators, allowing more to survive and reproduce. Leads to an increase in predator pop.
2. increased predator pop eats more prey organisms, causing a decline in prey population. Death rate of prey pop is greater than birth rate
3. reduced prey pop can no longer support the large predator pop. Intraspecific competition for food increases, resulting in a decrease in the size of the predator population.
4. Reduced predator numbers result in less of the prey pop being killed. More prey organisms survive and reproduce, increasing prey pop.
   Cycle starts again.

Question 12

What other factors can impact predator and prey populations?

Answer 12

availability of food of the prey, or the presence of other predators.
Fluctuations in numbers also result from seasonal changes in abiotic factors

Question 13

What is conservation?

Answer 13

It is the maintenance of biodiversity through human action or management. This includes maintaining biodiversity between species, maintaining genetic diversity within a species and the maintenance of habitats.

Question 14

What is reclamation?

Answer 14

The process of restoring ecosystems that have been damaged or destroyed. e.g. a habitat has been destroyed by floods, or as a result of new building projects. It also involves techniques such as controlled burning of areas of a forest, which can halt succession and increase biodiversity.

Question 15

What is preservation?

Answer 15

The protection of an area by restricting or banning human interference, so that the ecosystem is kept in its original state.

Question 16

What are the 3 main reasons that conservation is important?

Answer 16

Economic- to provide resources that humans need to survive and to provide an income.
Social- many people enjoy the natural beauty of wild ecosystems as well as using them for activities which are beneficial to health by providing a means of relaxation and exercise
Ethical- all organisms have a right to exist, and most play an important role within their ecosystem. Many people believe that we shouldn’t have the right to decide which organisms can survive and which we can live without. We also have a moral responsibility for future generations to conserve the wide variety of existing natural ecosystems.

Question 17

What are the aims of sustainability?

Answer 17

• Preserve the environment
  -ensure resources are available for future generations
• allow humans in all societies to live comfortably
• enable less economically developed countries to develop, through exploiting their natural resources
  -create a more even balance in the consumption of these resources between more economically developed countries and less economically developed countries

Question 18

How can small scale timber production be done more sustainably?

Answer 18

Rotational coppicing- woodland is divided into sections and trees are only cut in a particular section until all have been coppiced. Coppicing then begins in another area allowing time for newly coppiced trees to grow. This process continues until you reach the trees that were first coppiced.
This maintains biodiversity, as the trees never grow enough to block out the light. Hence, succession cannot occur so more species can survive.

Question 19

How can companies ensure that large scale timber production remains sustainable?

Answer 19

• Practice selective cutting which involves removing only the largest trees
• Replace trees through replanting rather than waiting for natural regeneration. This also helps to ensure that the biodiversity and mineral and water cycles are maintained.
• Plant trees an optimal distance apart to reduce competition. This results in higher yields as more wood is produced per tree.
• Manage pests and pathogens to maximise yields
• Ensure that areas of forest remain for indigenous people.

Question 20

What techniques are used to make sustainable fishing techniques?

Answer 20

-Use only nets with different mesh sizes e.g. mesh sizes can be made sufficiently large enough that immature fish can escape. Only mature fish are caught, thus allowing breeding to continue.
- Allowing commercial and recreational fishing at certain times of the year. This protects the breeding season of some fish species and allows the fish levels to increase back to a sustainable level.
- Introduction of fish farming to maintain supply of protein food, whilst preventing the loss of wild species.

Question 21

What is the Masai- Mara National reserve ecosystem like?

Answer 21

It is mainly savannah ecosystem, divided by the main Mara river. The fertile regions close to the river are a combination of rich grasslands and woodland- further from the river are open plains with scattered shrubs and trees.

Question 22

What animals are present in the Masai Mara?

Answer 22

Zebras, wildebeest, buffalo, elephants, leopards, lions, and black rhinos.

Question 23

What was grazing like previously in the Masai Mara and what is it like now?

Answer 23

• Was used by local tribes for livestock grazing, practiced semi-nomadic farming. Tribes would frequently move depending on the climate variation and the presence of tsetse flies- allowed time for vegetation to recover
• Now limited to the areas on the edge of the reserve, as local tribes are prevented from entering the park. Populations have grown in these marginal areas. Larger herds graze the grassland areas, and more trees are removed for fuel. As the vegetation is removed, the risk of soil erosion increases.

Question 24

What is ecotourism?

Answer 24

It is tourism directed towards natural environments to support conservation efforts and observe wildlife. It is a type of sustainable development which aims to reduce the impact that tourism has on naturally beautiful environments. This is usually seen as a less invasive use of land than agriculture.

Question 25

What are the key principles of ecotourism?

Answer 25

-Ensure that tourism doesn’t exploit the natural environment or local communities
- Consult and engage with local communities on planned developments
-Ensure that infrastructure improvements benefit local people as well as visitors.

Question 26

What scientific research projects have been undertaken in the masai mara?

Answer 26

• study into the behaviour and physiology of the spotted hyena
• flow assessment of the mara river basin to identify river flows needed to provide for both the basic human needs of the million people who depend on the water, and to sustain the ecosystem in it’s current form.
  -cataloguing and monitoring lion populations throughout the region. Identify population trends and responses to changes in land management, human settlements, livestock movements and tourism.
• monitoring cheetah population and evaluate the impact of human activity on cheetah behaviour and survival.

Question 27

What is the ecosystem like in nepal?

Answer 27

Hot and humid in summer months and is composed of a fertile alluvial soil which is rich in nutrients. Terai is an area of extreme biodiversity.

Question 28

What plants and animals are found in the Terai region of Nepal?

Answer 28

Subtropical plants e.g. pipal and bamboo. Large areas of thick forest where animals such as the Bengal tiger, Sloth bear and the Indian rhinoceros is found.

Question 29

What impact did removal of large areas of forest in Nepal have on the ecosystem?

Answer 29

Exacerbated the effects of monsoon flooding, causing severe disruption to communities downstream. If it continues unabated, the communities of Terai would be left with only small, isolated pockets of forest. Bad for wildlife and people who rely on forest for income through tourism and through harvesting wood for building products and burning fuel.

Question 30

What successes have been seen in the Terai community in regards to sustainable foresting?

Answer 30

• Significant improvements in the conservation of the forested regions, both in terms of increased area and improved density.
• Improved soil and water management across the region.
  -An increase in the retail price of forestry products, and so a greater economice input into the region.
• Employment and income generation through forest protection, as well as through the production of non- timber forest products.
• Sustainable wood fuel sources, which contribute to 3/4 of the local household energy needs.
• Securing the biodiversity of the forested areas.

Question 31

What management techniques are used to promote sustainable agriculture?

Answer 31

• Promoting the production of fruits and veg in the hills and mountain regions to avoid further intensification of the Terai
• Improving irrigation facilities to enhance crop production.
• multiple cropping, where more than one crop is grown on a piece of land each growing season.
• The growth of nitrogen fixating crops tp enhance fertility of the soil.
• growing crop varieties resistant to varios soil, climatic, and biotic challenges through the use of modern biotechnology and genetic engineering
• improving fertilization techniques to increase crop yields

Question 32

Why is peat from peat bogs sold?

Answer 32

It can be used as fuel and can also be mixed into soil as a fertiliser as it increases acidity and improves soil structure. It has moisture- retaining properties when soil is dry and prevents excess water killing roots when soil is wet.

Question 33

What types of plants and animals are found in peat bogs?

Answer 33

Sphagnum mosses, bog cotton and heathers have adapted to grow and thrive in wet conditions with few nutrients. Supports insects such as butterflies, moths and dragonflies. The lack of predators and human disturbance makes some peatlands ideal for birds to nest and bring up their chicks.

Question 34

Why should we maintain peat bogs?

Answer 34

To maintain biodiversity- will also contribute to flood management, erosion control downstream and carbon storage.

Question 35

What is afforestation and why is it bad in peat bogs?

Answer 35

The establishment of a forest or a stand of trees in an area where there was no forest.
This extracts all the water out of the bogs, destroying the ecosystems and drying them out.

Question 36

How can peat bogs be conserved?

Answer 36

• Ensuring that the peat and vegetation of the bog surface is as undisturbed and as wet as possible.
• Ditch blocking may be required for a period of time to raise the water table and the bog surface.
• Removal of seedling trees from the area. Trees have a high water requirement due to transpiration. Will remove all the water from the peatland.
• Using controlled grazing to maintain biodiversity of peatland. Grazing ensures a diverse wetland surface in terms of structure and species composition. This in turn provides a wide range of habitats for many insect species.

Question 37

What management techniques can be used to protect the Galapagos islands?

Answer 37

-Limiting the areas tourists can visit
-Controlling the movement of livestock
- Introducing anti-poaching measures
- replanting of forests and native plants
- limiting hunting through quotas and seasonal bans

Question 38

What animals are present in the Galapagos islands?

Answer 38

reptiles- only one species of land mammal, the rice rat. Galapagos giant tortoise, flightless cormorant, marine iguana

Question 39

what plants are present on the Galapagos islands?

Answer 39

• costal zone, contains salt-tolerant species such as mangrove and saltbush
• arid zone, contains drought tolerant species such as cacti
• humid zone, contains dense cloud forest. These trees support populations of mosses and liverworts.

Question 40

How are human activities controlled on the galapagos islands?

Answer 40

-Introduction of park rangers across the islands
- limiting human access to particular islands, or specific parts of islands
- controlling migration to and from the islands
-strict controls over movement of introduced animals such as pigs

Question 41

What animals are present in antartica?

Answer 41

All endothermic animals living on and around antartica rely on thick layers of blubber to insulate them from the cold.
Emperor penguin- only warm blooded animal in the Artic during the winter.

Question 42

What plants are present on the antatric?

Answer 42

They can only grow on the ice free regions- 2%. Lichens and moss grow in any favourable niches such as sand, soil, rock and on the weathered bones and feathers of dead animals.

Question 43

what impacts have humans had on the artic?

Answer 43

• Planet wide impacts such as global warming and ozone depletion
  -hunting of whales and seals and fishing of some antartic species has depleted the stocks of these organisms
• soil contamination around scientific research stations
• Discharging of wate into seas including human sewage

Question 44

What measures are being taken to control human impacts on the artic?

Answer 44

-scientific cooperation between nations
-protection of the Antarctic environment
- conservation of plants and animals
-designation and management of protected areas
-management of tourism

Question 45

What animals are present in snowdonia?

Answer 45

• Coast and estuary birds such as choughs, cormorants, and oystercatchers
• forest birds, pied flycatcher, wood warblers
• moorland and mountain birds e.g. ospreys, buzzards and sparrowhawks.

Question 46

What plants are present in Snowdonia?

Answer 46

contains plants that have evolved to survive at high altitudes and in harsh conditions as well as woodlands of oaks and alder.

Question 47

What are the key purposes of the Park authority in snowdonia?

Answer 47

• conserve and enhance the natural beauty, wildlife and cultural heritage of the area
• promote opportunities for the understanding and employment of the special qualities of the park
• enhance the economic and the social well-being of communities within the park

Question 48

What animals are found in the lake district?

Answer 48

water voles, natterjack toads, species of bat, red deer and birds of prey. Also have red squirrels and a species of fish that is only found in this region which appear on the IUCN endangered list.

Question 49

What plants are present in the lake district?

Answer 49

Central fells- there are habitats that exist above the tree line. They’re rare and support a diverse range of artic-alpine plant communities. Specialised trees have evolved in these harsh habitats such as the dwarf juniper and dwarf willow. Lower regions of the lake district have sundew, one of the Uks only carnivorous plants.

Question 50

How are human activities controlled in the lake district?

Answer 50

Role of the Lake District National Park Authority is like that of Snowdonia- to conserve the region while enabling access for many millions of visitors each year. Through the active management of the countryside, e.g. planting native tree species, this fragile ecosystem is being secured.