24 - Populations and sustainability Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Types of competition

A

Intra-specific competition
Inter-specific competition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Intra-specific competition

A

competition between members of the same species.​

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Inter-specific competition

A

competition between members of different species.​

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Population changes with intraspecific competition​
(population increasing, decreasing and growth)

A
  1. Population increasing – resources are plentiful, little competition, organisms can easily survive and reproduce
  2. Population decreasing – more individuals to share the resources in the ecosystem (food, space) which become limited – not all organisms survive
  3. Population growth – fewer individuals competing for resources, more survive and reproduce
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Niche

A

The ecological role and position a species occupies within an ecosystem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

principle of competitive exclusion states that

A

nly one species can occupy a particular niche within an ecosystem. One species will always outcompete the other.​

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Predator-prey relationships​ graphically

A
  • Prey population normally peaks at a higher number than predator’s (pyramid of numbers).
  • Predator population changes approx. 1/2 cycle after that of prey population.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is a limiting factor - in terms of population size

A

an environmental resource or constraint that limits population growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

population growth curve phases

A

phase 1 - a period of slow growth rate. Small numbers of individuals that are initially present reproduce to increase population. Birth rate > death rate

phase 2 - A period of rapid growth . As the number of breeding members increases, total population increases exponentially. No constraints act to limit the population growth

Phase 3 - a stable state. Further population growth is prevented by external constraints. Pop size does fluctuate but overall size remains stable. Birth rate = death rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

when does a short period of exponential growth occur

A

when conditions are ideal and the maximum growth rate is achieved

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

2 groups of limiting factors

A

Abiotic - non-living factors (pH, humidity and oxygen)
Biotic - Living factors (predators, disease and competition)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

carrying capacity

A

maximum population size than an environment can support

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

immigration

A

movement of individual organisms into a particular area increases population size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

emigration

A

movement of individual organisms away from a particular area decreases population size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

density independent factors

A

factors that have an effect on the whole population regardless of size
-> earthquakes, fires and storms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

conservation

A

the management of biodiversity through human action of management
-> involves the management of ecosystems so that natural resources can be used without running out

conservation is dynamic and needs to adapt to constant change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

forest stewardship council

A

ensures that forests are managed so that they provide a sustainable source of timber
-> mission is to promote socially beneficial, environmentally appropriate and economically viable management of forests across the world

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

conservation approaches also include r_______

A

reclamation
- the process of restoring ecosystems that have been damaged or destroyed
-> could look like controlled burning of a forest to halt succession and increase biodiversity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

preservation

A

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

-> commonly used when preserving ecologically sensitive

20
Q

importance of conservation

A

economic - provide resources that humans need to survive and to provide an income - rainforest species provide medicinal drugs, clothes and food

social- people enjoy the natural beauty of wild ecosystems

ethical - all organisms have the right to exist

21
Q

what is a sustainable resource

A

a renewable resource that is being economically exploited in such a way that it will not diminish or run out

22
Q

aims of sustainability are

A
  • 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 resource
  • create a more even balance in the consumption of there resources between low and high economically developed countries
23
Q

small scale timber production

A

to produce sustainable timber on a small scale coppicing is used
-> tree trunk is cut close to the ground
-> new shoots form an mature
-> new shoots are cut and in their place more are produced

24
Q

rotational coppicing

A
  • woodland is divided into sections and trees are inly cut in one section, until all have been coppiced
  • coppicing begins in another area allowing time for newly coppiced trees to grow
  • this repeats until you reach trees that were first coppiced
  • it maintains biodiversity as the trees never grow enough to block out light, so succession cannot occur and more species can survive
25
Q

pollarding

A

similar to coppicing but trunk is cut higher up to stop animals from eating shoots

26
Q

large-scale timber production

A
  • practice selective cutting - remove largest trees
  • replace trees through replanting not waiting for natural regeneration. this helps to ensure biodiversity and mineral and water cycles are maintained

-plant trees optimal distance apart to reduce competition

  • manage pests and pathogens
  • ensure that areas of the forest remain for indigenous people
27
Q

disadvantage to large scale timber production

A
  • habitats are destroyed
  • soil minerals are reduced
  • bare soil is left to erode
    (trees are important to binding soil together)
28
Q

Common Fisheries policies

A
  • fishing quotas provide a limited number of certain species of fish that are allowed to be caught in an area- use nets with different sized nets - so immature fish can escape to continue breeding
  • allow commercial and recreational fishing at certain times to protect breeding season
29
Q

semi-nomadic farming

A

farmers periodically relocate their farming operations within a defined area.

This mobility allows them to manage resources sustainably, often following seasonal patterns or land regeneration cycles.

vegetation is allowed to recover from grazing as farmers move to another area

30
Q

ecotourism

A
  • tourism directed towards natural environments to support conservation effort
  • a type of sustainable development that aims to reduce the impact tourism as
31
Q

key principles of ecotourism

A
  • ensure that tourism doesn’t exploit environment or communities
  • consult with and engage local communities on planned developments
  • ensures infrastructure improvements benefits local people
32
Q

types of succession

A

1- primary - occurs on an area that has been newly formed or exposes or exposed. there is no soil of organic material at the start

2- secondary - on areas of land where soil is present, but contains no plant or animal species. eg bare earth after a forest fire

33
Q

when does primary succession occur

A
  • volcanoes erupt, depositing lava. when it cool, igneous rock
  • sand is blown by the wind or deposited by the sea to create new sand dunes
  • silt and mud are deposited at river estuaries
  • glaciers retreat depositing rubble and exposing rocks
34
Q

stages of succession

A
  • barren land
  • pioneer community
  • intermediate community
  • climax community
35
Q

what is a pioneer community

A
  • it begins succession by colonising an inhospitable environment
  • they arrive as spores or seeds carried by the wind or by droppings
  • ## eg lichen and algae
36
Q

adaptations of pioneer species

A
  • ability to produce large quantities of seeds or spores
  • seeds germinate rapidly
  • ability to PHS to produce their own energy
  • tolerance to extreme environments
  • ability to fix nitrogen from the atmosphere
37
Q

what is humus

A

organic component of the soil
- due to when organisms of the pioneer species die and decompose

38
Q

what does humus allow for soil

A

soil becomes able to support the growth of secondary colonisers, as it contains minerals like nitrates and can retain some water

39
Q

what are secondary colonisers

A
  • arrive as spores or seeds
  • are able to grow on the humus
  • moss is an example
40
Q

how can tertiary colonisers grow

A

as the environment begins to improve, plants like ferns can grow
- they have a waxy cuticle that protects them from water loss
- can survive in conditions without an abundance of water - however they do obtain most of their water minerals from salts from the soil

41
Q

intermediate community

A
  • when rock continues to grow and mass of organic matter increases
  • deeper more nutrient rich soil that retains more water. as more organisms decomposer
  • at each stage plant and animal species are better adapted to the current conditions
    -they outcompete many species and become the dominant species
42
Q

climax community

A
  • community is in a stable state
  • a few dominant species of plant and animals
  • the species that make up a climax community depends on the climate
  • it is usually the least biodiverse
43
Q

biodiversity changes over succession

A
  • usually most biodiverse at mid-succession
  • decreases due to dominant species out competing pioneer and other species, resulting in their elimination
  • the more successful a dominant species the less biodiversity
44
Q

animal succession

A
  • primary consumer’s are the first to colonise an area as they consume and shelter in the mosses and lichens

-secondary consumers arrive once a suitable food source is established

  • larger organisms move in when biotic factors become favourable
45
Q

deflected succession

A
  • human activates can halt the natural flow of succession and prevent the ecosystem from reaching a climax community
  • when succession is artificially stopped it is called a plagioclimax
46
Q

examples of how deflected succession occurs

A
  • grazing and trampling of vegetation by domestic animals
  • removing existing vegetation to plant crops
  • burning as a means of forest clearance