8.4 - Human Populations And Carrying Capacity

Question 1

What is a carrying capacity

Answer 1

The maximum stable population size of a species that an ecosystem can support is known as the carrying capacity

Question 2

What affects do abiotic and biotic to a population and individual species

Answer 2

Every individual within a species population has the potential to reproduce and have offspring that will contribute to population growth
- In reality, however, there are many abiotic and biotic factors that prevent every individual in a population from making it to adulthood and reproducing

Question 3

Why does population size have a limit

Answer 3

Biotic and abiotic factors. This ensures the population size of each species is limited at some point (i.e. the carrying capacity of that species is reached)
This is why no single species has a population size that dominates all other species populations on Earth, with the exception of humans (as we have managed to overcome many of the abiotic and biotic factors that could potentially limit the population growth of our species)

Question 4

How do you know on a graph when carrying capacity is reached

Answer 4

The graph flattens out. At this point, the environmental (abiotic and biotic) factors that stop all individuals from surviving and reproducing result in the population no longer being able to grow in size

Question 5

What factors determine carrying capacity

Answer 5

• Resource availability
• Interactions between species
• Environmental conditions

Question 6

What influences the carrying capacity of species and give an example of it

Answer 6

The carrying capacity of an environment for a species is influenced by the availability of essential resources such as food, water, shelter, and space

• For example, a grassland ecosystem may have a carrying capacity for a specific number of herbivores based on the amount of grasses available for grazing

Question 7

How can interactions between species influence carrying capacity and give an example of it

Answer 7

The presence of predator-prey relationships, competition for resources, and symbiotic interactions among species can influence the carrying capacity of an environment
For example, the carrying capacity of a freshwater ecosystem for fish species may be influenced by the presence of predators, availability of prey, and competition for food resources

Question 8

How does the predator prey relationships change and give an example

Answer 8

The presence of predator-prey relationships, competition for resources, and symbiotic interactions among species can influence the carrying capacity of an environment
- For example, the carrying capacity of a freshwater ecosystem for fish species may be influenced by the presence of predators, availability of prey, and competition for food resources

Question 9

Explain the interactions between species

Answer 9

• The number of predators increases as there is more prey available
• The number of prey then decreases as there are now more predators
• The number of predators decreases as there is now less prey available
• The number of prey increases as there are now fewer predators
• The cycle now repeats

Question 10

How can enviromental factors influence carrying capacity and give an example

Answer 10

Factors like climate, temperature, rainfall patterns, and soil fertility can affect the carrying capacity of species within an environment
- For example, a forest ecosystem with favourable environmental conditions may have a higher carrying capacity for a certain bird species due to the availability of suitable nesting sites (e.g. the temperature, humidity and rainfall is suitable for incubating eggs and raising chicks)

Question 11

How do people estimate carrying capacity

Answer 11

Scientists use various methods to estimate the carrying capacity of an environment for a given species
- These methods include field observations, population surveys, mathematical modelling, and data analysis
- By studying population trends, resource availability, and species interactions, researchers can make informed estimates of carrying capacity

Question 12

What factors make it difficult to estimate human carrying capacity

Answer 12

• technology advancements
• cultural and social factors
• changing lifestyle and consumption patterns
• adaptive capacity

Question 13

How can technological advancements impact human carrying capacity

Answer 13

Human societies have the ability to modify their environment and overcome traditional carrying capacity limitations through technology
- For example, the development of agriculture and irrigation techniques has allowed humans to increase food production and support larger populations beyond what the natural environment could sustain

Question 14

How can cultural and social factors impact human carrying capacity

Answer 14

• Human population dynamics are influenced by cultural norms, social behaviours, and economic factors
• These can affect fertility rates and migration patterns, for example, making it difficult to accurately predict or estimate carrying capacity for human populations

Question 15

How can changing cultural and social factors impact human carrying capacity

Answer 15

Human population dynamics are influenced by cultural norms, social behaviours, and economic factors
These can affect fertility rates and migration patterns, for example, making it difficult to accurately predict or estimate carrying capacity for human populations

Question 16

How can changing lifestyle and consumption patterns change human carrying capacity

Answer 16

Human populations are characterised by varying lifestyles and consumption rates, which can significantly impact resource demands and environmental impacts
- For example, urbanised societies with high levels of consumption may strain the carrying capacity of their surrounding areas due to increased resource demands and waste generation

Question 17

How can adaptive carrying capacity influence human carrying capacity

Answer 17

More so than any other species, humans have the ability to adapt and innovate in response to changing environmental conditions

This adaptability can affect carrying capacity by influencing resource use efficiency and the development of technological solutions

Question 18

What does the concept of population growth dynamics refer to

Answer 18

How humans interact with their enviroment to change in number over space and time

Question 19

How have human overcome limiting environmental factors

Answer 19

Humans have overcome these by finding medicines and vaccines to reduce or control rates of disease, and developing technologies to increase food supply to allow for population growth

Question 20

What is optimum population

Answer 20

perfect balance between population and resource use that allows for the highest standard of living

Question 21

Why do wealthier populations have a larger carrying capacity

Answer 21

Wealthier countries usually have a larger carrying capacity than poorer countries because:
They export waste to poorer countries
They import products from poorer countries
This means that although poorer countries use fewer resources, they are supporting the resource use of the richer countries

Question 22

What is a ecological footprint

Answer 22

An ecological footprint (EF) is a theoretical concept that acts as a valuable tool used to assess the environmental impact of human populations
It quantifies the area of land and water required to support a specific population at a particular standard of living

Question 23

How does ecological footprint measure demand

Answer 23

The ecological footprint provides a comprehensive measure of the demands that human populations place on the environment
- It takes into account the resources consumed by individuals, such as food, energy, water, and materials, as well as the waste generated and the ecosystem services required to absorb that waste
- By considering these factors, ecological footprints help to evaluate the sustainability of human activities

Question 24

What factors can vary ecological footprint

Answer 24

• Lifestyle choices
  Enviromental value system
• productivities of food production systems
  The efficiency and sustinability of agricultural practices also contributes to variations on the size of a countrys ecological system
• land use and industry
  The type of land use and industrial activities in a region can affect the size of its ecological footprint

Question 25

What does comparing the ecological footprint and available land provide an insight of

Answer 25

sustainability and carrying capacity

Question 26

What happens if ecological footprint exceeds land area

Answer 26

If the ecological footprint of a population exceeds the land area available to it, it indicates an unsustainable situation where resource consumption surpasses the environment’s ability to regenerate

This suggests that the population is exceeding the carrying capacity of the area, leading to ecological degradation and potential resource depletion

Question 27

What are some implication of changes to humanity increasing global ecological footprint

Answer 27

• Destruction of ecosystems such as forests and coral reefs with knock-on effects of extinction of plant and animal species
• Climate change
• Deforestation and changes of land use for growing urban areas, transport and industrial development
• Reduction of availability and quality of fresh water
• Reduction in soil quality through erosion leading to crop and food shortages

Question 28

What will limit the population growth

Answer 28

The degradation of the environment and the consumption of finite resources have significant implications for human population growth

Question 29

What is a finite resource

Answer 29

There is a limited amount available and it will at some point run out.

These resources have limited availability, and their extraction and consumption rates can outpace their natural replenishment

Question 30

Using overexplitation opt freshwater refusers explain how this can be a limiting factor

Answer 30

Overexploitation of freshwater resources can lead to water scarcity, affecting agricultural productivity, human health, and overall societal wellbeing - this is particularly crucial in regions already facing water stress or located in arid and semi-arid climates.

Question 31

What happens when carrying capacity is surpassed

Answer 31

• Resource scarcity intensifies, leading to food shortages, water scarcity, and energy crises - this can trigger social unrest, conflicts, and migrations as populations struggle to meet their basic needs
• Ecosystems can start to collapse, resulting in a loss of biodiversity, disruption of essential ecosystem services, and increased vulnerability to environmental disturbances - this can have cascading effects on human well-being and livelihoods

Question 32

What is Easter island and what does it provide in terms of a case study

Answer 32

Easter Island (also known as Rapa Nui), located in the southeastern Pacific Ocean, provides a notable case study where the degradation of the environment and the consumption of finite resources have significantly limited human population growth

Question 33

What did Easter islands inhabitants provide solely on

Answer 33

In the past, Easter Island was a thriving Polynesian society with abundant natural resources, including lush forests
The inhabitants of Easter Island relied heavily on the island’s forests for various needs, such as timber for construction, wood fuel, and agriculture

Question 34

What did overexploitation on Easter island lead to

Answer 34

Due to overexploitation of timber resources, the island’s forests were depleted, leading to significant deforestation
The loss of trees resulted in soil erosion, reduced agricultural productivity, and limited availability of other essential resources

Question 35

What did the degradation of the Easter island do to the carrying capacity

Answer 35

The degradation of the environment and the depletion of finite resources significantly decreased the island’s carrying capacity
The human population on Easter Island was no longer sustainable, and as a result, it declined dramatically

Question 36

Overall what does Easter island demonstrate

Answer 36

The case of Easter Island clearly demonstrates the consequences of unsustainable practices, emphasising the importance of responsible resource management and sustainable approaches to ensure long-term human well-being and environmental preservation