Ecosystem Dynamics

Question 1

Habitat

Answer 1

The place where an organism normally lives

Question 2

Population

Answer 2

All the organisms of one species in a particular habitat

Question 3

Community

Answer 3

Populations of different species living in the same place at the same time

Question 4

Ecological niche

Answer 4

The role of an organisms within its environment

Question 5

Ecosystem

Answer 5

the combination of all the biotic and abiotic factors in a particular area

Question 6

Population growth rate

Answer 6

change in population/ length of time

Question 7

Interspecific competition

Answer 7

Organisms from different species compete for the same resources
Consequences
-Reduced population sizes
-Species out coming each other (altering species distribution)

Question 8

Intraspecific competition

Answer 8

Organisms from the same species compete for the same resources
consequences: fluctuations in population size around the carrying capacity

Question 9

Predation

Answer 9

The predator population always follows the prey population as it is dependent on the prey for survival

Question 10

Symbiotic relationships

Answer 10

A close, prolonged relationship between organisms of different species

Question 11

Mutualism

Answer 11

Both organisms benefit from the relationship

Question 12

Commensalism

Answer 12

One organism benefits and the other is unaffected

Question 13

Parasitism

Answer 13

One organism benefits and the other is harmed

Question 14

Amensalism

Answer 14

One organism is unaffected and the other is harmed

Question 15

Ecological Niche

Answer 15

An organisms role within its habitat
includes all its interactions. with biotic and abiotic factors of an ecosystem, deterred by: habitat, feeding relationships, interactions with other species

Question 16

Sampling techniques

Transects and quadrants

Answer 16

Finding the number of individuals of a particular species or the percentage cover of a particular species

For abundance use random sampling as it removes bias
For distribution use transepts as it allows abiotic factors to be investigated at regular intervals (belt, interrupted and line transects)

Question 17

Extinction

Answer 17

When species fail to adapt to environmental changes, or are outcompeted for resources they may die out and cease to exists entirely
Extinction is more likely if the population has low genetic diversity as the population is less able to adapt to selection pressures (invasive species, temperature, disease, food sources)

Question 18

The bottleneck effect

Answer 18

As the population size of a species decreases and become closer to extinction, genetic diversity is continually lost, low biodiversity is maintained even if population size is restored. Human activates are currently the largest. threat to extinction (direct impacts - hunting and deforestation)
Indirect impacts - climate change and global warming)

Question 19

Studying past ecosystems

Rocks

Answer 19

Analysing rock
Studying fossils can give us an idea of the organisms that lived in an environment: their characteristics, their diet and their habitat.
Examining rock composition, shape and age gives us an idea of how the environment has changed, and climatic events that shaped the landscape.
Radiometric dating looks at how atoms present in a rock have decayed in order to determine the age of the rock.
Analysing ice
Ice cores are cylinders of ice that have been drilled out of glaciers.
Biotic factors, like pollen and microbes, can be extracted from the ice.
Abiotic factors, such as atmosphere composition, can be identified using gas analysis.
Analysing Aboriginal rock paintings
Aboriginal paintings depict animals that existed in the past.
This gives us an idea of the distribution and abundance of organisms in a particular time period.

Question 20

Habitat destruction

Answer 20

decreases population size
increases vulnerability or organisms moving between fragments
causes the edge effect

Question 21

Invasive species

Answer 21

A non-native species that has a tendency to reproduce and spread in a way that damages the environment
Change the abiotic and botic factors, increasing selection pressures

Question 22

Overexploitation

Answer 22

occurs when populations are harvested at an unstable rate. Organisms are taken from the environment without leaving time for populations to recover. Population sizes shrink, leading to local or global extinction which has a flow on effect for predators and prey.

Question 23

Pollution

Answer 23

Causes chemical and physical changes which reduce biodiversity and drive extinction
Fertiliser allows for maximise food production by adding specific nutrients to soil (nitrogen and potassium) to assist plant growth. However not all the nutrients are taken up by the crop and the remaining nutrients either accumulate in the soil ruining nutrient. cycles or run into. rivers and lakes causing eutrophication
Litter
Atmospheric pollutants
Climate Change, increasing temperatures, driving migration and extinction

Question 24

Climate change

Answer 24

Climate change is the long-term shift in global or regional climate patters. Climate. change is mainly human-induced global warning and corresponding side effects. Climate change largely occurs due to human activities that cause an increase in atmospheric carbon dioxide and methane concentrations

The green house effect increase in greenhouse gas concentrations - global warming, rising sea levels and unpredictable weather patterns