Ecosystem Dynamics Flashcards
Habitat
The place where an organism normally lives
Population
All the organisms of one species in a particular habitat
Community
Populations of different species living in the same place at the same time
Ecological niche
The role of an organisms within its environment
Ecosystem
the combination of all the biotic and abiotic factors in a particular area
Population growth rate
change in population/ length of time
Interspecific competition
Organisms from different species compete for the same resources
Consequences
-Reduced population sizes
-Species out coming each other (altering species distribution)
Intraspecific competition
Organisms from the same species compete for the same resources
consequences: fluctuations in population size around the carrying capacity
Predation
The predator population always follows the prey population as it is dependent on the prey for survival
Symbiotic relationships
A close, prolonged relationship between organisms of different species
Mutualism
Both organisms benefit from the relationship
Commensalism
One organism benefits and the other is unaffected
Parasitism
One organism benefits and the other is harmed
Amensalism
One organism is unaffected and the other is harmed
Ecological Niche
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
Sampling techniques
Transects and quadrants
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)
Extinction
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)
The bottleneck effect
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)
Studying past ecosystems
Rocks
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.
Habitat destruction
decreases population size
increases vulnerability or organisms moving between fragments
causes the edge effect
Invasive species
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
Overexploitation
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.
Pollution
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
Climate change
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
