Ecosystem dynamics Flashcards
List 7 abiotic factors
- Temperature
- Water supply
- Air pressure
- Salinity
- Viscosity
- Buoyancy
- Gas concentration
How do abiotic factors effect the environment?
Affects the abundance and distribution of organisms in the ecosystem according to the organisms tolerance range. e.g where there are more resources (food, water, good climate etc) there will be more organisms living there.
What are the 3 main Selection Pressures?
- Resource availability
- food, shelter, mates - Environmental conditions
- weather, temperature, geographic location - Biological factors
- pathogens and predators
What are the 3 main community interactions in an ecosystem?
- Predation
- Competition
- Symbiosis (mutualism, commensalism and parasitism).
What are the types of biodiversity?
- Ecosystem diversity:
The diversity of ecosystems in an area eg grassland, stream, woodland etc. - Species diversity:
The diversity of species in an area (often referred to as biodiversity) - Genetic diversity:
The diversity of genes in a population of one organism
What is biodiversity and why is biodiversity important?
Biodiversity refers to the variety and abundance of different species of plants and animals.
The general health of the planet depends on biodiversity. In all ecosystems, the greater the biodiversity the more stable and resilient the system becomes.
What are the levels of organisation?
Ecosystem, Community, Population, Individual
Describe the predator - prey relationship
Constantly in a cycle of fluctuations.
The predator numbers copying those of its prey.
Prey will always peak first.
For either population to survive, there will always be more prey than predators
Identify and describe the two aspects of competition
Intraspecific -
* Between members of their own species.
* Intense due to common resource needs.
Interspercific -
* Between members of different species.
* Can lead to evolution due to selection pressures
Describe Alleopathy
It is competition between plants.
The biomolecules (allelochemicals) produced by a plant are released into the environment. This allows plants to keep other plants out of their space, meaning more light, water and soil is available.
Define Symbiosis
A relationship between two species living in close proximity
What are the types of Symbiosis
Mutualism +/+
Commensalism +/0
Parasitism +/-
Ammensalism -/0
Results of Symbiosis
Symbiosis contributes to:
* An increase in biodiversity and a more resilient ecosystem e.g coral reefs are only possible due to symbiosis. This environment is important for fish and other marine life.
Define Osmosis
The movement of water from a low concentration of solute to a high concentration of solute
(think of the fish)
What is the principal called where no two species can occupy the same niche
Competitive Exclusion Principal
What is Major Extinction?
when a number of different species become extinct around the same time.
What causes infectious diseases?
Pathogens (bacteria, virus, protozoan, prion, fungal) that are transferred between individuals
What are non-infectious diseases?
either environmental, genetic or nutritional and an not be transferred between individuals.
What is Facultative Mutualism?
Both organisms benet but don’t require each other to survive (Bee + flower)
What is obligate mutualism?
Organisms require each other to survive
What is an autotroph vs heterotrophs
A = plants / organisms that can produce their own food
H = needs to consume other organisms
