Changes in global ecosystems
18/10/2022 13:01
What is an ecosystems - an ecosystem is a geographical area
where living organisms interact with other biotic and abiotic
factors to an area of life.
What is an ecological niche? - The purpose of a living organism
and the role it plays in an ecosystem.
Indicator species - the species that indicates the health of a
habitat
Ecological succession
• The gradual process by which ecosystems change and
develop over times.
• There are 2 types:
○ Primary succession - the series of community
changes which occur on an entirely new habitats
which has never been colonised before.
○ Secondary succession - the series of community
changes which take place for a previously
colonised but disturbed or damaged habitat.
Pioneer species - the species that is the first to colonise a
newly formed habitat.
What could affect a wild population - natural changes
• Drought - an episodic deficit in water availability that
drives ecosystems beyond thresholds of vulnerability.
• Flood - an overflow of water that submerges land that is
usually dry.
• Wild fire - uncontrolled fires that burns in the wild land
vegetation.
• Disease - host pathogen interactions that affect host
individuals, populations , communities and ecosystems.
• Famine - regional failure of food supplies/production or
distribution systems, leads to a sharp increase in
mortality due to starvation.
• Natality - Increase to population size through
reproduction within a period of time.
• Mortality - the number of individuals that die over a
18/10/2022 13:01
What is an ecosystems - an ecosystem is a geographical area
where living organisms interact with other biotic and abiotic
factors to an area of life.
What is an ecological niche? - The purpose of a living organism
and the role it plays in an ecosystem.
Indicator species - the species that indicates the health of a
habitat
Ecological succession
• The gradual process by which ecosystems change and
develop over times.
• There are 2 types:
○ Primary succession - the series of community
changes which occur on an entirely new habitats
which has never been colonised before.
○ Secondary succession - the series of community
changes which take place for a previously
colonised but disturbed or damaged habitat.
Pioneer species - the species that is the first to colonise a
newly formed habitat.
What could affect a wild population - natural changes
• Drought - an episodic deficit in water availability that
drives ecosystems beyond thresholds of vulnerability.
• Flood - an overflow of water that submerges land that is
usually dry.
• Wild fire - uncontrolled fires that burns in the wild land
vegetation.
• Disease - host pathogen interactions that affect host
individuals, populations , communities and ecosystems.
• Famine - regional failure of food supplies/production or
distribution systems, leads to a sharp increase in
mortality due to starvation.
• Natality - Increase to population size through
reproduction within a period of time.
• Mortality - the number of individuals that die over a
