7.4 Populations In Ecosystems Flashcards
What is a habitat?
Where an organism lives
What is a population?
Multiple individuals of the same species living in an area
What is a community?
Multiple populations of different species in the same habitat
What is an ecosystem?
All the biotic and abiotic conditions in an area
That are abiotic conditions?
Non-living environmental factors
What are biotic conditions?
Living environmental factors
What is a niche?
The role of a species within its habitat/ecosystem
What is an adaptation?
A characteristic that increases an organism’s chances of survival and reproduction
What are the two rules about niches?
- A species cannot occupy more than one niche
- Two different species cannot share this niche.
What are the three types of adaptations?
- Behavioural (how organisms act)
- Anatomical (structural features of their body)
- Physiological (processes inside their body)
What is interspecific competition?
Competition between different species
What is intraspecific competition?
Competition between individuals of the same species.
What is the maximum size of a population that can be maintained for a long period of time called?
Carrying capacity
Why can’t the carrying capacity be infinite?
Limited resources
What are the biotic factors which influence carrying capacity?
- Interspecific competition
- Intraspecific competition
- Predation
What word is used to describe the process by which an ecosystem changes over time?
Succession
What are the two types of succession?
- Primary succession
- Secondary succession
What is the largest and most complex community an ecosystem can support called?
Climax community
Where does primary succession occur?
Newly formed land
Where does secondary succession occur?
Land that’s been cleared of all the plants but soil remains
Describe the stages of primary succession
- Pioneer species are the first species to colonise the newly exposed land.
- Pioneer species change the abiotic conditions making them less hostile for other species.
- Soil can form when the pioneer species dies and is decomposed.
- New species colonise the less hostile land.
- New species may out-compete pioneer species.
- Process repeats until climax community is reached.
Describe the stages of secondary succession
- Pioneer species colonise the damaged land.
- The environment in secondary succession is more nutrient-rich than in primary succession because there is already a soil layer.
- As pioneer species die, the soil becomes more nutrient-rich and more stable making the abiotic conditions less hostile.
- New species can colonise the land and can out-compete the pioneer species.
- More species can colonise our-competing older species until a climax community is reached.
Give two ways in which succession can be prevented
- Grazing - animals graze to prevent growth of vegetation.
- Burning - burning kills vegetation and allows secondary succession to take place.
What does conservation do?
Conservation protects ecosystems and the species within them to help prevent decreasing biodiversity.
