Ecology and energy transfers (5.1–5.4, 5.10–5.11, 5.21) Flashcards
Ecosystem
All the organisms living in a particular area and all the non living (abiotic) factors
Community
All of the organisms of different species that live in the same habitat and interact with each other.
Population
All the organisms of one species in a habitat.
Habitat
The place where an organisms lives.
Why do abiotic factors impact abundance of species?
They impact if a species can grow fast and reproduce successfully.
How does interspecific competition impact the abundance of species?
Interspecific competition when organisms of different species compete for the same resources.
Which means that the resources available to both populations are reduced. So the population will be limited.
What is interspecific competition?
Competition between different species.
What is intraspecific competition?
Competition within a species
What is the maximum stable size of a population called?
Carrying capacity
Why is prediation a biotic factor?
As population size of one changes so does the other.
What is a niche?
The role of a species within its habitat.
Define biotic factors and give an example.
Living features of an ecosystem eg predators and disease.
Define abiotic factors and give an example.
Non living factors of an ecosystem eg light temp pH of water/soil.
How do niches affect the abundance and distribution of organisms in a habitat?
No two species can occupy the same niche; interspecific competition excludes one species of the niche is divided according to adaptations.
What is meant by primary succession?
Where an area previously devoid of life is colonised by a community of organisms.
Summarise the process of primary succession.
- Pioneer species can survive harsh conditions and colonise the area.
- They change abiotic factors in their environment e.g. decomposition adds nutrients to the ground.
- Over time more complex organisms survive and outcompete the initial species.
What is a climax community?
Final seral stage of succession.
Ecosystem is stable in dynamic equilibrium over a long period of time.
Usually dominated by large trees or shrubs in rich soil.
How might a species alter the environment that develops during succession?
- May improve environment to make it more suitable for other species.
- May worsen the environment by making it less suitable for other species.
Define NPP
The rate at which energy from the sun is converted into the organic molecules that make up new plant biomass.
Define GPP
The energy transferred to primary consumers.
Give the mathematical relationship between GPP and NPP
NPP= GPP - plant respiration
What is biomass?
Total dry mass of tissue or mass of carbon measured over a given time in a specific area.
Units for biomass
Area= gm-2
volume= gm-3
Why does biomass decrease at each trophic level?
- Energy lost in nitrogenous waste (urine) and faeces.
- Some of the organisms is not consumed
- Energy lost to surroundings as heat.
