4.7.1.1 Communities Flashcards
Ecosystem:
the interaction of a community of living organisms (biotic) with non-living (abiotic) parts of the environment
What are the different levels of organisation within an ecosystem?
- an individual is part of a species but lives in a habitat within a population
- many different populations interact in the same habitat, creating a community - the populations are often dependent on each other
What do organisms require to survive and reproduce?
to survive and reproduce organisms require a supply of materials from their surroundings and from the other living organisms there
When do organisms compete?
- organisms which need the same resources compete for it
- there can be competition between a species or between different species
What may plants compete for?
- plants in a community or habitat may compete for:
- light
- space
- water + mineral ions from the soil
What may animals compete for?
- food
- mates
- territory
- space
- water
Interdependence:
- within a community each species depends on other organisms for food, shelter, pollination, seed dispersal etc.
- if one species is removed it can affect the whole community
- so interdependence describes how organisms in a community depend on other organisms for vital services
What may the removal or addition of a species to a community affect?
the removal or addition of a species to the community can affect the populations of others greatly - as it changes prey or predator numbers
Stable community:
- one where all the species and environmental factors are in balance so that population sizes can remain fairly constant
- when they are lost it is v. difficult to replace them e.g. tropical rainforests, oak woodlands, coral reefs
Community:
all the plants and animals living in an ecosystem
Habitat:
where a living organism lives in an ecosystem
Biodiversity:
the range of different plant and animal species living in an ecosystem
Niche:
the particular place or role that an organism has its own ecosystem
