Back to B7 Home
B7 B) Competition
B7 B) Competition
To survive and reproduce, organisms require materials from both their surroundings and other organisms. For example:
Organisms compete with both different species and members of their own species for these resources.
- Plants need sunlight, space, water and minerals ions
- Animals need food, water, mates and territory
Organisms compete with both different species and members of their own species for these resources.
Interdependence
All organisms in an ecosystem depend on each other for food, shelter, pollination and seed dispersal. We call this interdependence. Let’s have a look at the food chain below that contains grass, rabbits and foxes.
All organisms in an ecosystem depend on each other for food, shelter, pollination and seed dispersal. We call this interdependence. Let’s have a look at the food chain below that contains grass, rabbits and foxes.
In the above food chain, grass is the producer, rabbits are the primary consumers and foxes are the secondary consumers.
Let’s now suppose that there was an event that resulted in the population of foxes decreasing (e.g. a virus that killed some of the foxes). Foxes are predators for the rabbits, so fewer foxes means that less rabbits are killed, which results in the population of rabbits increasing. An increase in the population of rabbits means that more grass is eaten, which results in the population of grass decreasing. So, a decrease in foxes (due to a virus) will lead to an increase in rabbits and a decrease in grass.
A small change in the population of one organism can have a huge effect on the populations of other organisms and the whole ecosystem. The effects on an ecosystem of a change in the population of one organism can be very hard to predict because of how interdependent all the organisms are. Also, in our example, we only looked at one food chain; there is usually lots of different food chains in an ecosystem, which is why we sometimes use food webs instead of food chains – we will be looking at food webs later on.
Let’s now suppose that there was an event that resulted in the population of foxes decreasing (e.g. a virus that killed some of the foxes). Foxes are predators for the rabbits, so fewer foxes means that less rabbits are killed, which results in the population of rabbits increasing. An increase in the population of rabbits means that more grass is eaten, which results in the population of grass decreasing. So, a decrease in foxes (due to a virus) will lead to an increase in rabbits and a decrease in grass.
A small change in the population of one organism can have a huge effect on the populations of other organisms and the whole ecosystem. The effects on an ecosystem of a change in the population of one organism can be very hard to predict because of how interdependent all the organisms are. Also, in our example, we only looked at one food chain; there is usually lots of different food chains in an ecosystem, which is why we sometimes use food webs instead of food chains – we will be looking at food webs later on.
Stable Communities
A stable community is a community where all of the species and environmental factors are in balance, which results in the populations of all of the different organisms remaining fairly constant. The populations may go up and down slightly, but overall the population sizes remain fairly constant. The rainforest is an example of a stable community.
A stable community is a community where all of the species and environmental factors are in balance, which results in the populations of all of the different organisms remaining fairly constant. The populations may go up and down slightly, but overall the population sizes remain fairly constant. The rainforest is an example of a stable community.