Balance In An Ecosystem

An ecosystem can only accommodate as many organisms as its resources (food, water and
shelter) can carry.
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The balance can be disturbed by natural or human factors:
o
natural factors include extreme changes in patterns of weather and climate, such as
floods, drought, extreme and sudden changes in temperature.
o
human factors include removing organisms from the ecosystem (such as poaching),
human-induced pollution.

These factors can contribute to an imbalance in an ecosystem, seriously impacting on its
components and altering its nature.
In this section will examine the balance between the different trophic levels in ecosystems,
since all organisms in the ecosystem have to rely on the resources the area can supply. Any
area can only support a limited number of animals. Look at the ecosystem below and decide
which resources the organisms depend on. Remember to take some notes.
A balanced savanna ecosystem.
If all the grass and trees die, what would happen to the zebra and elephants? What would
later happen to the cheetah and hyena? Why is this? The balance in an ecosystem refers to
how many animals it can support for long periods. If the balance is upset, the whole system
could fail.
Try
your
hand
at
balancing
a
dessert
ecosystem!
https://pbskids.org/plumlanding/games/ecosystem/feed_the_dingo.html
One of the factors that we can look at within an ecosystem to see if it is balanced is the
population growth of different species over time.
Population growth
Over time ecological populations interact and change within a community. All populations
change over time and grow. The population growth of a species in the wild is kept in balance
by a number of different factors.
Human intervention can sometimes cause serious damage to an animal population, such as the
critically endangered Riverine Rabbit. There are fewer than 200 individuals left in South
Africa. It only eats from a few plant types, so its habitat is restricted to where these plants
are found, like small areas of the Karroo. During the day, it hides under bushes on the river
banks, but many of its home areas have been invaded by humans or destroyed.
The Critically Endangered Riverine Rabbit
Instructions:
1.
Study the diagram that shows the threats to the Riverine Rabbit.
Learn more about the Riverine Rabbit
http://www.edgeofexistence.org/mammals/species_info.php?id=3
Explain the different limiting factors on the population growth of the Riverine Rabbit using
the information in the diagram. Classify those factors whether it belongs to NATURAL or
HUMAN FACTORS.
1.
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The main goal of any species is to reproduce and ensure the survival of the species. Factors
beyond the control of the species often influence this and limit the growth of the population,
as with the Riverine Rabbit. These disruptions cause an imbalance in the ecosystem and can
affect the organisms that live there as well as the ecosystem as a whole.
Equilibrium
All living things must remain in balance, or equilibrium, also known as homeostasis. As the
number of carnivores in a community increases, they eat more and more of the herbivores,
decreasing the herbivore population. It then becomes harder and harder for the carnivores to
find herbivores to eat, and the population of carnivores decreases. In this way, the carnivores
and herbivores stay in a relatively stable equilibrium, each limiting the other's population. A
similar equilibrium exists between plants and plant-eaters.
Ecosystem equilibrium is when populations of organisms in the ecosystem are in balance.
Ecosystems become out of balance when there are too many or too few of a species,
particularly keystone species.
https://www.accuweather.com/en/weather-news/how-would-a-species-extinction-impact-the-food-web-our-ecosystems/349723