Ecosystems

1. An ecosystem is all the living and nonliving things that interact in an environment.

2. An ecosystem contains both living and nonliving things. Living things are called biotic and nonliving things are called abiotic. Which things in this ecosystem are biotic? Abiotic?

Important abiotic factors: Water Sunlight Oxygen Soil

3. A habitat is the place where an organism lives out its life. Examples of habitats

4. A species is a group of organisms that can mate and produce fertile offspring += Different breeds of dog are all still the same species.

+ = Donkeys and horses can breed. They are not the same species and produce infertile mules. Mules are prized because they are strong and work very hard. Sometimes, people overestimate how strong mules are.

Lions and tigers are also not the same species. When bred together, they produce a liger (shown here). Ligers cannot produce babies because the males are not fertile. Ligers are big enough that you probably would not want to meet one alone in a dark alley.

+= Different races of humans are the same species. They can have reproduce and their babies can eventually reproduce.

+ = Nothing If no offspring results, the two organisms are not the same species.

5. A population is all the members of a species in a particular area. All the frogs in this pond are part of the same population.

Are the largemouth bass in these three ponds part of the same population?

Community All of the populations living within an ecosystem

6. Many resources in an ecosystem are limited and affect the size and health of a population in that ecosystem. a. The sun – All food energy comes from sunlight. This is the least limited resource in most ecosystems. All food energy on Earth comes from the sun.

How does the amount of sun affect the ecosystems in each of these examples?

b. Food – There is almost always a limited amount of food in an ecosystem. These wolves are defending food from other wolves. In the winter, there often isn’t enough food to feed everything

c. Space – There isn’t always enough space for all the organisms in an environment. Population changes result. There isn’t enough breeding space for all these seals, so there are fights over the available space.

d. Water - In some ecosystems, water is a limited resource. In other ecosystems, water is limitless. How limited is water in this ecosystem?

What about in this ecosystem?

e. Oxygen – Required by most life forms and usually unlimited, except in extreme environments. How much oxygen do you think is in this water?

f. Shelter – in most ecosystems, there is rarely enough shelter for all. How many raccoons can live in this one hollow log?

As parts of this rainforest are cut down, there is less shelter and the population of organisms drops.

7. Every organism has a specific niche – a role or position a species has in its environment. The traditional meaning of the word “niche.”

Ivory-billed woodpecker

Koalas occupy a niche. They can only eat eucalyptis leaves