An Organism Interacts with Both the Living and Nonliving Things in Its Environment. The

Ecosystems

All the living and nonliving things that interact in a particular area make up an ecosystem. Organisms live in a specific place within an ecosystem. Examples of ecosystems are mountain streams, deep oceans, dense forests, and deserts. The place where an organism lives and that provides the things that it needs is called its habitat. An organism obtains food, water, shelter, and other things it needs to live, grow, and reproduce from its habitat. A single ecosystem may contain many habitats. For example, mushrooms grow in the damp soil, while termites live under tree trunks, and birds make nests in tree branches. Organisms live in different habitats because they have different requirements for survival. You wouldn’t see a penguin in the desert because it does not meet its needs.

An organism interacts with both the living and nonliving things in its environment. The living parts of an ecosystem are called biotic factors. These include grass, plants, worms, fungi, bacteria, and animals. The nonliving parts of an ecosystem are called abiotic factors. Abiotic factors include water, sunlight, oxygen, temperature, and soil. Remember, all living things require water, not just to carry out their life processes, like digestion, but also for producers to make food in the process of photosynthesis. These autotrophs provide the energy for many of the other organisms in same ecosystem.

A species is a group of organisms that are physically similar and can reproduce with each other to produce fertile offspring. All the members of one species in a particular area are referred to as a population. i.e. all the pigeons that live in New York City. But not all the trees in NYC are a population because they are not all the same species. There are pines and maples, and birches, and others.

All the different populations that live together in an area make up a community. To be a community, they have to interact, meaning they have to use the same resources. For example, foxes, snakes, and owls can be in the same community because they use the same forest to hunt the same kind of prey.

The smallest unit of organization is a single organism or individual, which belongs to a population of other members of its species. The population belongs to a community of different species. The community and abiotic factors together form an ecosystem. Ecosystems that are similar across the world are called biomes. Biomes make up the biosphere, which consists of all the living organisms on land, in the air, and in the water

The study of how living things interact with each other and with their environment is called ecology. Ecologists, scientists who study ecology, look at how all the biotic and abiotic factors in an ecosystem are related. They study how organisms react to changes in their environment. Living things constantly interact with their surroundings, responding to changes in the conditions around them. A picture of this is when a prairie dog sees a hawk overhead and gives a warning bark. The other prairie dogs hear the bark and respond by hiding in their burrows. Or when the temperature changes, animals migrate thus changing the food supply.

Draw your own picture and write a caption about something

that you learned in this reading.

Write your caption in the box below.

Name______Ecosystems

What is an ecosystem? ______
Give some examples of an ecosystem. ______
Within an ecosystem, the specific place that a particular organism lives is called its ______.
True or False? Habitats contain most of what an organism needs to survive.
An ecosystem contains ______and ______factors.
List some examples of biotic factors. ______
List some examples of abiotic factors. ______
What is the basic difference between abiotic and biotic factors? ______

______.

What kind of factor is water? ______Besides being used for body processes, why is it such an important factor for an ecosystem?

______

10. A group of organisms that are physically similar and reproduce with each other to produce fertile offspring is called a ______.

11. All the members of a species in a particular area are called a(n)______.

12. True or False? All the trees in the Rockies belong to the same population since they are all in the

same area.

13. Different populations sharing the same resources in an ecosystem are called a(n) ______.

14. The smallest unit of organization is a single ______or ______.

15. Similar ecosystems across the world, such as the tundra, or rain forests, are called ______.

16. All living things in the air, on or under the land, and in water, make up the ______.

17. The study of how living things interact with each other and their environment is called ______.

Review: Did you get it??????

1. Complete the diagram above to show the levels of organization in an ecosystem. Start with the smallest unit.

2.a. Choose one of the ecosystems listed and name three populations commonly found in it.

a forest, a desert, the jungle, or a coral reef

______

b. Name four abiotic factors in the ecosystem you chose above.

______

c. Identify two different habitats in the ecosystem you chose. Name one organism found in each habitat.

______

Cycles of Matter

We bring our paper, plastic, glass, and metal to be recycled in order to conserve the resources we have. Recycling of resources must also happen for the ecosystem to survive and not run out of what it needs. The matter (resources) recycled in ecosystems includes water, oxygen, carbon, nitrogen, and many other substances. Three of the most important cycles of matter are the water cycle, the carbon-oxygen cycle, and the nitrogen cycle.

The hydrologic cycle, or water cycle, is the continuous process by which water moves from Earth’s surface to the atmosphere and back. The processes of evaporation, condensation, and precipitation make up the water cycle. Evaporation is the process by which molecules of liquid water absorb energy and change to the gas state. Some of this water evaporates from plants in the process of transpiration. Most of the water evaporates from the ocean, but it also comes from rivers, lakes, and streams on land. Once it evaporates from Earth’s surface in the form of a water vapor, a gas, it goes up into the atmosphere. When water vapor in the atmosphere cools,it turns back into tiny droplets of liquid water. The process by which a gas changes to a liquid is called condensation. As more water vapor condenses, the drops grow larger and heavier. Eventually, the heavy drops fall back to Earth as a form of precipitation—rain, snow, sleet, or hail. Then the water is recycled again and again.

The next important cycle in an ecosystem is the carbon cycle. Carbon is the building block for the matter that makes up the bodies of living things. Producers take in carbon dioxide from the atmosphere during photosynthesis. In this process, the producers use carbon from the carbon dioxide to produce other carbon-containing molecules. These molecules include sugars (C6H12O6) and starches. Consumers obtain energy from these molecules by breaking them down into simpler molecules through the process of cellular respiration.

The consumers release water and carbon dioxide as waste products of the process. At the same time, producers release oxygen during photosynthesis. Other organisms, like us, take in oxygen from the atmosphere and use it in their life processes. Carbon is also returned to the environment when burning fossil fuels. What problem may be caused by the burning of these fuels? ______

Write the chemical equations for photosynthesis and cellular respiration.

Draw lines from the products of one equation that become reactants of the other equation.

______6CO2 + 6H20 ______C6H12O6 + 6O2______

______C6H12O6 + 6O2______6CO2 + 6H20______

Like carbon, nitrogen is a necessary building block in the matter that makes up living things. Even though the air contains mostly nitrogen, (78%), most organisms cannot use nitrogen gas (N2) in the air. Nitrogen gas is called “free” nitrogen because it is not combined with other kinds of atoms. Most organisms can use nitrogen only when it has been “fixed”: or combined with other elements to form nitrogen- containing compounds. The process of changing nitrogen gas into a usable form of nitrogen is called nitrogen fixation. Lightning can break the bonds of N2 to make it useable. But most nitrogen fixation is performed by certain kinds of bacteria. Some of these bacteria live in lumps called nodules on the roots of certain plants. Once the producers have their nitrogen fixed, it can be used by consumers to build proteins and other complex substances. Consumers return the nitrogen in their wastes and when they die. Decomposers break down complex nitrogen compounds in these wastes and dead organisms to form ammonium ions (NH3). Nitrifying bacteria will change it to nitrites and nitrates that can be used again by plants (nitrification). Denitrifying bacteria, however, break down the nitrogen compounds completely into N2(denitrification). This becomes free nitrogen that is released back into the air, and the cycle starts again.

Name______Cycles of Matter Date______

1. What are three important cycles of matter that an ecosystem must have to survive? the ______, the ______, and the ______.

2. Another name for the water cycle is the ______cycle.

3. Identify each process labeled in the diagram of the water cycle.

a.______b.______

c.______d.______

e. ______

4. What is the source of energy for the process of evaporation? ______

5. What chemical can be found in the bodies of all living things? ______

6. How do producers use carbon dioxide? (Name the process)______

7. How does the carbon cycle help give energy to the organisms in the ecosystem? DO NOT OMIT!!!

______

8. How is oxygen returned to the atmosphere? ______

9. By what process do organisms return carbon dioxide to the ecosystem? ______

10. Another building block in matter that makes up living things is ______.

11. How much of our air is nitrogen? ______. What kind is it? ______

12. What is the problem with “free” nitrogen? ______

13. True or False? Lightning can “fix” N2. (Circle your answer.)

13. What process makes nitrogen usable? ______

14.a. What organism is responsible for “fixed” nitrogen?______

b. Where can it be found? ______c. What happens to it next? ______

______