Name:
Date:
Block:
Ecosystems: What does it take to make one?
We have been studying and looking at different parts of Ecology. Today, we will begin
putting those parts of ecology together to build our own ecosystem, to investigate the
interactions between variables in a closed ecosystem, and to see what it takes to sustain
life in a closed environment. You will create this ecosystem inside a bottle, attach your
waste water filter to the top of it, and seal it off. First of all, let’s talk about what an
ecosystem is…
WORD
DEFINITION
EXAMPLE of 3 Biomes
Ecosystem
Your project that you will begin today is to build an ecosystem that will sustain life for 1
week. Before we do this, we need to think about what things are essential for life. USING
WHAT WE KNOW ABOUT FOOD WEBS AND CHAINS, THE BIOGEOCHEMICAL
CYCLES, AND PRODUCERS AND CONSUMERS, we will start brainstorming and putting
together an ecosystem of our own!
Answer the questions below with your group! People might have different ideas for
what the answers are, and that is fine! Put your own ideas down!
Intro questions
1. What are 3 things do you have around you that are ESSENTIAL for life? (Not
iPods, cell phones, or shoes… what do you need to live; things that you would die
without).
2. How do you get those things? In other words, where do the things that are
essential for life ORIGINATE FROM? (Think about where the oxygen you breathe
comes from… also think about what grocery store you go to…)
3. Looking at the background information for the Biogeochemical cycles, and
thinking about your understanding of how nutrients move through soil and water
(from the food systems unit), what does each cycle do to help life in an ecosystem?
DESCRIBE WHAT EACH CYCLE PROVIDES TO HELP SUSTAIN LIVING
THINGS!
a. Nitrogen Cycle-
b. Water Cycle-
c. Carbon Cycle-
d. Phosphorus Cycle-
Now for the fun part…
Your project: You and your group will build a closed ecosystem that will try to sustain life
for 1 week. By closed, I mean that we will make your ecosystem, then completely seal it
(make it airtight), and see whether life will be sustained for the entire time.
(Note: This is definitely possible, if you think carefully about the specific things that an
ecosystem needs to sustain life!)
Some restrictions and warnings:
1. The only organisms you can use are:
a. Plants
b. Insects and worms (by this I mean crickets, ants, snails, etc.). You can get
feeder insects at any pet shop…)
c. A goldfish (feeder fish at the petshop)
d. Ask me if you have more specific questions about the organisms you can
use.
2. You can use any ABIOTIC (nonliving) thing in your ecosystem. For example, rocks,
sand, etc.
3. You may only use things that you can fit in the top of a 2 liter soda bottle.
4. You must consider all the different factors of ecology that we have studied, before
you put the ecosystem together. You will do this below.
Brainstorming Your Ecosystem
Now, you get to brainstorm what you will put in your ecosystem. Use your work from the
Intro Questions Section, notes on your nutrient cycles, etc. to help you create an
ecosystem that will sustain life.
1. First of all, what kind of ecosystem do you want to put together (an aquatic marine,
aquatic freshwater, desert, rainforest…)?
2. What ABIOTIC THINGS will you include in your ecosystem (think about what the
ecosystem that you are building usually has…)?
3. What BIOTIC THINGS will your ecosystem contain – both plants and animals?
Remember that you can only use plants, a fish, and insects or invertebrates in your
ecosystem. We will have a limited supply of living things for groups to use; all other
living things are YOUR RESPONSIBILITY to find).
HOMEWORK!!!
Do the Guided Reading on Ecosystem: Concepts and Fundamentals (Botkin and
Keller, 2011).
4. Fill in the chart below for each organism that will be in your ecosystem.
Type of
organism
What will that
organism eat
(where will that
organism get
energy from)?
The Cycles in Your Ecosystem
What will eat that
organism? (Also,
think about what
happens when
the organism
dies…)
How will that organism
“Breathe” (get carbon dioxide
or oxygen…think about what
you can add to your
ecosystem, to make sure
that your organisms get what
they need)
By now, you should have an introductory understanding of the water, carbon, nitrogen, and
phosphorus cycles… Enough to think about how those cycles will move through your
ecosystem. Below, you will write out how you think these cycles will work in your system.
Use the BACKGROUND INFORMATION on the following pages to help you. ***IF YOU
THINK THAT THERE IS NO WAY FOR THOSE CYCLES TO HAPPEN IN YOUR
SYSTEM, YOU MIGHT WANT TO RETHINK HOW YOUR ECOSYSTEM IS SET UP!!!***
Draw out a diagram, with appropriate terms, on how carbon will move through YOUR
SPECIFIC SYSTEM (think about carbon dioxide, trophic levels and how nutrients return to
the soil…)
Draw out a diagram about how nitrogen will move THROUGH YOUR SPECIFIC SYSTEM
(think about Nitrogen in the air, the soil, and what uses nitrogen…)
Draw out a diagram about how water will move THROUGH YOUR SPECIFIC SYSTEM
(think about the sunlight that your ecosystem will get, and how it moves water…)
Draw out a diagram about how phosphorus can move through your system (think about
where phosphorus exists… NOTE: The phosphorus cycle happens VERY slowly, so you
probably won’t see significant phosphorus movement in your ecosystem.
BACKGROUND INFORMATION ON NUTRIENT CYCLES
(Also use your Food Systems Task 2 cross sectional Diagram)
Carbon Cycle
Carbon is an element found in nature. It's in the graphite that make up the "lead" of your pencil. It's found in
the shiniest diamonds and in the gasoline we use to run our cars. It's one of the most important elements
found on earth. Carbon is also found in all living organisms. In fact, living things are full of carbon!
During photosynthesis, plants combine carbon dioxide from the air and hydrogen
from water to make carbohydrates. Some of these carbohydrates are stored in the
tissues of the plant. Others are used by the plant for energy.
When that plant is eaten, the cells of the animal break down the plant's tissues during
digestion. This releases the stored carbon and other nutrients into the animal's system.
As the animal breathes out (exhales), carbon dioxide is released into the air (atmosphere) and the cycle can
begin again. This is known as respiration.
Respiration is not the only way carbon makes it into the air (atmosphere). Carbon and/or carbon dioxide is
also released when dead plants and animals are decomposed and when fossil fuels are burned.
The Nitrogen Cycle
Nitrogen is the most common gas found in the earth's atmosphere. It is necessary for plant growth. In fact,
it's necessary for the survival of all ecosystems!
Free nitrogen - the nitrogen found in the atmosphere (nitrogen gas),
animal wastes, and dead and decaying organisms - is all around.
However, only a few organisms can use it just as it is. These
organisms "fix" the nitrogen for all other organisms to use. They
are called nitrogen-fixing bacteria.
You might find it helpful to study the nitrogen cycle in two parts!
In the nitrogen fixation part of the cycle, nitrogen-fixing bacteria found in the soils
and in the roots of certain plants, change (or convert) free nitrogen into substances
that other organisms can use. When the fixing process is finished, free nitrogen is
converted into nitrates, nitrites, and ammonia. These substances can be used by
plants. As the plants become food, the nitrogen can be used by animals.
Just as there are nitrogen-fixing bacteria, some bacteria have the job of denitrifying
the soil to keep the nitrogen in balance. These bacteria take the nitrogen
compounds and return them to nitrogen gas that is released back into the
atmosphere.
The Water Cycle
Water, like other nutrients, cycles through nature. The cycle begins when the
energy from the sun causes water to evaporate.
Look closely at the word evaporate. You can see the word "vapor" sitting right in the
middle! During evaporation, water becomes water vapor and is returned to the
atmosphere.
Water in this part of the cycle comes from many places. Some of
these places include: oceans, ponds, lakes, streams, leaves
(needles) of plants, soil, glasses of water, and from your body as
you sweat (perspire).
Water vapor in the atmosphere begins to cool. As it does, it condenses and forms
droplets of water. When these droplets become to heavy and dense to remain in
the atmosphere, they fall to the earth. You know this as precipitation (like rain or
snow).
As precipitation falls, some of it evaporates immediately. Some of it soaks into the
ground. Water that does this is called groundwater. Not all of the precipitation can
soak into the soil. This excess water becomes what is called runoff. This is the
water that moves from land back into lakes, streams, ponds, and the ocean.
Groundwater is used by plants immediately. Roots gather the water needed for
photosynthesis. As the sun shines down and provides more energy, water begins
its return to the atmosphere.
Phosphorus Cycle
Phosphorus (P) is another one of the essential elements that cycle through the
ecosystem. It is an element that is found in the ground and then taken up by plants
and animals. Phosphorus starts its existence as phosphate ions (PO4) in the rocks
of the world. When it rains, the phosphates and other minerals are removed from
the rocks and distributed in soils and the water all over the planet.
Plants on land take in the inorganic (compounds without carbon) phosphorus
compounds from the soil. The phosphorus atoms are then incorporated into many
organic compounds that are used in cells. Animals can get their phosphorus by
eating plants or drinking water. Algae and water plants are able to absorb the ions
from the water.
When plants and animals die, the phosphates return to the soil. Phosphorus is
heavily used in the farming industry and fertilizers filled with phosphates are used
all over the world to help plants grow