Community and Ecosystems Cover Page

Community and Ecosystems

At the end of this unit, I will

  • LS 2-4: Use mathematical representations to support claims forthe cycling of matter and flow of energyamong organisms in an ecosystem.
  • LS 2-2: Use mathematical representations to support and revise explanations based on evidenceabout factors affecting biodiversity and populations in ecosystemsof different scales.
  • LS 2-7: Design, evaluate, and refine a solution forreducing theimpacts of human activitieson the environment and biodiversity.
  • LS 4-6: Create or revise a simulation to test a solution to mitigate adverseimpactsof human activity on biodiversity.
  • LS 2-6: Evaluate the claims, evidence, and reasoning thatthe complex interactions in ecosystems maintain relatively consistent numbers and types of organismsin stable conditions, but changing conditionsmay result in a new ecosystem.
  • ETS 1-1: Analyze a major global challengeto specify qualitative and quantitative criteria and constraints for solutions that accountfor societal needs and wants.
  • ETS 1-1: Analyze a major global challengeto specify qualitative and quantitative criteria and constraints for solutions that accountfor societal needs and wants.
  • ETS 1-2: Design a solution to a complex real-world problemby breaking it down into smaller, more manageable problems that can be solved through engineering.
  • ETS 1-3: Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offsthat account for a range of constraints, including cost, safety, reliability, and aestheticsas well as possible social, cultural, and environmental impacts.
  • ETS 1-4: Use a computer simulation to modelthe impact of proposed solutions to a complex real-world problem with numerous criteria and constraints oninteractions within and between systems relevant to the problem.

Roots, Prefixes and Suffixes I will be able to understand when I see them in words are:

  • Bio-, eco-, sym-, troph-, mutual-, commense-, succeed-, commune-
  • –ism, -system

The terms I can clearly define are:

  • Background extinction, Bioaccumulation, Biodiversity, Biomass, Commensalism, Community, Competition, Ecosystem, Extinction, Genetic diversity, Habitat, Introduced/Invasive species, Mass extinction, Mutualism, Niche, Over-exploitation, Parasitism, Predation, Primary succession, Secondary succession, Symbiotic relationship, Trophic levels

The assignments I will have completed by the end of this unit are:

Ecological pyramids virtual lab activity

Pyramid of biomass vs. pyramid of numbers

Energy in trophic levels

Deadly links game

What is bioaccumulation?

DDT in real life

Notes: Biodiversity

Notes: Ecological succession

Why conserve biodiversity?

Invasive species and biodiversity

Conserving biodiversity

Lab Activity: Vanishing Frogs

Chlorophyll in lakes

Carbon cycle review

Reforestation: impact on climate

Community & ecosystems unit concept map

Parent page

Community & ecosystems study guide

Notes: Community Interactions
(read pages 36-40 in your textbook)

What is a community? / A biological community is ______
______
What is an ecosystem? / An ecosystem is ______
______
What is the difference between a habitat and a niche? /
  • Habitat – ______
______
  • Ex. A tree or grove of trees
  • Niche - ______
______
  • How it meets its needs for food, shelter, and reproduction.

What are 3 ways communities can interact? /
  1. Competition
  2. Occurs when ______
______
  1. Predation
  2. The act of ______
______
  1. Symbiotic Relationships
  2. The close relationship ______
______
List and describe 3 types of symbiotic relationships. /
  • Mutualism:
______
______
  • Example:
  • Commensalism:
______
______
  • Example:
  • Parasitism:
______
______
  • Example:

Good Buddies

Organisms / Symbiotic Relationship
(parasitic, commensalistic, or mutualistic) / Brief Overview of Relationship:
Barnacle/Whale / Barnacles create home sites by attaching themselves to whales. As the barnacle is a filter feeder, it gets access to more water (and more food) due to the relationship. Whale is unaffected.
Cuckoo/Warbler / A cuckoo lays its eggs in the nest of the warbler. The cuckoo’s eggs hatch first and the young kick the warbler eggs out of the nest. The warbler raises the cuckoo babies and the warbler babies aren’t hatched.
Remora/Shark / Remoras attach themselves to a shark’s body. They travel with the shark and feed on the leftover food scraps after the shark has finished its meal. The shark is unaffected as it’s done eating anyway.
Ostrich/Gazelle / Ostriches and Gazelles feed next to each other. They both watch for predators. Because the visual abilities of the two species are different, they can each identify threats that the other animal may not see as readily. Both species benefit.
Mistletoe/Spruce / Mistletoe extracts water and nutrients from the spruce tree to the detriment (ill effect) to the spruce.
Silverfish/Army Ant / Silverfish live and hunt with army ants and share the prey. They neither help nor harm the ants.
Oxpecker/Rhinoceros / Oxpeckers (bird) feed on the ticks found on a rhinoceros. Both species benefit… the oxpecker gets food and the rhino gets rid of a parasite.
Mouse/Flea / A flea feeds on a mouse’s blood to the mouse’s detriment
Honey Guide Bird/Badger / Honey guide birds alert and direct badgers to beehives. The badgers then expose the hives and feed on the honey first. Next the honey guide birds eat. Both benefit
Cowbird/Bison / As bison walk through grass, insects become active and are seen and eaten by cowbirds. This relationship neither harms nor helps the Bison.
Human/Tapeworm / Tapeworms reside in human intestine and take nutrients from the human.
Yucca Plant/Yucca Moth / Yucca flowers are pollinated by Yucca moths. The moths lay their eggs in the flowers with the larvae hatch and eat some of the developing seeds. Both benefit.
Wrasse Fish/Black Sea Bass / Wrasse fish feed on the parasites found on the Black Sea Bass’s body (usually in the mouth). Dental floss for fish-both species benefit.
Clown Fish/Sea Anemone / Clown fish live among anemones acting as a lure for the sea anemone’s prey. The clown fish gets protection and shelter from the anemone.
Human/E. Coli / E. Coli is a bacterium that lives in the gut of humans. The human provides the ideal habitat for e coli reproduction and the e coli provides the extra Vitamin K that we use.
Ant/Aphid / Ants offer protection for the Aphids who (have no protective features of their own) would otherwise be food for all sorts of other organisms. The aphids “repay” the ants by providing honeydew (a liquid they secrete) for the ants to use as food.
Trees/Epiphytes / Epiphytes are a class of plants that grow in the crooks of tree branches. They simply use the tree branches as a way to get higher and closer to sunlight needed for photosynthesis. The tree’s aren’t affected by this relationship.
Deer/Tick / The tick feeds off the blood of the deer. The deer is negatively affected.
Maribou Stork/Bee / The stork uses its saw-like bill to cut up the dead animals it eats. As a result, the dead animal carcass is accessible to some bees for food and egg layers. The stork is neither harmed nor helped by this relationship.
Hermit Crab/Shell / Hermit crabs will more into an old abandoned shell when their shell is no longer big enough to contain them. As the shell is inanimate (not living) it is not affected by this relationship.

Intentionally Left Blank
for additional notes, activities, brain-storming

Predator[MA1]-Prey Simulation

Objective: To simulate predator prey interactions, the numbers of predator and prey in their “ecosystem” will be recorded and graphed.
Materials:

  1. 200 small squares cut from index cards (approximately 1 inch squared) -- The small squares represent the prey population (or hares)
  2. 50 large squares cut from index cards (cut index cards in half) -- The large squares represent the predator population (or mountain lion)
  3. Data table and blank graph to graph

Instructions: Create an ecosystem by taping a square that is 11” x 17” using blue painter’s tape or use 11” x 17” construction paper. (please clear all objects)

  1. On your data table generation 1, start by recording 1 predator and 3 prey.
  2. Drop 3 “prey” or hares on your grid. (randomly dispersed)
  3. Drop 1 “predator” or mountain lion onto the grid and attempt to make the card touch as many “prey” as possible. In order to survive, the predator must capture at least 3 prey. It will be impossible for your predator to survive at this point.
  4. Remove any “prey” captured or eaten. Remove any predator that did not eat at least 3 hares. (They starved). Record your data for the 1st generation, under the number of prey remaining and the number of predator remaining.
  5. The “prey” population doubles each generation. Count how many hares you have left on your table, double that number and add prey cards to the table, and disperse them evenly. Record the number in the data table under the 2nd generation “number of hares”. (It should be 2x the number you have under the “hares remaining” for generation 1)
  6. Your predator died during the first round, but that’s okay, a new predator moves in for the second round. If your predator died, put 1 in the “number of predators” for generation 2 to represent the new arrival. Repeat the dropping procedure and record your data for the second generation.
  7. Again, number of prey doubles, if your predator didn’t “capture” 3 prey, it died. But a new one moves in for the next round. Keep going, adding to the number of prey each round.
  8. Eventually your predator will be able to capture enough prey to survive. Guess what happens? The number of predators doubles. Add to your predator population by adding predator cards. Now when you drop your predators, you will be dropping more than one. Don’t forget to remove any “captured” prey. Don’t forget to remove predators that do not eat at least 3 prey. Don’t forget to make predators that survive reproduce and double in number.
  9. Continue to record the data through 20 generations.

Predator-Prey Data Table

Generations / Number of Mountain Lions (Predator) / Number of Hares (Prey) / Number of Mountain Lions (Predators) Remaining / Number of Hares (Prey) Remaining
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

Predator-Prey Graph: Construct a graph. On the X-axis, put generations 1 through 20, on the Y-axis you will have the population numbers for each generation (number of predators, number of prey). Use one line for the predator and one line for the prey to graph the data. Provide a legend!

Title: ______


Legend:
Analysis Questions

1. What is a carrying capacity?

2. Did the predator and prey reach carrying capacity in this simulation? If so, are the carrying capacities of the predatorand the prey population the same?

Explain.

3. What affects the carrying capacityof preypopulations?

4. What affects the carrying capacityof predatorpopulations?

5. What type of graph did you create? Explain.

6. Which population always increased first? ______Why?

7. Which population always decreased first? ______Why?

8. How long did a cycle of increase and decrease take for hares? ______

For mountain lions? _____

9. Which population was almost always in greaternumbers?

10. Which population was almost always in smallernumbers?

11. What effectsdid the rabbit population have on the mountain lion population?

12. What effectsdid the mountain lion population have on the rabbit population?

13. Keep in mind that as in any simulation, certain assumptions are made and many variables are overlooked. What other limiting factors could subject a natural population to pressure and disturbance? Name and explain at least four factors. Within your explanation, classify each factor as density dependent or density independent.

Ecological Pyramids

While the producers set an ecosystem's total energy budget, energy is "spent" at each step of the food web. As each consumer feeds, some energy is transferred from the lower trophic level to the higher trophic level. But most of the available energy stored in the prey organism's biomass leaves the system. For example, when a caterpillar eats a leaf, about 50 percent of the energy stored in the leaf passes out of the caterpillar's body in its wastes (feces). The caterpillar uses 35 percent of the leaf's stored energy to support its life processes, such as moving and reproducing. The caterpillar transforms only about 15 percent of the leaf's stored energy into new caterpillar biomass.

To depict information about energy, biomass, and numbers of organisms at different trophic levels, ecologists use three types of diagrams: energy pyramids, biomass pyramids, and pyramids of numbers. In each case, the foundation of the pyramid is the producer level. The primary consumers form the next block, and so on.

Energy Pyramids:Anenergy pyramid, sometimes called a food pyramid, emphasizes the energy loss from one trophic level to the next. In general, an average of only 10 percent of the available energy at a trophic level is converted to biomass in the next higher trophic level. The rest of the energy—about 90 percent—is released from the ecosystem as heat.

Notice that the amount of energy available to the top-level consumer is tiny compared to that available to primary consumers. For this reason, it takes a lot of vegetation to support higher trophic levels. This explains why most food chains are limited to three or four levels; there is simply not enough energy at the top of an energy pyramid to support another trophic level. For instance, lions and killer whales have no natural predators; the energy stored in populations of these top-level consumers is not enough to feed yet another trophic level.

Biomass Pyramids:Abiomass pyramidrepresents the actual biomass (dry mass of all organisms) in each trophic level in an ecosystem. Most biomass pyramids narrow sharply from the producer level at the base to the top-level consumers at the peak (Figure 36-8). There are some exceptions, however. In certain aquatic ecosystems, the zooplankton (primary consumers) consume the phytoplankton (producers) extremely rapidly. As a result, the zooplankton have a greater mass at any given time than the phytoplankton. The phytoplankton grow and reproduce at such a rapid rate that they can support a consumer population that has a greater biomass. A biomass pyramid for this ecosystem would appear top-heavy.

Figure 36-8
Biomass pyramids and pyramids of numbers are two other ways of modeling information about an ecosystem. A biomass pyramid (left) represents the dry mass of all organisms at each trophic level in an ecosystem. A pyramid of numbers (right) depicts the number of organisms at each trophic level.

Pyramids of Numbers:Apyramid of numbersdepicts the number of individual organisms in each trophic level of an ecosystem. These pyramids are also organized like energy pyramids, with producers found at the foundation and higher trophic levels on each step above them. In most cases, the foundation is again the widest section, indicating that there are more individual producers than there are primary consumers, and so on (Figure 36-8). This pyramid emphasizes how few top-level consumers an ecosystem can support. Exceptions to the usual shape of a number pyramid occur when small organisms eat larger ones. For example, a single tree (producer) may be the sole food source for hundreds of insects (primary consumers).

Notes: Ecological Pyramids

(read pages 42-44 in your textbook)

What is an ecological pyramid? / An ecological pyramid is ______
______
How is energy passed on in an ecological pyramid? / ______of all energy is not transferred to the level above it.
This energy gets:
  • Consumed by ______
  • Or released ______

What is biomass? / Biomass is ______
______

Ecological Pyramids Virtual Lab Activity

Directions: Place the organisms in the correct trophic levels to complete the pyramids for 3 different ecosystems. After you have correctly placed all the organisms fill in the data in the tables below for the pyramids of numbers and energy.

Data for Pyramid of Energy

Ecosystem / Primary Producers
(amount of energy) / 1st Order Heterotrophs
(amount of energy) / 2nd Order Heterotrophs
(amount of energy) / 3rd Order Heterotrophs
(amount of energy)
Deciduous Forest
Hot Desert
Grassland
Antarctic Ocean Shore
Freshwater Lake

Now you can ask yourself, “how well does the energy transfer from one trophic level to the next?” What you want to know is how much energy is left over from one trophic level to the next. To do this you will complete a “conversion efficiency” between each tropic level. You divide the energy at the higher energy level by the energy at the lower trophic level. This gives you a ratio that you can use for comparison.Write your answer as a decimal. Complete this for all three of your ecosystems.

EXAMPLE

1st Order Heterotrophs (amount of energy)= 744 units of energy = 0.992
Primary Producers (amount of energy) 7,500 units of energy

Ecosystem / 1st Order Heterotrophs
(amount of energy)

Primary Producers (amount of energy) / 2nd Order Heterotrophs
(amount of energy)

1st Order Heterotrophs
(amount of energy) / 3rd Order Heterotrophs
(amount of energy)

2nd Order Heterotrophs
(amount of energy)
1.
2.
3.

Ecological Pyramids Virtual Lab Activity