1. Communities &Ecosystems

2. Community Define: _______________________________
___________________________________
Population- group of organisms
of the same species
Habitat- place, location, defined
by its abiotic and
biotic features.

3. Ecosystem
Ecosystems are dynamic interactions between plants, animals, and microorganisms and their environment working together as a functional unit.
The water, water temperature, plants, animals, air, light and soil all work together.
Examples of Ecosystems: _______________________
______________________________________________

4. A community includes all the organisms inhabiting a particular area
Community Ecology is concerned with factors that
influence species composition and distribution of communities and
affect community stability.
Student Misconceptions and Concerns
For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
Teaching Tips
1. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights.
2. In human society, a community might be roughly equivalent to a local population, perhaps all the people living in a town or city. The definition of a biological community is more inclusive, comprising all of the populations of organisms living close enough together for potential interaction. 4

5. Interspecific interactions are fundamental to community structure
3 types of Symbiosis: 1. 2. 3.
Predation
Herbivory
Student Misconceptions and Concerns
For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
Teaching Tips
1. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights.
2. Examples of interspecific competition are as close as the nearest lawn. Although students may be more likely to think of animal examples, the various grasses and weeds in a lawn reveal different strategies in their competition for sunlight, moisture, and soil.
3. If your class includes students with business interests, they may enjoy the following analogy. To better understand competition, students might think about fast-food restaurants in your region. Challenge your students to identify the strategies employed by these restaurants to compete with each other. As each restaurant makes changes, does the other restaurant respond? Restaurants changing strategies in response to each other is analogous to coevolution. 5
© 2012 Pearson Education, Inc.

6. Types of Symbiosis

7. Mutualism benefits both partners
Reef-building corals and photosynthetic dinoflagellates illustrate the win/win nature of mutualism. Photosynthetic dinoflagellates
gain shelter in the cells of each coral polyp,
produce sugars used by the polyps, and
provide at least half of the energy used by the coral animals.
Student Misconceptions and Concerns
For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
Teaching Tips
1. Students who are business-oriented may also enjoy this analogy. Many corporate leaders describe the best business deals as mutualistic, fostering a win-win relationship. For example, perhaps a new company creates a marketable product from another company’s wastes.
2. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. 7
© 2012 Pearson Education, Inc.

8. Competition may occur when a shared resource is limited
An ecological niche is the sum of an organism’s use of the biotic and abiotic resources in its environment.
Interspecific competition occurs when the niches of two populations overlap.
Competition lowers the carrying capacity of competing populations because the resources used by one population are not available to the other population.
Student Misconceptions and Concerns
1. For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
2. The concept of an ecological niche can be confusing. Ecologist Eugene Odum has suggested that an ecological niche is like an organism’s habitat (address) and its occupation combined.
Teaching Tips
1. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights.
2. If your class includes students with business interests, they may enjoy the following analogy. To better understand competition, students might think about fast-food restaurants in your region. Challenge your students to identify the strategies employed by these restaurants to compete with each other. As each restaurant makes changes, does the other restaurant respond? Restaurants changing strategies in response to each other is analogous to coevolution. 8

9. Competition between members of the different species can result in:
Extinction (competitive exclusion- G.F. Gause experiment)
Subdividing an essential resource (Resource Partitioning)
MacArthur's Warblers

10. Theoretical Niche = Fundamental Niche Actual Niche = Realized Niche
Competition may lead to an altered niche.
Theoretical Niche = Fundamental Niche
Actual Niche = Realized Niche

11. Effect of competition: COMPETITIVE EXCLUSION
Species competing for the same, limited resources will result in one being
more successful & ultimately eliminating the other
Paramecium caudatum
both sp. grown together
Paramecium aurelia

12. Effect of competition: RESOURCE PARTITIONING
Competitors use resources in different ways or at different
times to minimize competition & allow for coexistence
Ex: competition for soil nutrients= roots different lengths!
Bristly
foxtail
Indian
mallow
Smartweed

13. Predation benefits the predator but kills the prey.
Predation, another form of community interaction, leads to adaptations in prey species
Predation benefits the predator but kills the prey.
Prey adapt using protective strategies that include
____________________
Student Misconceptions and Concerns
For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
Teaching Tips
1. Rattlesnakes are a good example of a highly specialized predator. Since they are unable to move fast enough to catch their prey, rattlesnakes typically ambush them, a process facilitated by their camouflaged bodies. Rattlesnakes often feed during the cooler parts of the day, using heat-detecting facial pits to identify prey before injecting them with fast-acting venom. The prey is immediately released (perhaps to avoid damage to the snake from struggling prey), but is disabled by the venom within seconds. The rattlesnake then uses a variety of senses to track the prey the short distance to where it has collapsed.
2. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. 13

14. PREY DEFENSES Camouflage Warning Disruptive Chemicals
cryptic coloration
Warning
Aposematic coloration
Disruptive
Chemicals
Secondary Compounds

15. adaptations that overcome prey defenses
PREDATOR RESPONSES
adaptations that overcome prey defenses
Examples- behaviors, stealth, camouflage…
poison-spraying tail

16. Types of mimicry PREY DEFENSES (con’t) Batesian Mimicry
Muellerian Mimicry
Stinging bee
Stinging wasp
Stinging fly

17. Herbivory leads to diverse adaptations in plants
Herbivores and plants undergo coevolution,
a series of reciprocal evolutionary adaptations in two species,
in which change in one species acts as a new selective force on another.
Student Misconceptions and Concerns
For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
Teaching Tips
1. If your class includes students with business interests, they may enjoy the following analogy. To better understand competition, students might think about fast-food restaurants in your region. Challenge your students to identify the strategies employed by these restaurants to compete with each other. As each restaurant makes changes, does the other restaurant respond? Restaurants changing strategies in response to each other is analogous to coevolution.
2. Coevolution is illustrated by organisms that exhibit reciprocal evolutionary adaptations. Challenge students to explain how rewarding a pollinator with nectar has benefited some plants. Why would plants that have adaptations for only certain pollinators have an advantage? In many cases, pollinators that are restricted to certain species are more likely to transport pollen between members of that species instead of wasting pollen by taking it to other species.
3. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. 17
© 2012 Pearson Education, Inc.

18. Coevolution: the evolutionary arms race
Coevolution is the mutual evolutionary influence between two species (the evolution of two species is dependent on each other). Each of the species involved exerts selective pressure on the other.
Moth collects pollen
Flies to another flower
Pierces the ovary
Lays eggs inside ovary
Pollinates that flower
Seeds develop
Moth eggs hatch
Larvae eat a few seeds
BOTH ORGANISMS REPRODUCE!

19. EVOLUTION CONNECTION: Herbivory leads to diverse adaptations in plants
A plant whose body parts have been eaten by an animal must expend energy to replace the loss.
Thus, numerous defenses against herbivores have evolved in plants.
Plant defenses against herbivores include
spines and thorns and
chemical toxins.
Student Misconceptions and Concerns
For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
Teaching Tips
1. If your class includes students with business interests, they may enjoy the following analogy. To better understand competition, students might think about fast-food restaurants in your region. Challenge your students to identify the strategies employed by these restaurants to compete with each other. As each restaurant makes changes, does the other restaurant respond? Restaurants changing strategies in response to each other is analogous to coevolution.
2. Coevolution is illustrated by organisms that exhibit reciprocal evolutionary adaptations. Challenge students to explain how rewarding a pollinator with nectar has benefited some plants. Why would plants that have adaptations for only certain pollinators have an advantage? In many cases, pollinators that are restricted to certain species are more likely to transport pollen between members of that species instead of wasting pollen by taking it to other species.
3. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. 19

20. “Prey”/Plant Defenses
Poison ivy
hemlock

21. Parasites and pathogens can affect community composition
A parasite lives on or in a host from which it obtains nourishment.
Internal parasites include nematodes and tapeworms.
External parasites include mosquitoes, ticks, and aphids.
Pathogens are disease-causing microscopic parasites that include
bacteria,
viruses,
fungi, or
protists.
Student Misconceptions and Concerns
For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
Teaching Tips
1. Pathogens are probably what most people refer to as germs. Students might believe that this general term refers to some specific type of organism.
2. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. 21

23. Non-native pathogens can have rapid & dramatic impacts.
Non-native pathogens can have rapid & dramatic impacts.
The American chestnut was wiped out by a protist (early 1900’s).
A fungus-like pathogen is currently causing sudden oak death on the West Coast.
Emerald ash borer is currently
threatens to kill billions of ash trees in North America
Non-native pathogens can cause a decline of the ecosystem.
Student Misconceptions and Concerns
For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
Teaching Tips
1. Pathogens are probably what most people refer to as germs. Students might believe that this general term refers to some specific type of organism.
2. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. 23

24. Species diversity includes relative abundance and species richness
Species diversity is defined by two components:
Species richness, the number of species in a community, and
Relative abundance, the proportional representation of a species in a community.
Student Misconceptions and Concerns
For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
Teaching Tips
1. Diversity within a species has some of the same advantages as diversity within a community. In both situations, diversity limits the damage from a pathogen or predator specialized to attack one variation within a species or one species in a community.
2. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. 24

25. Species diversity has consequences for pathogens.
Plant species diversity in a community affects the species diversity of animals.
Species diversity has consequences for pathogens.
Low species diversity is characteristic of most modern agricultural ecosystems.
Student Misconceptions and Concerns
For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
Teaching Tips
1. Diversity within a species has some of the same advantages as diversity within a community. In both situations, diversity limits the damage from a pathogen or predator specialized to attack one variation within a species or one species in a community.
2. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. 25

26. Table 37.10 Relative Abundance of Tree Species in Woodlots A and B26

27. Woodlot A Figure 37.10A Figure 37.10A Species composition of woodlot A27

28. Keystone species have a disproportionate impact on diversity
A keystone species
is a species whose impact on its community is larger than its biomass or abundance indicates and
occupies a niche that holds the rest of its community in place.
Examples of keystone species in marine ecosystems include
Pisaster sea stars and
long-spined sea urchins.
Student Misconceptions and Concerns
For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
Teaching Tips
1. Many keystone species have been identified in ecosystems, including sea otters, elephants, freshwater bass, and Pisaster, a sea star noted in Figure 37.11B. Challenge your class to explain how the concept of keystone species impacts the efforts of conservation biologists. Why might some species be more important to conserve?
2. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. 28
© 2012 Pearson Education, Inc.

29. A species with a very strong or far-reaching impact
KEYSTONE SPECIES
A species with a very strong or far-reaching impact
on a community
Important to food web
Alters the environment- provide
benefit to other organisms

30. Disturbance is a prominent feature of most communities
Disturbances
are events that damage biological communities and
include storms, fires, floods, droughts, overgrazing, or human activity.
The types, frequency, and severity of disturbances vary from community to community.
Student Misconceptions and Concerns
1. For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
2. The idea that ecosystems are relatively stable is common. Natural disturbances of any sort (fires, earthquakes, floods, or strong storms) are typically viewed as tragic and damaging to ecosystems. Before beginning the topic of ecological disturbances, consider asking your students to briefly respond to news that a state or federal park has (a) been burned, (b) been struck by high winds and/or lightning, or (c) been temporarily flooded. In addition, consider asking what, if anything, should be done to prevent or repair this damage?
Teaching Tips
1. Before and after images of the impact and recovery of an ecosystem from a natural disaster can be more powerful than any verbal explanation of the process. Consider locating before and after images of ecosystems damaged by hurricanes, fire, or the 1980 eruption of Mt. St. Helens, to show recovery.
2. Depending upon your location and its circumstances, consider a short field trip on or near your campus to show disturbed regions and signs of recovery.
3. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. 30
© 2012 Pearson Education, Inc.

31. pioneer species colonize new areas
Primary SUCCESSION
pioneer species colonize new areas
Opportunistic: high dispersal rate, grow & mature quickly, produce many offspring
Tolerant
Build and improve soil
Ex: moss, lichens, grasses

32. Figure 37.12A Primary succession on a lava flow32

33. Secondary SUCCESSION A disturbed area recovers
Abandoned farming fields, forest fire, volcanic eruption,…
Characteristics of soil control rate of recovery

34. Annual plants Perennial plants and grasses Shrubs Softwood trees
Figure 37.12B
Figure 37.12B Stages in the secondary succession of an abandoned farm field
Annual
plants
Perennial
plants and
grasses
Shrubs
Softwood trees
such as pines
Hardwood
trees
Time 34

35. Invasive species can devastate communities
Invasive species
are organisms that have been introduced into non-native habitats by human actions and
have established themselves at the expense of native communities.
The absence of natural enemies often allows rapid population growth of invasive species.
Examples of invasive species include the deliberate introduction of
rabbits into Australia and
cane toads into Australia.
Student Misconceptions and Concerns
For many students, understanding ecosystems is like appreciating art. Although both are visible to the naked eye, some background is required to understand the method of composition, the significance of components, and the nature of interactions. The fundamentals introduced in this chapter are new ways to see generally familiar systems.
Teaching Tips
1. The United States Department of Agriculture sponsors the National Invasive Species Information Center, which maintains a website at
2. Students who are interested in wildlife may collect an animal to keep as a pet, or to admire for a few days. This might be a good time to remind them that if they hope to return a wild animal to its natural environment, they should do so quickly and return it to within a few feet of the spot of its collection. Reintroducing an organism to a nearby environment may spread disease and potentially extend the organism’s natural range. Further, the introduction of commercial specimens from fish tanks, such as the marine algae Caulerpa dumped into the ocean, has had devastating consequences. The following web site addresses this example
3. The accidental introduction of the Brown Tree Snake into Guam during World War II has had a devastating impact on the ecology and economy of Guam. Extensive details can be found at
4. Many students have been exposed to diverse ecosystems only through television and movies, which have likely focused on a few species. Before discussing this chapter, consider showing the class a good video (it need not be long) about an ecosystem. The video can then serve as a shared recent experience to which you can relate the content of this chapter. Alternately, you can relate some of the basics of this chapter to a local or regional example with which most students are familiar. There may even be a distinct community on your campus, such as a pond, wooded area, etc., that students could visit and return from with new insights. 35
© 2012 Pearson Education, Inc.

36. Invasive Species in Australia
Rabbits introduced as a game species.
No predators
Prolific breeders
Destroyed farm and grazing land
Cane toad introduced for biological control of beetles in sugar cane fields
Skin toxic to other animals
Did not eat the beetles

37. Invasive Species in VA Kudzu Introduced accidentally
from Exposition in 1876
Grows rapid,
overgrows other plants
Hydrilla
released in the 1960s from
aquariums into waterways
in Florida
Clogs boating channels

38. You should now be able to
Define a biological community. Explain why the study of community ecology is important.
Define interspecific competition, mutualism, predation, herbivory, and parasitism, and provide examples of each.
Define an ecological niche. Explain how interspecific competition can occur when the niches of two populations overlap.
Describe the mutualistic relationship between corals and dinoflagellates.
Define predation. Describe the protective strategies potential prey employ to avoid predators. 38
© 2012 Pearson Education, Inc.

39. You should now be able to
Explain why many plants have chemical toxins, spines, or thorns. Define coevolution and describe an example.
Explain how parasites and pathogens can affect community composition.
Describe the two components of species diversity.
Define a keystone species.
Explain how disturbances can benefit communities. Distinguish between primary and secondary succession.
Explain how invasive species can affect communities 39
© 2012 Pearson Education, Inc.