Communities and Ecosystems
CHAPTER 37:
Communities and Ecosystems
Chapter Objectives
Opening Essay
Explain how hippos contribute to the ecological communities in which they live.
Community Structure and Dynamics
37.1Define a biological community. Explain why the study of community ecology isimportant.
37.2Define interspecific competition, mutualism, predation, herbivory, and parasitism, and provide examples of each.
37.3Define an ecological niche. Explain how interspecific competition can occur when the niches of two populations overlap.
37.4Describe the mutualistic relationship between corals and dinoflagellates.
37.5Define predation. Describe the protective strategies potential prey employ to avoidpredators.
37.6Explain why many plants have chemicals, spines, or thorns. Define coevolution and describe an example.
37.7Explain how parasites and pathogens can affect community composition.
37.8Identify and compare the trophic levels of terrestrial and aquatic food chains.
37.9Explain how food chains interconnect to form food webs.
37.10Describe the two components of species diversity. Explain why large fields of a single crop are vulnerable to devastating disease.
37.11Define a keystone species. Explain why the long-spined sea urchin is considered akeystone species.
37.12Explain how disturbances can benefit communities. Distinguish between primary and secondary succession.
37.13Explain how invasive species can affect communities.
Ecosystem Structure and Dynamics
37.14Compare the movement of energy and chemicals through ecosystems.
37.15Compare the primary production of tropical rain forests, coral reefs, and open ocean. Explain why the differences between them exist.
37.16–37.17Describe the movement of energy through a food chain. Explain why there are more producers than consumers and why eating meat counts as a great luxury.
37.18–37.21Explain how carbon, nitrogen, and phosphorus cycle within ecosystems.
37.22Describe the results of the long-term study of the HubbardBrookExperimentalForest. Explain why this ecosystem is particularly useful for this sort of experimentation.
37.23Define cultural eutrophication and explain its causes. Describe the experiment conducted by Dr. David Schindler that demonstrated the impact of phosphorus pollution in aquatic ecosystems.
Key Terms
abiotic reservoir
biogeochemical cycle
biological control
biomass
chemical cycling
coevolution
community
decomposer
decomposition
detritivore
detritus
disturbance
ecological niche
ecological succession
ecosystem
energy flow
food chain
food web
herbivory
interspecific interactions
interspecific competition
invasive species
keystone species
mutualism
nitrogen fixation
predation
primary consumer
primary production
primary succession
producer
quaternary consumer
secondary consumer
secondary succession
species diversity
tertiary consumer
Word Roots
a- 5 without; bio- 5 life (abiotic reservoir: a part of an ecosystem where a chemical, such as carbon or nitrogen, accumulates or is stockpiled outside of living organisms)
geo- 5 Earth (biogeochemical cycle: any of the various chemical circuits that involve both biotic and abiotic components of an ecosystem)
de- 5 from, down, out (decomposer: prokaryotes and fungi that secrete enzymes that digest organic material and break it down into inorganic forms)
detrit- 5 wear off (detritus: dead organic matter); -vora 5 eat (detritivore: an organism that consumes organic wastes and dead organisms)
herb- 5 grass; -vora 5 eat (herbivory: the consumption of plant material by an animal)
inter- 5 between (interspecific interactions: interactions between organisms of different species;interspecific competition: competition between individuals or populations of two or more species for a limited resource)
mutu- 5 reciprocal (mutualism: an interspecific relationship in which both partners benefit)
quatr- 5 four (quaternary consumer: an organism that eats tertiary consumers; the fourth step onthe food chain)
terti- 5 three (tertiary consumer: an organism that eats secondary consumers; the third step onthe food chain)
Student Media
Community Structure and Dynamics
Activity: Interspecific Interactions (37.2)
Activity: Food Webs (37.9)
Activity: Primary Succession (37.12)
Process of Science: How Are Impacts on Community Diversity Measured? (37.1)
Discovery Channel Video Clip: Leafcutter Ants (37.4)
Discovery Channel Video Clip: Rain Forests (37.9)
Video: Clownfish and Anemone (37.4)
Video: Cyanobacteria (37.4)
Video: Sea Horses (37.5)
Video: Shark Eating a Seal (37.8)
GraphIt!: Species Area Effect and Island Geography (37.10)
Ecosystem Structure and Dynamics
MP3 Tutor: Energy Flow in Ecosystems (37.16)
Activity: Energy Flow and Chemical Cycling (37.14)
Activity: Energy Pyramids (37.17)
Activity: The Carbon Cycle (37.19)
Activity: The Nitrogen Cycle (37.21)
Activity: Water Pollution from Nitrates (37.21)
Process of Science: How Do Temperature and Light Affect Primary Production? (37.15)
Discovery Channel Video Clip: Trees (37.14)
Discovery Channel Video Clip: Space Plants (37.19)
GraphIt!: Animal Food Production Efficiency and Food Policy (37.17)
BLAST Animation: Energy Flow (37.14)
BLAST Animation: Carbon Cycle (37.19)
BLAST Animation: Nitrogen Cycle (37.21)