Biology, Eighth Edition (Raven)

Chapter 57: Dynamics of Ecosystems

Learning Outcomes

• Understand the nature of an ecosystem.
• Discuss the five primary biogeochemical cycles, including the reservoirs and unique organisms upon which each cycle depends.
• Explain the difference in nutrient cycling and energy flowing through an ecosystem.
• Discuss the effects of deforestation on the water cycle, flood control, and overall fertility.
• Understand the relationship of one trophic level with another in terms of energy and biomass.
• Differentiate between gross and net productivity and explain how each is related to biomass.
• Compare the overall productivity of each of the major ecosystems to one another.
• Explain why algal beds and coral reefs have a larger NPP per unit area than do tropical rain forests.
• Identify the components of a general food chain. With the exception of deep ocean vents, explain why an autotroph is absolutely required to be in the first “trophic link” in a food chain.
• Explain what an ecological pyramid is and what different shapes indicate.
• Understand how trophic cascades and bottom-up effects influence populations at other trophic levels and how the two effects interact.
• Compare species richness and species diversity and the factors that promote each.
• Understand the importance of the equilibrium model in island biogeography.
• Be able to explain the graphs that are used to illustrate the island biogeography mode