Chapter 10: Community and Ecosystem Ecology

By the end of this chapter, you will be able to:

• Describe key interspecific interactions within biological communities (e.g., competition, predation, herbivory, parasitism, mutualism, and commensalism) and explain how they impact the survival and reproduction of species.
• Analyze the role of coevolution in shaping species traits and behaviours, providing examples of how evolutionary pressures from interactions such as predation and mutualism drive adaptive changes.
• Interpret the structure of trophic levels and food webs in an ecosystem, including the roles of producers, consumers (primary to quaternary), detritivores, and decomposers in the flow of energy and cycling of matter.
• Explain the concepts of energy flow and ecological pyramids, including how energy is transferred through trophic levels and why energy availability limits food chain length and top predator populations.
• Illustrate the processes and significance of biogeochemical cycles (water, carbon, nitrogen, and phosphorus), identifying the main reservoirs, pathways, and human impacts on each cycle.
• Evaluate the ecological consequences of human activities such as deforestation, fossil fuel combustion, agriculture, and fertilizer use on biodiversity, nutrient cycling, and ecosystem stability.