Page 640 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

19
concepts
key learning
Ecosystem Essentials
After reading the chapter, you should be able to:
• Define ecology, biogeography, and ecosystem.
• Explain photosynthesis and respiration, and describe the world pattern of net
primary productivity.
• Discuss the oxygen, carbon, and nitrogen cycles, and explain trophic relationships.
• Describe communities and ecological niches, and list several limiting factors on species distributions.
• Outline the stages of ecological succession in both terrestrial and aquatic ecosystems.
• Explain how biological evolution led to the biodiversity of life on earth.
The atlantic Forest of Brazil consists of highly vulnerable tropical ecosystems that rival the amazon rain forest in biodiversity. extending along the coastal region through the most populous part of Brazil and into portions of Paraguay and argentina, the atlantic Forest is disappearing. Current estimates place this forest at 7% of its size when europeans arrived in the 1500s. The remaining area is fragmented, with many species critically endangered by the effects of logging, agriculture, industry, and devel- opment. Protected areas, including Serra dos Órgäos national Park pictured here, are helping to preserve species diversity. This chapter discusses the essential processes of functioning ecosystems, including impacts on biodiversity from human activities and human-caused climate change. [kevin Schafer/Corbis.]