Biodiversity is threatened when human activities place pressure on species and the ecosystems they depend on. This lesson introduces the major threats and explores why habitat loss is especially damaging.
The central underlying pressure on biodiversity is the combination of human population growth and the resources people use. People need food, materials, water, and energy, but these resources are often removed or used faster than ecosystems can replace them.
All flashcards
Habitat loss
Destruction or alteration of the places and ecological conditions a species needs to live.
Overharvesting
Removing organisms from a population faster than the population can recover.
Tragedy of the commons
A situation in which individual incentives can lead to overuse of a shared resource.
Invasive species
An introduced species that establishes itself and threatens native species or ecosystems.
Timing mismatch
A disruption that occurs when seasonal resource availability no longer aligns with an organism’s life-cycle timing.
Quiz questions
Why can shared access to a fishery encourage overharvesting?Answer: Fishers may benefit from catching more now while the costs of declining populations are shared.
What does the collapse of a fishery mean about the fish species?Answer: The fishery can be depleted even if some individuals of the species remain alive.
What distinguishes an invasive species from an exotic species?Answer: An invasive species establishes itself and threatens native species or ecosystems.
How did zebra mussels reach the Great Lakes from Europe?Answer: They were transported in ships’ ballast water and discharged at their destination.
What contributes directly to sea-level rise as the climate warms?Answer: Melting glaciers and the expansion of warmer ocean water.
Based on Concepts of Biology by Samantha Fowler, Rebecca Roush, James Wise (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.