Ecological disturbances change environmental conditions and can reshape ecosystems. This lesson introduces what disturbance means, how disturbances vary in scale and timing, and how both natural processes and human activities can cause them.
An ecological disturbance is a change in environmental conditions that causes a pronounced change in an ecosystem. It may rapidly alter the physical arrangement of living components (biotic elements) or nonliving components (abiotic elements), such as soil, water, and sunlight. Some disturbances act suddenly, while others develop over long periods and gradually affect biodiversity or species abundance.
All flashcards
What is an ecological disturbance?
An environmental change that causes a pronounced alteration in ecosystem conditions, structure, or community.
What is a pulse of recruitment?
An initial increase in establishment, such as seed germination or colonization, after disturbance.
What is ecological succession?
Change in species abundance and dominance as ecological conditions and interactions change over time.
What is a compound disturbance?
Multiple disturbances affecting the same place in quick succession, with combined effects that may differ from individual effects.
What are pioneer species?
Species that rapidly exploit newly available space and resources after disturbance.
Quiz questions
How can the spatial extent of a large burned area influence plant recovery?Answer: Seed dispersal and herbivory may be stronger near the edge than in the interior.
Which statement best describes ecological succession?Answer: Species abundance and dominance shift as conditions and interactions change over time.
What makes a windstorm followed quickly by a fire an example of compound disturbance?Answer: The combined effects may differ from those expected from either event alone.
How can serotinous cones benefit some pines in fire-prone forests?Answer: Heat opens the cones and releases seeds into newly opened habitat.
What can happen when fire is suppressed in ponderosa pine forests?Answer: Shade-tolerant Douglas fir may replace ponderosa pine and reduce light near the forest floor.