Lesson 2: Stability and change Flashcards
What is ecosystem stability?
A: The ability of an ecosystem to maintain its structure and function over time despite disturbances.
What factors affect ecosystem stability?
supply of energy
recycling of nutrients
genetic diversity
climatic variables remaining within tolerance levels.
What is a tipping point in ecosystems?
A critical threshold where a small change causes a large, often irreversible shift in the ecosystem.
example of tipping point
Deforestation in the Amazon reduces rainfall, leading to desertification.
example of keystone species
Sea otters control sea urchin populations, protecting kelp forests.
How can resource harvesting from natural ecosystems be made sustainable?
By setting quotas, protecting biodiversity, and using methods that minimize environmental damage, such as selective logging or sustainable fishing practices.
What factors affect the sustainability of agriculture?
Soil health, water availability, pest control, crop diversity, and the use of sustainable practices like crop rotation and organic farming.
What is eutrophication, and how does it affect ecosystems?
Excess nutrients (e.g., from fertilizers) cause algal blooms, which deplete oxygen in water, leading to dead zones and loss of aquatic life.
What is biomagnification of pollutants?
The increase in concentration of toxins (e.g., mercury or DDT) as they move up the food chain, affecting top predators the most.
What are the effects of microplastic and macroplastic pollution in oceans?
A: Microplastics harm marine life by entering the food chain, while macroplastics entangle animals and disrupt habitats.
What happens during primary succession?
Pioneer species colonize barren land (e.g., after a volcanic eruption), gradually forming soil and allowing more complex communities to develop.
What is cyclical succession?
A repeating pattern of species replacement in an ecosystem
What is the difference between climax communities and arrested succession?
Climax communities are stable, mature ecosystems, while arrested succession occurs when disturbances prevent an ecosystem from reaching its climax state.
