Resistance and Resilience Are Key to Stability
Definition
Ecosystem Stability
Ecosystem stability is the ability of an ecosystem to maintain structure and function over time, even when faced with disturbances like climate change, natural disasters, or human activity. High biodiversity plays a critical role in promoting this stability.
- Resistance: The ability of an ecosystem to thrive despite disturbances without significant changes.
- Resilience: The ability of an ecosystem to recover quickly after a disturbance.
High Biodiversity Promotes Ecosystem Stability
- Redundancy: Multiple species perform similar roles, so if one species is lost, others can take over, preventing system collapse.
- Complex Interactions: Diverse ecosystems have predator-prey relationships, mutualisms, and competition that regulate populations and prevent imbalances.
- Genetic Diversity within Species: Populations with high genetic diversity are more resilient to diseases, climate changes, and environmental stress.
A genetically diverse population of trees is less likely to succumb entirely to pests and drought, ensuring the ecosystem remains functional.
ExampleCoral reefs with genetically diverse corals are more likely to survive bleaching events.
Exam technique- Mention redundancy, genetic diversity, and interactions when explaining biodiversity's role in stability.
- Use real world examples like coral reefs or tropical rainforests to strengthen your argument.
Threats to Ecosystem Stability
1. Human Activities
- Deforestation: Reduces habitat availability, disrupts water and carbon cycles, and eliminates species that play crucial roles in ecosystem stability.
- Pollution: Introduces toxins that harm species and disrupt nutrient cycles.
- Overexploitation: Unsustainable hunting, fishing, or harvesting collapses key populations and destabilizes ecosystems.
The Amazon rainforest loses large areas of habitat annually due to logging and agriculture, leading to species extinctions and disrupted climate regulation.
Analogy- Think of a forest as a sponge that abosrbs are regulates water.
- Deforestation is like poking holes in the sponge, it loses its ability to retain water, affecting local and global water cycles.
- How do human activities like pollution reflect a lack of understanding of interconnected systems?
- Is it ethical to prioritize short-term benefits over long-term ecosystem health?
2. Loss of Keystone Species
What are Keystone Species?
- Keystone species are organisms that have a disproportionately large impact on their ecosystem compared to their abundance. Their removal can trigger cascading effects across the food web.
- Removing wolves from Yellowstone National Park allowed elk populations to grow unchecked.
- Overgrazing damaged vegetation, soil stability, and biodiversity.
- Reintroducing wolves restored balance by controlling elk populations and enabling vegetation recovery.
- Clearly explain why the loss of a keystone species has cascading effects.
- Use specific examples, like wolves in Yellowstone or sea otters controlling sea urchins in kelp forests.
- Always describe how their removal destabilizes the entire food web.
- Explain how human activities and the loss of keystone species threaten ecosystem stability.
- Include examples of cascading effects and propose ways to mitigate these threats.
