A major disturbance that the ecosystem was able to recover completely from.

Ecosystems are dynamic entities that can experience various disturbances, both natural and anthropogenic. A major disturbance that an ecosystem was able to recover completely from is the eruption of Mount St. Helens in 1980.

Step 1: Define the Problem

Identify the key components of the question:

• Major disturbance: Mount St. Helens eruption
• Ecosystem recovery: Complete recovery over time

Step 2: Break Down the Problem

Divide the problem into smaller parts:

• Nature of the disturbance
• Immediate impact on the ecosystem
• Recovery process and timeline
• Factors contributing to recovery

Step 3: Apply Relevant Concepts

Use ecological theories and concepts:

• Succession: The process by which ecosystems recover after a disturbance
• Resilience: The ability of an ecosystem to absorb disturbance and reorganize while undergoing change

Step 4: Analysis, Verify and Summarize

• Nature of the Disturbance: The eruption of Mount St. Helens was a catastrophic event that destroyed vast areas of forest and wildlife.
• Immediate Impact: The eruption resulted in the loss of vegetation, wildlife, and altered the landscape significantly.
• Recovery Process:
  • Primary succession began with pioneer species like lupines and mosses.
  • Over time, more complex plant and animal communities re-established.
• Factors Contributing to Recovery:
  • Presence of surviving organisms that acted as seed sources.
  • Natural processes like wind and water dispersal aiding in recolonization.
  • Human intervention was minimal, allowing natural processes to dominate.

Final Answer

The ecosystem around Mount St. Helens demonstrated remarkable resilience by undergoing natural succession processes, leading to a complete recovery over several decades. This recovery illustrates the inherent ability of ecosystems to regenerate after significant disturbances.