Question

A species in an ecosystem that plays a central role in the health of that ecosystem and whose removal may cause the collapse of the ecosystems, is called a(n)

• A. Indicator species
• B. Keystone species
• C. Specialist species
• D. Foundation species

Hint:

Think of a "keystone" in an arch: it is the central stone at the top that holds the entire structure together. If you remove it, the arch collapses, just like removing a keystone species collapses an ecosystem.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Ecosystems are composed of diverse species that interact in complex ecological webs.
Certain species exert a disproportiotely large influence on community structure and ecosystem function relative to their physical abundance or biomass.

Step 2: Detailed Explation:
Let us alyze the ecological definitions of the options:
- Keystone Species: This term, coined by Robert Paine, refers to a species that plays a critical role in maintaining the structure and integrity of an ecological community.
The removal of a keystone species triggers a trophic cascade, causing dramatic changes in the populations of other species and potentially leading to the collapse of the entire ecosystem.
Examples include top predators like sea otters and wolves, or ecosystem engineers like beavers.
- Indicator Species: A species whose presence, absence, or health reflects the specific environmental conditions or pollution levels of an area.
- Specialist Species: A species with a rrow ecological niche that can tolerate only a specific range of environmental conditions and diet.
- Foundation Species: A highly abundant species that plays a major physical role in structuring a community by creating and defining the biophysical habitat (such as kelp in kelp forests or reef-building corals).

Step 3: Fil Answer:
The species whose removal can lead to the collapse of an ecosystem is called a keystone species.
Hence, the correct option is (B).