What Is the Edge Effect?

The edge effect refers to the distinct ecological conditions and increased biodiversity often found at the boundary between two different habitats or ecosystems, such as a forest and a grassland. This zone can support species from both adjacent ecosystems, as well as unique species adapted to the edge environment.

Evaluating the Statements

Let’s analyze each statement about the edge effect:

(1) Moving corridors connecting two ecosystems are always harmful

This statement is NOT true.
In fact, moving corridors—such as strips of vegetation, rivers, or hedgerows—are often beneficial for biodiversity. They enable the movement of species between habitats, promote genetic exchange, and help maintain healthy populations. Corridors can mitigate the negative impacts of habitat fragmentation and are widely used in conservation planning.

(2) It has its unique physical environment differing from both ecosystem

This statement is true.
The edge or ecotone often has unique physical and microclimatic conditions, such as differences in light, humidity, and temperature, compared to the adjacent ecosystems.

(3) It has different species composition as compared to both sides

This statement is true.
The edge zone typically supports a distinct mix of species, including some from each adjacent ecosystem and others that are unique to the edge itself.

(4) It has high biodiversity

This statement is true.
Edges often have higher biodiversity than the interiors of the adjoining ecosystems due to the overlap of species and the presence of edge specialists.

Conclusion

The incorrect statement about the edge effect is:

(1) Moving corridors connecting two ecosystems are always harmful

In reality, corridors are usually beneficial and play a vital role in supporting biodiversity and ecosystem health.

Correct answer:
(1) Moving corridors connecting two ecosystems are always harmful