Which of the following is not an example of terrestrial ecosystem?

The correct answer is Option (1) → Wetland

Ecosystems are divided into two basic kinds: terrestrial (on land) and aquatic (in water).

Option (1) Wetland — Not a terrestrial ecosystem. A wetland is land covered or soaked by water, so it is an aquatic ecosystem, like a pond, lake, river or estuary.

Option (2) Grassland — A terrestrial ecosystem.

Option (3) Forest — A terrestrial ecosystem.

Option (4) Desert — A terrestrial ecosystem.

NCERT Extract:
Ecosystem–structure and Function – “… Since this system is too much big and complex to be studied at one time, it is convenient to divide it into two basic categories, namely terrestrial and aquatic. Forest, grassland and desert are some examples of terrestrial ecosystems; pond, lake, wetland, river and estuary are some examples of aquatic ecosystems.”