Q. Which of the following is/are characteristic/s of ecotone?
1.It may be very narrow or quite wide.
2.It has the conditions intermediate to the adjacent ecosystems.
3.It is linear as it shows progressive increase in species composition of one in coming community and a simultaneous decrease in species of the other outgoing adjoining community
Choose the correct answer from below given codes:

[A] 1 only

[B] 1 and 2 only

[C] 2 and 3 only

[D] 1, 2 and 3

Answer: D
Notes:

Explanation: Ecotone is a zone of junction between two or more diverse ecosystems. For e.g. the mangrove forests represent an ecotone between marine and terrestrial ecosystem. Other examples are – grassland, estuary and river bank.

Characteristics of Ecotone:

  • It may be very narrow or quite wide.
  • It has the conditions intermediate to the adjacent ecosystems. Hence it is a zone of tension.
  • It is linear as it shows progressive increase in species composition of one in coming community and a simultaneous decrease in species of the other outgoing adjoining community.
  • Well-developed ecotones contain some organisms which are entirely different from that of the adjoining communities.
  • Sometimes the number of species and the population density of some of the species is much greater in this zone than either community. This is called edge effect.

Source: SHANKAR IAS Environment