(d) The transitional zone between two distinct communities is known as Ecotone, such as forest and grassland. An ecotone acts as the boundary or barrier between two biomasses. It is the area where two distinct types of environments merge and blend. The word ‘ecotone’ was coined from a combination of ‘eco(logy)’ plus‘tone’ from the Greek ‘tonos’ or‘tension’, meaning a place where ecologies are in tension.