OBJECTIVE FORESTRY

Detailed explanation-1: -mangrove. Respiratory or knee roots (pneumatophores) are characteristic of many species; they project above the mud and have small openings (lenticels) through which air enters, passing through the soft spongy tissue to the roots beneath the mud.

Detailed explanation-2: -Breathing roots: Underground tissue of any plant requires oxygen for respiration and in mangrove environment, oxygen in soil is very limited or nil. This necessitates mangrove root system to take up oxygen from the atmosphere.

Detailed explanation-3: -Lenticels are small openings in the bark of trees. Many species have these roots, which can also be referred to as the knee roots or respiratory roots. Examples of pneumatophores are Avicennia germinans and Laguncularia raecemosa.