The adaptation of pneumetaphores of mangroves to the waterlogged soils environment.

Introduction:
Plants when grow in areas of bad conditions such as waterlogged soils must be able to deal with environmental extremes not experienced by other plants. Mangroves live in the swamp, bathed twice a day by the sea and having their roots in waterlogged soils which are devoid of oxygen, poorly drained, rich in organic matter and anoxic. Because of the lack of oxygen in the soils, mangroves rely on numerous erect aerial roots called pneumetaphores, the mangrove¡¦s breathing roots, to obtain oxygen from the air by means of aerial roots that descend like buttresses from the trunk and lower branches for its extensive root system. The pneumetaphores have corky, water-resistant bark and a spongy interior stiffened by an axis of vascular tissue. Oxygen once taken up will be diffused through aeration tissue in the lateral roots and spread to the rest of the plant.

The height of pneumetaphores varies from one to another, is it related to the height of seawater level or it just ha...