Thursday, March 19, 2009 5:59 AM
Article 4 Mangrove forests form along sheltered coasts particularly where rivers meet the sea. Mangrove trees grow in this intertidal zone that is covered with seawater at high tide and where the ground is covered with soft, oxygen-poor mud. Here they are also exposed to dry, coastal winds. The unusual features of mangrove trees are adaptations to these challenging conditions. Mangrove trees can grow partially submerged in water. You can see where the water usually comes up to the tree by the change in the colour of the bark and the animals that encrust the tree roots and trunk. How do the trees do this? There is little oxygen in the fine mud usually found in mangroves. Mangrove trees have special breathing roots to absorb oxygen from the air. These roots also help mangrove trees to stay upright in the soft mud. Mangrove trees also have ways to extract freshwater from salty water. Some block out the salt at the root level, others get rid of excess salt on their leaves. Much like desert plants, mangroves store this precious extracted freshwater in thick leaves. Hairy or waxy leaves help reduce evaporation in the drying coastal winds. Some mangrove trees give their seeds a headstart in a harsh habitat. The seeds germinate on the mother tree instead of simply dropping off when ripe. For example, long green seedlings develop on the Bakau tree. Other trees provide a large food store for their seeds before sending them off. Article abstract from http://www.wildsingapore.com/chekjawa/text/m001.htm Reflection 4 After reading the article, I learn that the mangrove trees can grow partially submerged in water and where the water usually comes up to the tree by the change in colour of the bark and the animals that encrust the tree roots and trunk. They did by as they have special breathing roots that can absorb oxygen from the air and help the tree stand upright in the soft mud. Mangrove trees also have another unusual feature is that it can obtain freshwater from salt water by blocking out the salt at the root level or by getting rid of the excess salt on their leaves. They are quite alike as the desert plants, they store the extracted freshwater in thick leaves and their waxy or hairy leaves will help to reduce evaporation in the drying coastal winds. Some mangrove trees when dispersing their seeds, mangrove tree give their seeds a headstart in a harsh habitat. The seeds will germinate on the mother tree instead of dropping off when ripe. The trees will provide a large food store for their seeds before sending them off. (185words) ( Some of the information in my reflective journal is taken from the article)
