Sunday 27 November 2011

chapter 8 : Mangrove Swamp





State the unsuitable conditions for habitation in the mangrove swamp. Describe the adaptation of  plants to survive in this environment.



                        Nyatakan keadaan-keadaan persekitaran yang tidak sesuai untuk kehidupan di paya bakau dan kemudian huraikan adaptasi  tumbuhan  untuk hidup dalam keadaan tersebut.



F1: Soft muddy // strong coastal winds pose support problems.

E1 : To  support themselves, mangrove trees such as the Avicennia sp. have long, highly branched underground cable root //the Rhizophora sp. have prop roots/ aerial roots to anchor the plants on to the muddy soil.                                                                                    



F2 : Waterlogged conditions of the soil reduce the amount of oxygen available

E2 : the Avicennia sp. has breathing roots called pneumatophores which grow vertically upwards.



F3 : Direct exposure to the sun/wind leads to a high rate of transpiration

E3: The leaves of the mangrove are covered by a thick layer of cuticle which reduces transpiration during hot days// the leaves are thick and succulent which able to store water.



F4:The high salinity of the sea water makes the surrounding water in the soil hypertonic when compared to the cell sap of the root cells.



E4: The cell sap in the roots cells of the mangrove trees has a higher osmotics pressure than the soil water that surrounds them.This ensures that the roots do not lose water by osmosis// the excess salt in the hypertonic solution of the soil the roots and then then excreted as crystalline salt from the hydathodes



F5: Seeds which fall onto the ground die because they are submerged in the soft and waterlogged soil.

E5: mangrove seeds are able to germinate while still attached to mother plant/viviparity (this phenomenon increases the chances of survival of the mangrove as the seedlings can float horizontally on the water and subsequently get washed up on the sand or mudflats where they settle to establish a new population.


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