Mangroves Restoration

Mangroves Restoration:

Restoring mangroves is often recommended when the ecosystem has been modified to such an extent that it cannot regenerate naturally. However, Planting mangroves within eroded areas is far more difficult than planting at other sites because of the harsh physical conditions. As such, quite low survival rates of planted mangroves at the shoreline area were reported at the Visayas and at other areas in the Philippines, as well as at Surat Thani and at Samuth Songkram in Thailand (Lewis 2004), re-emphasizing the need for rehabilitating the inter-tidal mud coast . Because under such conditions, ecosystem homeostasis has been permanently hampered and the normal processes of secondary succession (Clements, 1929) or natural

Species of mangroves selected(adapted from Roy Lewis 2004)

As a function of history and increasing capability to attenuating waves, coupled with increasing rate of trapping sediments, three good species of mangroves will be selected; Avicenia spp., Rhizophora spp., and Laguncularia

Avicennia spp., (Avicenniaceae) is a tree that grows to 10 m tall and is characterised by its pencil-like pneumatophores, to avoid suffocation in the oxygen poor (anaerobic) mud. It grows throughout the intertidal zones of estuaries, lagoons and backwater. It prefers fine clay and alluvial soil, and tolerates a wide range of soil salinity. The species can be easily propagated by propagules.(Biwas et al., 2009; Chan H.T 2009). Thus the trees stabilise the shores because of its increasing level of trapping of sediments, preventing erosion and allowing other plants to grow.

Rhizophora mucronata (Rhizophoraceae) is a tree that reaches 25-30 m in height. Trees are characterised by stilt roots looping from the base of trunks. The species grows well along creek banks in deep soft mud, which is rich in humus. Growth is generally vigorous and planted trees are reproductive 3-4 years after

The building of the intertidal flats through the use of Bamboos or Melanguera, are considered soft engineers to reduce the energy of waves and trap sediments favouring the development of Mangroves as reported by Winterwerp 2013, and not the Planting of Mangroves on eroding coastal flats which will lead to less survival rates of such Mangroves.

Moreover, in restoring Mangroves in any part or region of the globe, a dire need for proper study of the main stressors of Mangrove losses and addressing of such stressor through ecological engineering before restoration of mangroves. The emulation of restoration processes should be disregarded as this has led to lots of losses of rehabilitation projects. As such, If this principles and integrated ecological engineering approaches are applied in area of Thailand, and other prone areas around the globe, this will create high survival rates of the Mangroves species that can keep the coastal areas safe from impeding erosion, flooding and land subsidence as seen in Mekong Delta, Vietnam. Hence the need for Ecological engineers to work concomitantly with the Civil Engineers and the Local citizens to creating a better and more sustainable