Dead planet, living planet: Biodiversity and ecosystem - UNEP

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CASE STUDY #23
Mekong Delta mangrove forest restoration
Large-scale restoration of mangrove forests are feasible and
affordable. The largest mangrove restoration was that of the
The costs to successfully restore both the vegetative cover and
ecological functions of a mangrove forest have been reported
to range from USD 225/ha to USD 216,000/ha (Lewis, 2001).
Mangrove restoration projects have been classified into three
categories (Lewis, 2001; 2005): (1) planting alone, (2) hydrologic
restoration, with and without planting, and (3) excavation
or fill, with and without planting. The first type, planting only,
although inexpensive (e.g.: USD 100–200/ha) usually does
not succeed due to a failure to appreciate the physiological tolerances
of mangroves to tidal inundation. The second type,
mangrove forest in the Mekong Delta completely destroyed by the
US Air Forces in the 1970’s (above) and subsequently restored by
the Vietnamese government.
Black and white insert: “Results of Defoliation Operation”, illustration from
‘Vietnam Studies: Tactial and Material Innovations’, by Lieutenant General
John H. Hay, Jr.; www.army.mil/cmh-pg/books/Vietnam/tactical. Colour image:
Professor Nguyen Homg, Universidad de Hanoi, Vietnam.
hydrologic restoration, can be done for similar costs, and with
proper planning has a high success rate. Successful restoration
of abandoned shrimp aquaculture ponds is an example
of this method. Planting should only be done if natural recolonization
fails, and can double the cost of a project. Scientific
data indicates that using this method, ecological functions are
quickly restored, with fish populations typically reaching reference
site diversity and densities within 5 years. The third type,
excavation and fill, is the most expensive due to the high costs
of large scale earthmoving.