The mangrove ecosystem

Story by: Viatori Photography by: César Zacarías/UNDP Translated by: Alejandra Palencia lun 16, Nov 2020

Mangroves are coastal ecosystems of great importance for human beings, and for the maintenance of marine-coastal biodiversity, by providing critical habitat for terrestrial, marine and coastal species, and serving as nursery areas for many of them. They constitute a natural barrier that protects coastal communities from extreme weather events such as hurricanes and floods. They also stabilize and reduce soil erosion.

In addition to the numerous ecosystem services and wood production provided by the mangrove, this type of forest favors the reproduction of mollusks, crustaceans and fish (Ronnback, 1999) that are sources of substantial income for neighboring populations.

The Guatemalan mangrove forest has five mangrove species: the main one is the red mangrove (Rhizophora mangle L.) that covers 67% of the mangrove area, while the white mangrove (Laguncularia racemosa (L) Gaertn.f.) is the second most common, with 33%. The black mangroves (Avicennia germinans L.) and buttonwood (Conocarpus erectus L.) follow, occupying smaller areas, with 3 and 0.3% respectively (MARN, 2013).

Currently there are records of two more mangrove species in Guatemala: Rhizophora racemosa G. Mey also known as red or red mangrove and another black mangrove Avicennia bicolor Standl.

In Guatemala, multiple efforts have been made to seek the recovery of the resource, one of them is the incorporation, in the PROBOSQUE Law, of a mangrove restoration modality, which pays incentives to those who carry out mangrove restoration and protection actions.

According to the National Strategy for the Restoration of the Forest Landscape of Guatemala, there is an area of ​​10,000 hectares (ha) that has great potential for the restoration of the mangrove forest. According to the analysis of restoration opportunities carried out in mangroves, there are four scenarios where restoration is proposed or where there should be mangrove coverage: 1) sparse mangrove forest and plantations; 2) natural grass and low shrub vegetation; 3) cultivated grass and low shrub vegetation with altered water flow; and 4) permanent crops.

Restoration and rehabilitation

The Santa Rosa area is home to two mangrove species that only grow here, which makes them special throughout Guatemala. Photo: Jorge Rodríguez/Viatori

In each of the scenarios, restoration practices such as natural and induced regeneration, rehabilitation of water flow, planting and nucleation are proposed. To restore 10,000 ha, an estimated investment of approximately Q69 million ($7.8 million) is needed. 62% of this amount would be needed for implementation, while the remainder would be invested to cover maintenance expenses throughout year 2 to 5. About 40% of these costs correspond to labor for restoration.

Restoration techniques must take into account environmental conditions on which the good development of the mangrove depends. For example, salinity, tidal duration and frequency, and topography are very important for mangrove restoration.

In addition, a financial cost-benefit analysis was carried out which allows to identify to what extent mangrove restoration can generate economic opportunities for the inhabitants of the marine-coastal area.

Said financial cost-benefit analysis covered economic activities associated with the mangrove ecosystem such as artisanal fishing, extraction of wood and firewood.

This analysis made it possible to evaluate under which conditions mangrove restoration could be economically viable and profitable. Due to its low opportunity cost and a faster recovery of the ecosystem, regeneration and plantation in sparse mangroves is the most attractive scenario since it offers the highest marginal Net Present Value, both at 10 and 35 years.

It should be noted that 75% of the expected financial benefits come from the extraction of molluscs and crustaceans, while the forestry incentives and the extraction of firewood and wood represent 24% and 3% respectively.

The benefit-cost ratio of the restoration technique, plantation and regeneration of sparse mangrove swamps is 1.46 to 10 years, that is to say that for each quetzal that is invested in restoration, the benefit obtained in 10 years would be Q 1.46 / ha.

In addition to the financial benefits directly associated with the mangrove ecosystem, the benefits can be considered in terms of reducing damage caused by storms, hurricanes and increasing carbon stocks (Narayan et al., 2017), which can be very significant compared to a scenario where there was no mangrove. Now, if the mangrove is a natural defense against extreme events associated with climate change, it is also vulnerable to it.

Text published by UNDP

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