Mangrove Restoration project

Introduction

In April 2013, ForestSense, together with partner organizations, EUC Coastal & Marine, Rhizophora Consultants, the Filippijnengroep Netherlans and local partner organization Process-Bohol developed a feasibility study for a mangrove restoration project in the Philippines. The project activities are planned at two locations:  municipals of Badian on the island Cebu and along the coast of Maribojoc Bay, on the southwest of the island of Bohol.

Philippine mangrove ecosystems remain largely deforested, with a reforestation rate remaining at an alarmingly low level. Most deforestation of mangrove is caused by the mangrove conversion to fish ponds. Besides this mangroves also provide construction timber for houses and fish traps and firewood. Ironically, the government’s promotion of aquaculture to boost production by the fisheries sector has not been helpful as it resulted to more mangrove forests being converted to aquaculture ponds. It is no secret that the primary reason for the loss of large tracts of mangrove forests in the country has been due to the proliferation of fish ponds during the 70’s and 80’s.
Communities and civil society organizations are cognizant of the need to continue reforesting degraded mangrove ecosystems largely for the many economic benefits coastal communities derive from it. While often overlooked, perhaps the most important benefit derived from mangrove forests is its capacity to provide fishing families temporary relief from poverty especially during lean seasons. Mangroves forests are still where coastal communities turn to when income is lacking yet there’s the need to put food on the table. Thus, mangroves have steadily protected coastal communities from being more vulnerable to hunger and poverty and it will continue to do so.
The communities are the ones that advocate for mangroves reforestation as being the original users of these resources, who were deprived of its traditional uses when it was converted into fishponds. The increasing threats of extreme weather conditions due to climate change made a compelling argument for mangroves reforestation. Coastal managers are now fully aware of the protection mangrove stands provide in times of flooding and storm surges.

Impact & project revenues

Growth of mangroves is related to the storage of carbon in the trees. Although not much empirical data is present regarding the storage of carbon by mangrove, first studies indicate that most of the carbon is stored in the first 1 – 3 meters in the soil and secondly in the above ground biomass. Examination of literature and field data collected by Spalding et al. (2010, World Atlas of Mangroves) indicate that for the Philippines around 12 tCO2/ha/y may be expected, which is a conservative estimate.
Below the estimated carbon revenue potentials for the proposed project locations is listed at 12 tCO2/ha/y. In literature, values range between 5.2 tCO2/ha/y up to 18 tCO2/ha/y. Development and carbon sequestration depends a lot of the establishment of proper growing conditions (e.g. excavating the site prior to planting to establish proper and regular flooding of the mangrove plantation sites) and careful species selection (e.g. some species are more easy to propagate and show far better growing rates than others).
In much of the literature, the units of measurements are unclear (fresh biomass versus dry biomass, tC/ha versus tC/ha/y, tC/ha/10/yrs versus tC/ha/30/yrs, etc.) The average value for plantation mangrove was established from literature from a Plan Vivo project (Mikoko Pamoja project), a research of Komiyama et al. (2008) and Alongi (2009) and finally a research of Naohiro Matsui et al. (2012). Number from these sources indicated that carbon sequestration varied between 8 to 18 to even 20 tCO2/ha/y for average development of mangrove trees. Hence, a value of 12 tCO2/ha/y is considered average and conservative. Estimates can be calculated more accurate in a feasibility study wherein the conditions (e.g. species selection, planting distance, etc.) can be determined in more detail.