Abstract

Informal small-scale mangrove wood harvesting has received limited attention, though it is a widespread threat to mangroves in many parts of the tropics. We investigated wood use and the impacts of harvesting on mangrove forests in the Bay of Assassins in southwest Madagascar. We measured forest structure, composition, and harvesting across 60 vegetation plots and investigated human uses of the mangroves through Rapid Rural Appraisal techniques. We found that unlike other mangroves in the region, those in the Bay of Assassins are dominated by Ceriops tagal. Tree harvesting rates are high, with a mean of 28.7% (SD 19.4) of trees harvested per plot. This is similar to heavily harvested mangroves in other parts of the tropics. A comparison of tree versus sapling importance of the different mangrove tree species indicates that the composition of the mangrove forest is changing, with C. tagal becoming more important. Livelihood activities drive the harvesting of certain species and size classes. Mangrove wood is used mainly for the construction of traditional housing and fencing. There are also emerging uses of mangrove wood, including seaweed (Kappaphycus alvarezii) aquaculture and the production of ‘sokay’, a lime render made by burning sea shells in mangrove wood kilns and used to improve the durability of houses. Small-scale selective harvesting of mangrove wood is important for local livelihoods but may have wide-ranging impacts on forest composition and structure. Demand for mangrove wood has grown in relation to new commodity chains for marine products, demonstrating the need for integrated landscape management that considers wetland, terrestrial and marine resources together.

Highlights

  • Intertidal mangrove forests are globally threatened (Polidoro et al 2010; Hamilton and Casey 2016) by a range of pressures such as aquaculture and agriculture, urban development, harvesting for paper pulp, fuelwood, charcoal and construction materials, changes in hydrology and sediment budgets, and sea-level rise (UNEP 2014)

  • Mangrove deforestation and degradation in lowincome nations is of particular concern, as poor rural communities rely heavily on a wide range of ecosystem services provided by mangrove forests

  • The mix of species in the Bay of Assassins is typical of southwest Madagascar’s mangroves, with five species recorded in our plots, compared to a total of six species known to be present in the Bay (Benson et al 2017)

Read more

Summary

Introduction

Intertidal mangrove forests are globally threatened (Polidoro et al 2010; Hamilton and Casey 2016) by a range of pressures such as aquaculture and agriculture, urban development, harvesting for paper pulp, fuelwood, charcoal and construction materials, changes in hydrology and sediment budgets, and sea-level rise (UNEP 2014). Mangrove deforestation and degradation in lowincome nations is of particular concern, as poor rural communities rely heavily on a wide range of ecosystem services provided by mangrove forests. These include the direct provisioning of building materials, fuelwood, charcoal, animal fodder, (shell)fish and non-timber forest products (Bandaranayake 1998; Dahdouh-Guebas et al 2000; Walters 2005a; Barbier et al 2011; Lau and Scales 2016), alongside the benefits that these communities gain from regulating services (e.g., coastal protection) and cultural services (e.g., recreation, aesthetic and spiritual values)

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call