Ecosystem Services Valuation of Mangrove Restoration in Tropical Coastal Zones

Abstract

Mangrove forests supply a disproportionately large bundle of ecosystem services relative to their global areal
extent, yet the economic case for restoring them, as opposed to simply avoiding further loss, has been assembled
piecemeal across a literature that spans storm-surge attenuation engineering, blue-carbon accounting, fisheries
ecology and contingent-valuation survey work, each with its own methods, spatial scale and units. We synthesise
valuation evidence published mainly between 1999 and 2023 across four service categories most commonly costed
for restored or restoring mangrove stands: coastal protection and storm buffering, carbon sequestration and
long-term soil carbon storage, fisheries nursery-habitat support, and water quality regulation, drawing on primary
valuation studies, regional meta-analyses and global benefit-transfer exercises identified through a structured
literature review. Reported per-hectare annual values vary by more than two orders of magnitude within every
service category, driven less by underlying ecological differences than by valuation method, the land-use
counterfactual assumed, and whether avoided-damage, replacement-cost, market-price or stated-preference
approaches were used. Coastal protection values are consistently the largest and most variable component of
aggregate estimates, reflecting their sensitivity to local exposure, population density and infrastructure value at risk;
carbon values are comparatively narrow when confined to sequestration flux but widen sharply once
avoided-emissions accounting for soil carbon stocks in degraded or converted mangroves is included; fisheries and
water-quality values are the most sparsely and unevenly studied, concentrated in a handful of Southeast Asian and
Latin American sites. Restoration-specific studies, as distinct from valuations of intact mangrove extent, remain a
minority of the evidence base and rarely track service recovery trajectories beyond five to ten years post-planting,
leaving the time profile over which restored stands approach the service values of mature forests poorly
constrained. We argue that the field's most pressing methodological need is not further point estimates of service
value but a common reporting standard, explicit counterfactuals, and longer-term monitoring of restored sites,
without which benefit-transfer exercises used to justify restoration investment risk compounding uncertainty rather
than resolving it.