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ATLAS REPORT
Mangrove ecosystem report: Madagascar
Generated 15 October 2026, 08:22 from live Atlas data
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Executive summary
Atlas holds 319,264 mapped features and 38,648 observations in 44 datasets. The mapped mangrove canopy covers 261,598 ha in 26,508 polygons across 1 formation classes; Mangrove dominates with 100.0% of the area. The median patch is only 0.172 ha, while patches of 10 ha or more hold 93.6% of the area. 0 ha (0.0%) lies within 10 km of the LAPSSET development footprint.
Single mapping epoch (2019). Areas are geodesic hectares recalculated from geometry.
Species & formations
| Formation | Polygons | Area (ha) | Share | Mean patch (ha) |
|---|---|---|---|---|
| Mangrove | 26,508 | 261,598.3 | 100.0% | 9.87 |
Shannon evenness by area: 0.00
Fragmentation & landscape metrics
- Patches
- 26,508
- Mean / median / largest
- 9.87 / 0.172 / 4,899.5 ha
- Effective mesh size
- 956.6 ha
- Largest patch index
- 1.9%
- Power-law exponent α
- 1.54
Spatial clustering
Global Moran’s I = 0.141 (z = 6.5, p < 0.001). Hot-spot cells (Gi*, ≥95%): 78; cold-spot cells: 31.
| Top hot-spot cell | Polygons | Area (ha) | Gi* z |
|---|---|---|---|
| -15.55, 47 | 126 | 811 | 4.24 |
| -15.6, 47 | 96 | 1,378 | 4.20 |
| -15.6, 46.95 | 45 | 872 | 3.84 |
| -15.65, 47 | 175 | 898 | 3.80 |
| -15.65, 46.95 | 6 | 628 | 3.71 |
| -15.55, 47.05 | 66 | 786 | 3.48 |
Methods & limits
Areas and lengths are recomputed on the WGS 84 ellipsoid; units are harmonised (ha, m, %, UTC). The mapping is a single 2019 epoch; the source publishes no licence; field plots are a sample; scenario figures are illustrative assumptions. Cite the original publishers listed above. Full methods: Methodologies page.