Estimating leaf area index of mangroves from satellite data

• Published in: Aquatic botany 1997-07, Vol.58 (1), p.11-19
• Main Authors: Green, Edmund P., Mumby, Peter J., Edwards, Alaisdair J., Clark, Chris D., Ellis, Angie C.
• Format: Article
• Language: English
• Subjects: Brackish; Coastal management; Remote sensing
• ISSN: 0304-3770; 1879-1522
• DOI: 10.1016/S0304-3770(97)00013-2

The relationship between the normalised difference vegetation index (NDVI) and leaf area index (LAI) was modelled for mangroves growing on the Caicos Bank, Turks and Caicos Islands. NDVI values were used to predict LAI with this model and a thematic map of LAI produced from satellite data for the whole Bank. Mangrove LAI ranged between 0.8 and 7.0, with a mean of 3.96. LAI data, estimated from in situ measurements of canopy transmittance for a set of sites independent of those used to derive the LAI/NDVI model, were used to test the accuracy of this image. Accuracy was defined as the proportion of accuracy sites at which the LAI value (as estimated from field measurements) lay within the 95% confidence interval for the predicted value of LAI. The accuracy of this map was high (88%) and the mean difference between predicted and measured LAI was low (13%). Remote sensing is thus demonstrated as a powerful tool for estimating the spatial distribution of LAI for whole mangrove ecosystems. This information can be obtained rapidly compared to alternative methods of measuring LAI and can minimise the logistical and practical difficulties of fieldwork in inaccessible mangrove areas.