|Monitoring forest conditions in a protected Mediterranean coastal area by the analysis of multiyear NDVI data|
Maselli, F. (2004). Monitoring forest conditions in a protected Mediterranean coastal area by the analysis of multiyear NDVI data. Remote Sens. Environ. 89(4): 423-433
In: Remote Sensing of Environment. Elsevier: New York,. ISSN 0034-4257, more
The operational utilization of remote sensing techniques for monitoring terrestrial ecosystems is often constrained by problems of undersamplingin space and time, particularly in heterogeneous and unstable Mediterranean environments. The current work deals with the use ofthe NOAA-AVHRR and Landsat-TM/ETM+ images to produce long-term NDVI data series characterising coniferous and broadleavedforests in a protected coastal area in Tuscany (Central Italy). Two methods to extract NDVI values of relatively small vegetated areas fromNOAA-AVHRR data were first evaluated by comparison to estimates from higher resolution Landsat-TM/ETM + images. The optimalmethod was then applied to multitemporal AVHRR data series to derive 10-day NDVI profiles of coniferous and broadleaved forests over a15-year period (1986-2000). Trend analyses performed on these data series showed that notable NDVI decreases occurred during the studyperiod, particularly for the coniferous forest in summer and early fall. Further analysis carried out on local meteorological measurements ledto identify the likely causes of these negative trends in contemporaneous winter rainfall decreases which were significantly correlated withthe found NDVI variations.