Long-term satellite ndvi data sets: Evaluating their ability to detect ecosystem functional changes in South America

BALDI, G; NOSETTO MD; ARAGÓN, MR; AVERSA, F; PARUELO, JM; JOBBAGY, EG

SENSORS

Molecular Diversity Preservation International

Lugar: Basel (Suiza); Año: 2008 vol. 8 p. 5397 - 5397

1424-8220

span lang="en">In the last decades, South American ecosystems underwent important functional modifications due to climate alterations and direct human intervention on land use and land cover. Among remotely sensed data sets, NOAA-AVHRR ��Normalized Difference Vegetation Index�� (NDVI) represents one of the most powerful tools to evaluate these changes thanks to their extended temporal coverage. In this paper we explored the possibilities and limitations of three commonly used NOAA-AVHRR NDVI series (PAL, GIMMS and FASIR) to detect ecosystem functional changes in the South American continent. We performed pixel-based linear regressions for four NDVI variables (average annual, maximum annual, minimum annual and intra-annual coefficient of variation) for the 1982-1999 period and (1) analyzed the convergences and divergences of significant multi-annual trends identified across all series, (2) explored the degree of aggregation of the trends using the O-ring sta