Environmental controls of NDVI dynamics in Patagonia based on NOAA-AVHRR satellite data |
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Authors: | Jos M Paruelo Martin R Aguiar Rodolfo A Golluscio Rolando J C Len Gloria Pujol |
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Institution: | José M. Paruelo,Martin R. Aguiar,Rodolfo A. Golluscio,Rolando J. C. León,Gloria Pujol |
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Abstract: | Abstract. Variation in vegetation in extra-Andean Patagonia (Argentina) was analyzed using spectral data derived from AVHRR/NOAA satellite. The study of seasonal dynamics of the Normalized Difference Vegetation Index (NDVI, i.e. a combined index of the reflection in the red and infrared bands) highlighted similarities in functional aspects between regional vegetation units which are dissimilar in a geographical, physiognomical and/or floristical way, and also suggested that gross primary production is correlated with mean annual rainfall. The first axis in a Principal Component Analysis of NDVI data was correlated (r2 = 0.90) with NDVI as integrated for the study period. The second axis was correlated (r2 = 0.50) with the differences in NDVI during the growing season, reflecting seasonality. Mean annual rainfall accounted for 60% of integrated NDVI variability among vegetation units. Much of the residual variance (62%) was accounted for by the inverse of the distance to the Atlantic Ocean, which is interpreted as an ocean effect on vegetation functioning in the extra-Andean Patagonia. |
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Keywords: | Argentina Grass steppe NDVI Primary Production Satellite imagery Shrub steppe Correa (1969-1984) |
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