Annual and seasonal variation of NDVI explained by current and previous precipitation across Northern Patagonia

FABRICANTE, IRENE; OESTERHELD, M; PARUELO, JOSÉ

JOURNAL OF ARID ENVIRONMENTS

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Año: 2009 vol. 73 p. 745 - 753

0140-1963

Temporal variation of aboveground net primary production (ANPP) of arid ecosystems has been asso-ciated with precipitation regimes with different results. The objective of this paper was to characterizethe relationship between interannual variation of annual and seasonal Normalized Difference VegetationIndex (NDVI), as a surrogate for ANPP, and precipitation in the steppes of Northern Patagonia. In 11 sitesencompassing a wide range of conditions and vegetation physiognomies, we studied a 20-year monthlydata set of NDVI and precipitation. We took into account the precipitation of current, as well as previousperiods of variable length. Interannual variation of annual NDVI was little correlated with annualprecipitation, either current or previous. In contrast, it was highly and widely correlated with precipi-tation accumulated during a few months of the previous growing season. Interannual variation ofseasonal NDVI was little correlated with current seasonal precipitation. In contrast, it was significantlycorrelated with precipitation accumulated during previous periods of variable length according to theseason and site under consideration. NDVI was more tightly coupled with precipitation in drierecosystems. Lags of response between NDVI and precipitation provide an opportunity for forecastingANPP and suggest even longer lags between climatic variation and herbivore performance.