IPEEC - CENPAT   25619
INSTITUTO PATAGONICO PARA EL ESTUDIO DE LOS ECOSISTEMAS CONTINENTALES
Unidad Ejecutora - UE
artículos
Título:
Risks of neglecting phenology when assessing climatic controls of primary production
Autor/es:
BANDIERI, L.M.; BANDIERI, L.M.; FERNÁNDEZ, R.J.; FERNÁNDEZ, R.J.; BISIGATO, A.J.; BISIGATO, A.J.
Revista:
ECOSYSTEMS (NEW YORK. PRINT)
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2020 vol. 23 p. 164 - 174
ISSN:
1432-9840
Resumen:
We evaluated the effect that integrating annual aboveground net primary production (ANPP) along different 12-month periods has on temporal models of productivity (ANPP as a linear function of annual precipitation). We studied Argentinean Patagonia, which encompasses a variety of climates and biomes. Using MODIS normalized difference vegetation index(NDVI) to estimate green biomass, we assessed the date of maximum annual NDVIfor 2000-2016. One quarter of Patagonia (West/South region) exhibited a well-defined seasonality, with maximum NDVI during spring-summer, whereas the rest (Central/East region) showed a much less well-defined maximum NDVI, generally during fall. Then we calculated temporal models for each pixel, considering both annual and seasonal precipitation (PPT), in two ways: (i) Centered models, integrating NDVIfor a period centered at the actual growing season (GS), i.e. July-June for West/South region and January-December for Central/East region, and (ii) Displaced models, switching the NDVI integration period. Our results indicate that, with the centered models, 84% of the Central/East region exhibited significant temporal models, but only 52% of the West/South region did. For the displaced models, 60% (40%) of pixels of Central/East (West/South) region changed their best predictor of ANPP. In general, the best predictor changed from current year to current plus previous-year PPT or from current year fall to previous-year fall. Our results suggest that more attention must be paid in choosing the integration period for annual ANPP. This is more than a formal matter since the putative best predictor of ANPP can dramatically change depending on the assumed phenology.