INVESTIGADORES
BALDI german
congresos y reuniones científicas
Título:
Relations between the NDVI variability and the interannual growth in Anarthrophyllum rigidum in the shrubs steppes of Patagonia
Autor/es:
SRUR, ANA M.; VILLALBA, RICARDO; BALDI, GERMÁN
Lugar:
Vancouver
Reunión:
Congreso; First American Dendrochronology Conference - AmeriDendro 2008; 2008
Resumen:
The Normalized Difference Vegetation Index (NDVI) is a linear indicator
of absorbed photosynthetic active radiation, and therefore, it
represents a measure of carbon flux across ecosystems. The annual bands
of growth in woody species are a useful tool for monitoring
environmental changes and ecosystem dynamics at different temporal and
spatial scales. We combined temporal series of NDVI and growth rings to
document changes in productivity and ecosystems in xeric regions of
Patagonia. Our objective was to determine the temporal relationships
between NDVI and the radial growth of Anarthrophyllum rigidum in the
shrubby steppes across Patagonia. Anarthrophyllum rigidum (Mata guanaco o
Pataguilla) is a shrub native of Patagonia. Cross-sections were
collected at 16 sites located from southern Mendoza to Santa Cruz,
Argentina. Across of the spatial distribution of Anarthrophyllum
rigidum, there is a strong relationship between the annual integral of
the NDVI and the total annual precipitation. The values of NDVI during
de period 1982 to 1999 were provided by the program LechuSA (Land
Ecosystem Change Utility for South America, http//lechusa.unsl.edu.ar).
The growth rings reflect the CO2 uptake in the ecosystems during the
season of growth (December to March); which is coincident with the
seasonal peak of NDVI in the area. For the sampling sites in the
southern range of the Anarthrophyllum rigidum distribution, the
relationship between radial growth and NDVI also includes April and May
suggesting a delay in the growth ring formation in the southern sites.