| ------In this article we review the main
characteristics of the Patagonian climate, the spatial and temporal patterns
of the most important climatic variables, and the influence of climate on
ecosystem processes. The winter distribution of precipitation determines
an asynchrony between the wet and the growing season in Patagonia. The amount
of water that can be transferred from the wet season to the growing season
depends mainly on the physical characteristics of the soil. In the semiarid
steppe of Chubut, drainage accounted for 10% of annual precipitation. Winter
distribution of precipitation determines also an asynchrony dynamics of
evaporation and transpiration fluxes. The ENSO phenomenon, have a significant
impact on regional precipitation. In central-west Patagonia, spring precipitation
(September to November) was lower than normal during La Niña events
and greater than normal during El Niño events. From December to February
the opposite pattern can be observed: higher than normal precipitation during
La Niña events and lower than normal precipitation during El Niño
events. The impact of this phenomenon on the seasonal temperature was not
as clear as for precipitation. We did not detect any temporal trends in
annual precipitation for the period 1961-1996. The phenology of carbon gains
is quite homogeneous in Patagonia. Most of the region showed a peak of production
in November, when, simultaneously, water availability and temperature are
high. Toward the west, production peaked later (December). Deciduous forests
showed the peak in January and February. |