IAI-Science-ISP-3-077-002:The Climate of Patagonia: General Patterns and Controls on Biotic Processes

"In this article we review the main
characteristics of the Patagonian climate and 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 to the growing season depends mainly on the
physical characteristics of the soil. In the semiarid steppe of Chubut,
drainage accounted for by 100f annual precipitation. Winter distribution of
precipitation determines also an asynchronic 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 Nina events and greater than normal
during El Nino events. From December to February the opposite pattern can be
observed: higher than normal precipitation during La Nina events and lower than
normal precipitation during El Nino 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".