1.

Archeologists have discovered evidence within the Amazon rainforest for four different mega-Nino events in the past 2000 years. These events are characterized by brief yet frequent periods of drought and inundation that can cause severe impact on populations of biota. Through the use of archeological evidence, charcoal remnants under soil, and observations from more recent (and smaller) events, scientists are able to characterize the larger events, presumed to have occurred around 1500, 1000, 700, and 500 B.P (years ago).

• Archeological evidence: archeologists studying ceramic sequences pertaining to specific regions and time periods of prehistoric communities have identified certain ?phases? in pottery making that were replaced abruptly without normal transition. These jumps between phases could be the result of the sudden migration or extinction of populations, triggered by some external event. The times of these jumps were identified as 1500, 1000, and 700 B.P by C-14 dating. 
• Pollen cores from Amazonia serve as evidence for brief periods of  replacement of forest by savanna around 1500, 1200, 700, and 400 B.P. 
• Charcoal has been found under regions of forest that under normal conditions do not burn dating back to 1500 and 700 B.P. In addition, C-14 dating had been used to identify ?brief drastic declines? in the water level of the Magdalena River in Colombia around 1400, 900, and 700 B.P.

These dates coincide with reports of massive flooding on the Peruvian coast around 1500, 1000, 700, and 500 B.P., increasing the likelihood that these were in fact major El-Nino events.
       
During the very strong rated Nino of 1982-3, massive flooding on the Peruvian coast occurred as well as rainfall 70% below normal during January and February. As a result, fires burned uncontrollably in some regions of the rainforest.
Much of Amazonian biota possess adaptations that possibly evolved during the past Nino events including reproductive strategies, fire resistance, and drought tolerance that tend toward resiliency and recovery.

However these events still have adverse effect on the flora including fire damage and inability to flower or fruit, which in turn forces fauna that normally feed on certain species of flora to damage others in the search for food.

It is important to study these events and their effects, not only because the current pattern of a large-scale Nino event about every 500 years suggests we are about due for another, but because many of the damaging properties of the events (such as alteration of rainfall patterns and drought) are occurring now as a result of human activity.