Ó Jean Hervé Daude
Easter Island - The Lost Forest
The combined effect of a climatic disruption and action of man
A number of the many mysteries surrounding Easter Island (Rapa Nui) have been solved, among others that of the secrets behind the manufacture, transport and erection of the monumental statues that are scattered across the island, and which have made its reputation. In fact, it has now clearly been shown that an abundant forest cover composed of large trees covered the island in the past. From this thousand-year-old forest, the Rapanui (native inhabitants of Easter Island) thus had taken the wood indispensable for setting up the great statues.
Nevertheless, an enigma an entirely satisfactory answer to which has yet to be found has persisted. How can the total deforestation of the island be explained ? For some, this deforestation, noted by the first Western navigators on their arrival, was the work of the islanders themselves. The Rapanui people have become the typecast and abundantly cited example of the carelessness and imprudence of a people who rush blindly toward their own destruction by misusing the limited resources they have at their disposal. The deforestation of their island in consequence is said to have caused the complete disappearance of the Rapanui civilization and the quasi-extinction of the island's population. For others, this deforestation is more likely due to a major climatic incident, which alone explains the complete destruction of forest cover across the land.
We have seen that the Polynesians, and thus the Rapanui, knew only too well the importance of trees; their entire way of life was based on the resources trees provided. Moreover, by means of a system of very strict taboos, they managed their resources prudently so as to ensure their long-term preservation. It therefore appears very unlikely that the Rapanui simply thoughtlessly cut down all of the island's trees for domestic purposes, or even more unreasonably, so as to be able to manufacture, transport and erect their famous Moai.
We have also seen that the inhabitants of Easter Island whom the first explorers encountered seemed healthy and lived comfortably within the limits of their resources. In addition, it is here asserted that it was not the deforestation of the island that caused the quasi-disappearance of the population and dealt a final blow to their civilization, as well as to the transmission of local traditions and knowledge. This devastating situation was more likely the consequence of diseases brought by Westerners at the time of first contact, and of the abduction of a great portion of the population at the time of the great slave raid of 1862.
We have seen that the Pacific Islands and their inhabitants have always been affected on a regular basis by a natural phenomenon that tends to rage in that area of the globe, the El Niño phenomenon. Major El Niño episodes seem moreover to have been cited over a long period in Polynesian oral tradition, these major episodes often involving significant disruptions, to the point of putting at risk the very survival of the human populations there.
More significantly again, the existence of even more severe climatic disturbances called mega El Niños, of an intensity incomparable to that known for regular El Niños has here been outlined.
Easter Island, which is subject on a regular basis to El Niño disturbances, has to be sure not managed to escape the upheavals inherent to mega El Niños, since this is a global climatic phenomenon and since the island is located at the heart of the most affected area. It has extremely probably been subject to several of them in its history. The authors do not however believe either that a climatic phenomenon, even one of very great scale such as a mega El Niño, could alone, without the intervention of other exacerbating factors, cause terminal deforestation of the island. Indeed, although mega El Niño have had devastating effects on the island each time they have hit, nature had also resumed its normal cycle each time, and the forest had always regenerated itself before man settled there permanently. Such was however not the case at the time of the last mega El Niño to have devastated the island. In fact, not only were the Rapanui increasingly numerous on the island at this time, but additionally they had introduced the Polynesian rat, which had then multiplied across the territory. This rodent had a varied diet, but just as did the people, it consumed palm tree nuts.
In the light of recent discoveries concerning mega El Niños, the authors are persuaded that the deforestation of the island was due to the combination of several determining factors which had never appeared simultaneously before and which, had they occurred separately, would have not had such dramatic consequences.
The principal factors were the significant weakening and damage to the forest cover due to an unusual climatic disturbance, a mega El Niño. To these principal factors would have been added aggravating elements : ecological pressure imposed on the ecosystem by an expanding human population that exploited scarce resources, and also by the voracity of a multitude of small rodents, the Polynesian rats, which consumed palm tree nuts every bit as much as did man, therefore preventing the forest from regenerating itself.
Pursuant to the passage through of the last mega El Niño, famine was all the more serious since there existed no immediate solution to the lack of resources that presented itself. The severe drought occasioned by the El Niño phenomenon must have caused devastation of harvests. The warming of the ocean caused by the mega El Niño had also caused coastal fish to migrate out and consequently, with it the departure of numerous colonies of the sea birds that consumed those fish.
As the Rapanui were truly prisoners of their isolated island, they could not escape the extremely difficult living conditions imposed on them by the arrival of the mega El Niño. The Moai Kavakava statuettes, with prominent rib cage and backbone, traditional Rapanui carvings, are perhaps an illustration of the punishing conditions that afflicted the population of the island at that time.
The inhabitants of Easter Island, in a context where resources were scarce, inevitably quickly exhausted these : they cut down the last useable trees and hunted fowl species to complete extinction. Both the regeneration of the forest and the survival of several species of birds were permanently compromised.
We have been able to see that the king and the great priests charged with ensuring abundance on the island in all likelihood lost a large part of the prestige and powers they held. Clan wars must have erupted, leading to chaos. In addition to this, the production of the great statues appears to have ceased abruptly at this time. Pursuant to this, the introduction of the cult of the Birdman among the Rapanui is thought to have put an end to this chaotic circumstance.
The authors are convinced that the simultaneous presence of man and a large Polynesian rat population prevented Easter Island from recovering from the consequences of the last mega El Niño that the island experienced. Victims of famine, the Rapanui found themselves confronted with extreme survival conditions. They must have exhausted their last essential resources, even while being conscious of the fact that in the long run they would probably be without them definitively. In order to ensure harvests capable of feeding them, they were also probably obliged to encroach onto land that could otherwise have been gradually naturally reforested. Moreover, not only the rats, but also the people themselves, in order to survive, consumed the nuts of the increasingly scarce palm trees, thus definitively preventing the regeneration of the forest, which had been composed primarily of large palms.
The Rapanui finally adapted their way of life to the new conditions, among other things by concentrating their efforts on the breeding of chickens.
The Polynesian people have from time immemorial lived according to the rhythm of El Niño. These climatic disturbances have moreover made it possible for the Polynesians to establish new colonies on the majority of the inhabitable islands of the Pacific, including those towards the east, whereas the usual direction of the winds did not normally allow them long journeys in that direction. Indeed, the El Niño phenomenon caused a change in the direction of the winds that could extend over rather long periods and facilitated exceptional eastward navigation. Unfortunately, the major upheavals generated by strong-intensity El Niños also brought with them their fair share of calamities, threatening the islanders' survival on certain islands, with famines and other kinds of catastrophes that could become sources of major conflicts and mortality.
Easter Island then does not after all seem to be the prototypical example, a warning from history, of the carelessness of men who misuse nature thoughtlessly and waste in extensive measure limited natural resources. Because of its extreme isolation, when a climatic disruption of very strong intensity raged across the island, an extraordinary situation was produced whereby man was confronted with the problems of his environment. However, in spite of extremely difficult conditions caused by the passage through of a mega El Niño, the Rapanui survived by adapting their lifestyle to the new conditions of a less hospitable environment wherein they were deprived of forest. The disappearance of forest cover removed from them major elements of their traditional lifestyle and, at the same time, limited or caused the disappearance of the other resources they possessed. Nevertheless, they succeeded in adapting to the circumstances, and it was a proud and vigorous Rapanui people that Europeans discovered in 1722.