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By Root 2001 0

of pollen analysis (palynology), which involves boring out a column of sediment deposited in a swamp or pond. In such a column, provided that it has not been shaken or disturbed, the surface mud must have been deposited most recently, while more deeply buried mud represents more ancient deposits. The actual age of each layer in the deposit can be dated by radiocarbon methods. There remains the incredibly tedious task of examining tens of thousands of pollen grains in the column under a microscope, counting them, and then identifying the plant species producing each grain by comparison with modern pollen from known plant species. For Easter Island the first bleary-eyed scientist to perform that task was the Swedish palynologist Olof Selling, who examined cores collected from the swamps in Rano Raraku’s and Rano Kau’s craters by Heyerdahl’s 1955 expedition. He detected abundant pollen of an unidentified species of palm tree, of which Easter today has no native species.

In 1977 and 1983 John Flenley collected many more sediment cores and again noticed abundant palm pollen, but by good luck Flenley in 1983 also obtained from Sergio Rapu Haoa some fossil palm nuts that visiting French cave explorers had discovered that year in a lava cave, and he sent them to the world’s leading palm expert for identification. The nuts turned out to be very similar to, but slightly larger than, those of the world’s largest existing palm tree, the Chilean wine palm, which grows up to 65 feet tall and 3 feet in diameter. Subsequent visitors to Easter have found more evidence of the palm, in the form of casts of its trunks buried in Mt. Terevaka’s lava flows a few hundred thousand years ago, and casts of its root bundles proving that the Easter palm’s trunk reached diameters exceeding seven feet. It thus dwarfed even the Chilean palm and was (while it existed) the biggest palm in the world.

Chileans prize their palm today for several reasons, and Easter Islanders would have done so as well. As the name implies, the trunk yields a sweet sap that can be fermented to make wine or boiled down to make honey or sugar. The nuts’ oily kernels are rated a delicacy. The fronds are ideal for fabricating into house thatching, baskets, mats, and boat sails. And of course the stout trunks would have served to transport and erect moai, and perhaps to make rafts.

Flenley and Sarah King recognized pollen of five other now-extinct trees in the sediment cores. More recently, the French archaeologist Catherine Orliac has been sieving out 30,000 fragments of wood burned to charcoal from cores dug into Easter Island ovens and garbage heaps. With a heroism matching that of Selling, Flenley, and King, she has compared 2,300 of those carbonized wood fragments to wood samples of plants still existing today elsewhere in Polynesia. In that way she has identified about 16 other plant species, most of them trees related to or the same as tree species still widespread in East Polynesia, that formerly grew on Easter Island as well. Thus, Easter used to support a diverse forest.

Many of those 21 vanished species besides the palm would have been valuable to the islanders. Two of the tallest trees, Alphitonia cf. zizyphoides and Elaeocarpus cf. rarotongensis (up to 100 and 50 feet tall respectively), are used elsewhere in Polynesia for making canoes and would have been much better suited to that purpose than was the palm. Polynesians everywhere make rope from the bark of the hauhau Triumfetta semitriloba, and that was presumably how Easter Islanders dragged their statues. Bark of the paper mulberry Broussonetia papyrifera is beaten into tapa cloth; Psydrax odorata has a flexible straight trunk suited for making harpoons and outriggers; the Malay apple Syzygium malaccense bears an edible fruit; the oceanic rose-wood Thespesia populanea and at least eight other species have hardwood suitable for carving and construction; toromiro yields an excellent wood for fires, like acacia and mesquite; and the fact that Orliac recovered all of those species as burnt fragments from fires proves