There are no trees more than 10 ft. tall on Easter Island. That's not its most famous mystery--there's the little matter of those giant brooding statues--but it is kind of weird. Easter Island is less forested than any other island in Polynesia. What happened to the trees? And what, for that matter, caused the islanders themselves to die off almost completely?
Most people would leave questions like those as rhetorical and quietly tiptoe away, but Jared Diamond asks and relentlessly answers them in Collapse: How Societies Choose to Fail or Succeed (Viking; 575 pages). Diamond, a professor of geography (surely an endangered species itself) at the University of California, Los Angeles, won a Pulitzer Prize in 1998 for the best-selling Guns, Germs, and Steel, his attempt to understand how Western nations rose to political and technological pre-eminence (the title gives you a pretty good hint). In Collapse, he's a little like the title character in Dr. Seuss's The Lorax: he perches on the smoking ruins of extinct societies and calmly explains how they fell--and why, in almost every case, they never even saw it coming.
Easter Island is one of the most isolated patches of land in the world, 2,300 miles off the coast of Chile, a civilization in a bottle. Diamond uses archaeological data to meticulously piece together its decline. Despite its current denuded state, it turns out that Easter Island was at one time home to the largest species of palm tree in the world. It seems the Easter Islanders overtaxed their tiny home's unusually fragile ecosystem. Once they chopped down all the palms, they couldn't make canoes to go fishing in, and soil erosion devastated any attempts at agriculture. "The further consequences," Diamond observes dispassionately, "start with starvation, a population crash, and a descent into cannibalism." You can imagine where they end. Diamond interprets the Easter Island statues as increasingly desperate pleas for help from powerful ancestors.
While all that was going on, a colony of about 5,000 tenacious Norsemen was suffering a similar fate thousands of miles to the north. They had audaciously established a settlement on Greenland's comparatively mild southern coast, but they too overextended their environment and paid the price. Among many other blunders, they shortsightedly depleted the local forests (deforestation is a major theme in Collapse), which left them without the wood they needed to smelt iron. Icelanders were stunned when Greenlanders sailed into port in ships held together with wooden pegs and baleen instead of nails.
The Norse had bigotry and ignorance working against them too. They referred to the local Inuit as skraelings (loosely, wretches) while ignoring the fact that those wretches nimbly harvested calorie-rich seals and whales using their technologically sophisticated kayaks. And amazingly, although the fjords and lakes of Greenland are crammed with scrumptious haddock, cod, trout and char, it never occurred to the Norse to go fishing, even as they starved and froze to death. They apparently considered fish taboo and beneath their dignity.