By Eva Ciabattoni

The mystery of Easter Island - how those enormous stone statues were erected on an isolated, barren island - led some to postulate that it must have been visited by space aliens. But reason prevailed as more imaginative visitors gazed around them and reached a stunning conclusion: There must have been trees on Easter Island at one time. Not only that, they must have been large trees that yielded timber for transporting and erecting the statues and for building large, strong canoes.

In his new book, “Collapse” (Viking, 2005), UCLA professor Jared Diamond examines Easter and other societies that have collapsed (often soon after reaching peak power) and a few that haven’t. Not content to speculate from behind a desk, Diamond, originally trained as an ornithologist, is a scientist in the best sense, one who is willing to leave the comforts of home in order to do rigorous fieldwork firsthand. Engaging, thoughtful and thought-provoking, “Collapse” follows Diamond’s Pulitzer Prize-winning “Guns, Germs, and Steel,” about how certain societies came to power.

In the Easter Island scenario, Diamond describes the science and monotonous work required to solve the mystery. Garbage middens were unearthed and examined; they revealed a steady change in the Easter Islanders’ diet away from ocean fish toward shellfish and rats. Pollen trapped in layers of swamp sediment was analyzed as were fossilized palm nuts. The researchers found that Easter Island was once home to the largest palms in the world, as well as other tree species. Over time, the Easter Islanders deforested their entire island, which led to erosion and crop failures. Without the large palms to make oceangoing canoes, they had to eat what they found on land or in shallow water.

What happened? Diamond analyzed nine physical factors and found eight of them present on Easter. Among them: Easter was a cooler island with less rainfall, less soil fertility and slower plant regrowth; in other words, Easter had a particularly fragile ecosystem, one whose resources in essence were being mined rather than harvested.

In detailed studies, Diamond shows how a society’s success or failure is affected by these major factors, alone or in combination: environmental destruction, climate change, relations with hostile or friendly neighbors, and the society’s response to its problems. His study of the island-sharing Dominican Republic and Haiti illustrates two different responses to similar pressures - and the vastly different resultant quality of life.

Some problems are simply exported, like in the case of Japan, which has preserved its own forests but is the largest importer of wood. Most striking is the map of the world’s political trouble spots on the same page with the world’s environmental hot spots. The two maps are exactly the same. Diamond argues persuasively that every country’s problems become the world’s problems. Countries tend to make the best decisions when those in power cannot insulate themselves from the rest of society.

The problem comes down to: too many people consuming too many of the world’s resources at a rate at which they cannot be replenished. Diamond calls the outcome a horse race, and he, like most of us, hopes the sustainable horse will win.