What Happened to Angkor?
Columbia tree-ring scientists journey to a remote forest in Cambodia to search for clues about the demise of a lost civilization.by David J. Craig Published Spring 2011
In the Cardamom Mountains of southwest Cambodia, the rain forest grows thick. During monsoon season, a canopy of phayom, rosewood, pinang baik, and white meranti trees blocks out the sun. At night, the forest emits its own soft orange light, as hunters burn campfires to ward off elephants.
“It’s seriously rough country, a wild and beautiful place,” says Brendan M. Buckley, a Columbia scientist who led a research expedition here in January. “You move slowly, bashing and slashing your way through the vegetation.”
Buckley is here because he thinks these woods, which are among the most remote in Asia, hold secrets to the disappearance of a city that once existed in the jungle some 100 miles north of the mountains. This was the city of Angkor, which, at its pinnacle in the 12th century, was home to 750,000 people and covered some 400 square miles — the largest footprint of any urban development in the preindustrialized world. Its workers built gigantic Hindu temples out of sandstone and planted rice paddies that stretched far over the horizon. Its engineers created dams and reservoirs to irrigate crops, even waterways to travel around the settlement by boat.
And then this civilization vanished. By the time Portuguese missionaries arrived in the 16th century, the city had been largely abandoned and its temples enshrouded in vegetation.
What happened to Angkor? “There are few written accounts that have survived from the period, so it’s an enduring mystery,” says Victor Lieberman, a professor of Southeast Asian history at the University of Michigan. “We historians don’t have much evidence to grasp onto.”
But that’s changing now that Buckley is discovering new clues — not in stone carvings or long-lost travelogues, but in the flesh of evergreen trees.
The scent of conifer
Climbing up a ridge in the Cardamoms, Buckley spots a cluster of evergreens known as Dacrycarpus imbricatus, a rare species with no common name in English. With their needle-shaped leaves and shrubby limbs, the trees look out of place in a rain forest.
“Even in the tropics, we find evergreens in the highest, coolest altitudes,” says Buckley, an associate research professor at Columbia’s Tree-Ring Laboratory. “We look for evergreens because they show their growth rings clearly. They’re prized for their soft lumber, too, so we have to go into remote areas to find any old ones still standing. These here are really nice — maybe 500 years old.”
Buckley unzips his knapsack and removes a wood borer, a hand-operated drill with an extremely long, hollow bit. He presses the borer gently into the side of a tree, aiming it straight for the core. Then, gripping the borer’s T-shaped handle with both hands, Buckley leans into the tree and begins rotating the tool as if it were a tire iron. With each half-turn, the scientist lets out a grunt and the wood produces a nasal, birdlike squawk. The oily, slightly floral scent of conifer wafts in the air. After 15 minutes (“I’ve had bursitis in both elbows”), Buckley stops, the borer having disappeared almost entirely into the tree. He inserts a tiny spoon into the back of the tool’s hollow bit and pulls out a long beige dowel partitioned by some 450 orange stripes — a chronicle of this tree’s life.