When provided with continuous nourishment, trees, like people, grow “complacent”—the word tree-ring scientists use to describe trees like those on the floor of the Colorado River Valley, whose roots tap into thick reservoirs of moist soil. Complacent trees aren’t much use for learning about climate history, because they pack on wide new rings of wood even in dry years. To find trees that feel the same climatic pulses as the river, trees whose rings widen and narrow from year to year with the river itself, scientists have to climb up the steep, rocky slopes above the valley and look for gnarled, ugly trees, the kind that loggers ignore. For some reason such “sensitive” trees seem to live longer than the complacent ones. “Maybe you can get too much of a good thing,” says Dave Meko, a tree-ring scientist who has been studying the climate history of the western United States for decades. Tree-ring fieldwork is hardly expensive, but during the relatively wet 1980s and early ’90s, Meko found it difficult to raise even the modest funds for his work. “You don’t generate interest to study drought unless you’re in a drought,” he says.
【Group】46 What is the best title for this passage?
(A)Tree Rings in the Colorado River Valley
(B)Tree Rings and Climate History
(C)Trees and People in Complacent Life
(D)The Protection of Trees in Colorado