During a long-term research project in a Central American rain forest, mature trees grew more slowly in warm years than they did in cooler ones. This observation hints that tropical forests may become less efficient at removing planet-warming carbon dioxide from the atmosphere if global temperatures continue to rise.
From 1984 to 2000, scientists studied the old-growth forest at La Selva, Costa Rica. Annually, the team measured the diameter of all mature trees within a 2-square-kilometer area. They found that diameter growth varied significantly from year to year and was related to average daily temperature. The annual tree growth from 1984 to 1986, the coolest interval during the period, averaged 81 percent gr