Researchers have discovered that fragments of temperate broadleaf forest in the northeastern U.S. absorb more carbon than expected along their edges. But the scientists also found that those forest edges are more susceptible to heat stress and that rising temperatures from climate change are likely to significantly reduce the ability of temperate woodlands to absorb CO2. Scientists from Boston University took core samples from 210 trees in 21 fragmented forest plots around Boston to gauge rates of growth and carbon sequestration. The higher-than-expected rates of CO2 absorption along forest edges was due to reduced competition among trees, enabling remaining hardwoods to rapidly grow and absorb CO2. But growth and CO2 uptake along those same forest edges, which are exposed to more wind and sun, slows considerable in hot weather, the researchers reported in the Proceedings of the National Academy of Sciences.