More carbon in the atmosphere might give evergreens a competitive edge over deciduous trees, or those that lose their leaves, according to new research in the journal Science Advances.
As CO2 levels rise, evergreens — pines, spruces and their relatives — use water more efficiently. In drought, that might help these trees survive over birches, oaks and other deciduous varieties. Furthermore, they might have an even greater advantage in cooler climates, like in Ireland or the northern U.S.
The team compared leaf samples collected between 1988 and 1991 to leaves they pulled recently from the same species and locations, down to the exact GPS coordinates, says study co-author Jennifer McElwain, a paleobotanist at Trinity College Dublin in Ireland. Samples of the leaf datasets showed the researchers how much of two carbon varieties resided in the leaves — one version that trees select when they have water to spend, another that ...
