Depending on where you live, you may still have a few tenacious leaves hanging onto their trees. And these days, you’re likely to have more of those tenacious leaves. Measurements in europe have revealed that the color change and falling of the leaves has moved back about one and a half days per decade for the past thirty years. Spring has also sprung forward, and that’s clearly linked to global warming. But new research suggests that the delayed falls are mostly due to the direct effects of increased carbon dioxide.
Researchers from the University of Southampton in the UK raised poplars in today’s CO2 levels, and in levels predicted for 2050. They found that the 2050 trees used the extra CO2 to make compounds that kept their leaves alive and green longer. Their findings appear in Global Change Biology. this could be good and bad. The trees will be more productive, but they might not prepare as well for winter. Either way, this finding means that increasing levels of carbon dioxide can affect trees both indirectly through global warming and directly as a chemical compound.