Publication Summary

There has thus far been no clear agreement on whether autumn phenology events such as leaf color are more influenced by day length or temperature in temperate systems. The authors found that both have an influence.

Temperature and daylight length strongly influence the range of ragweed, an invasive weed. Ragweed can only reproduce in areas where its seeds can mature before the winter frost. This means that as the climate warms, ragweed will be able to grow in more places.

Warming temperatures are prompting many trees in temperate regions to put on leaves in the spring earlier than they have in the past. Climate change models predict continued warming of up to several degrees C by 2100. A team of researchers at Princeton University, led by David Medvigy, developed a nuanced model to predict the timing of leaf-out in the future.

Spring leaf-out phenology observations have proven valuable in predicting how arctic plant communities may change in coming decades. Models used to predict changes in plant communities have traditionally taken phenology into account, but have used a single date for leaf-out averaged across all plant species. As participants in Nature’s Notebook know first-hand, the timing of leaf-out varies by species.