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Green Wave Midwest - Maples, Oaks, Poplars
We invite you to join us in tracking the “green wave”—the flush of green that accompanies leaf-out–-over the course of the spring season, as well as the spread of seasonal color across the country in the autumn.
Observations of these trees are of extra importance because they can help decision makers develop forecast models and early warning systems for use in forest management and public health administration via pollen forecasting. In fact, researchers are already using data that have been reported for these species to validate models that predict how changes in climate will impact phenology of trees, and also to learn that deciduous trees may leaf out weeks earlier under climate warming.
Join us in this special campaign! Make it easy on yourself...choose that tree that you see every day - either the one in your yard or the one you pass each day. Observations from just one tree can help fill critical data gaps!
How to Participate...
1. Select one (or more) individual maple, oak, or poplar trees to track from the list below. Species marked with * are of special interest for your region.
boxelder (Acer negundo)*
northern red oak (Quercus rubra)
balsam poplar (Populus balsamifera)
quaking aspen (Populus tremuloides)
Eastern cottonwood (Populus deltoides)
red maple (Acer rubrum)
sugar maple (Acer saccharum)
Don't have one of the target species at your site? Your observations are still valuable! select from our list of many other maple, oak, or poplar species for which we have protocols.
2. Join Nature's Notebook. If you haven't already, create a Nature's Notebook account. See our specifics of observing if you need more details on getting started.
3. Sign up to receive our Green Wave campaign messaging (in the right sidebar of this page - you may need to scroll back up to see it). You will receive messages approximately every 4-6 weeks during the growing season, providing early results, encouragement, observation tips, interesting links, and campaign-specific opportunities. Don't miss out!
4. Take observations. We invite you to track leaf out in your trees ideally 2-4 times a week, in the spring and autumn. We are especially interested in the following phenophases, though you are welcome to report on flowering and fruiting as well.
5. Report your observations. As you collect data during the season, log in to your Nature's Notebook account and enter the observation data you recorded. You can also use our smartphone apps to submit your observations!
While you reported that northern red oak and quaking aspen leafed out about the same time this year and last year, you reported that sugar maple leafed out several weeks earlier in 2016 than in 2015, which had a cooler preceding winter. The phenology calendar below shows your reports of breaking leaf buds in sugar maple, northern red oak, and quaking aspen in the Midwest for 2015 and 2016. Green bars indicate "yes" reports, while gray bars indicate "no" reports for that phenophase.
The majority of your reports of colored leaves for sugar maple, northern red oak, and quaking aspen show a slightly later leaf color change in 2016 than in 2015. Both years had summers that were warmer than average, though 2016 was much above average (1895-2016 average, NOAA.gov).