Greetings!
This year's Green wave campaign has come to a close. We hope you have enjoyed making observations of flowering and leaf color on your maples, oaks, and poplars this year.
This year we asked you to observe flowering in your maples, oaks, and poplars to help us learn about pollen timing. We are collaborating with researchers to explore the potential of using your pollen data to create predictions of allergy season.
Below, we take a look at some of the patterns that emerged in your data this year. You can explore more Green wave data in our Visualization Tool. Start with our Seasonal Stories to discover the different types of visualizations available and how to use the tool.
We hope that you will continue to participate in this campaign next year. Observations made on the same trees over time are very valuable as they show us how trees respond to changing climate conditions.
|
|
What did you report on maples, oaks, and poplars? |
|
This year, 1,504 observers reported data on Green wave species at 1,193 sites, up from 878 sites last year. You recorded onsets of open flowers for 743 individual trees, onsets of pollen release for 316 trees, and onsets of colored leaves for 1,870 individual trees.
|
|
In total we had 1,504 observers contributing observations at both LPP sites and personal sites, which is nearly half of the number of observers who have been active this year! Thank you all for your efforts!
|
|
In order to better understand the timing of pollen release, we can look at when you reported "open flowers" on your maples, oaks, and poplars. We also have a phenophase on the Nature's Notebook datasheet for "pollen release". However, this can be difficult to record, especially in large trees where flowers are far off the ground.
The map below generally reflects a pattern in earlier flowering in the south and later flowering in the north. Some higher-elevation oaks (Quercus, denoted by the hexagon shapes) in Colorado and Arizona had later flowering.
|
|
Sites reporting "yes" for open flowers in Green wave species in 2020. Colors correspond to the first day of year open flowers were reported at the site. Shapes denote maples, oaks, or poplars. Green outlines indicate more than one genus observed at that site. |
|
In the Southeast, you started reporting open flowers first for Green wave trees in the maple (Acer) genus. The first peak in open flowers occurred in late January with a second peak in March. Green wave trees in the oak (Quercus) genus had open flowers starting in January with a peak in early April.
|
|
In the Northeast and Midwest, open flowers in maples (Acer) started in February, peaked in April, and ended in July. Open flowers in poplars (Populus) started in March, peaked in April, and ended in July. Open flowers in oaks (Quercus) started in March, peaked in May, and ended in July.
|
|
In the West, poplars (Populus) started flowering in late January and peaked in late March. Oaks (Quercus) first flowered beginning in January, with a peak in March and again in April. Maples (Acer) started flowering in late January and peaked in late April.
|
|
You reported colored leaves both early in the year and in the late summer and fall. Some maples and oaks have young leaves than can appear red, which may be why some of you reported colored leaves early in the year. Remember that you should only report colored leaves in full-sized leaves.
You should report leaves that change color due to cooling temperatures in the fall and also leaves that may change color due to stress from drought or insect damage. Add a comment with your observation with the suspected reason for color that happens outside of the typical autumn season.
|
|
Sites reporting "yes" for colored leaves in Green wave species in 2020. Colors correspond to the first day of year colored leaves were reported at the site. Shapes denote maples, oaks, or poplars. Green outlines indicate more than one genus observed at that site. |
|
In the Southeast, you reported colored leaves in a small number of oaks (Quercus) from January to February with a larger period from August to December. You reported colored leaves in maples (Acer) from July to December. You had a few reports of colored leaves in poplar (Populus) in September and October.
|
|
In the Midwest and Northeast, you reported colored leaves in oaks (Quercus) from January to April, with another larger period of leaf color from July to December. You reported colored leaves in maples (Acer) and poplars (Populus) from July to December.
|
|
In the West, you reported a small number of trees in all three genera with colored leaves in January. The peak for all three genera occurred from September to November. |
|
Did you earn your Tree Tracker badge this year? See it on your Observation Deck.
We hope you will join us again next year to continue tracking flowering and leaf color in your maples, oaks, and poplars.
Thank you for your contributions to this important project!
|
|
|
|
|
Contact
Erin Posthumus
erin@usanpn.org
520-621-1670
|
|
|
|
|
|
|
