Climate Change Could Delay Fall Foliage Colors

[JRLeft]

It’s that time again: time to take a hike and enjoy the splendid fall foliage. Or, if you live in a tourist town like I do, time to see “leaf peepers” driving their cars aimlessly throughout the countryside searching for a stand of incredibly red maples or golden oaks. If climate change continues on its present course, however, you might want to mark future calendars a bit later than usual for the best day to take that walk or ride.

Trees use a combination of cues to determine when to drop their leaves, but the two primary signals are the length of daylight, and temperature. Sunlight is the major factor; as trees sense fewer hours of light, they curtail photosynthesis in their leaves. Green chlorophyll fades, and colors emerge. Climate change has no effect on day length, but it does on temperature. If autumn days are warm, trees tend to delay the color change, and if autumn days are cool, they tend to hasten the pace. If global temperatures generally rise, you may need to take that walk a few days later. Indeed, Massachusetts officials have determined that the average peak color change has shifted about three days later over recent decades.

Climate change could also alter precipitation, which can affect colors as well. The amount of rainfall does not seem to be a factor, but more cloudy days lowers the level of daylight, which tends to lessen the intensity of a leaf’s color.

Video at the link: http://blogs.scientificamerican.com/observations/2012/10/02/climate-change-could-delay-fall-foliage-colors-video/

[porphyrian]

1. We're already starting to turn in Iowa. n/t

[JRLeft]

3. Has Iowa been warmer this fall?

[porphyrian]

5. I'm new here, so I don't know what it's usually like, but we had a heat wave this Summer...

...and we had some unseasonably cold days prior to the beginning of Fall, according to the local weather. I'm not denying global warming, I just noted that the leaves started yellowing almost exactly on the first day of Fall. I'm from Florida, so the concept of actually having four seasons is new to me.

[Saturday]

10. We were in northeast Iowa...

last weekend and I'd say the leaves were pretty close to "peak". Really beautiful.

[porphyrian]

12. I'm between there and the Quad Cities. I'm not sure how long it lasts around here...

...but it is really pretty.

[MadHound]

2. Out here in the Midwest, there are going to be very few fall foliage colors,

The drought has basically killed the colors. A lot of trees dropped their leaves early in order to preserve themselves. The leaves that are left aren't going to be very vibrant at all, mostly brown interspersed with a few reds and yellows.

[JRLeft]

4. Scary stuff. We are reaching a breaking point.

[HereSince1628]

6. Here in SE Wisconsin colors are great, and blamed on the drought!

It makes me wonder if the experts predicting the colors have a hue clue.

[MadHound]

7. From what I've observed over the decades,

You have more vibrant colors during years where rainfall is normal or above normal. You have dull colors in dry years. That's just my observation, take it for what it's worth.

[HereSince1628]

13. I think I'll trust my lying eyes on this one. The colors are about 2 weeks early

a state arborist says that's due to accumulated degree-days which the tree uses to measure it's way to the end of the growing season.

[badtoworse]

8. I'm up in the Adirondacks right now and the colors are at peak...

and as beautiful as ever. There is no problem here.

[Blue_In_AK]

9. We had good color here,

but with all the rain it's been hard to get out and enjoy it.

[DollarBillHines]

11. A lot of our harvest is running 2-3 weeks late. nt

[cherokeeprogressive]

14. Colors already changing in the So. Cal. mountains. n/t