Sunday, August 30, 2020

Fall colors might arrive early due to Colorado drought

 

 If you're planning on taking a trip to see the changing colors of the leaves this fall, you may want to check your travel dates so you won't miss them. 



Colorado is in a state-wide drought and the lack of rain and long heat waves this summer could change how quickly leaves turn colors and fall from the trees.


According to Colorado’s State Forest Entomologist, Dr. Dan West, rain is the biggest factor in how leaves change from year-to-year.  

“The only variability that we really see is precipitation. That certainly does drive whether or not we're going to get right on average,” West said. “It looks like because of the drought, we're seeing we might be a little bit ahead.”


West said that in the northern parts of Colorado, where the drought is not as severe, the leaves will drop close to the average peak in the middle of September. But in areas of extreme drought like southern Colorado, the changes could happen up to a week early. 

The good news, West said, is the fires don’t impact the time-frame or leaf coloring too much. It’s all about day-to-day shifts in the weather. 

“The smoke doesn't necessarily trigger the tree to block off the leaves any earlier than what we would see from just a cloudy season or cloud events,” West said. 

The biggest factor in color is the temperature variability over the course of the day.


“Those leaves changing is really a factor of day length, and then cool nights,” West said. “The cool nights trap the sugars in the leaves and that gives us those reds. And if we don't have those cool nights and it just kind of goes from really warm to really cold or frost, we just get the yellows and oranges that are already in the leaves.”


West said not to worry if you don’t see those gorgeous aspen trees changing right away. Each group of aspen has individual factors like fungus or insect growth that can change when it turns. So a patch just down the road might be perfect, even if the first one you saw isn’t at its peak yet.