<\/p>\n
Across Southwest Colorado, juniper trees may look like they\u2019re dying, but local foresters say the situation is a lot more complicated \u2013 and puzzling \u2013 than meets the eye.<\/p>\n
\u201cIt\u2019s very strange,\u201d said Gretchen Fitzgerald, a forester for the U.S. Forest Service based in Durango. \u201cNo one is really sure what\u2019s going on except that it seems to be potentially related to the weather.\u201d<\/p>\n
This December, foresters in the region started to notice junipers turning from green to brown, which began internal discussions about what may be afflicting the hardy tree that grows in high desert terrain and can live for hundreds of years.<\/p>\n
For starters, any chance of beetle kill or fungus-related diseases were immediately ruled out.<\/p>\n
Dan West, an entomologist with the Colorado State Forest Service, was traveling through Dolores and La Plata counties last month when he pulled off the road to inspect the junipers after he noticed the abnormality.<\/p>\n
\u201cI didn\u2019t see anything that would indicate it was an insect or disease issue,\u201d he said. \u201cIt looks to me they\u2019re just struggling from the temperature fluctuations. It\u2019s been such a weird season.\u201d<\/p>\n
Southwest Colorado is home to two species of junipers: the Utah, which grows at elevations between 2,000 and 8,000 feet, and the Rocky Mountain, at elevations between 5,000 and 7,000 feet.<\/p>\n
This discoloration, foresters said, tends to be occurring to both species at an elevation band of 7,000 feet throughout Southwest Colorado, from Durango north to Gunnison.<\/p>\n
What\u2019s confusing foresters is that the junipers don\u2019t appear to be showing the usual signs that would indicate they are dying. And, what\u2019s equally perplexing is that the juniper\u2019s ecological neighbor, the less drought resistant pi\u00f1on tree, isn\u2019t showing any signs of stress.<\/p>\n
That\u2019s led researchers to believe the junipers are adapting to the early stages of extreme stress caused by drought conditions and wildly fluctuating daytime and overnight temperatures.<\/p>\n
Normally in the winter, junipers do turn a hue of purple as a result of the tree shutting down its system in a sort of plant-induced hibernation to save resources and energy.<\/p>\n
This year, however, the trees appear to be turning a brownish-orange not seen in years past, which could be the result of warm daytime temperatures forcing the trees to continue to operate as if it were summer, said Todd Gardiner of the U.S. Forest Service. Then, overnight lows throw the trees\u2019 system out of whack.<\/p>\n
\u201cIt being dry is one thing,\u201d Gardiner said. \u201cIt being dry and warm outside is a whole other thing.\u201d<\/p>\n
In the 20 years she\u2019s worked in the region, Fitzgerald said she\u2019s never noticed junipers take this kind of turn. Her colleagues, too, say it\u2019s a first.<\/p>\n
While the 2002 winter may be comparable in terms of the lack of precipitation in the region, this year is markedly warmer.<\/p>\n
The warm and sunny days that have defined this winter so far can increase the amount of water lost from the needles. And with no moisture in the soil, roots are deprived of the water they need, which causes the tree to lose its green pigment.<\/p>\n
Local foresters agree that since this is the first time they\u2019re seeing this phenomenon, there hasn\u2019t been enough research into the color shift to say this theory is definitive.<\/p>\n
However, the numbers certainly back it up.<\/p>\n
According to National Weather Service data, the average high in December in 2017 was 47.8 degrees, with an average low of 11.3 degrees \u2013 a change of 36.5 degrees from daytime to overnight temperatures.<\/p>\n
The month as a whole was 3.2 degrees warmer than normal. Based on 30-year averages, December has an average high of 40 degrees and an average low of 14 degrees, which amounts to only a 26 degree spread.<\/p>\n
Take these temperature shifts into consideration with the utter lack of precipitation \u2013 0.02 inches recorded in December at Durango-La Plata County Airport, 1.15 inches below normal \u2013 and the reason for the junipers\u2019 struggle becomes more clear.<\/p>\n
Kent Grant, a forester with the Colorado State Forest Service based in Durango, said the district has received calls from residents noticing the pronounced color shift. Many people are worried the trees are dying.<\/p>\n
\u201cI can see why people are getting concerned,\u201d Grant said. \u201cThey are looking different than they typically do this time of year.\u201d<\/p>\n
While the stressed junipers have warranted attention from foresters, it\u2019s too early to say whether there will be serious ramifications, such as a massive die-off, as a result of drought conditions and unusually warm temperatures.<\/p>\n
For now, they\u2019re taking a wait-and-see approach. If winter finally arrives and brings reliably cold temperatures and moisture, it\u2019s likely the trees will rebound in the spring, Fitzgerald said.<\/p>\n
\u201cIt\u2019s unusual, but the trees are hardy, and we think they\u2019ll bounce back,\u201d Fitzgerald said. \u201cBut we aren\u2019t sure. We won\u2019t know how this ultimately affects them until the spring.\u201d<\/p>\n