From the outset, beetle kill and disease were ruled out, leading foresters to believe the discoloration was somehow related to extreme stress caused by drought conditions and wildly fluctuating daytime and overnight temperatures during the winter.<\/p>\n
Adding to the confusion, however, was the fact the junipers weren\u2019t showing the usual signs they were dying. And, it\u2019s ecological neighbor, the less drought-resistant pi\u00f1on tree, wasn\u2019t showing any signs of stress.<\/p>\n
\u201cIf anything is going to survive the drought around here, it\u2019s going to be those junipers,\u201d said Mark Loveall, Durango supervisory forester for the Colorado State Forest Service. \u201cThey\u2019re about as tough a tree as you can get.\u201d<\/p>\n
All foresters could do was wait and see how the junipers would progress over the spring and summer.<\/p>\n
Inexplicably, and fortunately, over the past months, the junipers recovered and returned to their natural green color.<\/p>\n
Fitzgerald said she started to notice the junipers along U.S. Highway 160 between Durango and Bayfield and up toward Hermosa turn green after it started to rain in the spring.<\/p>\n
The trees continued to show healthy signs over the summer, despite the relative lack of precipitation, she said.<\/p>\n
\u201cA couple died \u2013 the ones that had turned really brown,\u201d Fitzgerald said. \u201cBut the ones that turned orange turned green again.\u201d<\/p>\n
Dan West, an entomologist with the Colorado State Forest Service, said a survey of junipers around Dolores and Mancos in August also came back with the same positive results.<\/p>\n
\u201cEverything looked green and just fine,\u201d he said. \u201cWe just haven\u2019t seen any further issues with junipers.\u201d<\/p>\n
What caused the junipers to turn brown in the first place, and what led to the junipers to return to normal, remains a guessing game.<\/p>\n
Southwest Colorado received some rain over the summer, but the region is still in an exceptional drought. Since Jan. 1, a weather station at the Durango-La Plata County Airport has recorded just 4 inches of rain.<\/p>\n
That\u2019s more than 7 inches below normal.<\/p>\n
Fitzgerald speculated that last year\u2019s hot and dry winter caused the junipers to shut all the way down. Then, when modest rains did fall over the spring and summer, they rebounded.<\/p>\n
West said perhaps the discoloration was connected to a late spring frost in May 2017, and the trees didn\u2019t show the effects until that following fall. Or, maybe it was just some reaction to the prolonged drought.<\/p>\n
\u201cI\u2019m just not real sure,\u201d West said. \u201cWe didn\u2019t set up any permanent plots for monitoring, so there\u2019s no data to back it up, other than anecdotally.\u201d<\/p>\n
The outlook for junipers across the Four Corners, however, isn\u2019t so encouraging.<\/p>\n
Monica Gaylord, a forest entomologist for the U.S. Forest Service based in Flagstaff, Arizona, said there have been reports of massive juniper die-off all over Arizona and Utah.<\/p>\n
And no one knows why.<\/p>\n
\u201cAll of a sudden the junipers are just dead,\u201d she said. \u201cAnd in all honesty, it\u2019s a mystery right now.\u201d<\/p>\n
Junipers in these states didn\u2019t show that bronzing discoloration like they did in Southwest Colorado, Gaylord said. Instead, the trees just started dying this summer.<\/p>\n
And there seems to be no historical precedent for the die-off, she said.<\/p>\n During the last major drought in 2002, foresters noted significant pi\u00f1on mortality, but the junipers made it through fine. This year, pi\u00f1ons aren\u2019t showing any signs of stress, Gaylord said.<\/p>\n The juniper trees are also showing no signs the deaths are related to beetle kill or disease.<\/p>\n \u201cWe\u2019re just not really seeing a smoking gun,\u201d Gaylord said.<\/p>\n