Kaibab officials work to save aspen stands
WILLIAMS - Aspen trees are known for bringing crisp golden colors to the Southwest in the fall.
Unfortunately, they also are becoming known for their rapid decline in northern Arizona.
That's why the Kaibab National Forest's tree specialists are working to protect and restore aspen on the forest's Williams Ranger District.
Through grants from the National Forest Foundation and the Salt River Project's Trees for Change program, Kaibab Forest officials have built protective fencing and cleared out conifers around a number of severely imperiled aspen clones on the Williams Ranger District.
Such efforts have proven to be highly successful on other areas of the forest at promoting aspen regeneration and protecting young seedlings from browsing by elk and deer, forest officials said.
The fencing enclosed aspen in 11 separate areas across the district this summer and fall.
Each of the field fences reaches about seven feet in height and protects aspen generation, known as suckers, from browsing by large herbivores.
"This fence protection is absolutely critical to protect young suckers from elk browsing," silviculturist Alvin Brown said. "Lower elevation aspen clones are in serious decline throughout the forest, and without these restoration efforts, will continue to rapidly disappear from the forest environment."
Over the last 15 years, a serious decline has occurred in aspen across the Kaibab National Forest.
This decline has resulted in 60 percent to 95 percent mortality of low-elevation (lower than 8,500 feet) aspen. This is of particular concern on the southern portion of the forest where aspen is limited in quantity and is often found in small, isolated patches.
While the reasons for aspen decline are not fully understood, a variety of factors are at work including weather and climate events, lack of frequent fire on the landscape, insects and disease.
When aspen dies back, it attempts to develop new aspen by resprouting from the roots of the older trees. This is how aspen maintains its populations across the forest over time.
Heavy elk and deer browsing has eliminated almost all of the new aspen sprouts that have attempted to develop in declining aspen stands on the southern portion of Kaibab National Forest. This has seriously impeded the ability of these declining stands to regenerate and perpetuate aspen across the forest, officials said.
"That's why these fences are so important," silviculture technician Woody Rokala said. "You can see the difference inside the fence. We are basically creating a nursery for the young aspen to grow."
The fencing is part of a larger effort by Kaibab National Forest to protect and restore aspen sites.
Forest officials also have removed other tree species within and around aspen stands. They compete with aspen for sunlight, nutrients and water. Their removal increases the vigor of the aspen. This treatment is known as aspen release.
Aspen trees aren't just valuable for their good looks and the sweet-sounding stirring of their leaves.
They also are considered islands of habitat diversity amidst a sea of conifers because they support unique invertebrate communities that, in turn, increase the abundance of many species of birds.
"Aspen forests are widely recognized for their importance as biologically diverse wildlife habitat, as well as for their aesthetic and recreational values," silviculturist Mark Herron said. "We want to preserve this desirable tree species for future generations and for the wildlife species that use them."
The aspen restoration work is one of three projects on the Kaibab Forest that recently received money through the partnership of the National Forest Foundation and the Salt River Project.
A total grant of $98,144 was awarded to the forest, with money also going to reforestation efforts on the Tusayan and North Kaibab ranger districts in areas burned by wildfire.