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Posts Tagged ‘Gatlinburg’

A double-petaled Large-flowered Trillium

No one knew what to expect for the Spring Wildflower Pilgrimage this year.  It was scheduled two weeks earlier than the traditional timing (April 11-15), park officials put several restrictions on trails and program size, and the wildfire last November left sections of the park charred and scarred.  The week also corresponded with one of many spring breaks and the Easter holiday.

Traffic and parking proved the only real negatives.  It might as well have been the height of summer in Gatlinburg.  Pilgrimage goers have never seen this town so crowded during the work week.  We think curiosity about the devastating fire and a desire to help the city recover drove the exceptional visitation.

Silverbell

Every year the wildflower status for Pilgrimage week increasingly becomes a roll of the dice.  2017 turned out to be a jackpot year.  Trees were barely leafing out at lower elevations, most ferns were still rolled in tight crosiers, but the herbaceous wildflowers were going nuts.  A concentrated flush of flowering placed remnant Bloodroot, Liverleaf, Trout Lily, Wood Anemone, and Fringed Phacelia in direct competition with emerging Crested Iris, Fire Pink, Yellow Trillium, Wild Geranium, and Robin’s Plantain.  Both Silverbell and Flowering Dogwood were showy, and a few Serviceberries joined in for good measure.  It was simply spectacular.

Yellow Trillium whose flower parts have reverted to leaves.

Some unique sightings added to the flora fun.  During our hikes, we saw a Large-flowered Trillium (Trillium grandiflorum) with two sets of petals and a cluster of Yellow Trillium (Trillium luteum) whose floral parts had all reverted to mottled green leaves.

The weather was unseasonably warm, daily highs hovering near 80º, and very dry.  No April showers for days is unusual.  These conditions guarantee the colorful parade of flowers will pass quickly.

Burned ridges from the Chimney Tops 2 Fire viewed from the Carlos Campbell Overlook on Feb. 13, 2017

Fire ecology became the default theme of this year’s Pilgrimage.  Officials with the park and southeastern universities helped everyone understand the role fire plays in the natural landscape.  We hiked part of the bleak, blackened forest and witnessed the first stirrings of recovery.  Rob Klein, Fire Ecologist for the park, gave a presentation on fire, including pictures of the most severely burned areas.

Same view April 12, 2017

Chimney Tops 2 fire (the second fire in that area in 2016) started Nov. 23 on the Chimney Tops Trail, initated by two teenagers striking matches in the drought-plagued forest.  It was a slow fire creeping through the underbrush in an area of steep and difficult terrain, nearly impossible to access and fight effectively.  Park officials watched it carefully.  By Nov. 26, it had impacted only 40 acres.  Two days later, an approaching storm system arrived earlier than expected and brought winds much stronger than predicted into the area, generating a phenomenon known as mountain wave winds.

Right hand ridge from Balsam Point, Feb. 13

The National Oceanic and Atmospheric Administration describes this wind pattern: “Mountain waves develop on the lee, or downwind, side of mountains.  These waves are generated when strong winds flowing toward mountains in a generally perpendicular fashion are raised up over the mountains.  As the winds rise, they may encounter a strong inversion or stable air barrier over the mountains that causes the winds to be redirected toward the surface.  Instead of reaching back down to earth, the winds continue in an up-and-down wave-like pattern downwind of the mountains that may extend for hundreds of miles.”

Close-up view of ridge showing effects of a high severity fire

These mountain wave winds, hitting velocities of 80 to 100 mph, struck November 28 and within hours the 40-acre fire mushroomed into a 17,000-acre conflagration that destroyed hundreds of homes and businesses in Gatlinburg and sparked electrical fires from downed trees as far away as Cosby.  Fourteen people lost their lives.

Dead and downed wood smouldered on the Cove Hardwood Trail.

The fire burned 11,000 acres within the park according to Klein.  On half of those acres, the fire was low severity, removing the litter layer and a bit of the underlying duff.  It left evergreen shrub foliage brown on lower branches and green at the top.  A more open forest understory results, which will rebound within 5 to 10 years.  Cove hardwood communities escaped with little to no fire impact.  These moister, protected environments are less likely to support a hot fire even in drought.  The Cove Hardwood Trail at Chimneys Picnic Area, appears mostly untouched except for a few old logs and stumps that smoldered and charred.

Moderately severe fire on Baskins Creek Trail

Twenty-five percent of the burned acres experienced a moderately severe fire.  Litter and most of the duff was consumed.  Shrubs were completely browned to burnt, perhaps compromising the ability of rhododendrons to resprout.  Tree bark and pine needles were scorched.  Moderate fires open the forest and produce changes to its structure and composition.

Areas of high severity fire occurred primarily in the montane oak, pine, and heath communities found along ridges, approximately 1,000 acres.  Litter and duff were completely consumed, shrubs killed, and trees burned top to bottom.  Klein’s photo reveals a bare and blackened landscape with broken stubs of tree trunks like burnt matchsticks.

Bullhead and the severely burned heath bald (far right)

The Carlos C. Campbell Overlook on Highway 441 gives visitors a overall view of seven different community types in the park, and the intensely scorched sections correspond perfectly to the oak, pine, and heath ridges noted on the interpretive signage.  Some people have noted the right ridge line fire scar’s resemblance to an angel.

In the next few years, these areas of high severity will become dense with native herbaceous plants like fireweed and other weedy species that dominate highly disturbed wild lands.  Pine seedlings will germinate and carpet the landscape in a “dog-hair thicket” of saplings within 5 to 10 years.

Open and closed Table Mountain Pine cones

This rebirth has already begun.  The large cones of Table Mountain Pine (Pinus pungens), an Appalachian endemic, are serotinus.  A resinous substance seals the scales shut and only loosens with higher temperatures from solar radiation or the heat of fire.  Three days after the fire on Dec. 1, park officials documented pine seeds “raining” down.  On March 2, they noted the first sprout, and by April 13, numerous sprouts could be found.

Open cones of Table Mountain Pine on Baskins Creek

These ridge communities of oaks, pines, and members of the heath family are fire adapted, tolerating fires every 5 to 15 years on average.  Thicker bark, an ability to sprout from the stump, and the need for an open canopy to germinate and grow allow them to survive recurring fires.  In turn, these fires ensure regeneration of the species, maintenance of wildlife habitat, and reduction of fuel loads.  This last benefit prevents future fires from becoming too destructive and disruptive to the community.

In fire adapted communities, lack of fire can prove just as disruptive, leading to species decline and the possibility of severe canopy fires.  Along Baskins Creek Trail, the fire was of moderate severity in the Table Mountain Pine stand.  Cones on the trees are open, and pine seedlings are sprouting in the open understory.

Table Mountain Pine seedling

Forests may look very different in the aftermath of a big fire, but they begin their march back almost immediately.  The same is true for Gatlinburg.  Most fire damaged properties have been cleaned up, and construction is booming.  The forests and the town are well on their way to recovery.

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