Credits

Created by Stephanie Bilodeau, Explore Natural Communities Intern Summer 2017, NatureServe.

Sound: Maple Fire, recorded by Jennifer Jerrett, NPS. Public Domain.

Music: Angel Share, by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: Attribution 3.0.

Photo: Mixed Oak / Heath Forest, by Alli Kenlan, courtesy of NatureServe. Licensed under Creative Commons: Attribution 4.0.

References: 
The Oasis: The Seasonal Newsletter of Prince William Forest Park 

Transcript

Podcast time: 3:38 minutes

[Music starts]

Charred logs. Blackened tree stumps hidden among greenery. What happened here?

To understand the story, we need to know the forest. The plants you see here are part of the hardy Mixed Oak / Heath Forest, a natural community full of – you guessed it! – a variety of oak trees (Quercus spp.) and heath shrubs (Ericaceae family). Low-growing "heaths" include flowering plants like mountain laurel and pink azalea, and also huckleberries (Gaylussacia spp.), blueberries (Vaccinium spp.), and wintergreen (Gaultheria procumbens).

Distinctive white oaks with leaf edges like smooth, rounded fingers and chestnut oaks with scalloped or wavy-edged leaves are both found here. You may also spot sharp, spiky-leafed black (oaks) and scarlet oaks, and even the occasional pine tree (Pinus spp.).

But wait... this is an oak forest – what are pines doing here? Fast-growing species like Virginia pine are often an indication that the forest has been disturbed in the past, which opens up spaces in the canopy. Virginia pine's seeds germinate on bare soil, and these canopy gaps let in the light that pine seedlings need to grow.

The charred logs and tree stumps scattered through the forest are more clues of disturbance in this area. Here's what happened: [sound of wildfire] In early spring of 2006, a wildfire covering more than 300 acres started in the forest around the Oak Ridge campground. The park had to call in help to fight the fire, which burned for 9 days in this dry forest, creeping along the ground and even jumping to the tops of some trees.

For an area recovering from such a blaze, the community sure has a lot vegetation today. That's because plants in the Mixed Oak / Heath Forest are awesome fire survivors! The oak trees here have thick bark that helps protect them from burning under conditions where thin-barked species like beech will die. And while those low-growing heath shrubs may be quick to burn, they're also quick to grow back after a fire, thanks to an extensive, shallow network of roots that stays safe under the soil, ready to re-sprout once the fire has passed. Recurrent fires are actually important for the health of this community. They promote plant regeneration and help prevent the buildup of flammable leaves and underbrush, which fuel bigger, more dangerous wildfires like the one in 2006.

Trees and shrubs in this forest thrive in dry, acidic soil, where few other plants can. The groundcover here may look scrubby, but wait until mid-summer when many of those heaths are laden with juicy blueberries and huckleberries. If you're not in the forest in time for the harvest, don't worry! The squirrels, deer, bears, and birds will happily eat the berries themselves. Come fall, acorns from the oak trees provide another tasty treat. Squirrels gnaw on closed Virginia pine cones to eat seeds; birds peck at open cones. Throughout the year, this resilient community provides food and shelter for many local animals.

Overcoming everything from acidic, nutrient-poor soil to blazing wildfires, the amazing plants in the Mixed Oak / Heath Forest are truly survivors!

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