Biodiversity of Moss Rock

prickly pear cactus (Opuntia humifusa)
prickly pear cactus (Opuntia humifusa)
- Photo Credit: Scot Duncan
Moss on the Rocks
- Photo Credit: R Scot Duncan

Moss Rock’s sandstone glades may look barren, but they’re surprisingly rich in the number of different kinds of grasses and herbaceous plants. What’s more, many of the plant species there can’t be found in forests nearby, including Nuttall’s Rayless Goldenrod (Bigelowia nuttallii), Pineweed (Hypericum gentianoides) and Eastern Prickly Pear, which is a cactus (Opuntia humifusa).

Although the glades stand out, the preserve contains a wide range of habitats, including pine, hardwood and mixed forests and streams. According to the Friends of Moss Rock, 66 kinds of trees, 136 species of wildflowers and herbs and at least 106 species of birds have been tallied in the park.

One of the easiest ways to see the park’s diversity is through its trees. The areas around the glades give a sense of the rare mountain longleaf pine (Pinus palustris) woodland that once covered much of the area. Today, because most remaining forest around Birmingham has been cut for timber and natural wildfires have been prevented from clearing out the underbrush, other pines and hardwoods have taken over. But volunteers at Moss Rock Preserve have cut and raked a quarter-acre area to restore the understory and hope to do more in the future.

You can even find examples of the threatened Georgia Oak (Quercus georgiana), which is listed as “imperiled” in Alabama — one step away from the most severe conservation ranking. This small tree, which often grows more like a shrub, is only known to be in a few spots in Georgia, Alabama and South Carolina, usually at the margins of rocky outcrops.

Along the ridges and upper slopes of the preserve, you’ll find mixed pine stands, which contain all four of the pines native to the park – Loblolly Pine (Pinus taeda), Virginia Pine (Pinus virginiana), Longleaf Pine (Pinus palustris) and Shortleaf Pine (Pinus echinata) – plus Eastern Red Cedar (Juniperus virginiana).

Along the streams lie cove hardwood forests, which have the greatest number of tree species, including White Oak (Quercus alba), Tulip-poplar (Liriodendron tulipifera), American Beech (Fagus grandifolia), Southern Sugar Maple (Acer barbatum), American Sycamore (Platanus occidentalis), Water Oak (Q. nigra) and Black Willow (Salix nigra). Below, wildflowers like Crested Iris (Iris cristata), Bellwort (Uvularia perfoliata), Liverleaf (Hepatica nobolis) and Mayapple (Podophyllum peltatum) bloom in early spring.

More wildflowers can be found along a trail in the clearing along the power lines, where plants can find the bright sun that is scarce in the dense hardwood forests. In summer, various asters and sunflowers bloom, followed by goldenrods and accompanying Monarchs (Danaus plexippus) and other butterflies in autumn.

Situated in a fast-growing suburb, Moss Rock has one of the last big chunks of mature forest for birds in Hoover. It’s one of the few places some birds can find the habitat they need to breed, including the Hooded Warbler (Wilsonia citrine), Kentucky Warbler (Oporornis formosus), Summer Tanager (Piranga rubra) and Broad-winged Hawk (Buteo platypterus). It’s also critical habitat for dozens of migrating birds like the Magnolia Warblers (Dendroica magnolia), American Redstarts (Setophaga ruticilla), and Swainson’s Thrushes (Catharus ustulatus). Year-round residents include Pileated Woodpeckers (Dryocopus pileatus), Barred Owls (Strix varia) and Red-shouldered Hawks (Buteo lineatus). Except for Eastern Gray Squirrels (Sciurus carolinensis), Eastern Chipmunks (Tamias striatus) and Eastern  Cottontails (Sylvilagus floridanus), mammals are less likely to be spotted during the day, although White-tailed Deer Odocoileus virginianus), Woodchucks (Marmota monax) and Gray Foxes (Urocyon cinereoargenteus) do occasionally emerge.

But some of the park’s most interesting species are also the smallest and least showy. In areas that stay wet, you can find not just mosses but also liverworts and ferns, especially resurrection fern (the same ferns commonly seen on oak trees, which lies brown and dormant until a rain “resurrects” it to green. The boulders and glades are also covered with lichens, which give them their spots and colors and have poetic names such as Gold Dust (Chrysothrix candelaris), Smoky-eye (Porpidia albocaerulescens) and Dixie Reindeer (Cladonia subtenuis).

R Scot Duncan