It’s hard to imagine that two sides of the same hill can have very different environments. But at Oak Mountain State Park, it’s easy to see on the drive to Peavine Falls or along any trail that climbs Double Oak Mountain. The mountain’s northwestern flank is draped in tall, moist, dense forests of broadleaf trees, but its southeastern slope is home to short, dry open forests of conifers, especially Longleaf Pine (Pinus palustris).
The distinction is due to two reasons: the bedrock below and the sun above. Because the sun is always to the south in the Alabama sky, south-facing slopes get more direct light each day. That means the southeastern slopes are hot and dry and support pines, hardy shrubs, and scrubby oaks. The northeastern slopes support broadleaf trees – like Northern Red Oak (Quercus rubra), American Beech (Fagus grandifolia) and Tulip-poplar (Liriodendron tulipifera) – that need more moisture and cooler temperatures.
In addition, the composition of the mountain can affect the plants that grow above. The difference is most noticeable in the sandstone glades found along the southeastern slopes of Double Oak Mountain. These outcroppings of sandstone make for an especially harsh environment where only the toughest grasses and flowers and a few stunted trees survive. This is a rare and fragile ecosystem in need of protection.
Oak Mountain’s sheer size and number of habitats, from rocky outcrops to woodland streams, mean many animals make their home there. Visitors often spot wildlife along the trails, especially White-tailed Deer (Odocoileus virginianus), Wild Turkey (Meleagris gallopavo), Raccoon (Procyon lotor), and Virginia Opossum (Didelphis virginiana). A peek below the leaves on the forest floor reveals a world of smaller species: salamanders, snakes, and centipedes. And above, birds like tanagers, vireos, and warblers make the park a birdwatcher’s paradise.
-R. Scot Duncan