Davidson-Arabia Mountain Nature Preserve

These next few blog posts will be dedicated to a class I am currently taking at Georgia State University concerning the natural environments of Georgia. 

Granite outcrop communities have been said to be the crown-jewel of Georgia natural communities because they feature a rare suite of endemic or nearly endemic species, and Georgia has more of these outcrops than any other state. (L.Edwards,The Natural Communities of Gerogia p.303) Mount Arabia is a perfect example of one of these communities, consisting of granitoid rocks known as Lithonia gneiss which is a nomenclature distinct to Mount Arabia.  It is with much awe that I also mention that although Arabia Mountain, Panola Mountain, and Stone Mountain are all granite outcroppings within 20 miles of one another they each are composed of a distinctly different composition of granitoid rock. Mount Arabia is a perfect example of the healthy successional plant community that is adapted to all three of these just mentioned.  The many stages of succession can be observed here, starting from Xanthos and Endolithic lichens and Elf Orpine, and moving all the way up to Virginia Pine trees and Muscadine Vines. Many of these plants are endemic and/or federally endangered, so be careful where you step! If you plan on exploring the mountain in the summer please be aware of ticks, which are abundant here! This is a truly special place that we are lucky to have so close to the city and still largely intact.  

Find out more about the trails and history here:  arabiaalliance.org

Here are some of our field findings from Mount Arabia on September 16th, 2016:

(Photos taken from trails located in Davidson-Arabia Mountain Nature Preserve)

rock moss, (Grimmia laevigata)

The top of the mountain was dry and sunny, as Georgia had been experiencing drought conditions. Pictured here is rock moss, which can appear dark grey or even black when dry but puffs up and turns green when wet.  Here the green colored rock moss has been watered by our teacher with a water bottle.

Ornate Chorus Frog (Pseudacris ornata) found camouflaged in one of the water filled seepage pools on the mountain top.

water-filled seepage pools on the rock outcropping create a temporary wetland habitat of standing water and mineral breakdown

Haircap moss (Polytrichum commune) and Reindeer lichens (Cladonia spp. and Cladina spp.) growing on rock outcrop

After flipping through field guides and looking through several online data-bases, this appears to be 

           Puck's orpine (Sedum pusillum), 

a federally endangered species that is very similar to the famous Elf orpine, but prefers to grow in the shadier borders of the granite outcrop and not in the vernal pools.  It tends to be found under the shade of the Juniper tree or in cracks in the granite, such as pictured here. If can also be green when found in the shade but develops a more reddish color when exposed to full sun. 

Pine weed (Hypericum gentianoides) is well adapted for the harsh environment and full sun of the granite outcrop with it's modified photosynthetic stems.  

The rare and endemic Confederate daisy (Helianthus porteri)

exposed rock that has been cut in early quarry operations 

with only 11 known sites of this species left, federally endangered Elf-orpine (Diamorpha cymosa or Diamorpha smallii) 

seed pod awaits the harsh summer sun before germinating in the Fall

Xanthoparmelia conspersa,

a slow growing lichen seen of a quarried granite slab just off the walking trail. I never tire of getting lost in the patterns of lichens.