Forest Succession

 

Science Quad

From the perspective of a pioneer tree, this grassy lawn is an opportunity. Nearby pioneer species include tulip poplar (Liriodendron tulipifera, right in front of you), loblolly pine (Pinus taeda, diagonally across the quad, on its northwest corner), and sweetgum (Liquidambar styraciflua, at the northwest corner of the Chapel Gardens). These early successional trees would leap at the chance to colonize this field. All we would need to do is stop mowing the grass!

Science Quad

Succession is a pattern of change from one natural community to another over time. In the first years after abandoning this lawn, we would expect weeds and grasses to dominate, followed soon by larger grassy plants, by woody shrubs, and by seedlings of our pioneer trees. These early successional species tend to share some characteristics: they are fond of sunlight, grow fast, and are adept at dispersing seeds that can wait for just the right moment to germinate.

But the hares would lose the race to the tortoises: long-lived oaks, hickories, and beeches might eventually establish a canopy to shade out many sun-loving plants and, left undisturbed, could establish a climax community. That climax forest would be more diverse, energy-rich, and stable than earlier ones. Not so very long ago, mature forests of this type were everywhere in Atlanta, the “City in the Trees.” But from 1974 to 1996, according to American Forests, development reduced heavy tree cover in the metro area from 47.5% to 26.4%. Here at Agnes Scott, we are doing our part by planting new trees on campus and maintaining our areas of continuous tree canopy.