The ecology of the A.C. Moore Garden begins with its geologic history.  Much of downtown Columbia and the USC campus lie on old river terraces formed by the ancient Congaree River.  Although the area normally receives about 45 inches of rain per year, the permeability of the sandy soils causes it to be both dry and of low fertility, as nutrients are rapidly leached away.  Some areas are marked by springs and seeps, which in turn produce small streams.  The pond in A.C. Moore Garden is fed by such a spring.

The geologic setting of the area results in equally distinctive vegetation; much of the flora in this region is xerophytic, meaning it is adapted to dry conditions.  However, in the garden, steep slopes, shade, and the naturally boggy area around the pond provide a variety of growing conditions, which in turn support plants not normally seen in the Sandhills.  Native trees found in the garden range from live oaks, which prefer dry conditions, to cypresses, which prefer a wet location.  Click here to learn more about the trees in the garden.  Similarly, native shrubs, grasses, and herbaceous plants found in the garden prefer a wide range of habitats.  The aquatic environment of the pond adds one more vegetation type to the garden's mix:  Algae in the pond are at the base of a complex food chain, aided by aquatic plants such as the native lizard's tail and water lilies.  For a list of plants found in the garden, click here.

This diversity of plant life in turn supports a diversity of animal life.  Although few formal surveys have been completed, the garden supports a number of typical urban bird species year-round and is host to less common spring and fall migrants.  Mammals seen in the garden include the ubiquitous gray squirrel, as well as less visible rodents such as mice.  The garden also hosts occasional visitors such as opossums and muskrats.  The pond supports a variety of life, much of it invisible to passersby.  Zooplankton support larval insects and invertebrates living in and under the muddy bottom.  These in turn support larger animals ranging from tadpoles to fish, frogs, and turtles.

Because of human intervention, not all of the plants and animals seen in the garden are native to the area.  Beginning in 1938, when the University first dredged and stocked the pond, fish have been added - some natives caught in nearby waterways, some aquarium fish left by departing students.  Non-native plants have also been added, some purposely planted as ornamentals, and some accidentally "planted" by wind or birds.  Non-native plants and animals can disrupt the ecological relationships that keep the system in balance.  Of particular concern are highly invasive species such as English ivy, periwinkle, and Japanese honeysuckle, which quickly crowd out native species.