News  Ants and spring wildflowers

Have you ever wondered why a slope with sugar maples seems to be carpeted with lots of early spring flowers, while a mixed hardwood and softwood forest nearby has so few? The reason might be ants! Ants are important in determining where some plants occur. A woodland rich in ants is also a woodland rich in spring wildflowers.

Ants are everywhere, though people rarely notice them except when they are foraging above the ground. They live mostly below the ground, where we can’t observe them easily. They are the prime creators and mixers of soils in New England, rather than earthworms, as New England has few, if any, native earthworms. Most of the earthworms in New England originally came from Europe with the colonists. Ants are important scavengers and garbage recyclers in our forests, and prey on smaller insects and arthropods. Ants are also important sources of food for birds, small mammals, and larger insects and spiders. 

There are several early spring blooming plants, also known as spring ephemerals, that rely almost entirely on ants to distribute their seeds. To attract the ants to the seeds, the plants attach a structure known as an elaiosome to each of their seeds, which is made of lipids, an edible fat. This is so attractive to the ants that they will haul the seeds with the elaiosomes to their nest. The elaiosome is removed from the seed and is used as food by the ant colony. Some plants that rely on ants to move their seeds around include wake robins (Trillium spp.), bloodroot (Sanguinaria canadensis), wild ginger (Asarum canadense), several species of sedges (Carex spp.), and violets (Viola spp.)

Many violets have elaiosomes attached to their seeds which are an attractant to two common species of ants in sugar maple forests, the rough aphaenogaster (Aphaenogaster rudis) and the pitch-black aphaenogaster (A. picea). Both ant species might be found in old rotten logs, tree stumps, and under bark, fallen tree limbs and in small cavities. Violets have spring flowers which are pollinated by bumblebees (Bombus spp.) and several early moth and butterfly species. The seeds develop in rounded, three-sided capsules. When the seeds are ripe, the capsules explode, throwing the seeds several feet away from the mother plant. The further the seeds are tossed, the more likely they are to be located and carried off by ants. The ants will bring these seeds to their nests, eat off the elaiosome, and leave the violet seeds in their mini compost piles of vegetative waste, a perfect place for a new violet to grow. 

Enjoy taking in the sights of colorful wildflowers this spring!