Grassy Fields

Vol. 8 Issue 3, Summer 2003

By Leslie McCasker

I hate to mow the lawn. It’s an onerous chore I perform once or twice a week from March (after the frost has dried), throughout the summer under the glaring heat of sun, right until the chill of fall paints the grass with frost again. This year has been different ― with the over-abundance of rain, I have had a reprieve and so has my yard.

In a low lying area where my weeping willows thrive, I have a grassy field that has not yet been touched by the tractor. It’s amazing to watch the native grasses and plants step up to fill in their rightful place, as well as the creatures that find refuge, comfort and nourishment in this grassland.

In the eastern U.S. most grassy fields are pastures and meadows ― ephemeral plant communities that depend on people to survive. If left untouched by mower, plow, cattle, herbicide, flood, or fire, a field is usually choked out by a transitional thicket community of perennials — goldenrods, milkweeds, asters, fleabanes, cinquefoils, clovers — which finally wither under the rising tide of seedlings that ultimately become forest. Each succession of plants prepares the ground for the next community by aerating the soil, fertilizing the ground with decaying leaves, and ultimately creating an awning of shade. This succession of plant communities can take centuries.

Sometimes, the “field-to-forest” progression is interrupted, and a particular stage persists for years and years. Fields that remain grassy are a good example of this. The secret of their staying power is the sod-layer — the result of years of grass growth. Grass has probably been around since mammals appeared, about 65 million years ago. Of the 7,500 species of grasses, most have long, narrow, parallel-veined leaves alternately attached to a jointed stem. The base of each leaf wraps around the stem to form a sheath, while the blade spreads out and up from the side of the plant. The stem is hollow, except at each joint, where a single leaf originates. On the end of the stem are clusters of tiny, feathery flowers and seeds.

The characteristic of grasses that allows them to tolerate mowing is their dense fibrous root system. This also allows them to survive drought, flood, fire, and grazing. Most of the grasses’ biomass is below the surface in the form of roots and rhizomes (underground runners that pop up as grass tufts some distance away). Each new grass plant develops its own fibrous roots and puts out more runners, etc. Eventually, the soil beneath the surface is rife with miles of roots. You can get a glimpse of this when you pull up a clump of grass and get a ball of root-bound soil along with it.

Because grassy fields are uniform habitats — compared to the stratified deciduous forest, with its varying heights and branch patterns — they support a less diversified group of animals and plants. Animals influence the development of grass, and grass in turn molds the evolution of animals. Fields are often visited by animals that don’t necessarily live there year-round. They may come only at certain times of the day, or in certain seasons when food in other habitats is scarce. Part of the magic of fields is that they are so different from the habitats that surround them.

Because they are in the sun for much of the day, fields are among the first places to lose snow cover. Grasses begin to green long before other fresh foods are available. Browsers such as white-tailed deer are regular visitors, eager for a succulent meal after a winter of woody browse. Hibernators such as woodchucks and snakes want to bask in the warmth of the sun after the long, dark internment of winter.

Flowering plants also abound in grassy fields, and with them come the insects drawn by their fragrance and nectar. Birds sit in nearby shrubs and trees, venturing out at intervals for midair snacks. On the ground, grasshoppers provide tasty morsels for northern harriers, while flickers probe the ground, hoping to find a colony of juicy ants.

The bristling blades of grass hide the nests of several ground-dwelling birds, including horned larks, sparrows, northern bobwhites, and killdeer. In addition to cover, the parents find an abundant supply of insects to fill their nestlings’ gaping beaks. Aerial predators survey the runways and burrow entrances of the meadow’s burrowers such as chipmunks, toads, and meadow voles—the openness making it an ideal hunting habitat.

As of now, the grassy field will remain a part of my landscape (at least until the water dries up). Then I think I will be forced to mow it down once again. But after this experience, I am looking at other areas of the property that would be more suitable for a NO-MOW zone. You too, should look for a corner to devote to a grassy field and watch the wonders of wildlife ― even if just for a year.