Prairie Wanderings: Winter in the Tallgrass Prairie
By PAUL G. JANTZEN
Contributing writer
When winter comes to the tallgrass prairie, plant growth aboveground comes to a virtual halt. But it is only the annuals that die. But even most annuals don't actually die; their fallen seeds contain the kernel of life by which the plant renews its growth in another year.
During late summer and fall, perennials transfer some of their nutrients from stems and leaves to their buds, underground bulbs, corms, rhizomes, and roots where they are stored for renewed growth in spring.
Big bluestem transfers so much of its stored nutrients from its leaves and stems that some prairie ecologists believe that bison may have migrated westward to midgrass and shortgrass prairies where the shorter grasses retain most of their nutrients above ground in winter. At Maxwell Wildlife Refuge in McPherson County, the diets of confined bison and elf are augmented with pellets of grains and alfalfa through the winter months.
The leaves, stems, and even some fruits remaining above ground in winter supply nutrients for herbivorous animals which become food for carnivores and scavengers. So, even in death, they serve a function in the web of life.
The dried stems and leaves left over also form a protective cover which, along with a blanket of snow, restrains winter winds and conserves the moisture needed for resumption of growth in spring. (Winter is often a dry season in this prairie.) The insulating blanket of snow also holds heat in the ground, protecting plants from extreme cold.
On Konza Prairie, near Manhattan, freezing temperatures can occur from October through mid-April reaching, at times, a low of -35 degrees Fahrenheit (-37 degrees Celsius) in January. In the winter newsletter of the Kansas Native Plant Society, board member Nancy Goulden suggests that winter can be a good time to appreciate the colorful fruits of various native prairie plants that persist into the dormant period.
The prairie wild rose bears bright red hips with a diameter of 10-15 millimeters at the top of a prickly stem. Sepals, now dried, are still attached on top. Some birds and mammals eat the hips. They served as emergency food for Native Americans. A good source of vitamin C, the hips may be eaten raw or used to make tea, preserves, or soup. This rose is woody, but dies back partly or completely to ground level each year.
Buckbrush, or coralberry, is another woody shrub bearing red berry-like fruits; these are 4-6 millimeters in diameter, deep red, and 2-16 per cluster. Apparently they are not often eaten by birds and mammals as they remain on parent plants for most of the winter.
Or you may encounter a perennial herb with yellow spines and yellow berries. This is a Carolina horsenettle, a relative of potatoes and tomatoes. Its berries are smooth when fresh but appear wrinkled late in the season. They are 1-2 cm in diameter. The berries are reported to be poisonous to cattle, sheep, deer, and humans.
Another herb with a perennial root is the buffalo gourd. Its fruit is about the size and shape of an orange and, in late summer is green with yellow or orange stripes. In winter, the gourd fades to a pale tan. Its pulp contains saponin which produces a soapy lather and can be used as soap.
These fruits and others can lead you back to wildflower patches next spring and summer when those species are in bloom.
The dried leaves and stems not eaten during the prairie winter, deteriorate more rapidly in the warmth and moisture of spring and the resulting increased activity of bacteria, fungi, worms, and other users of organic matter. There is some evidence that organic substances in the still-attached dried leaves and stems diffuse back to the growing parts of perennial plants in spring.
In spring, the prairie appears to become more active with short forbs sprouting, blooming, and dying before the taller plants leave them in the shade.
And, as Richard Manning describes it in Grassland, each spring and "summer the prairie rebuilds itself from the ground up, always advertising its work with a thick spray of flowers, the brisk yellows of the daisy-like composites, the regal reds and purples of clovers, the lavenders of the asters
