Habitat – Discover-Nature

Midwestern Prairie

Grasslands make up the largest habitat in North America and cover about one-quarter of the Earth’s surface. There are many different types of grasslands, each with its own descriptive name. Prairie, found in North America, is from the French word for “meadow;” steppes, found in Asia, is Russian for “flat, grassy plain;” pampas, found in South America, is from Quechua meaning “flat surface;” and veldt, found in Africa, is from Afrikaans meaning “field.” In all of these areas, grasslands are characterized by flat or gently rolling countryside.

From upper left: The African veldt by Cello8, May 2007; Sunrise on the Mongolian steppes by Nicolas Mirguet, Apr 2011; Pampas grasslands, Uruguay, South America by Guilherme Boettcher, May 2010; Nachusa Grasslands, Lee County, Illinois by Justin Meissen, Jul 2007

Prairies in Illinois were formed by the action of glaciers retreating northward at the end of the last ice age. Massive ice fields compacted the soils and flattened the landscape. Many areas retained much of the melting ice in ponds, creeks, and rivers. These provided much needed moisture to help establish the new flush of vegetation that moved in as the climate warmed.

White River Prairie, Wisconsin by Joshua Mayer, Aug 2016

Several different types of prairies can be found, differentiated by the mixture of grasses and flowering plants, called forbs. We classify prairies as wet, mesic, meaning moderately moist, or dry. The determination is made based on how much water is retained in soil layers, but can be greatly influenced by temperature, rainfall amounts, and fire. Grasses have narrow leaves, can grow in drier environments, and are the dominant plant type in most prairies. Forbs have broad leaves and require more moisture than grasses. Prairie plants often have deep root systems to access water and nutrients.

From upper left: Big Bluestem, Andropogon gerardii by Matt Lavin, Sep 2019; Rattlesnake master, Eryngium yuccifolium by Adam B, Jan 2017; Grey coneflower seed heads, Ratabida pinnata by JanetandPhil, Nov 2010; Frosty Prairie dock, Silphium terebinthinaceum by Anne McCormack, Dec 2010; Indian grass, Sorghastrum nutans by Douglas Mills, Sep 2015

Animals that inhabit midwestern prairies are adapted to this habitat. They are able to find water and food in drier conditions, when water is scarce. They avoid the hazards of fire sweeping across the landscape. They keep warm during cold winter months. They avoid predators in a landscape with few hiding spaces. Many species are able to burrow underground for warmth, to avoid fire, and to escape predators. Others live near the ground in thicker vegetation that provides cover from wind, cold, and attack.

From upper left: American toad, Bufo americanus by Alan Huett, Jul 2008; Sedge wren, Cistothorus platensis by Joshua Mayer, Jul 2015; Thirteen-lined ground squirrel, Spermophilus tridecemlineatus by ChristaR., Nov 2016; Prairie kingsnake, Lampropeltis calligaster by Peter Paplanus, May 2022; Northern harrier, Circus hudsonius by Wendy Miller, Dec 2010

At this time of year, prairie plants are starting to go dormant and many bird species are migrating southward to warmer climates where food and water is abundant. It is a great time to get out and observe plants as they set seed and surprise us with the many hues of autumn. Birds are abundant as flocks fly overhead on their migration. Birds that spend the winter here are searching for areas that will provide seed and cover during the coming cooler months. Other animals are out to gather plants for insulation in their winter dens or seeds to store in their larder. Keep your eyes and ears open as you walk the prairie paths this month.

Midewin tallgrass prairie preserve, Wilmington, IL by CheapShot, Jun 2012

Carnivorous Plants

Plants and insects have myriad relationships to one another. Some are mutually beneficial, as when plants offer nectar to feed insects which in turn pollinate the plants. Other relationships only benefit the insects when they feed on leaves, stems, and roots. For carnivorous plants, preying on insects to fulfill their need for nitrogen and other nutrients benefits only the plants.

^{Venus flytrap, Dionaea muscipula by Len Worthington, Aug, 2016}

Pitcher plants are carnivorous, living in bogs and fens found in warm weather areas. In North America, most species are found along the southeastern coastal states from Texas to West Virginia. Bogs are depressions filled with rain or melted snow, while fens are similar but get their water from surface or groundwater. Both types of wetlands are low in oxygen and nitrogen, very acidic, and often quite cold. These characteristics slow down the rate of decay in the vegetation of the wetland, further reducing the availability of nitrogen which is a vital component of chlorophyll, the compound used by plants, along with water, carbon dioxide, and energy, to photosynthesize sugar for food.

^{Tracy’s sundew, Drocera tracyi by Matthew Paulson, May 2022; Venus flytrap, Dionaea muscipula by Judy Gallagher, Jun 2022; White-topped pitcher plant, Sarracenia leucophylla, showing downward hairs by Aaron Carlson, Sep 2013}

Carnivorous plants use several strategies to attract and trap insects. Pitfall traps have slippery faced leaves forming a funnel with a pool of digestive enzymes waiting at the bottom. Downward facing hairs on the leaves make it harder for insects to climb out. Some plants use an opposite strategy and cover their leaf surfaces with a sticky secretion, trapping any insects that land on them. Still others have a leaf-like structure made of two halves that snap together when an insect lands on an inner surface, trapping the insect inside. In both of the last two instances, digestive enzymes are then released to cover, kill, and break down the insect body for absorption by the plant.

^{White-topped pitcher plant, Sarracenia leucophylla, traps separated from flowers by NC Orchid, Apr 2016}

^{Two-spotted bumblebee, Bombus bimaculatus by Judy Gallagher, Jun 2022}

Carnivorous plants are insect pollinated and must be able to attract pollinators without trapping them. All of the plant species go through a dormant period as seasonal temperatures get cooler. Traps die back and are regrown when warmer weather returns. In several species, flowers bloom and attract pollinators with nectar, completing fertilization before traps develop. Other plants separate the flowers and traps by a physical distance. Traps usually lie close to ground level to attract crawling insects, and flowers are grown on top of tall stalks to attract flying insects. A third method is to make the flowers less attractive to potential prey, and make the traps less attractive to potential pollinators. This is achieved by using different colors, patterns, and scents on flowers and traps.

^{Metallic green sweat bee, Agapostemon sericeus by Dann Thombs, Aug 2008}

^{Cobra lily, Darlingtonia californica by Charles Peterson, Mar 2018}

Whether you are growing these unique plants at home or viewing them in a botanical garden or out in the wild, some of the plants and their pollinators to watch for include the white-topped pitcher plant, Sarracenia leucophylla and the two-spotted bumblebee, Bombus bimaculatus; the cobra lily, Darlingtonia californica and the mining bee, Andrena nigrihirta, Tracy’s sundew, Drosera tracyi and the metallic green sweat bee, Agapostemon sericeus, and the Venus flytrap, Dionaea muscipula and any of the hoverfly species, Toxomerus sp.