Tag Archives: Marshes

Native Plant Communities Of Iowa Article

By: Howard Bright

The Plant Communities of Iowa are vast but we will limit them to four major communities knowing there are many subgroups of these four.  What is a plant community? In nature, certain species are found growing together and they form specific colonies of plants called  “plant communities”. Native plants always grow in association with others to create plant communities that are essentially associations of indigenous species that have evolved over thousands of years and adapted to the specific geography, hydrology and climate of a particular area. The resulting “communities” are really groups of plants that exist together because of the given environmental conditions. 

Why is it important to know about natural plant communities?  It is very important because we can use these native plant communities as a prescription from nature in designing our wildflower gardens or landscapes.  There are four broad categories of native plant communities here in the Midwest and hundreds of sub categories as we break each of them down into more specific site conditions.  It is important to recognize which one of the four categories you would like to create or reconstruct.  The four major plant communities of the Midwest are: Prairies, Savannas, Wetlands and Woodlands.

When the white man drove deeper through the hardwood forest driving westward until they eventually broke through the dark shadows of trees and the shrubs of that forest land and peered out onto the blinding light of the open prairie, it was a sight to behold waving in the wind and appearing as a sea of rolling grasses dotted with the colors of blooming flowers.  Indeed this was a strange land to these new visitors.  Steeping out onto this sea of grass, the pioneer disappeared and kept moving westward.  This land was covered with Buffalo, Elk, Deer, Bear, Cougars, Prairie Chickens, Beaver and all kinds of wildlife.

It wasn’t long before this land was discovered, occupied and changed forever. In the 1800s, Iowans reworked the face of their new state with a speed and to an extent perhaps unparalleled in human history.  At the beginning of the century, a blanket of prairie cloaked three-quarters of this “land between two rivers.”  Pothole marshes dotted the flatter north-central part of the state, while a network of streams laced the rolling hills elsewhere across Iowa.  Dense forests engulfed some valleys in the east and groves of bur oaks climbed out of the river corridors and onto the ridges to form savannas.

Thousands of Native Americans lived on the land, harvesting wild plants and animals, growing crops, and occasionally managing the vegetation with fire.  By 1900, however, Euro-American settlers had claimed nearly all of Iowa’s 36 million acres as farmland. Non-Indian settlement officially began on June 1, 1833, when pioneers first were allowed to claim new land in the 6-million-acre Black Hawk Purchase along the west side of the Mississippi River.  By 1846, when Iowa became a state, census records listed 96,088 people.  The population doubled to 192,914 by 1850 and topped one million before 1870.  In 1900, Iowa had 2.2 million people, compared to 2.9 million people today.  Most lived on the state’s 200,000 farms, working land where 95 percent of the prairie, two-thirds of the woodlands, and most of the wetlands had been converted to agriculture.  This dramatic, swift, almost complete change of diverse prairie to a monoculture of cropland profoundly altered the ecosystem.  Twenty-eight million acres of bluestem, dropseed, compass plants, coneflowers, gentians, and hundreds other species were transformed, in a relative eye-blink, into a patchwork of corn, wheat, oats, hay, and pasture.  Those plots have expanded to the huge roadside-to-roadside corn and soybean fields that we see today.

Before Iowa was settled a map depicts the vegetation that was present around 1850.  Note the majority of the landscape was tall grass prairie.  There were thousands of acres of wetlands, especially in Central and Northwest Iowa.  The Woodlands were confined to the steep areas along streams and in the Driftless area of Iowa.  Rolling and steeper hills were occupied by Savannas.

It only took 60 to 70 years to almost completely change the ecosystem of Iowa.  It is said that this was one of the quickest and largest annihilations of a natural ecosystem.  Oxen with wooden and steel plows developed by John Deere ripped up the prairie sod and crops were planted.

Glacial deposits occurred over the entire state of Iowa during a period of 2.5 million years and as recent as 10,000 years ago.  The only region not affected by glaciations is northeast Iowa where bedrock is exposed in many areas.

A multitude of events were occurring simultaneously during the last glacial period known as the Wisconsian Glacial Age.  Notably, while the older glaciers of the Nebraskan, Kansan and Illinoinian had long retreated and left their heavy loads across the state, a new glacier advanced from the north covering the north central and central pars of the state.  At the same time huge amounts of silt were blowing in from the northwest from the exposed glacial plains due northwest of Iowa’s western border. Loose materials much younger than the bedrock beneath dominate the present land surface across Iowa. These materials consist of sediment originating from ice sheets, melt water streams, and strong winds during a series of glacial events between 2.5 million and 10,000 years ago (Quaternary). This familiar “dirt” consists of pebbly clay, sand, gravel, and abundant silt, which over time have weathered into Iowa’s productive loamy soils. These easily eroded “Ice Age” deposits account for the gently rolling appearance of much of the Iowa (and Midwestern) landscape.

During the Ice Age, glaciers advanced down into the mid-continent of North America, grinding underlying rock into a fine powder like sediment called “glacial flour.” As temperatures warmed, the glaciers melted and enormous amounts of water and sediment rushed down the Missouri River valley. The sediment was eventually deposited on flood plains downstream, creating huge mud flats. During the winters the melt waters would recede, leaving the mud flats exposed. As they dried, fine-grained mud material called silt was picked up and carried by strong winds. These large dust clouds were moved eastward by prevailing westerly winds and were redeposited over broad areas. Heavier, coarser silt, deposited closest to its Missouri River flood plain source, formed sharp, high bluffs on the western margin of the Loess Hills. Finer, lighter silt, deposited farther east, created gently sloping hills on the eastern margin. This process repeated for thousands of years, building layer upon layer until the loess reached thicknesses of 60 feet or more and became the dominant feature of the terrain.

Even though the prairie is gone, it has left us with a black treasure, our soil.  Over the eons of time the plants that grew on the prairie formed the richest soil on this planet.  Millions of acres are blanketed with black earth known as prairie soils.

What makes soils the way they are?  How did Iowa end up being the most fertile land in the world?   A unique combination and interaction of all of these factors formed our soils.  How are the soils of Iowa different?  By changing just one factor, we affect a major change in the soil.

Factors that interacted to form our soils can be simplified to: Parent Material, Climate, Topography, Vegetation, Time and Human Beings.

Soils are conceived, as we are, from our Parent Material.  Parent materials are composed of the raw earth that lays exposed to the elements. Major parent materials in Iowa consist of bedrock, glacial deposits called glacial till, water deposited material or alluvial deposits, and wind blown silt known as “loess”.  In other parts of the world, soils may be formed in volcanic ash or rock.

Climate has a profound effect on our soils as they are influenced by rainfall, temperature, freezing and thawing, sunlight and day length.

The way the land lays called Topography greatly influences our soils.  From the steep hills along river corridors to the level bottomlands, slope of the land can change the characteristics of our soils.

Vegetation and Organisms dramatically affect our soils.  Within a very localized area, we can note the effect of our past vegetation and what influence it has had on soils.  From the deep rich organic prairie soils developed under the influence of the tall grass prairie to the soils developed under a woodland condition depth of topsoil and fertility vary greatly.

We probably forget about a factor that is ever present and that factor is Time.  It is obvious when we think about the sediment deposited by a river or stream, which is in geologic times, is extremely young.  What a contrast when we sit atop a rock out crop that has been exposed for eons of time.  The stream deposited material stays forever young while the bedrock of a long ago sedimentized ocean bottom gets older and older.  Soils can’t hide their age either.

On the recent geologic scene came Humans and they have now joined the forces of soil forming factors.  By plowing, the natural vegetation and protection of the soil has been removed increasing erosion to an alarming rate.  Topsoil is destroyed, texture of the soil, which allows infiltration of water, is altered, soil forming organisms are eliminated, fertility is diminished as organic matter is washed away and soil tilth is destroyed.  Man has and is having his influence on our soils.  Fallow land and row crops now occupy land that was once a lush sponge to absorb water and cleanse it.

Once we understand the importance of our geologic past, recent history and soil forming factors, we can start to put together nature’s puzzle.  This intricate puzzle laid down over the eons is now at our fingertips for those who pay attention.

What other questions do we need to ask to get this right combination of plants that will fit our site?

  • What direction is your site facing, called Aspect?  A north and northeasterly direction may receive much less sunlight on a steeper slope than those facing south or west on the same steepness of slope due to the angle of the sun.
  • Is your site level, rolling or steep?  Slope as a steep south slope may be hot and dry while a steep north slope may be cool and moist.
  • How much Sunlight does your site get?  If it is dense shade versus full sunlight, you will need entirely different plants to suit your situation.
  • What is the condition of the soil in regards to Soil Moisture?  Drainage of the soil can range from saturated to excessively drained.
  • What are the sizes of the particles that make up your soil, called Texture.   It could range from sand to clay which an important characteristic to note as some plants will not tolerate these conditions.  For detailed description of your soils contact your local NRCS office and get a soil survey report of your county.

Absorbing and understanding the characteristics of our landscapes and soils allows us to then classify our sites.  In site classification we will assign a general category to our site based on all the previously mentioned information.  There are basically five sites to consider:

  • Dry
  • Dry Mesic
  • Mesic
  • Wet Mesic
  • Wet

Next we need to decide which plant community we are dealing with.  It may be a pre-existing condition or one that we want to create.  It is usually best to take what nature has given us if we have that opportunity.  However, if you live in an urban area, your site may have been severely altered and you will have to decide what you want to create there.  As mentioned before, we have four categories of plant communities:

  • Prairie
  • Savanna
  • Wetland
  • Woodland

Once the plant community is determined, select the most appropriate species for your plant community.  Now you are using nature’s prescription for success in creating your native wildflower planting.

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Liatris: Blazing Star of Prairie and Garden

Liatris is a tough and undemanding prairie plant, tolerant of poor soil and less-than-ideal moisture situations. It’s also a perennial border standout and florist’s staple. The long-lasting blooms of this summer- and fall-blooming American native attract butterflies, bees and hummingbirds. This is one wildflower that stands out wherever it’s planted, be it roadside, naturalized area or formal garden.

Identification
Some 30 species of liatris are native to nearly every state east of the Rocky Mountains as well as parts of Canada and Mexico. A number of the species and several cultivars are considered worthy of the ornamental garden. Early American settlers called this member of the Aster family “blazing star” or “gayfeather” because of its bright bottle brush-like flowers. Another pioneer name, “colic root,” referred to its medicinal use as an intestinal antispasmodic. Some types of liatris were known as “devil’s bite” or “button snakeroot” because of their reputation as a remedy for snakebite, particularly from rattlesnakes.

Image
Monarch on L. aspera

The foliage of liatris is spiky and grass-like, with leaves that are larger at the base of the plant and become smaller at the top.  In mid- to late summer, the stems produce many tiny, star-like florets. Unlike most other spike-flowered plants, liatris (with the exception of L. aspera) opens from the top of the spike downward, rather than from the bottom up. Depending on the variety, the spikes’ blossoms may be purple, pinkish-purple or white, and grow from 1 to 5 feet high. In the fall, liatris foliage turns an attractive shade of bronze, and the dried stalks serve as swaying perches for birds attracted to the seedheads.

Culture
Liatris plants prefer full sun but will accept some degree of shade. They are tolerant of a wide range of soils, but most require a well-drained situation. Plant in either early spring or in late summer or early autumn, spacing the plants about 1 foot apart. Watering regularly during its first year helps liatris become established, after which it becomes fairly drought-tolerant. Avoid overwatering, because it can cause plants to rot, and don’t overfertilize, because it can cause the flower stalks to flop. 

Depending on the species, liatris may emerge from a corm, rhizome or elongated root. Once liatris matures, you can propagate it by dividing large clumps in the spring, just as the leaves are emerging. Use a knife or sharp spade to separate the corms or roots.

Varieties
Many kinds of liatris are readily available from nurseries and garden centers. Even small plants often bloom the first year they are planted, and they become more impressive every year. Species liatris are also readily grown from seed. Some varieties to look for include:

Image L. scariosa (Eastern blazing star, New England blazing star, tall gayfeather) typically grows from 2 to 4 feet. If cultivated in a more fertile setting, it may require staking. The lavender, rose or white flowers resemble buttons, with individual flower heads growing from short stalks coming off the stem.
Image L. aspera (rough blazing star) features pink flowers on 1- to 3-foot spikes, blooming from August through October. Hardy to zone 4, this liatris prefers dry to moderately moist soil, and can be found growing in sandy fields and dunes.
Image L. pycnostachya (prairie blazing star, Kansas gayfeather, cattail gayfeather or button snakeroot) is hardy to zone 3 and prefers moist or even wet sites. The flowers may be purple, rose-purple or white, and appear on 2- to 5-foot spikes between July and September.
Image L. ligulistylis (meadow blazing star, round-headed blazing star, showy blazing star) prefers moderate moisture, and can be found growing in meadows, prairies and along the banks of streams. Pink to purple, 3- to 5-foot flower spikes appear in August and September. This liatris is particularly attractive to butterflies and is hardy to zone 4.
Image L. punctata (dotted blazing star or spotted gayfeather) is a drought-tolerant native of the Great Plains. Its long tap root makes it useful for xeriscaping. Pink flowers appear on 1- to 2-foot spikes in July through September. L. punctata is hardy in zones 4 through 8.
Image L. spicata (dense blazing star or spike gayfeather), hardy to zone 3, likes moisture and is found in marshes and meadows. Its rose-purple flower spikes reach 1 1/2 to 5 feet in August and September. Among the hybridized forms of L. spicata are ‘Alba’, with pure white flowers and ‘Floristan Violet’ with strong, bright violet stems. ‘Kobold’ is a small, compact plant, reaching only 18 to 24 inches high, with deep purple blooms.

Garden Uses
Liatris is an obvious choice for providing color to a naturalized planting, where it pairs well with prairie grasses, echinacea and coneflower. It’s also right at home in more formal settings, where the tall stalks provide punctuation and contrast to mound-shaped perennials. The warm rosy-purple blooms of liatris are a good foil for yellow flowers such as goldenrod, coreopsis and later-blooming golden daylilies, as well as silver-leaved plants like lamb’s ears and wormwood. Although the spikes look handsome planted in large groups or drifts, they also work well planted here and there as single accents. Shorter cultivars are best appreciated near the front of the border. Taller varieties needn’t be relegated to the rear of the garden — they make great “see-through” perennials, adding texture and variety to the border when you place them in front of shorter plants. 

Liatris and Critters
Image
In my research about liatris, I learned that this plant is beneficial to the diet of deer and antelope, and can be used as food for grazing livestock such as sheep. Although I have no livestock, my urban garden is home to herds of rabbits and chipmunks. Unfortunately, these critters do more than just nibble foliage — once they bite through a tall stalk, you can say goodbye to its flowers for the season. After bunnies decimated most of my magnificent 5-foot-tall white L. pycnostachya, I salvaged the remaining two stalks by wrapping them in plastic netting (the kind that oranges come in) up to about 12 inches — not pretty to look at, but preferable to gnawed stumps.

Cutting and Drying
Floral arrangers favor tall stems of liatris for adding a colorful vertical element to their designs. You can also use liatris in dried arrangements. Whether you’re harvesting the flowers for fresh or dried use, cut the stalks when the flowers are only one-half to two-thirds open. Liatris is easy to preserve by hanging the stalks upside down and allowing them to air dry for several weeks. Good air circulation is important as the flowers dry, otherwise they are apt to become moldy. Drying liatris in a dessicant such as sand or silica gel may help preserve more of the flower’s bright color.


Photo credits:
thumbnail by wallgrom
butterfly on L. aspera by mccormaka
L. spicata by Sentrawoods
DG Member photos:
L. scariosa by poppysue
L. aspera by sittingbones
L. pycnostachya by ADKSpirit
L. ligulistylis by Moby
L. punctata by Joy

L. spicata by Floridian

Article Taken from DavesGarden Website

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