Dune Ecology

June 23, 2018


 

Kitchel Lindquist Hartger Dunes near Grand Haven Michigan and in Ferrysburg, Michigan

The high wooded dunes rise above the Grand River, as they have for several thousand years, a part of the landscape both residents and tourists in the Tri-Cities area enjoy.    For a closer look, people can follow a self-guided nature trail through the dunes.  On Earth Day, the community pitches in and picks up debris blown into the dunes by the winter winds.  It’s a favorite place for people whether they simply look at it as a familiar part of the landscape, or use it for walking or cross country skiing in the winter for it abounds in wildlife, grasses, flowers, and trees. It’s a good place to study the lessons of ecology.

These Dunes, near the shore of Lake Michigan and on the north bank of the Grand River are a gift from the river and the west wind; water and wind currents carried sand deposited by Ice Age Glaciers 4,000 years ago.  It is a perfect place to study how a dune land changes over decades, centuries, millennia.  It is a good place to observe dynamic changes from  season to season, and even from hour to hour.     Ecologists say dunes are dynamic because they change rapidly.

First to develop the discipline of ecology, Henry Chandler Cowles published his work in l899. His scientific studies of the sand dunes along Lake Michigan in Indiana and Michigan pointed out the relationships between the shifting sands of the dunes and the changing plant communities that survive under harsh conditions.  The scientific observations Cowles made in the Indiana and Michigan sand dunes made him the father of ecology.  He saw that plants and animals change more rapidly in the dunes than in other places, therefore the dunes  made a perfect outdoor laboratory. Cowles’ observations on one group of plants replacing another is called succession.  Each stage in dune succession depends upon an earlier stage.  The first plants to grow were perhaps nourished by a dead fish that washed ashore. Insects such as the springtail and bacteria and molds broke the fish down into nutrients the plants could use. After their root systems stabilized the sand, and helped build the dune, other plants were able to establish themselves nourished by nutrients in a layer of topsoil formed by decaying matter.

Here is how the dune ecosystem changes with time:

0-20 years Beach grasses

20-50 years Cottonwood, beach grasses, cherry, willow, herbs

50-l00 years Increasing variety of shrubs, trees, and herbs, Jack pine may dominate

l00-years Black oak may be among the first forest dominants

Oak and hickory_l00-l,000 years  Beech and maple climax forest (extension_bulletin E-l529 Sea Grant)

Marram grass and sand reed grass are not discouraged by the harsh environment of a sand dune: hot, desert like conditions in the summer, strong winds, and cold arctic conditions in the winter.  Dune plants are adapted to extreme heat, cold, and a lack of moisture. The marram grass and the sand reed grass hold the fort on the fore dune by binding the sand with their huge, hair like root systems that may extend down to the water table for a hundred feet. Their stems grow upward even when covered by sand repeatedly.    On these dunes, 52 acres, there is a surprising diversity of life which makes its dune scape an ever changing panorama: plants especially adapted to the dune bloom, each in their season: A self-guided nature trail with  numbered stations shows the succession of plants in the dunes along the footpath are: horsetails, interdunal ponds or pannes with rushes, sedges and various insects and amphibians. A delicate looking yet hardy plant bearberry or kinnikinick was used by the Native Americans as tobacco, and there are junipers of two types, an endangered species: Pitcher’s thistle, pines, dune grasses, poison ivy, sand cherry, and various types of hardwoods such as red oak.  On top of the highest dune are beech and maple. There are also witchhazel trees that bloom in October and sassafras that turn brilliant colors of red and orange in autumn. Some trees are entwined with bittersweet with orange fruit birds feed upon.    Dune forests can grow up on dunes that have been pioneered by grasses and shrubs which stabilize the sand and over the years  help to build a layer of topsoil that can support tall trees.  In the spring, wildflowers such as trillium grow in profusion on south slopes of forested dunes where they can absorb more sunlight. In the open sunny areas of the dune, the yellow hairy puccoon flourishes: its gray green color and fuzzy leaves help it to reflect light and retain water.

Migrating birds rest in the high tree branches while permanent residents such as the pileated woodpecker and the horned owl go about earning their livings in their particular niches.  Whitetail deer browse on vegetation and red fox feeds upon everything from berries and insects to frogs and small mammals such as the white-footed mouse.  With the climax forest, the dunes have produced a diverse community of plants and animals that are an important part of the Great Lakes’ ecosystem. It may have taken a_thousand years between the time the first grasses colonized the sand and the tall trees found enough nutrients for theirseeds to grow.  These dunes are not replaceable. They are of more value to the whole ecosystem as dunes rather than as industrial sand or real estate. They protect inland areas from wind damage since wind blowing off the lake will glance off of a tall dune and rise up into the air.  They also protect inland areas from flooding, but perhaps their most appreciated value is their beauty.  Dune plants may be able to live through harsh summer and winter weather but, they cannot stand up to off the road vehicles or heavy foot traffic.  Building houses on dunes may also cause wind erosion when the plants stabilizing the dunes are removed. This is called a blowout and it forms a saddle shaped or U shaped depression in a stable sand dune.  In the past, many Lake Michigan dunes were trucked away load by load since their fine sand has industrial uses.

In order to protect Michigan’s coastal sand dunes, the state government passed a law in l989 that will prevent harmful development and protect the dunes we still have left. Governor Blanchard signed the bill into law at Kitchel Lindquist Hartger Dunes. Henry Chandler Cowles would have been proud.

In the deep valleys between sand dunes, wetlands with the same sort of living things found in ponds, may appear and then disappear when the weather becomes dry. Before the water disappears, tadpoles may change into frogs and toads. Salamanders may make their transformation from a water to a land animal.    With the climax forest, the dunes have produced a diverse community of plants and animals that are an important part of the Great Lakes’ ecosystem. It may have taken a thousand years between the time the first grasses colonized the sand and the tall trees found enough nutrients for their seeds to grow.  These dunes are not replaceable. They are of more value to the whole ecosystem as dunes rather than as industrial sand or real estate. They protect inland areas from wind damage since wind blowing off the lake will glance off of a tall dune and rise up into the air.  They also protect inland areas from flooding.  In the winter, people_cross country ski through scenic dune trails; in springtime, people come to admire the wildflowers and listen to the music of migrating birds; in the summer, people enjoy strolling through the cool forests and playing on the beaches. In autumn, the foliage changes to brilliant colors and dry leaves rustle underfoot.  Chipmunks scamper over fallen logs, their cheeks stuffed with beechnuts.     Hikers may be alarmed by a snake that rises in a pretty good imitation of a cobra, puffing out its hood to make itself seem fearsome although it is a perfectly harmless snake, and part of the dune ecosystem.  It is the eastern hognose snake (sometimes called the puff adder) with its shovel like nose the snake uses to burrow into the sand in search of it favorite food: toads. In fact, toads are the only food the puff adder will eat. There are also a few Mississauga rattlesnakes in the dunes , so if you take a hike, it’s a good idea to stay on the marked trails and keep your eyes open. There is a lot to see and enjoy.

Great Horned Owl

horned owl

wild flowers

wild flowers

Marram grass

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Great Blue Heron

April 8, 2016


The wetlands are important for wildlife and for filtering pollution.  The great blue heron is part of the web of life found in and around the Great Lakes and especially the wetlands surrounding them.  Read more about wetlands and food webs in my book,

The Dynamic Great Lakes.   blue heron


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This critically acclaimed book is also available in paperback from many bookstores and online at Amazon.com, bn.com and many other places.

 

DynamicGreatLakes-Independent_FullCover copy


oil pipelines under the straits click the link

 

munch The Scream

Aging pipelines could break and oil pollute Lake Michigan and Lake Huron: fish, birds all living things.

Mac Bridge

Mackinac Bridge over the straits of Mackinac.  Under the bridge flows oil through very old pipelines.


The Dynamic Great Lakes

Freshwater seas.

Freshwater seas.

Review of the Dynamic Great Lakes


Image

The days are long and the sunsets beautiful here on Lake Michigan.  Sailboats, fishing boats, boogie boards, paddle boards, kite boards, seagulls, terns, peregrine falcons, and great blue herons enjoy the day.  Deer peer from behind the trees in the wooded dunes and then browse our gardens after dark.  Coyotes, and foxes grab whatever rodents or house pets they can. Foxes scent the air with their musk.

I painted the red fox in a wetland where it found good hunting. I think so.


A critically acclaimed non-fiction book.

 

 

I wrote my non fiction book, The Dynamic Great Lakes to share some of the important information I have learned over the years, even before the first Earth Day. The book has a search inside feature on Amazon.com with key words, reading levels and now it is available for the Kindle reader. It is also available at Barnes & Noble and many other bookstores.

Above all, it is a book that encourages people to take care of the planet. It’s the only one we have.

The Dynamic Great Lakes

December 14, 2011


A Critically Acclaimed non-fiction book about the five Great Lakes

The Dynamic Great Lakes is available in the new edition at Barnes & Noble online or in stores. It is also available at Schuler Books and Music, The Bookman, Amazon.com (paper and Kindle edition) and many other fine stores.


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To learn about the Great Lakes and their interesting features, The Dynamic Great Lakes is for you.

Now updated in a fourth edition, Amazon has made the book available on the Kindle e reader as well as in paperback. The book is concise and suitable for all readers.


I will be at Barnes & Noble in Norton Shores, MI Saturday, July 23 at 11 a.m. to sign books and to chat about the Great Lakes.
In addition to my non-fiction book, The Dynamic Great Lakes I will have two more books on hand: The Wilderness Within and Sophia’s Lost and Found. I hope you will stop by.