Tree color reaches prime time

TREE LEAF COLORS are at their best right now. Take time to immerse yourself in the annual color show now playing at a forest near you. I urge you to get outside and take a hike. Hike into a forest area at any of several Marshall County Conservation sites to see close up and personal what a carpet of colorful leaves looks like, smells like and sounds like as you traverse a forest pathway. It is Mother Nature’s annual preparation of hardwood trees for an upcoming winter. Day lengths are getting shorter. Leaf photosynthesis factories are shutting down, taking time off, and allowing the tree to rest until next spring’s longer days, warmer weather and rain wakes up the trees for another year.

A primary driver of leaf color is the natural decline of chlorophyll in the leaf. A succession of warm, sunny days and cool crisp nights (but not freezing) seems to bring out the spectacular colors. Tree leaves are still producing sugars but cool nights and gradually closing off the veins going into the leaf. This prevents sugars from moving out. So, the result is lots of sugar, lots of light which in turn allows for the production of anthocyanin pigments. We see the colors as purple, reds, and crimson. Carotenoids are always present in leaves so yellow and gold colors remain fairly constant from year to year.

Soil moisture in the soil can also affect leaf color. Since moisture levels are never identical from year to year. The net effect is that no two autumns are exactly alike. A countless combination of circumstances noted above mean leaf color will fluctuate. Our job as people is to take each fall season in stride, accept what is offered for what it is, and just enjoy this special time of year.

Deciduous tree drop their leaves in order to survive harsh winter weather. Stems, twigs and buds are equipped to survive extreme cold. Tender leaf tissues would freeze so trees have two choices, shed the leaves or protect the leaves somehow. Evergreen trees (soft woods) hold needles all year long. But those needles will develop a heavy waxy coating and in addition, fluids within the cells contain substances that resist freezing.

Falling leaves are not wasted. They decompose ands stock the soil with nutrients. Over time, a native forest floor has a deep rich layer of decomposing leaves that protect the roots of other plants in the forest. Forest floor leaves help hold moisture and absorb rainfall. If leaves never decayed, how deep in leaves do your think we would have to content with? Nature takes care of her recycling business very well. Only humans get ideas of “clean lawns” that are leaf free prior to the onset of winter snows. What if we just didn’t rake leaves? I’ll vote for that. If your neighbor complains, tell them you read this column. Enjoy this natural mulch layer that fallen leaves provide.

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Our area DNR Forester is Joe Herring. He wrote a description a few years back related to the History of Iowa’s Trees. He starts by asking this question…”Iowa’s original landscape was mostly covered by tall grass prairie” – True or False. Many people would say “true.” The truth is this is a false statement. Then he points out that this is a trick question because Iowa’s landscape has constantly changed. Think long term folks to understand the big picture.

A long, long time ago, say 350,000,000 years ago, what would become Iowa was carboniferous coal swamps. Fast forward to about 10,000 years ago and it was boreal forest and sedges, those initial plant soil stabilizers after the relatively recent melting of glacial ice. As ice waned, it transitioned to deciduous oaks, hickory, elm and ironwood. The climate naturally continued to get hotter and drier until 4,000 years ago when we were at our hottest and driest time frame with the result that trees were replaced by a large extent by tall grass prairie. Since that time, the climate has adjusted to get a bit wetter and cooler. This promoted the invasion of trees from the East. We are still in that phase today. Botanists call the ebb and flow of plant winners and losers part of the succession whereby plants compete to grow and survive.

Do you want proof that trees will ‘invade’ the landscape. Take a good look at an old grassland that has had no fire, natural or man-made, no mowing or grazing, and witness the slow but inevitable transition of the plant cover with cedars, elm, maple, cottonwood or other species. The only reason Iowa wasn’t more tree covered than it was when settlers arrived was because the natives were setting fires every fall to the tall grasses. Fire was friendly to grasses and a severe setback for woody shrubs and trees. It wasn’t because of lightning or spontaneous combustion that prairies burned. Humans were managing and modifying Midwest and Iowa landscapes far earlier than just the past 150 years.

Today we humans are managing the landscape in different ways. For an agriculturally rich State like Iowa, farm crops predominate each year for plant cover on the soil. Trees are mostly found along and adjacent to streams, rivers and rough topographic hilly sites. Forests, like grasslands or wetlands are unique elements of vegetation covering the land. There is no ‘right’ or ‘wrong’ way to do things says Herring, just recognize forests and habitats for what they are and what they do for wildlife, and then any landowner can manage them for whatever they think is best or most important to them. Those reasons include timber production, firewood supply, wildlife habitat, aesthetics, or just to consider trees and timber as the best use for that parcel of land. Maple syrup can be one reason all by itself to manage a forest. All are prime time reasons to like trees. Leaves are free.

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This coming Saturday, Oct. 29, IOWA PHEASANT and QUAIL SEASON begins. Iowa pheasants are making a slow and steady progress in the survival strategies of this important game bird. In 2015, and estimated 56,000 hunters took 270,000 rooster pheasants and about 28,400 quail. The quail numbers alone represent an increase of 165 percent from 2014. But pheasants are the real driver of upland game bird hunting. This fall, an estimated 60,000 hunters will try to put a rooster or two in the cooler for nice home cooked meals. A harvest of rooster pheasants a lot higher than last year is possible without hurting the population. Hen pheasants are not on the list of hunter birds. Their survival and ability to repopulate is more directly tied to mild winter weather of less than 30 inches of snow followed by a relatively dry spring.

During this fast summer, biologists and game wardens drove along standard routes, more than 200 routes in fact, to cover the entire state. Each route is 30-mile long. They were surveyed in early morning with clear skies, heavy dew from the night before and light winds. When all the survey data was gathered, an analysis showed higher counts from counties crossing the state from northwest to southeast. An average count was 21 pheasants per each 30-mile route.

Crop harvest is going well. That may mean a tendency for grassy fence lines to concentrate birds on private land. On public lands such as Hendrickson Marsh, the Colo Bogs Complex, Arney Bend or the Iowa River Wildlife Area, where lots of permanent grasses have been established, birds will be using that habitat. As per regulations, three rooster pheasants is the daily limit, with twelve in possession after day four of the season. A head, fully feathered wing or leg must stay attached to a pheasant carcass while transporting in home.

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Nov. 5 is the local PHEASANTS FOREVER banquet. The function will be held at the Central Iowa Fairgrounds in Marshalltown. Doors open at 5 p.m. Games, door prizes, raffles and good food awaits those who attend. Ticket cost per adult is $65 which include a standard PF membership and the top quality meal. Ticket prices go up if purchased after Oct. 31. Call Steve Armstrong at 751-1668 oe John Fox at 751-4487 to buy a ticket to this important fund raising banquet.

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Did you know that one way to determine the outside air temperature is to listen to crickets? Yes ladies and gentlemen, you heard that correctly. Just count the number of chirps a cricket makes in 15 seconds, and add 37. That will be the outside air temperature within plus or minus one degree Fahrenheit.


Garry Brandenburg is a graduate of Iowa State University with BS degree in Fish & Wildlife Biology. He is the retired director of the Marshall County Conservation Board. Contact him at P.O. Box 96, Albion, IA 50005.