The gas company has begun replacing the old gas lines here in Troy. Redington Avenue was the starting point and our home was the first on the list. We woke up one morning to the sound of heavy machinery and workers everywhere. A few days we had deep trenches and piles of dirt and tree roots all over the front and side of our lawn.

The construction men assured us that when the job was completed, our yard would be better than before. Does this mean we will not have dandelions? There were many comments on the large amount of tree roots they were encountering and wondered how old the trees were.

I was able to give them an exact answer because I had planted the five spruce trees in 1969.

Take a walk in any town or city and you will surely see trees with their roots either pushing up the sidewalks or growing down over the curb. We all know a tree’s roots help support, anchor and hold the tree erect, however what system of roots a tree will have depends on the species of tree.

Usually, evergreen trees do not have root systems that penetrate deep into the ground but rather a root system compared to a pancake that spreads out near the ground surface. While hardwood trees, such as oaks, have large tap roots that go deep into the soil.

The evergreen tree, which is more flexible when strong winds blow, will actually bend with the wind, depending more on its flexibility than on its root system. On the other hand, an oak tree is compared to a statue, with very little flexibility so it needs a strong tap root system to keep it erect.

A large root is merely underground wood that could be made into furniture. The most active parts of the root system are those that collect water, consisting of fine, smooth hairs that are very delicate and sensitive. These small roots, varying in length up to one third of an inch, are attached just behind the tips of main roots, which are scarcely larger than a strand of cotton thread. They are produced by the presence of moisture, which causes the outside cell of the rootlets to poke out sideways, making a hair of its own cell body.

The more moisture in the soil the more cells produced.

These cells, which reach out and wrap around particles of soil, unlock and then absorb the film of water from the soil particles. This is being done all along the length of the rootlets, wherever it touches moisture. At this same time, the thread, of the rootlets, pushes forward to reach new supplies. New hairs spring out, while older hairs having done their job are shriveling up and dying.

The roots of grass plants have a different construction plan. Grasses have what is known as a fibrous system, in which countless little roots grow out from the base of the grass stem, extending only inches below the plant. Trees have what is called the tap root system, which extends for yards beneath the tree.

According to Rutherford’s book “This Green World,” grass roots grow at an unbelievable speed. Officially measured grass plant roots grew 54 miles in 80 days; a crested wheat plant grew 315 miles in three years with the average root growth of green plants being 100 miles per year.

On the other hand a tree builds a vast, intricate system of tough and twisted branches. The root system extends farther out than the crown of the tree. A root wiggles and gropes into the soil. The ends of the roots are sensitive to hard objects, and if they encounter resistance, the root bends away to proceed in the direction of least resistance. A root grows around stones and other impenetrable barriers.

While growing, the root points also rotate slightly, which helps in penetrating the soil.

Another force of roots is expansion, which is so great that when growing into the crack of a rock the expansion will actually split the rock. Because of a broader surface, with which to push out, the horizontal pressure of a root is greater than the longitudinal pressure. Thus, the action of the root penetrating the ground is not so much like driving a nail but as a wedge that is able to split the toughest of rocks.

Another important job of the roots is to send water up through the tree and into the leaves. In a healthy tree, there could be one-hundred thousand leaves. Now, this takes a lot of imagination to think that water is traveling up a tall tree, however it is the same principle of oil running up the wick in an old-fashioned oil lamp. The water then sprays out through the leaf perforations. However, the leaves give off a spray so fine that it is invisible, and this is why it is said that the water is evaporating out of the leaf as water vapor.

Grasses are said to be the greatest water raisers because of their relatively large leaf area. Corn is a grass, and one stalk will lift 440 pounds of water during its brief growing season. An acre of grass will lift six-and-a-half tons of water per day at the height of its power in late June. Although the amount lifted by one plant could be only a few drops, the number of grass plants in an acre is unbelievable.

Water lifted by trees and plants is not an indispensable link in the transfer of water from earth to clouds. Evaporation from open water in seas, lakes and streams is far more important. Of course, a tree uses a small percentage of this water as a carrier of tree food. Humans are still puzzled as to why trees deliver so much water to the top of the tree. Water simply comes in at the bottom and goes out at the top.

Can you imagine how much water a tree that lives to be over a hundred years would have sent into the atmosphere?

Bill Bower is a retired Pennsylvania Game Commission Wildlife Officer. Read his blog and listen to his podcasts on the outdoors at www.onemaningreen.com.