Friday, February 5, 2016

Finishing Up the Mowing

Last night, I heard the first calls of courting Woodcocks from the prairies of Blue Jay Barrens.  This was a reminder to me that I had to complete my winter mowing before the female Woodcock began selecting nesting sites.  I only planned on mowing about two acres this winter and should have completed that back in November.  However, frequent rains and warm temperatures kept some of the areas too wet and soft to mow without making a mess.  I found myself with about an acre left to mow as we entered February.  This is one of the larger areas, the valley though which one of the main trails begins.

At one time, this valley was choked with Smooth Sumac and a hefty dose of Multiflora Rose.  Removal of the shrubs allowed prairie vegetation to move into the area.

The deep soil of the valley supports a healthy population of Monarda.  The flowers attract a wide range of butterfly and moth species during the summer.  Soil depth decreases rapidly as you leave the valley.  The slope in the background has less than a foot of soil over the bedrock.

Indian Grass crowds this section of trail.  As it grows, it leans into the open area.  The leaning grass was trimmed back several times during the late summer to keep the trail open.  Heavy snow sometimes bends the grass towards the trail, but our precipitation this year has been primarily rain, so the Indian Grass has remained upright.

The contours of the valley are easy to see following a mowing.  The steep hillsides terminate suddenly into the flat valley floor.  Underlying limestone bedrock follows the grade of the hillsides and continues that same angle to a point beneath the valley center.  Soil eroded from the hillsides has been trapped in the valley, gradually changing the shape from a sharp V to a gentle bowl.

A strange feature of this valley is the fact that a large portion of the storm runoff water travels through channels below the ground.  Under certain conditions you can hear the water rushing beneath your feet.  The water all emerges at the head of a stream farther down the valley.  Seasonal springs also discharge through this same system, but at a much lower volume.  The springs normally flow from January to July.

The sumacs cleared from this valley produced several large brush piles.  The remains of one can still be seen just right of center in the photo.  This pile remains because it contained several rot resistant Eastern Red Cedars along with the sumac.  Piles of all sumac, one of which was in the center of the photo behind the crooked Ash and another just downhill from the cedar on the left, decomposed quickly and disappeared back into the soil.

I don’t mow the fields every year, but I always take at least one pass along the trail edges.  This keeps the dead grass stalks, which will eventually fall, from dropping out into the trail.  A couple of years ago, I began blowing the cut grass onto the trail in an attempt to increase organic matter and nutrient cycling.  After 25 years of maintaining this trail with a lawn mower, I had unintentionally subjected it to a type of management known as soil impoverishment.  This is where you continue to remove vegetation and the nutrients it contains, without replacing the loss with soil additives.  Over time, this activity diminishes the supply of essential elements required for plant growth and plants grow poorly.  Each time I mowed, the cut grass was blown into the edge of the field.  Eventually, the grass on the trail began to thin out and the grass at the field edge prospered.  Trail grass seems to be responding well to my new strategy.

With the mowing comes the flags marking woody invaders that need to be removed in order to protect the desired mix of plant species.  Control of woody vegetation is the reason these areas get mowed.  Red flags mark small trees that need to be killed.  Most of these flags are marking Black Walnut seedlings that grew from nuts produced by those Black Walnut trees showing in the foreground.

Only one patch of nasty invasives in this mowing.  A clump of young Multiflora Rose.  I suspect the seeds came from a bird that rested in this tree.  My encounters with non-native invasives become more rare each year.  It’s a nice thing to see happening.  I should finish my mowing tomorrow and hope to see just as few non-native invasives then.

4 comments:

  1. Nice set of pictures. They give a good sense of what part of the property is like.

    ReplyDelete
    Replies
    1. Hi, Stew. This shape is typical of the low gradient valleys near the upper end of the watershed. As grade increases, the valley shape becomes more narrow and V shaped.

      Delete
  2. Do you know what kind of rock is under your property? I am curious as to whether you "hearing the water rushing beneath" is possibly some sort of small cave.

    ReplyDelete
    Replies
    1. Hi, Jared. The bedrock beneath the valley is dolomite, but the rock is a couple of feet lower than the flowing water. The water is moving through the soil in a channel not more than two feet below the surface. The path of the water is marked by several blow holes formed by water under pressure escaping to the surface. If you clear the dead vegetation from a hole, you can see the flowing water. The situation is similar to a deteriorating clay tile subsurface drainage system, but there was never any tile here.

      Delete