Draba Barrens Check

With the south facing slopes finally cleared of snow I was able to get out and assess the current state of plant growth in the barrens.  Since I’ve been following the progress of the container grown rare winter annuals, I was anxious to compare that impressive growth with the condition of the wild grown plants.  The big three species at Blue Jay Barrens are Leavenworthia uniflora, Draba cuneifolia, and Draba reptans.  All three grow in barrens areas typified by bare soil conditions and excessive dryness.  This site is one in which the Drabas seem to dominate.

Bare soil of the barrens is not always evident from a distance.  Plant spikes make an effective barrier and give the illusion of solid vegetation.

It’s not until you are in a position to view the ground from a more aerial perspective that the patches of soil become apparent.  Tufts of grass sit like a thousand islands with channels of soil running between.  The grass plays an essential role in protecting the soil from wind and rain.

In some areas a thin layer of dark soil exists.  The protective grass has not only offered protection, it has provided organic matter to fuel the soil ecosystem.

The typical barrens soil presents a less prosperous appearance.  A gardener faced with soil like this would probably begin looking for a new hobby.  However, for some special plants, this is the ideal home.

The layers of small pebbles associated with many of the barrens are a result of erosion.  Rainfall has broken the soil into its individual particles and the smaller of these have been carried down slope with the runoff water.  Left behind were the small stones and pebbles that form a protective layer over the soil surface.  The energy of the rain is now spent on the stones and the soil is left in place.

Other factors also assist in keeping the barrens soils in place.  Moss and lichens are two plants that tend to bond organic matter into a living mat that is much more rain resistant than the bare soil.

In some of the larger areas, annual grasses provide temporary winter cover.  The dried grass plants shown here are Sporobolus vaginiflorus, a low growing annual that thrives in hot, dry areas.

Other plants grow in the barrens soil, but often suffer from the elements.  This Rose Pink, Sabatia angularis, has lost several of its leaves from exposure to extreme cold temperatures.  The plant is still alive and will recover from this setback.

It only takes a little protection for a Rose Pink to make it through the winter unscathed.

A barrens plant that doesn’t seem bothered by the coldest of temperatures is Gray Goldenrod, Solidago nemoralis.  The perky little basal rosettes wait patiently until longer daylight hours spur them into growth.

I did find a few Draba cuneifolia, but they were much smaller than those grown in my artificial container barrens.  Drabas require full sunlight during their growth period and will quickly flower before the surrounding vegetation grows high enough to produce shade.  I’m sure they will prosper and produce a good supply of seeds for future years. 

Dry Prairie

Diversity in bedrock geology, soil type and topography brings about a great biological diversity in an area. Yesterday I was enjoying the tranquility of a shaded pool. By traveling a distance of only a few hundred feet, I’m now viewing a hot, parched grassland. Each area hosts its own unique suite of plant and animal life. The two areas are extremely different, but both represent healthy, vibrant, functioning ecosystems.

The Common Dropseed, Sporobolus vaginiflorus, is showing signs of severe drought stress. Some of the plants have turned completely brown and are probably past recovery, but the majority still show a central portion of healthy green leaves. Despite the lack of rain, there will be plenty of plants survive to produce seed for next year’s population.

People hate to see super dry ground. A sight such as this has many people wishing they could drag out the garden hose and soak the whole area. Changing the moisture regime on the site would certainly change its appearance. Regular irrigation could turn this into a lush, green landscape and most people would believe that they had really helped things out. The problem is that most of the plants now growing on the site would not survive to be a part of the new design.

Management of these sites requires that the manager have a clear concept of how the natural ecosystem should look. As with any type of habitat, there are certain plant and animal species associated with super dry locations. To successfully manage these areas, a good manager needs to avoid the natural bias against droughty sites with somewhat scraggly looking plants.

I enjoy visiting these dry areas. Judging from the number of old nests I discover each year, so do the box turtles. If box turtles consistently choose a site like this as providing the best chance of survival for their offspring, the super dry habitat must be a wonderful place.

Common Dropseed

If you like short growing grasses, this Common Dropseed, Sporobolus vaginiflorus, could become your favorite. A jumbo sized plant would reach 12 inches, including the seed stalk and the Blue Jay Barrens specimens rarely exceed six inches.

Common Dropseed is a summer annual that must produce a crop of seed if there are going to be plants the next year. Most of the seed is produced in the enlarged areas along the stem. These swollen areas are leaf sheaths enclosing the flowers. As the dead plant dries, the sheaths will unfurl to release the mature seed.

Annual plants such as the Common Dropseed are colonizers of bare or disturbed areas. This grass survives dry, low fertility conditions and is regularly encountered in the barrens. Its presence helps shield the soil against erosion and increases the organic matter in the soil. This stability and increased fertility creates a suitable environment for other plants to grow and become established.

Over time, the size of the bare areas decreases and perennial plants begin to dominate. Eventually the Common Dropseed can no longer compete and disappears from the site. Fortunately, Blue Jay Barrens is in no danger of running out of places for this grass to grow and it will remain an integral part of the barrens ecosystem.