Friday, March 7, 2014

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. 

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