Wednesday, September 21, 2011

Ft. Gordon - Erosion control test

Overcoming Erosion
Testing an erosion control blanket at Fort Gordon, GA – Mar. 2010 to Nov. 2010

The northwestern portion of TA 18 has a clay slope that may pose problems in getting native grasses established.  Several re-vegetation options were discussed and we decided that an erosion control blanket could be a viable solution.  During the first week of March 2010 Gary Pringle was able to get (at no cost) approximately 1000 square feet of erosion control blanket, which we installed on the clay-slope.  We seeded this the next day with some left-over’s from our collections and seeded the same amount over an adjacent area of similar size for future comparison.  We periodically checked in during site visits and were consistently impressed with how well the erosion control blanket seems to establish seedlings. 

Erosion control blanket - Nov 2010                                              No erosion control blanket - Nov 2010


As these photos taken in November 2010 show, this technique is worthy of further investigation.  After just 8 months there is a remarkable difference!

This is an ECSC-2 double net straw/coconut rolled erosion blanket.  The blanket is made to a standard dimension of 7.5 feet wide by 120 feet long (900 square feet) rated for erosion protection and vegetation establishment on slopes up to a 1:1 grade (45 degree angle, 100% slope) for up to 24 months.  The blanket consists of 70% straw and 30% coconut fiber and is stitched together with a degradable thread between a layer of UV-stabilized top netting and a bottom layer of polypropylene netting.  This particular blanket was old and in the process of degradation, but as we can see is still doing the job.

And here is a faux time-lapse showing establishment of vegetation on this clay slope with help from an erosion control blanket.

...and these from my latest visit...

Erosion control blanket - Sep 2011                                               No erosion control blanket - Sep 2011

Monday, September 12, 2011

Looking for Tephrosia virginiana...

We are trying to collect seed from Tephrosia virginiana, commonly known as goat's rue ... a densely hairy perennial herb growing erect, but only 1 to 2 feet tall.  Leaves are alternate and pinnately compund, flowers are pea-like with yellow, cream, and pink coloring. Flowers of T. virginiana are on shorter stalks than T. spicata.

We are interested to know if the pods (densely hairy) are still intact with seeds inside... flowers from May to June and fruits during July through October.

Tephrosia spp. should be growing in dry, open woods and the best places to collect seed would have been burned this past spring. 

Line drawing from: Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions.

Please let us know if you have a nice clump we could collect for our common garden study!

...all photos from the Southeastern Flora website: