Wednesday, May 25, 2011

Ft. Gordon Native Grasss Restoration Project


Land managers at Ft. Gordon, the U.S. Army installation near Augusta, GA that is home to The Signal Corps and Signal Center, enjoy a formidable stewardship challenge.  They are charged with providing training sites for soldiers, management of all natural resources, clean air, clean water, improving soil, hunting opportunities, recreation, habitat for endangered species, etc. , all while ensuring an economic return.  One Army slogan, “If you don’t conserve it, you don’t deserve it!”, effectively communicates their intense commitment to national security and protecting our quality of life admonishing anyone taking God’s green earth for granted.  This land was indeed made for you and me!  And who would argue with wisdom offered by tank-laden battalions of probably the toughest, missile-wielding fighting force on earth? 


                We (the USFS Southern Research Station) were approached with the challenge of figuring out how to establish native grasses and herbaceous plants on a typical forested stand just after a harvest operation, thus improving wildlife habitat while restoring ecosystem structure and function.  Which, incidentally, does improve our quality of life, but that requires explanation outside the scope of this article. 
The site we affectionately call training area (TA) 18 is approximately 46 acres of undulating sand hills which was clear cut between February and April of 2008.  A clear cut is a system by which you remove all (or most) of the mature canopy in order to artificially regenerate (that is, to plant) a predetermined forest stand.  In this case, the loblolly pine trees were removed that do not belong on sand hills to make way for planted longleaf pine, a species better-suited to the soil and environmental conditions of life at TA 18.  The harvest operation involved cutting all loblolly pine (the dominant over story species on site) from the site leaving any mature longleaf pine trees and mature hardwood trees (mostly oaks and cedars) already existing on site...



  Slash, debris from the harvest operation, was pushed into piles to be burned later, leaving a landscape void of any ground-layer vegetation or over story.  By February 2009, our blank canvas was ready to work on.
               

 
               There were two questions we had to answer before restoration efforts could begin.  What site preparation, if any, was needed to establish native grasses and herbaceous plants?  What seed source would work best on TA 18?  To answer our questions, we installed a pilot study during March 2009 that involved 4 site preparation methods and 2 seed sources.  The treatments we selected were (1) control (no site preparation) (2) clipping (remove all above-ground vegetation) (3) raking (remove surface litter and scarify soil) (4) digging (remove below-ground competition).  Both sets of seed were collected in November of 2008 and stored in a cool, dry seed shed.  One consisting of wiregrass (WG) a second seed source made up of a mix, wiregrass and bluestems (MIX).   
               


Control


Clipping


Raking


Digging

               We hypothesized that digging or raking would be best for establishing seedlings and that the MIX seed source would produce more successful germinants.  Native seeds in general have relatively low rates of germination, but wiregrass is considered below average.  Data were collected, analyzed, pondered.   Our results showed that raking, then digging established the best conditions for seedling development and that the two seed sources produced comparable seedlings.  Questions answered.
               


               By the end of our study (November 2009) the large piles of slash had been burned (May 2009) and an herbicide had been applied to inhibit growth of small diameter hardwood stems, notorious for derailing restoration plantings.  The site was still mostly devoid of vegetation.  Applying what was learned from our pilot study, we mimicked the raking treatment with a drum chopper (December 2009),...



              ...then decided to use seed from both sources since they were comparable in germinating desirable native species we want to promote on that site.   We collected these seeds during November and December 2009 at selected sites on base.  Selection criteria included; sites that had desirable native species, desirable soil types, species deemed important for our restoration goals, sites with appropriate fire regimes (influencing species composition and flowering, thus type, quality, and amount of seed), and accessibility.  Seed collections were accomplished both by hand and with the aid of a seed flail-vac, best described as a giant motorized dust buster mounted to the front of a small tractor.  We were frustrated by a paucity of sites, but able to collect an estimated 20 pounds of seed.
               




               We sowed seed on approximately 3 acres of TA 18 in January 2010 then procured 12,500 wiregrass plugs (seedlings grown under ideal conditions in containers) planting those on an additional 4 acres by the end of March 2010....





 ...Longleaf pine seedlings were planted across the entire site in April 2010.  Though small, our initial success has already been realized with the emergence of a continuous clump of native grasses on TA 18! 


               Slow and steady wins the race right?  Our short-term goal is to work out the kinks of native seed collection, storage, and sowing to establish desirable vegetation on TA 18.  All this in the hope of restoring our site to what ecologists call a “reference condition”,  a forest stand that presents the species composition, structure, function and health of an ideal tree-dominated ecosystem on that specific piece of land.  A condition that then provides all the benefits (training site, clean air, clean water, improved soil, habitat for endangered species, hunting, recreation, economic return, etc.) previously mentioned with increased abundance while improving ecosystem functions and services.



"I am the Lorax
I speak for the trees,
for the trees have no tongues."
-Dr. Seuss


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