Hurricane Ike ultimately destroyed all of the restoration sites, leaving no plants.
Still, several valuable lessons were learned that can be passed on to future attempts
at re-introducing U. paniculata (sea oats) to Galveston Island.
First, there is no seed stock available for the genetic Caminada or Western Gulf
variety of this plant, nor is there any readily available plant stock, regardless of the
fact that the USDA had worked to build such a stock in the past. The Western Gulf
variety has sterile seeds with effectively zero viability. All of the U. paniculata
that is currently available is actually a genetic variety from the Eastern Gulf.
Although it would be ideal to obtain the Western Gulf variety for the restoration
projects west of the Mississippi River, it is not feasible. The only other possibility
is to take cuttings from already established Western Gulf plants growing in the
field, but this is both destructive to the few plants that remain on the Upper Texas
Coast and has never been proven to work. Thus, this explains why all restoration
projects use the Eastern Gulf variety. Since the Eastern Gulf variety has viable
seeds, the long-term outcome of this restoration practice is that U. paniculata will
likely become a more resilient species on the Upper Texas Coast, but genetic
diversity may be lost (Franks et al. 2004).
In terms of planting survival, P. amarum is likely to be a much better choice
than U. paniculata for Galveston Island dunes. U. paniculata, if planted, needs to
be consistently watered for at least the first 3 months. In previous experience,
P. amarum has been seen to withstand much longer periods of drought than the U.
paniculata plants withstood in this project, with little to no adverse effects on their
long-term growth (Pirates’ Beach project, see Feagin 2005). Thus, if U. paniculata
re-introduction is not a priority, P. amarum should be used for restoration in the
Galveston area. Another potential strategy is to plant a mixture of the two plants,
with the majority being P. amarum, as recommended by the NRCS (2008).
Finally, hurricanes are a fact of life on Galveston Island, and when coupled with
the low seed viability of the native Western Gulf variety of U. paniculata and
historical usage of Galveston for cattle grazing and modern development of the
landscape immediately behind most foredunes on the island, may explain their
absence from Galveston Island. The plants cannot simply re-establish, and for this
reason it may be good practice to introduce the Eastern Gulf variety and allow the
two varieties to interbreed. Future work could attempt to breed these two varieties
in a planned manner, so as to preserve as much genetic diversity as possible while
also re-introducing the species to Galveston Island.
6.4 Protection of Infrastructure and Housing: Sandhill Shores
Project
Hurricane Ike flattened nearly all of the dunes on Galveston Island, Texas on 13
September 2008 (Williams et al. 2009). When Ike hit the Galveston Island community known as Sandhill Shores, the surge was approximately 4 m, with waves
of several m in height (Williams et al. 2009). The dune sands were pushed
6 Foredune Restoration Before and After Hurricanes
99
Still, several valuable lessons were learned that can be passed on to future attempts
at re-introducing U. paniculata (sea oats) to Galveston Island.
First, there is no seed stock available for the genetic Caminada or Western Gulf
variety of this plant, nor is there any readily available plant stock, regardless of the
fact that the USDA had worked to build such a stock in the past. The Western Gulf
variety has sterile seeds with effectively zero viability. All of the U. paniculata
that is currently available is actually a genetic variety from the Eastern Gulf.
Although it would be ideal to obtain the Western Gulf variety for the restoration
projects west of the Mississippi River, it is not feasible. The only other possibility
is to take cuttings from already established Western Gulf plants growing in the
field, but this is both destructive to the few plants that remain on the Upper Texas
Coast and has never been proven to work. Thus, this explains why all restoration
projects use the Eastern Gulf variety. Since the Eastern Gulf variety has viable
seeds, the long-term outcome of this restoration practice is that U. paniculata will
likely become a more resilient species on the Upper Texas Coast, but genetic
diversity may be lost (Franks et al. 2004).
In terms of planting survival, P. amarum is likely to be a much better choice
than U. paniculata for Galveston Island dunes. U. paniculata, if planted, needs to
be consistently watered for at least the first 3 months. In previous experience,
P. amarum has been seen to withstand much longer periods of drought than the U.
paniculata plants withstood in this project, with little to no adverse effects on their
long-term growth (Pirates’ Beach project, see Feagin 2005). Thus, if U. paniculata
re-introduction is not a priority, P. amarum should be used for restoration in the
Galveston area. Another potential strategy is to plant a mixture of the two plants,
with the majority being P. amarum, as recommended by the NRCS (2008).
Finally, hurricanes are a fact of life on Galveston Island, and when coupled with
the low seed viability of the native Western Gulf variety of U. paniculata and
historical usage of Galveston for cattle grazing and modern development of the
landscape immediately behind most foredunes on the island, may explain their
absence from Galveston Island. The plants cannot simply re-establish, and for this
reason it may be good practice to introduce the Eastern Gulf variety and allow the
two varieties to interbreed. Future work could attempt to breed these two varieties
in a planned manner, so as to preserve as much genetic diversity as possible while
also re-introducing the species to Galveston Island.
6.4 Protection of Infrastructure and Housing: Sandhill Shores
Project
Hurricane Ike flattened nearly all of the dunes on Galveston Island, Texas on 13
September 2008 (Williams et al. 2009). When Ike hit the Galveston Island community known as Sandhill Shores, the surge was approximately 4 m, with waves
of several m in height (Williams et al. 2009). The dune sands were pushed
6 Foredune Restoration Before and After Hurricanes
99