Yesterday, while surveying a brackish marsh restoration site near Port Arthur, Texas, we noticed that some of the planted Spartina alterniflora appeared to be falling down (left), especially around the edges of constructed mounds. Although the plants grew quickly (they are only about a year old!), is erosion around the edges of the mound going to undermine the long term success of these plantings? We noticed that mounds with fill added so that the sides are less steep seemed to have more upright plants (below). These shallower areas, however, had extensive cyanobacterial mats (green mats in the water in the picture below). What are the impacts of dense cyanobacterial mats on the animals in this system?
2 comments:
I believe that it is indeed due to the edges of the land washing out from around the roots. Restoration projects would benefit from some kind of wave barrier along the perimeter of the site.
In response to milcman's comment, I indeed agree with your suggestion, but would like to add, the mounds in the picture that have spartina falling over are actually part of a group of several mounds just like them, organized in rows (which actually end up forming a triangle) surrounded by tall stands of Schoenoplectus californicus terraces around the perimeter intended to act as such a wave barrier you speak of with only small openings for the inflow/outflow of water. Is this enough, though?
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