The Conservation Conversation: The Fight of the Century (Phragmites vs. Spartina, Part 1)

No, this isn't about a prize fight between two pugilists with strange names. Phragmites and Spartina are the Latin names of the two most common types of vegetation in our local tidal wetlands. They figure prominently in the ongoing fight to preserve and restore our remaining salt marshes. To drastically oversimplify a pretty complicated issue, Spartina is the guy you want to cheer for and Phragmites is the one you want to jeer.

Phragmities - pronounced "frag-my-tees" and often shortened to Phrag - is also known as the common reed. It's the slender stalk, up to nine or 10 feet tall with a fuzzy frond at the top, that you see all around Udalls Cove, Little Neck Bay and beyond. 

In fact, it is found throughout the United States and in many other places around the world. For many years, it was thought to be an invasive or alien in this country, having been brought here from Europe.

Recently, however, it has been shown that Phragmites existed in North America long before Europeans arrived (although the more aggressive European variety appears to have been introduced and probably accounts for the rapid spread of the plant in the past couple of centuries). 

Spartina (pronounced to rhyme with "china") is a genus with some 14 different species of grasses that grow in saltwater. Commonly known as cordgrass, Spartina is typically two to four feet tall, much shorter than Phrag. 

Two species are prevalent in our area - S. alterniflora (known as smooth cordgrass) and S. patens (a more wiry plant, also called salt hay). In the summer, you'll see large tracts of Spartina around the shorelines of Udalls Cove and the Bay, bright green and waving prettily in the breeze. In the winter, these will appear as brown mats covering the mudflats near the water's edge.

So why the prize fight metaphor in the title of this story? Again, to oversimplify, Spartina is one of the most ecologically productive and beneficial components of a tidal wetland. And tidal wetlands are among the most productive ecosystems in the world (along with coral reefs and tropical rainforests).   

Spartina serves as a nursery ground and food source for hundreds of animal species. It grows out seaward from the edge of the marsh where it accumulates sediment, expanding the wetland and enabling other valuable species, such as mussels, to gain a toehold. Stated simply - where Spartina grows, you have a healthy salt marsh.

Phragmites are also a natural part of the ecosystem and have some habitat value.  But unlike Spartina, Phrag thrives in - and is therefore indicative of - disturbed areas. Two types of disturbed areas are most common: marshland where filling or trash dumping has occurred, and unfilled marshland where "mudwaves" have raised the elevation of the soil. Where such disturbances occur, Spartina disappears and Phrag takes over.

Spartina loves saltwater. It likes to get wet twice a day with the incoming tide. In fact, it is happy being almost totally submerged at high tide, having evolved to exude excess salt from the undersides of its leaves. Phrag tolerates occasional inundation, but prefers conditions that are somewhat less wet. If the soil elevation of a healthy tidal marsh is raised by even a few inches, making it just a little dryer, Phrag will quickly crowd out and replace Spartina.

The soil elevation of a marsh may be raised because of intentional landfilling or casual dumping, but often it is raised by a mudwave - a phenomenon that occurs when heavy structures and roads are built on adjacent marshland. Imagine a large tray of jello. If you put a heavily weighted plate on top of the jello at one end of the tray, the adjacent jello is likely to be squeezed upward. Mudwaves are frequently to blame when a Spartina marsh is replaced by less productive Phragmites. 

Next time: helping Spartina win a few rounds.