To some folks, watching grass grow could seem sort of tedious, especially if they just planted it.
Ask Andrea Small about it, however, and it could lead to insights on subjects from saving shorelines to cutting carbon emissions.
“That’s the cool part,” said Small, surrounded by acre after acre of marsh grass near Guana Lake in St. Johns County. “The ratio of how much you have to take versus how much you benefit, because it is a fast-growing plant … it’s such a good return.”
Exactly what the ratio is really isn’t clear yet, but it could be fairly soon.
Small, manager of the state’s Northeast Florida Aquatic Preserves, is overseeing a two-year project to draw scientific lessons on growing and harvesting the saltmarsh cordgrass that lines miles of First Coast waterfront.
The project was launched last month with a $10,000 federal grant to cover the cost to monitor grasses, restore two acres as a demonstration and publish a guide on best practices for cultivating the cordgrass, known formally as Spartina alterniflora.
Spartina is used a lot now in places that aren’t natural, from highway berms and ridges to manicured golf courses, said Forest Beeman, vice president of Beeman’s Nursery in New Smyrna Beach.
That’s okay, Beeman said, if someone’s ready to water the stand of grass regularly and tend it carefully.
But that’s not the life cordgrass was built for, or the muddy, crawly environment where it flourishes.
It’s in the muck, it seems, where Spartina is most precious.
The grass is the foundation for a whole web of marsh life that brings both work and play to the region.
The marsh in the Guana Tolomato Matanzas National Estuarine Research Reserve – Small’s office is there, though she manages preserves up through Duval and Nassau counties – supports estuaries used by commercially important types of shrimp, grouper, seabass, snapper and flounder, as well as sport fish such as snook, drum, tarpon and pompano.
The Guana estuaries hold most of the $246 million in annual value the reserve was estimated a few years ago to add to the region through functions like controlling erosion, sheltering wildlife, pollinating plants and cleaning and controlling water that flows through the area’s waterways.
Animals from inch-long periwinkle snails to 1,000-pound manatees feed around the marsh, where tiny fish and crabs navigate near clumps of cordgrass that anchor waterlogged muck.
Spartina roots stabilize the muck enough for it to become rich soil where plants like saltwort and black needlerush sprout and clapper rails, saltmarsh sparrows and moorhens peck for meals. Upland animals – turkeys, deer, hogs – forage on firmer ground further from the shore.
The area’s marshes act like sponges during rainy seasons, holding in water while some developed areas flood, and become a buffer when storms crash in from the ocean.
But there are far fewer marshes now, meaning more pressure on the ones that remain.
“Loss of salt marsh habitat over the past two centuries is well documented for Florida’s coastline,” Small said, making steps to restore marshland more valuable.
The marsh also catches carbon in the environment and keeps it from being released into the atmosphere.
That’s something trees do, too – it’s what gives rain forests a good name as tools to contain greenhouse gases – but some recent research suggests salt marshes could be more efficient at it.
There are 169 acres of salt marsh at Guana where Small and restoration coordinator Cheryl Mannel will strip away part of the hollow-stemmed Spartina and painstakingly document how fast it returns to test lessons about its resilience.
With help from high school- and college-age volunteers, Mannel said about 40,000 plugs of Spartina will be pulled individually from the marsh and replanted in areas where boat wakes, waves from storms or other problems have eroded shorelines.
Where plugs of grass are removed, photos are run through computer software to figure the number of plants still standing and how much ground they cover. A chest-high square of PVC-like tubing with strings pulled into a grid makes it easier to track growth and thinning in the grasses.
Grasses that are thinned differently from one grid to another could end up pointing to lessons in the grass’s resilience. If 20 percent of the Spartina is pulled out in one grid and grows back as completely as the grass in an area where only 10 percent was taken, Mannel said, it could mean there’s no apparent effect from taking that much more.
Having material for more marshes could become a priority.
The State of the River report produced last month by scientists at Jacksonville University and the University of North Florida concluded that evidence on hand suggests “tidal wetlands will be impacted by sea level rise,” making it important for wetland plants to move inland as tide levels change in coming years.
First, though, there are questions to be answered about Spartina. And in a Guana marsh stretching deep into the distance, the growing grass has things to teach.
Steve Patterson: (904) 359-4263