Rising Tides, Vanishing Swamp Forest

Explanation: It is perhaps an early sign of sea level rise along the eastern seaboard of the U.S.

This week, we are wading in hip boots along the flooded bank of the Waccamaw River not far from its mouth emptying into the Atlantic Ocean, here in South Carolina, USA. The U.S. Geological Survey and cooperators are studying this stretch of swamp forest -- but why?

There is trouble brewing, and signs of climate change here. This scattered stand of stately, old-growth baldcypress trees is slowly becoming flooded. There is no regeneration of the trees apparent. And more worrisome, the tide waters are becoming more saline, more salty, over time.

It appears that the level of the sea is rising relative to the base of this swamp.

Baldcypresses often form fluted trunks known as buttresses, to help stabilize the dense, heavy tree in the saturated soil and to withstand storm surges and wind.

Also occurring in these coastal swamp forests is the black tupelo tree (also called black gum, Nyssa sylvatica), which might also be at risk from environmental changes associated with sea level rise.

So what? What good is swamp forest along the coast?

Riverine and coastal swamp forests actually provide quite a suite of important environmental services and ecological roles. They serve to reduce the impact of storm surge. They trap sediments and serve as filters and traps for pollutants. The wood of baldcypress trees is valuable as timber and is used for many purposes.

There is no sign of regeneration of this baldcypress swamp forest.

Moreover, swamp forests are key habitats for quite a bit of wildlife, including songbirds, squirrels, turkeys, shorebirds, mammals, amphibians, reptiles. And fish. Old baldcypress trees are used by eagles and osprey as nest sites. And as crucial habitat for the rare Swallow-tailed Kite (Elanoides forficatus).

On this river island, we discovered only a few younger baldcypress trees growing on the least flooded portion, still under tidal flood, but no new sprouts or seedlings.

Whether this will become the fate of baldcypress and other coastal swamp forests over the next few decades, as global climate continues to change, remains to be seen.

A lone, old-growth baldcypress remains, for now, fully flooded by
tidal influence, along the river banks largely covered by
bulrush (Schoenoplectus americanus).

EPOW - Ecology Picture of the Week