Important Message about LEARN NC

LEARN NC is evaluating its role in the current online education environment as it relates directly to the mission of UNC-Chapel Hill School of Education (UNC-CH SOE). We plan to look at our ability to facilitate the transmission of the best research coming out of UNC-CH SOE and other campus partners to support classroom teachers across North Carolina. We will begin by evaluating our existing faculty and student involvement with various NC public schools to determine what might be useful to share with you.

Don’t worry! The lesson plans, articles, and textbooks you use and love aren’t going away. They are simply being moved into the new LEARN NC Digital Archive. While we are moving away from a focus on publishing, we know it’s important that educators have access to these kinds of resources. These resources will be preserved on our website for the foreseeable future. That said, we’re directing our resources into our newest efforts, so we won’t be adding to the archive or updating its contents. This means that as the North Carolina Standard Course of Study changes in the future, we won’t be re-aligning resources. Our full-text and tag searches should make it possible for you to find exactly what you need, regardless of standards alignment.

Salt Marshes

Figure 14. Grasses in salt marshes are adapted to wide variations in the salinity of the water. (Photograph by the author. More about the photograph)

The single most important ecological feature of salt marshes along coastal rivers is their immersion/exposure cycle. The lower the marsh, the longer the surface is immersed in tidal waters. Low marshes in North Carolina are dominated by smooth cordgrass (Spartina alteriflora). These plants form a monoculture in the areas of the marsh that are regularly flooded by salt water. They have salt glands on their stems that excrete salt. Areas slightly higher in the marsh are dominated by the species you saw in Figure 13, black needle rush (Juncus roemarianus).

These plants have a very high tolerance for salinity variation. In the high marsh, the salt content of the soil goes up when freshwater evaporates on hot, dry days. As a result, the soil salinity may be more than double that of nearby estuarine water. When it rains, of course, the soil salinity drops rapidly, sometimes to levels near fresh water.