K-12 Teaching and Learning From the UNC School of Education

LEARN NC was a program of the University of North Carolina at Chapel Hill School of Education from 1997 – 2013. It provided lesson plans, professional development, and innovative web resources to support teachers, build community, and improve K-12 education in North Carolina. Learn NC is no longer supported by the School of Education – this is a historical archive of their website.

A blackwater river from sea to source: The White Oak River transect
A “virtual field trip” up the White Oak River in southeastern North Carolina, with discussion of how local ecology changes along the way due to decreasing salinity.
Format: slideshow (multiple pages)
Tidal freshwater section of the White Oak (2)
In A blackwater river from sea to source: The White Oak River transect, page 14
Figure 12 shows another part of the tidal freshwater section of the White Oak. Here you can see not only red cedars growing close to the river but also a few pines and maples. The presence of the latter species tells us that the water almost never gets salty...
By Dirk Frankenberg.
Mouth of the White Oak River
In A blackwater river from sea to source: The White Oak River transect, page 3
Figure 1 shows the mouth of the White Oak from Bear Island in Hammocks Beach State Park. The island on the far side of the inlet is Bogue Banks, and the buildings on the horizon at in the town of Emerald Isle. (These two islands are visited in the Large Sand...
By Dirk Frankenberg.
White Oak River estuary
In A blackwater river from sea to source: The White Oak River transect, page 8
Figure 6 is a view of the high salinity, open water area of the White Oak River estuary about 4 miles inland of the mouth. Salt marsh still occurs on the estuary floor, but it is clearly much less extensive than closer to the ocean and its sources of sediment....
By Dirk Frankenberg.
The White Oak River: Introduction
In A blackwater river from sea to source: The White Oak River transect, page 1
One of the interesting things to do during field study of natural areas is to follow an environmental gradient across the landscape. This is particularly rewarding if your gradient extends up a river, as the exploration takes on the aura of a classic “search...
By Dirk Frankenberg.
Sawgrass fronts blackwater swamp forest (2)
In A blackwater river from sea to source: The White Oak River transect, page 16
Figure 14 is the bank of the White Oak opposite that shown in figure 13. The swamp forest community shown in the background of figure 13 is growing right to the edge of the water here. Note the large loblolly pines in the right foreground and some bald cypress...
By Dirk Frankenberg.
Coastal plain blackwater bottomland hardwood forest community (2)
In A blackwater river from sea to source: The White Oak River transect, page 18
Figure 16 show a view of the White Oak where it is usually nothing but a creek-sized stream about 25 feet across and a few inches deep. As you can see, the floodwaters of Hurricane Floyd continue to keep it out of its banks almost two months later. The are...
By Dirk Frankenberg.
Coastal plain blackwater bottomland hardwood forest community (1)
In A blackwater river from sea to source: The White Oak River transect, page 17
Figure 15 shows a coastal plain blackwater bottomland hardwood forest community about 100 yards back from the river. This community has a variety of small trees growing under the canopy trees of oak, maple, sweet gum, and pine. If you look closely at the forest...
By Dirk Frankenberg.
Upstream section of White Oak, twenty miles from the sea
Upstream section of White Oak, twenty miles from the sea
Format: image/photograph
Tidal freshwater section of the White Oak (1)
In A blackwater river from sea to source: The White Oak River transect, page 13
Figure 11 is a view of a marsh about 10 miles upriver from the ocean. Here you see black needle rush along the water's edge along with a new plant, the freshwater sawgrass (cladium jamaicense) growing landward of it. In the background,...
By Dirk Frankenberg.
Sawgrass fronts blackwater swamp forest (1)
In A blackwater river from sea to source: The White Oak River transect, page 15
Figure 13 is a view of a tidal freshwater section of the river where freshwater marsh dominated by sawgrass fronts a typical blackwater swamp forest. This is about 12 miles from the sea and does not get salt water very often at all. The log in the foreground...
By Dirk Frankenberg.
Red cedar marsh invasion
In A blackwater river from sea to source: The White Oak River transect, page 11
Figure 9 is a view of another tributary creek to the White Oak. Here, about 7 miles from the sea, we find that most of the marsh is dominated by black needle rush, with salt marsh cord grass occurring only in a few light-green patches along the water's edge....
By Dirk Frankenberg.
Ocean section of Bogue inlet: the mouth of the White Oak River
Ocean section of Bogue inlet: the mouth of the White Oak River
Format: image/photograph
White Oak River Basin Map
White Oak River Basin Map
Format: image/map
Salt marsh cord grass & black needle rush plants (1)
In A blackwater river from sea to source: The White Oak River transect, page 9
Figure 7 shows us where the salt marshes are located in this high-salinity section of the White Oak estuary. Marshes develop mostly along the banks of tributary creeks. Here, you see the creek's mouth facing into the main portion of the estuary and the marshes...
By Dirk Frankenberg.
Harmony Hall Plantation
This historic home in Bladen County sits on a property with other old buildings including a schoolhouse, a chapel, a corn crib, a log home, a store, a kitchen and other preserved buildings to show what the area may have looked like in the 1800s.
Format: article/field trip opportunity
How does decreasing salinity affect blackwater rivers?
In A blackwater river from sea to source: The White Oak River transect, page 2
All rivers that reach the sea have ocean water at their seaward ends, and freshwater at their sources. A trip up a river takes you along a gradient of salt concentration from near 3.5 percent (the average salinity, or salt content, of seawater) to zero. There...
By Dirk Frankenberg.
Pocosin wetland community
In A blackwater river from sea to source: The White Oak River transect, page 19
Figure 17 is a view of a pocosin wetland community like those that comprise the source of the White Oak in Hoffman State Forest about thirty miles inland of Bogue Inlet. Pocosin is a Native American word reputed to mean “swamp on a hill.”...
By Dirk Frankenberg.
Sediment salt marshes
In A blackwater river from sea to source: The White Oak River transect, page 6
Figure 4 shows salt marshes growing inside the mouth of Bogue Inlet on sediment that has settled out of flooding tides. Areas of open water separate these marshes, but there is clearly more marsh than open water this close to the inlet. How these plants got...
By Dirk Frankenberg.
Extensive salt marsh
In A blackwater river from sea to source: The White Oak River transect, page 7
Figure 5 is a view looking towards the mainland from the high dunes on Bear Island. It shows the extensive salt marsh that has developed on intertidal sands and mud west of Bogue Inlet. These are the marshes you could see in the right-hand background of figure...
By Dirk Frankenberg.