BELT TRANSECT OF THE MARSH 117 
A boardwalk runs obliquely across the northern border of the Scirpus belt. 
It is built partly on a low ridge of gravel, hauled in for the purpose, and partly 
on posts. The gravel forms a strip about 4 inches above the level of the Marsh, 
and about 5 feet wide. The boards occupy a width of about 2 feet, and the 
plants for 2 feet on either side of them are kept mowed off with a scythe to a 
height of about 3 inches. These conditions have greatly affected the adjacent 
vegetation. Asclepias incarnata is especially abundant on the south side of the 
barrier. Juncus gerard is scattered about in the Scirpus belt north of the walk. 
Between the boards and on the gravel occur: 
Agropyron resens. Distichlis spicata. Rhus toxicodendron. 
Ambrosia artemisiifolia. Erechtites hieracifolius. Rumesx acetosella. 
Anaphalis margaritacea. Fragaria virginiana. crispus seedlings. 
Asclepias incarnata. Lactuca sp. Scirpus americanus. 
Aspidium thelypteris. Lycopus virginicus. Solidago sempervirens. 
Aster nove-belgii. Myrica gale. Spartina patens. 
Atriplex patula hastata. Plantago lanceolata. -  Paraxacum officinale. 
Bidens frondosa. major. Verbascum thapsus. 
Carex tenera. Prunus serotina. 
Dactylis glomerata. Rubus allegheniensis. 
Total number of spermatophytes aside from boardwalk area, 20; pterido- 
phytes, 1; additional species along boardwalk, 21; total, 42, 
4, JUNCUS-SPARTINA BELT, 
The fourth belt is in every way much broken and diversified. It extends from 
the limits of Scirpus americanus to the pure growth of Spartina patens at 95 
to 150 south. The 8-foot contour cuts its northern border. Many small tide- 
pools and naked mud-flats break the continuity of the spermatophytic vegeta- 
tion. With these exceptions, nearly all of the area is covered with Spartina 
patens. In places this is pure, but other large areas are distinctly dominated 
by Juncus Gerardi. So dense is the Juncus as to give the impression of a pure 
growth.* Its brown fruits, over-topping Spartina patens by 1.5 to 2 dm., give it 
a characteristic appearance which is noticeable a hundred yards away. But 
except in some few patches, Spartina is always mingled with Juncus. On the 
southern border of our belt, Juncus is scattered through the Scirpus zone as far 
as the boardwalk. Juncus also occurs scattered in the Spartina areas in several 
places. But the boundaries of the Juncus patches are usually very sharp and 
easily recorded. At 150 south and 1,100 east is a mixture of Juncus and 
Spartina which it seemed best to describe as Juncus with a mingling of Spar- 
tina (see plate xx11). There is a distinct tendency for the tide-pools to be 
bordered by Spartina rather than by Juncus. But in several cases one plant 
borders one side and the other borders the opposite side of the same pool. The 
average height of Juncus is 4.5 to 5 dm.; of Spartina 2 to 3.5 dm. or rarely 4.5 
dm. In three places (150 south and 1,050 east, 200 to 250 south, 295 to 300 
2 On 5 different plots of 4 square inches each there were counted (August 1911): 
SUNCUS QETATAT . dane. tbs cn ee i's 30 12 5 20 
Sporting patens. 05 «sie as sees 3 0 0 1 2 
Aster. eu bulatis.. ives + 2eees2 0 0 0 0 1 
This gives an average of 604.8 Juncus per square foot. In pure growths, Spartina 
patens averages about 1,400 stalks per square foot. Actual counts gave on 4 square 
inches, 40 and 43 stalks, and on 16 square inches, 151 stalks. 
