Dune stabilization with Panicum amarum along the North Carolina coast

[From the U.S. Government Printing Office, www.gpo.gov]

--' ter for Marine and Coastal Studies- North Carolina State University
Coastal Zone
Information 3
Center

Dune Stabilization with Panicum amarum
Along the North Carolina Coast

COASTAL ZONE
INFORMATM CENTER

By MAY 2 6 1977
E. D. SENECA, W. W. WOODHOUSE, JR.,
and S. W. BROOME

REPORT NO. 77-1
UNC-SG-77-03
FEBRUARY, 1977

57.2
N6
no. 77-03

COASTAL ZOE
JNF~Timo CENTER

CENTER FOR MARINE AND COASTAL STUDIES
NORTH CAROLINA STATE UNIVERSITY
RALEIGH, NORTH CAROLINA

Dune Stabilization with Panicum amarum
Along the North Carolina Coast

E. D. Seneca, W. W. Woodhouse, Jr.,
and S. W. Broome

Report No. 77-1
UNC-SG-77-03

February, 1977

COASTAL ZONE
INEhHUNU ~CENTER
ACKNOWLEDGEMENTS

This publication is a reprint of Miscellaneous Report No. 76-3 prepared
by the Coastal Engineering Research Center, U. S. Army Corps of Engineers
dated February, 1976. In addition to funding by the North Carolina State
Coastal Research Program, financial support was provided by the Univer-
sity of North Carolina Sea Grant College Program, Office of Sea Grant,
NOAA, U.S. Department of Commerce under Grant Number 2-35178, and the
North Carolina Department of Administration. The U.S. Government is
authorized to produce and distribute reprints for governmental purposes
notwithstanding any copyright that may appear hereon.

PREFACE

This report is published to assist coastal engineers in dune stabili-
zation by the establishment and development of vegetation. The work was
carried out under the coastal ecology research program of the U.S. Army
Coastal Engineering Research Center (CERC).

The report was prepared by E.D. Seneca, Associate Professor of Botany
and Soil Science; W.W. Woodhouse, Jr., Professor of Soil Science; and
S.W. Broome, Research Associate in Soil Science; North Carolina State
University, Raleigh, North Carolina, under CERC Contract No. DACW72-73-
C-0025. Support was received from the North Carolina Sea Grant Program,
Office of Sea Grant, National Oceanic and Atmospheric Administration,
Department of Commerce, Grant No. 2-35178 and 04-3-158-40; the North
Carolina Coastal Research Program; and the North Carolina Agricultural
Experiment Station.

The authors express appreciation to personnel of the Cape Hatteras
and Cape Lookout National Seashores, National Park Service, for permission
to obtain the original transplants and for cooperation during the study.
Special 'thanks are due D.M. Bryan, C.L. Campbell, Jr., and U.O. Highfill
for their assistance in all phases of the fieldwork, and to D.W. Woodard,
marine biologist, formerly of CERC, for his encouragement throughout the
course of this study.

Mr. R.M. Yancey, Chief, Ecology Branch, was the CERC contract monitor
for the report, under the general supervision of Mr. R,P. Savage, Chief,
Research Division.

Comments on the publication are invited.

Approved for publication in accordance with Public Law 166, 79th
Congress, approved 31 July 1945, as supplemented by Public Law 172, 88th
Congress, approved 7 November 1963.

JMS L. TRAYB
Colonel, Corps Engineers
Commander and rector

CONTENTS

Page

I INTRODUCTION. .........................7

II METHODS .. ..........................9
1. Nursery Propagation. ...................9
2. Planting at Duck, North Carolina . .........._9
3. Planting at Drum Inlet, North Carolina. .........14

III RESULTS AND DISCUSSION .. ...................16
1. Duck Planting. ......................16
2. Drum Inlet Planting. ...................20

IV SUMMARY AND CONCLUSIONS. ...................40

LITERATURE CITED. .......................42

TABLES

I Mean number of leaves, mean number of culms, and mean cover
per 14-meter transect at Duck, 1973. .............18

2 Stand count by treatment for certain plots at Duck, 1973 ....19 .

3 Invading flowering plants to the experimental planting at
Duck, June and September 1974. ................22

4 Frequency for 13 plant species at Duck, 1974. .........23

5 Mean estimated cover for all plant species at Duck, 1974 ....24

6 Mean aboveground biomass for five plant species at
Duck, 1974. ..........................25

7 Mean number of leaves per transect for four dune grasses
at Drum Inlet, 1973. .....................28

8 Mean number of culms per transect for four dune grasses
at Drum Inlet, 1973. .....................29

9 Mean cover per transect for four dune grasses at
Drum Inlet, 1973. .......................30

10 Frequency for six dune plants at Drum Inlet, 1974. .......32

11 Mean estimated cover for all plant species at Drum
Inlet, 1974 ..........................3

CONTENTS

TABLES-Continued
Page
12 Mean aboveground biomass for five dune plants at Drum
Inlet, 1974 ..........................35

13 Cumulative mean volume of sand accumulated over 3-, 15-,
and 27-month periods at Drum Inlet ...............38

FIGURES

1 Panicum craumaw (bitter panicum) near Duck ............ 8

2 Map of bitter panicum sites of origin, nursery, and
experimental planting sites ..................10

3 Bitter panicum nursery at Clayton, North Carolina, 1972,
6 months after establishment ..................11

4 Bitter panicum transplants; pruned and unpruned ......... 12

5 Experimental planting site at Duck, June 1973 ..........13

6 Experimental planting site at Drum Inlet, March 1973 ...... 15

7 Experimental planting site at Duck, September 1973 ....... 17

8 Experimental planting site at Duck, June 1974 .......... 21

9 Experimental planting site at Duck, September 1974 ....... 21

10 Sand accumulation on the sound side of 0.61-meter fence at
Drum Inlet planting site, May 1973 ...............27

11 Experimental planting of American beachgrass, bitter
panicum, and sea oats at Drum Inlet ..............27

12 Bitter panicum treatment in experimental planting at
Drum Inlet, September 1973 . . . ................31

13 Bitter panicum treatment in experimental planting at
Drum Inlet, October 1974 ....................31

14 Experimental planting of American beachgrass, bitter
panicum, and sea oats at Drum Inlet, October 1974 ....... 33

15 Hatteras beachgrass treatment in experimental planting at
Drum Inlet ...........................36

CONTENTS

FIGURES-Continued
Page
16 Mean dune cross sections in meters above mean sea level
for seven treatments at Drum Inlet, 1973 to 1975 . . . . . . . . 39

DUNE STABILIZATION WITH PANICUM AMARUM ALONG THE
THE NORTH CAROLINA COAST

E.D. Seneca, W.W. Woodhouse, Jr.,
and S.W. Broome

I. INTRODUCTION

The perennial coastal dune grass Panicum amarumn Ell. (bitter
panicum) (Fig. 1) is distributed on foredunes in a discontinuous manner
from New England to Florida, and around the gulf to Texas. The
taxonomy, distribution, and habitat preferences of bitter panicum have
been described in a study by Palmer (1975). She indicated that this
grass is a sterile form of Panicum amarulum Hitchc. & Chase (shoredune
panicum), and is well adapted to the foredune habitat. The shoot and
rhizome systems have the potential to produce new shoots and roots at
the respective nodes as described by Dahl, et al. (1974). The growing
season (aboveground growth) along the North Carolina coast is from May
through October, which is about 2 to 3 months less at this latitude than
that of Ammophila breviligulata Fern. (American beachgrass). However,
unlike American beachgrass which is a temporary stabilizer and often
loses dominance within 5 to 10 years along the southeastern coasts,
bitter panicum forms a part of the permanent cover along with UnioZa
paniculata L. (sea oats).

There is no universal agreement among dune researchers as to the
reason for the discontinuous distribution and, until recently, for the
relative sparsity of bitter panicum along much of the coast. Some
researchers believe that this grass was grazed out by free-roving
livestock, while others feel that certain environmental factors are
responsible. Dahl, et al. (1974) noted that it is preferred by cattle
to several other dune grasses on the Texas coast. Whatever the
limiting factors were in the past, within recent years established
stands of bitter panicum on the North Carolina coast have spread and new
areas are being colonized.

Earlier dune building and stabilization studies along the North
Carolina coast have concentrated on American beachgrass (Woodhouse and
Hanes, 1967) and sea oats (Woodhouse, Seneca, and Cooper, 1968).
Although American beachgrass is a good dune builder at this latitude, it
is attacked by a scale insect, Eriococcus carolinae Williams (Campbell
and Fuzy, 1972), is susceptible to the mushroom-forming fungus,
Marasmius sp. (Lucas, et al., 1971), and appears less drought tolerant
than sea oats. A controlled environment study with seedlings grown from
seed collected along the Atlantic and gulf coasts suggested that
temperature is a major factor responsible for the observed replacement
of American beachgrass by sea oats south of the Virginia-North Carolina
line (Seneca, 1972). A recent study on the Texas coast established that
bitter panicum and sea oats were the two best adapted plants tested for

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dune building and sand stabilizing (Dahl, et al., 1974). In that study,
American beachgrass was not successfully established, and bitter
panicum was more successfully transplanted and easier to procure and
handle than sea oats.

This study began in the spring of 1972 to determine the dune
building and sand stabilizing potentials of bitter panicum along the
North Carolina coast.

II. METHODS

1. Nursery Propagation.

Plants of bitter panicum were collected from Hatteras Island and
Ocracoke Island, North Carolina, in March 1972, to establish a nursery
at Clayton, North Carolina (Fig. 2). Single culm (stem) plants were
spaced 0.6 meters apart in rows 1.1 meters apart. These transplants
were cultivated to control weeds, and fertilized in mid and late summer.
By fall, there were about 10 culms for every original one (Fig. 3).
This number coverts to about 660 culms per are (100 square meters) in
the first year. By the end of the second growing season there were
about 1,650 culms per are.

Field experiments with these plants began in the spring of 1973,
at Duck and Drum Inlet (Fig. 2). About 2 man-hours were required to
prepare 1,000 plants for field planting. Processing included digging,
breaking apart into usable transplants (Fig. 4), dipping in a clay
slurry, and packaging in reinforced paper to prevent desiccation.
These plants and two other dune grasses were used to test the dune
stabilization effectiveness of mixed species plantings with primary
emphasis on bitter panicum.

2. Planting at Duck, North Carolina.

The experimental planting at Duck was located about 300 meters
inland on a relatively broad, high, unstabilized sandy site (Fig. 5),
which is a part of the barrier island site of the Coastal Engineering
Research Center (CERC) Field Research Facility. This area was once part
of an aerial practice gunnery range and was largely denuded of
vegetation. Stabilization at this site became more of a concern than
dune building.

The planting was established on 4 and 5 April 1973, using
mechanical procedures developed earlier (Woodhouse and Hanes, 1967).
Six planting treatments were replicated three times in 14- by 50-meter
plots. Each plot consisted of plants in 14 rows running toward the
ocean with 0.9 meters between rows and 0.9 meters between plants within
rows except for certain rows in which bitter panicum plants were buried.

The six treatments consisted of: (a) nursery transplants of
bitter panicum from Hatteras Island stock; (b) nursery transplants of

EASTERN NORTH CAROLINA

4-DUCK
360 N. Lat.

0 CLAYTON

ISLAND
,,... HATTERAS

HATTERAS
OCRACOKE ISLAND
35 N. Lat.

CAPE LOOKOUT

340 N. Lat.

CAPE FEAR

Figure 2o Map of bitter panicum sites of origin (Hatteras and Ocracoke
Islands), nursery (Clayton), and experimental planting sites
(Duck and Drum Inlet).

Figure 3. Bitter panicum nursery at Clayton, North Carolina, September
1972, 6 months after establishment0

Figure 4. Bitter panicum transplants; top transplant pruned to
facilitate machine planting, bottom transplant unpruned.

- - -~~~~~~~~~~~~~~~

Figure S. Experimental planting site at Duck, North Carolina, June 1973.

bitter panicum from Ocracoke Island stock; (c) nursery transplants of
Hatteras beachgrass, a locally adapted strain of American beachgrass;
(d) a combination of transplants used in (a) and sea oats from Duck;
(e) a combination of transplants used in (a) and (c); and (f) a
combination of transplants used in (a), (c), and (d).
The planting was sampled in October 1973 and 1974. Nine 14-meter
transects were sampled in 1973, across the width of each of the 18
experimental plots. A modification of the line intercept technique was
used to determine number of leaves, culms (stems), and percentage of the
length of the transect actually occupied by shoots (plant cover) for
American beachgrass, bitter panicum, and sea oats. A stand count was
also conducted on selected plots to compare the number of living bitter
panicum plants per row where the entire transplant was buried in a furrow
with those established by the conventional upright planting technique.
Five 1-square-meter quadrats (subplots) were sampled in 1974, in
each of the 18 plots. The different species present and the estimated
combined cover were recorded for each plot. The aboveground vegetation
was clipped for selected species for subsequent biomass determinations,
and dried at 70� Celsius prior to dry weight determinations for
American beachgrass, bitter panicum, shoredune panicum, Triplasis
purpurea (Walt.) Chapm. (purple sandgrass), and sea oats.
The planting was observed periodically and fertilized at the rate
of 56 kilograms of nitrogen per hectare (one time the first growing
season and three times the.second).

3. Planting at Drum Inlet, North Carolina.

The experimental planting at Drum Inlet was located about 100 meters
inland on the level strand 1 or 2 meters above the normal mean high tide
level (Fig. 6). There were scattered clumps of native Spartina patens
(Ait.) Muhl. (saltmeadow cordgrass) and sea oats throughout the planting
site. Since the study was concerned with dune building as well as
stabilization at this site, a 0.61-meter sand fence (Fig. 6) was
constructed in February 1973 to accumulate a ridge of sand before
planting.
The planting was established during 13 to 15 March 1973, using
mechanical procedures cited earlier. The variably spaced, mixed
species planting was designed to determine dune building and dune
stabilization response by three species of grass with primary emphasis
on bitter panicum. Seven treatments consisted of nursery-grown
transplants of: (a) NJ-327 American beachgrass; (b) Cape American
beachgrass (Gaffney and Duell, 1974) formerly NJ-390; (c) Hatteras
beachgrass, a locally adapted strain of American beachgrass; (d)
bitter panicum from Hatteras Island; (e) a combination of (c) and
(d); (f) a combination of (d) and sea oats from Drum Inlet; and (g) a
combination of (c), (d), and (f). One row of sea oats and two rows of
bitter panicum (buried) ran through all plots of all treatments.
Saltmeadow cordgrass was not planted. The planting was oriented

Figure 6. Experimental planting site at Drum Inlet, North Carolina,
March 1973.

parallel to the beach with each treatment replicated twice by 14- by
70-meter plots. Within these 16-row plots, the center 4 rows were
spaced 0.46 meters apart, the 4 rows on either side of the center 4
rows were spaced 0.76 meters apart, and the outermost 2 rows on either
side were spaced 1.1 meters apart. In the spring of 1974, greenhouse-
grown seedlings of sea oats were planted 1.5 meters apart on the crest
of the dune in barren areas.

The planting was sampled in October 1973 and 1974. The 14
experimental plots were sampled in 1973 in the same manner as those
at Duck except that saltmeadow cordgrass was also sampled. Eight 1-
square-meter quadrats were sampled in 1974 on the oceanside and 8 on
the sound side of the dune in each of the 14 plots. The plant species
present and the estimated combined cover were recorded for each
quadrat. The aboveground vegetation was clipped by species for
subsequent biomass determinations, and dried at 700 Celsius before
dry weight determinations for American beachgrass, Euphorbia
poZygonifoZia L. (seaside spurge), bitter panicum, saltmeadow cordgrass,
and sea oats.

The planting was observed periodically and fertilized twice during
the first growing season at the rate of 56 kilograms of nitrogen per
hectare. Elevation surveys were conducted in June 1973, 1974, and
1975, by running two cross sections per plot with a level to determine
sand accumulation. The experimental area was also repaired in the
spring of 1974, by filling gaps with sand and replanting barren areas.

III. RESULTS AND DISCUSSION

1. Duck Planting.

a. 1973. There was little growth in the April transplants by
June 1973 (Fig. 5). Although much of the sand was still bare of
vegetation in September 1973, surviving transplants of bitter panicum
were well established and the area was becoming stabilized (Fig. 7).
With the exception of plot 3, which was a mixed species treatment
consisting of bitter panicum plus Hatteras beachgrass, the number of
leaves, culms, and the cover was greater with bitter panicum than either
of the other two dune grasses in all plots of two- and three-species
treatments (Table 1). Only bitter panicum yielded cover values of
more than 0.50 percent. American beachgrass and sea oats were
initially found in scattered clumps throughout the planting site
(Table 1).

A count on selected plots indicated the number of living bitter
panicum plants was greater in rows where the entire plant had been
buried in a furrow than in rows established by the conventional upright
planting technique (Table 2). Average percentages of living transplants
were 31 for Hatteras beachgrass, 62 for bitter panicum, and 16 for
sea oats. Although survival of bitter panicum was good, growth during
the first growing season was slow compared to the other experimental

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Figure 7. Experimental planting site at Duck, North Carolina,

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Table 1. Mean number of leaves, mean number of culms, and mean cover per 14-meter transect at Duck,
North Carolina, 19731.

Treatment Plot No. Mean No. leaves Mean No. culms per Mean cover
per 14-m transect 14-m transect per transect (percent)
A2 P3 U4 A2 P3 U4 AZ P3 U4

Bitter panicum (Hatteras) 1 0.78 35.33 4.22 0.44 11.00 1.33 0.02 1.35 0.11
7 30.78 7.67 8.22 1.33 1.17 0.23
14 56.78 14.22 1.86

Bitter panicum (Ocracoke) 5 46.22 12.78 1.55
11 0.33 42.44 0.11 12.44 <0.01 1.40
16 1.00 21.78 17.22 0.33 8.67 4.78 0.03 0.63 0.47

Hatteras beachgrass 4 6.67 2.00 0.09
12 5.89 1.11 2.33 0.33 0.14 0.03
13 7.22 2.22 0.19

Bitter panicum (Hatteras)
plus 2 0.56 11.33 5.11 0.22 4.00 1.11 0.02 0.39 0.11
Sea oats (Duck) 9 0.44 9.00 2.44 0.22 5.00 0.56 <0.01 0.60 0.07
17 32.56 1.00 10.11 0.33 1.12 0.02

Bitter panicum (Hatteras)
plus 3 10.89 11.22 4.56 3.22 2.67 1.33 0.15 0.30 0.09
Hatteras beachgrass 8 3.44 28.11 0.78 1.00 7.11 0.33 0.06 0.93 0.01
15 1.89 24.56 0.78 8.78 0.03 0.92

Bitter panicum (Hatteras)
plus 6 3.56 14.44 1.44 3.78 0.07 0.54
Sea oats (Duck) plus 10 4.33 15.11 0.89 1.78 3.89 0.22 0.08 0.50 0.02
Hatteras beachgrass 18 2.44 24.89 1.00 0.89 7.22 0.22 0.05 0.79 0.02

1. Based on nine transects per plot per treatment, n = 162.
2. Ammnophila breviligulata (American beachgrass).
3. Panicum amarn (bitter panicum).
4. UnioZa panicuZata (sea oats).

Table 2. Stand count by treatment for certain plots at Duck, North Carolina, 1973.

Treatment Plot No. Survival (percent)
American Bitter Sea oats
beachgrass panicum
buried2 upright3

Bitter panicum (Hatteras) 1 62 56
7
14 73 47
Bitter panicum (Ocracoke) 5 69 50
11
16 59 50
Hatteras beachgrass 4
12 36
'0 13 29
Bitter panicum (Hatteras) plus 2 9
Sea oats (Duck) 9 13
17 25
Bitter panicum (Hatteras) plus 3
Hatteras beachgrass 8
15
Bitter panicum (Hatteras) plus 6
Sea oats (Duck) plus 10
Hatteras beachgrass 18 27 77 16

1. Number of living plants divided by the total number of possible transplants per row
by standard upright planting technique.

2. Entire transplant buried in a furrow.

3. Transplant planted upright.

planting site at Drum Inlet. There were no noticeable differences in
the performance of the selections of bitter panicum from Hatteras and
Ocracoke. The low survival of Hatteras beachgrass cannot be explained;
it is possible that the transplants were initially of low vigor. The
low survival of sea oats is consistent with results from other
experiments and those of Dahl, et al. (1975).

b. 1974. Plant cover was estimated to be about 70 percent in June
1974. Of the three dune grasses planted in April 1973, only bitter
panicum contributed an appreciable amount of this estimate (Fig. 8).
The remainder of the cover was composed of native plants that invaded the
planting (Table 3); a few seedlings of American beachgrass and sea oats
were observed. Cenchrus tribuliodes L. (sand spur), Diodia teres Walt.
(buttonweed), Oenothera humifusa Nutt. (evening primrose), and purple
sandgrass were the most widely distributed invading species (Table 4).
Only 0. hwnifusa is a perennial.

By September 1974, plant cover was estimated to be about 75 percent
(Fig. 9). Again, only bitter panicum contributed an appreciable amount
of this estimate, with the remainder composed of the invading native
plants (Table 3). Purple sandgrass, one of the four abundant invaders,
was the most prominent. Although the shoots of bitter panicum were well
developed, the rhizomes had not proliferated rapidly over the area.
This growth response was possibly due to the lack of sand movement.
Bitter panicum is most healthy and vigorous in areas accumulating
moderate amounts of sand.

Plant frequency, the percentage of sample plots in which a plant
species occurs, is a relative measure of distribution. In the October
sampling, values of 60 percent and above were obtained for bitter
panicum in all plots of original planting (Table 4). However, for both
American beachgrass and sea oats, frequency values were 60 percent or
below in the experimental plots; in several plots these species were not
recorded in the sample.

Except for plot 18, cover values were 70 percent and above (Table
5). The relatively high cover values were largely due to the invading
species, particularly the annual, purple sandgrass.

Bitter panicum contributed about 27 percent of the aboveground dry
weight, and averaged about 30 grams per square meter in the plots of
original planting, 1, 2, 3, 5, and 6, and where purple sandgrass biomass
was also determined (Table 6). Purple sandgrass was sampled for biomass
in only six plots, but since it was uniformly distributed it probably
contributed at least a minimum biomass of 37 grams per square meter
which would be more than that of bitter panicum (Table 6).

2. Drum Inlet Planting.

a. 1973. Survival of transplants in June 1973 was estimated at
75 percent, except for the two rows adjacent to the 0.61-meter sand

Figure 8o Experimental planting site at
Duck, North Carolina, June 1974,

Figure 9o Experimental planting site at
Duck, North Carolina, September
1974.

Table 3. Invading flowering plants to the experimental planting at
Duck, June and September 1974.

Name Growth Abundance1 Month
form recorded

Ambrosia artemisiifoZia L. (ragweed) herb infrequent Sept.
Carex sp. sedge rare June
Cenchrus tribuloides L. (sand spur) grass abundant June, Sept.
Chenopodium ambrosioides L. (Mexican-
tea) herb rare Sept.
Cyperus iria L. (rice flatsedge) sedge rare Sept.
Digitaria fiZiformis (L.) Koeler
(slender fingergrass) grass infrequent Sept.
Diodia teres Walt. (buttonweed) herb abundant June, Sept.
Erigeron canadensis L. (horseweed) herb infrequent June, Sept.
Euphorbia poZygonifolia L. (seaside
spurge) herb common Sept.
GhaphaZium obtusifoZium L. (rabbit
tobacco) herb infrequent June, Sept.
Myrica pensylvanica Loisel. (bayberry) shrub rare June, Sept.
Oenothera humifusa Nutt. (evening
primrose) herb abundant June, Sept.
Panicum amaruZum Hitchc. & Chase
(shoredune panicum) grass common June, Sept.
PhysaZis viscosa ssp. maritima
(M. A. Curtis) Waterfall (ground
cherry) herb infrequent June, Sept.
Spartina patens (Ait.) Muhl.
(saltmeadow cordgrass) grass rare June, Sept.
TripZasis purpurea (Walt.) Chapm.
(purple sandgrass) grass abundant June, Sept.

1. Scale of abundance from most to least abundant: abundant, common,
infrequent, rare.

Table 4. Frequency for 13 plant species at Duck, North Carolina, 1974.

u) CA CA

0 co ' $ O

Treatment Plot .c
~No. . C b 30 Cu
No C O b. C 0 Q 0 bh

Bitter panicum
C7 4P. 4 10 0 00 6 1
14 40 6$0 0 100

Bitter panicum
(Ocracoke) 5 2 0 60 20 20 20 80 20 80
11 60 80 60 1 00 4100
16 80 100 20 80 20 100 c
12 40 ;840 80 80 20 100

13 20 20 100 40 . 20 100
Bitter panicum
(Hatteras) 2 4 0 0 20 20 10 80 10 20
Sea oats0 (Duck) 9 40 10 0 100

17 80 -100 40 80 60 .100
Bitter panicum
(Hatteras) plus 16 803 60 100 2 0 80 20 100
Hatteras beachgrass 4 60 100 20 80 100 40 100
12 40 80 80 80 20 100 20
13 20 20 100 40 80 20 100
Bitter panicum
(Hatteras) plus 2 40 100 80 20 40 80 80 20
Sea oats (Duck) 9 40 100 20 100 20 100
17 80 - 100 40 100 60 .100
Bitter panicum
(Hatteras) plus 3 60 100 60 20 40 80 20 100
Hatteras beachgrass 8 20 100 100 80 100 100
is 100 100 40 80 20 100

Bitter panicum
(Hatteras) plus' 6 60 60 40 80 20 100
Sea oats (Duck) plus 10 40 80 80 80 60 20 100 20
Hatteras beachgrass 18 60 60 60 100 20

1. The percentage of sample plots in which a species occurred, based on five 1-square-meter
sample subplots in each replicate (plot) per treatment, n = 90.

1
Table 5. Mean estimated cover for all plant species at Duck,
North Carolina, 1974.

Treatment Plot No. Mean estimated
cover (percent)

Bitter panicum (Hatteras) 1 75
7 80
14 80

Bitter panicum (Ocracoke) 5 75
11 75
16 75

Hatteras beachgrass 4 80
12 70
13 60

Bitter panicum (Hatteras) plus 2 80
Sea oats (Duck) 9 75
17 75

Bitter panicum (Hatteras) plus 3 80
Hatteras beachgrass 8 80
15 80

Bitter panicum (Hatteras) plus 6 75
Sea oats (Duck) plus 10 70
Hatteras beachgrass 18 55

1. Percentage of ground surface covered by shade as determined by
projecting area covered by vegetation groundward, based on five
1-square-meter sample subplots in each replicate (plot) per
treatment, n = 90.

Table 6. Mean aboveground biomassl for five plant species at Duck,
North Carolina, 1974.

Treatment Plot Mean aboveground dry wt (g/m2)
No. A p3 p4 T U

Bitter panicum (Hatteras) 1 67 113
7 17
14 46
x7 43

Bitter panicum (Ocracoke) 5 1 72 2 37
11 45
16 58 6
x7 58

Hatteras beachgrass 4 10 9 96 3
12 1 5 1
137 3 3
x 3

Bitter panicum (Hatteras) plus 2 26 6 102 25
Sea oats (Duck) 9 85
17 91 94
x 61

Bitter panicum (Hatteras) plus 3 15 35 149
Hatteras beachgrass 8 5 15
15 7 55 25
x 35

Bitter panicum (Hatteras) plus 6 23 74
Sea oats (Duck) plus 10 5 6 1
Hatteras beachgrass 18 7 7 1
x 12

1. Based on five 1-square-meter sample subplots in each replicate
(plot) per treatment, n = 90.

2. Ammophila brevitigutata (American beachgrass).

3. Panicuwn amarum (bitter panicum).

4. Panicmn amarulum (shoredune panicum).

5. Triplasis purpurea (purple sandgrass); sampled in only one replicate
(plots 1 to 6).

6. Vnioa panicutata (sea oats).

7. Treatment means for bitter panicum only, standard error of the
difference among equally replicated treatment means, s- = 21;
lsd =47. d
0.05

fence where sand accumulation had buried the transplants about 45
centimeters deep (Fig. 10). Dahl, et al. (1975) noted that survival
of transplants buried by 15 centimeters or more of sand was less than
the upright transplants. Growth and vigor of the surviving plants at
Drum Inlet continued to be good through the remainder of the growing
season (Fig. 11).

The number of leaves, culms, and the cover in the October sample,
was equal to or greater for American beachgrass and sea oats than for
bitter panicum in all plots with treatments of two and three species
(Tables 7, 8, and 9). All three selections of American beachgrass
(NJ-327, Cape, and Hatteras beachgrass) produced greater values for
number of leaves, culms, and the cover than the Hatteras selection of
bitter panicum in single species treatments. The relatively large
values for sea oats were partly due to a row of this species running
through all plots. There were also scattered clumps of native
saltmeadow cordgrass and sea oats in the experimental area.

b. 1974. Growth of bitter panicum and sea oats was healthier
and more vigorous during the 1974 growing season. The increased amount
of sand trapped and cover established from 1973 to 1974 was readily
apparent (Figs. 12 and 13).

In the October sample, frequency values of 50 percent and above
were obtained for the originally planted species (Table 10), except for
sea oats in the three-way mixture (Hatteras beachgrass plus bitter
panicum plus sea oats) (Fig. 14). Bitter panicum had spread into all
six American beachgrass experimental plots, but was more prevalent on
the oceanside of the dune. American beachgrass was not found in the
bitter panicum experimental plots 4 and 8, and plot 6 of the bitter
panicum plus sea oats treatment. Annuals, CakilZe edentuZa (Bigelow)
Hooker (sea rocket) and seaside spurge, invaded some of the
experimental plots (Table 10). Except for plots 10, 12, and 14,
cover values were higher on the oceanside than on the sound side of
the dune (Table 11). This condition was largely due to burial of
first-year transplants on the sound side of the dune sections by
about 45 centimeters of sand. In general, cover values were somewhat
higher in the plots with bitter panicum than in the three American
beachgrass treatments.

Although a few plants invaded the experimental planting, the three
originally planted species (American beachgrass, bitter panicum, and
sea oats) still constituted 99.5 percent of the aboveground biomass
after two growing seasons (Table 12). Bitter panicum provided more cover
per unit biomass than American beachgrass. This condition is well
illustrated by comparing oceanside of the dune bitter panicum plots
4 and 8 (Fig. 13) with oceanside of the dune American beachgrass plots
3 and 13 (Fig. 15). All of these plots had frequencies of 100 percent,
but the bitter panicum plots had higher cover values (Table 11) and
the American beachgrass plots had higher biomass values (Table 12).

Figure 10. Sand accumulation on the
sound side of 0.61-meter
fence at Drum Inlet planting
site, May 1973

Figure 11. Experimental planting of
American beachgrass, bitter
panicum, and sea oats at Drum
Inlet, September 1973.

Table 7. Mean number of leaves per transect for four dune grassesl at
Drum Inlet, North Carolina, 1973.

Treatment Plot Mean No. leaves
No. per 14-m transect
A2 P3 S4 U5

NJ-327 American beachgrass 1 104.33 0.33 2.11 4.33
12 201.67 2.78 3.78 14.33

Cape American beachgrass 2 105.00 4.56
14 158.11 5.56 3.56

Hatteras beachgrass 3 162.00 4.67
13 167.89 1.44 6.89 15.89

Bitter panicum (Hatteras) 4 69.78 0.56 4.33
8 37.78 15.22

Hatteras beachgrass plus 5 78.11 17.22 7.89
Bitter panicum (Hatteras) 11 81.89 32.00 59.11

Bitter panicum (Hatteras) plus 6 1.56 19.22 66.33
Sea oats (Drum Inlet) 10 5.33 32.44 8.44 61.33

Hatteras beachgrass plus 7 29.22 9.44 3.33 19.11
Bitter panicum (Hatteras) plus 9 35.78 9.89 41.67
Sea oats (Drum Inlet)

1. Based on nine transects per plot per treatment, n = 126.
2. AmmnophilZa brevilZiguZata (American beachgrass).
3. Panicum amarum (bitter panicum).
4. Spartina patens (saltmeadow cordgrass).
5. UnioZa panicuZata (sea oats).

Table 8. Mean number of culms per transect for four dune grasses at
Drum Inlet, North Carolina, 1973.

Treatment Plot Mean No. culms
No. per 14-m transect

A P S4 U5

NJ-327 American beachgrass 1 27.56 0.22 0.09 1.33
12 61.89 0.78 1.11 2.78

Cape American beachgrass 2 31.22 1.67
14 42.00 2.67 1.33

Hatteras beachgrass 3 37.00 0.89
13 36.22 0.44 2.00 3.44

Bitter panicum (Hatteras) 4 15.89 0.22 1.11
8 11.56 4.89

Hatteras beachgrass plus 5 17.78 5.00 1.89
Bitter panicum (Hatteras) 11 23.89 8.56 13.67

Bitter panicum (Hatteras) plus 6 0.44 4.22 18.44
Sea oats (Drum Inlet) 10 1.22 8.67 3.89 16.11

Hatteras beachgrass plus 7 10.22 3.00 1.67 5.78
Bitter panicum (Hatteras) plus 9 8.00 3.11 9.89
Sea oats (Drum Inlet)

1. Based on nine transects per plot per treatment, n = 126.
2. AmmophiZla breviZiguZata (American beachgrass).
3. Panicum amarum (bitter panicum).
4. Spartina patens (saltmeadow cordgrass).
5. Uniola panicuZata (sea oats).

Table 9. Mean cover per transect for four dune grasses at Drum
Inlet, North Carolina, 1973.

Treatment Plot Mean cover
No. per transect (percent)

A2 P3 S4 U5

NJ-327 American beachgrass 1 2.18 0.02 0.03 0.05
12 4.01 0.04 0.05 0.26

Cape American beachgrass 2 2.51 0.03
14 3.55 0.06 0.10

Hatteras beachgrass 3 2.63 0.16
13 2.61 0.07 0.07 0.30

Bitter panicum (Hatteras) 4 1.74 <0.01 0.02
8 1.30 0.37

Hatteras beachgrass plus 5 1.39 0.60 0.14
Bitter panicum (Hatteras) 11 1.19 1.16 1.17

Bitter panicum (Hatteras) plus 6 0.03 0.73 1.40
Sea oats (Drum Inlet) 10 0.14 1.30 0.08 1.30

Hatteras beachgrass plus 7 0.76 0.32 0.04 0.48
Bitter panicum (Hatteras) plus 9 0.81 0.38 0.81
Sea oats (Drum Inlet)

1. Based on nine transects per plot per treatment, n = 126.
2. AmmophiZa breviZiguZata (American beachgrass).
3. Panicum amarum (bitter panicum).
4. Spartina patens (saltmeadow cordgrass).
5. UnioZa paniculata (sea oats).

Figure 12. Bitter panicum treatment in
experimental planting at Drum
Inlet, September 1973.

Figure 13. Bitter panicum treatment in
experimental planting at Drum
Inlet, October 1974.

Table 10. Frequencyl for six dune plants at Drum Inlet, North Carolina, 1974.

Treatment Plot Oceanside Frequency (percent)
No. or sound
side of 2 6 7
dune A C3 E4 p5 S6 U

NJ-327 American beachgrass 1 ocean 100 62
sound 100
12 ocean 75 62 12 12
sound 88 12 25 25
Cape American beacligrass 2 ocean 88 12 38 12
sound 100
14 ocean 100 12 12 12
sound 100 12 38 12
Hatteras beachgrass 3 ocean 100 50
sound 100 25
13 ocean 100 62
sound 100 12
Bitter panicum (Hatteras) 4 ocean 100
sound 12 50
8 ocean 12 100 25
sound 88
Hatteras beachgrass plus 5 ocean 100 88 12
Bitter panicum (Hatteras) sound 100 12 62
11 ocean 88 12 100 25
sound 75 12 50 88 38
Bitter panicum (Hatteras) plus 6 ocean 12 88 100
Sea oats (Drum Inlet) sound 50 88
10 ocean 12 100 100
sound 25 12 100 75
Hatteras beachgrass plus 7 ocean 50 12 7S 75
Bitter panicum (Hatteras) plus sound 75 12 75 75
Sea oats (Drum Inlet) 9 ocean 50 88 12 75
sound 88 75 12

1. The percentage of sample plots in which a species occurred, based on eight 1-square-meter sample
subplots on oceanside and eight on sound side of dune per plot per treatment, n = 224.
2. AmnophiZa breviligulata (American beachgrass).
3. Cakie edentuta (sea rocket).
4. Euphorbia polygonifotia (seaside spurge).
5. Panicum amarwn (bitter panicum).
6. Spartina patens (saltmeadow cordgrass).
7. UnioZa panicuZata (sea oats).

Figure 14o Experimental planting of American beachgrass, bitter panicum,
and sea oats at Drum Inlet, North Carolina, October 1974.

1
Table 11. Mean estimated cover for all plant species at Drum Inlet,
North Carolina, 1974.

Treatment Plot Oceanside Mean estimated
No. or sound cover
side of (percent)
dune

NJ-327 American beachgrass 1 ocean 16
sound 8
12 ocean 21
sound 22
Cape American beachgrass 2 ocean 16
sound 8
14 ocean 12
sound 21
Hatteras beachgrass 3 ocean 24
sound 18
13 ocean 20
sound 14
Bitter panicum (Hatteras) 4 ocean 33
sound 13
8. ocean 46
sound 16
Hatteras beachgrass plus 5 ocean 18
Bitter panicum (Hatteras) sound 16
11 ocean 33
sound 29
Bitter panicum (Hatteras) plus 6 ocean 36
Sea oats (Drum Inlet) sound 33
10 ocean 26
sound 41
Hatteras beachgrass plus 7 ocean 17
Bitter panicum (Hatteras) plus sound 16
Sea oats (Drum Inlet) 9 ocean 30
sound 11

1. Percentage of ground surface covered by shade as determined by
projecting area covered by vegetation groundward, based on eight
1-square-meter sample subplots on oceanside and eight on sound side
of dune per plot per treatment, n = 224.

Table 12. Mean aboveground biomassl for five dune plants at Drum Inlet, North Carolina, 1974.

Treatment Plot Oceanside Mean aboveground dry
No. or sound weight (g/m2)
side of
dune A2 E3 p4 S5 U6

NJ-327 American beachgrass 1 ocean 162 23
sound 73 4
12 ocean 120 50 25
sound 223 3 25 13
Cape American beachgrass 2 ocean 120 43
sound 110
14 ocean 214 12 3
sound 345 1 6
Hatteras beachgrass 3 ocean 268 6
sound 174
13 ocean 225 35 2 1
sound 234
Bitter panicum (Hatteras) 4 ocean 142
sound 49
8 ocean 157 14
sound 58
Hatteras beachgrass plus 5 ocean 142 45 3
Bitter panicum (Hatteras) sound 100 57
11 ocean 87 117 34
sound 84 58 48

Bitter panicum (Hatteras) plus 6 ocean 90 116
Sea oats (Drum Inlet) sound 68 119
10 ocean 86 60
sound 16 200 34

Hatteras beachgrass plus 7 ocean 99 1 29 143
Bitter panicum (Hatteras) plus sound 24 82 6
Sea oats (Drum Inlet) 9 ocean 116 82 10 22
sound 46 33 1

1. Based on eight 1-square-meter sample subplots on oceanside and eight on sound side of dune per
plot per treatment, n = 224.

2. AmnophiZa breviZiguZata (American beachgrass).
3. Euphorbia poZygonifolia (seaside spurge).
4. Pcmianur amarn (bitter panicum).
5. Spartina patens (saltmeadow cordgrass).
6. Uniola panicuZata (sea oats).

.1~~~~~ /

Figure 15o Hatteras beachgrass treatment in experimental planting at
Drum Inlet, North Carolina, October 1974o

c. Sand Accumulation.. Volumes of sand accumulated :during the
initial 3 months (Table 13) were largely due to sand accumulation by the
0.61-meter fence (Fig. 10), not the planted vegetation. After 3 months,
the bitter panicum plots had as much or more sand than the other
experimental plots except the American beachgrass plots 1 and 2 (NJ-327
and Cape, respectively). These values had no uniform correlation with
the 15- and 27-month values. For example, plots 1, 2, 4, and 6 had
higher values after 3 months than the other replicate plots (12, 14, 8,
and 10) in the respective treatments, but lower values after 27
months (Table 13). These results indicate that the. sand fence'did
not significantly influence the 15- and 27-month values which were
primarily due to the differential sand-trapping potentials of the
vegetation.

After 27 months, the three American beachgrass treatments had
trapped more sand than all other treatments, and over twice as much
as the bitter panicum treatment (Table 13, Fig. 16). The Hatteras
beachgrass treatment accumulated slightly more sand over the 24-month
period, June 1973 to June'1975, than the other two American beachgrass
treatments. Over this same period, the bitter panicum treatment
averaged about l:cubic meter of sand accumulation per linear meter of dune
which is about one-fifth as much sand as any other treatment. Even if the
best replicate of the bitter panicum treatment is considered, sand accumu-
lation during this period was only-l.9 cubic meters per linear meter or
one-third the sand accumulated by other treatments.

All three mixed species treatments accumulated over 5 cubic meters
of sand per meter of dune over the 24-month period. Although the
bitter panicum plus sea oats treatment accumulated more sand'than the
other two mixed species treatments, American beachgrass or sea oats
planted with bitter panicum accumulated more sand than did bitter
panicum alone.

Three treatments (Hatteras beachgrass, bitter panicum plus sea oats,
and Hatteras beachgrass plus bitter panicum plus sea& oats) trapped over
1 cubic meter of sand per meter of dune more in June 1973 to June 1974,
than in June 1974 to June 1975. Only the NJ-327 American beachgrass
treatment accumulated more than one-half meter of sand per meter of
dune during the second 12-month period. If the supply of moving sand
was equal over both years, the vegetation should have caught more sand
during the second year since the vegetation was more dense at that time.

Cross-section profiles indicate that the dune crest in all
treatments moved seaward about 3 meters from June 1973 to June
1975 (Fig. 16). The dune crest in the Hatteras beachgrass treatment
moved the most, about 5 meters. We have observed other experimental
American beachgrass dunes move seaward more rapidly than those
of sea oats. This movement is due partially to American beachgrass'
tremendous vegetative growth (by rhizomes) potential under conditions

Table 13. Cumulative mean volume of sand1 accumulated over 3-, 15-, and
27-month periods at Drum Inlet, North Carolina.

Treatment Plot Volume of sand (cubic meters
No. per meter of dune) by time
after planting2
3 months 15 months 27 months

NJ-327 American beachgrass 1 3.4 4.8 7.1
12 2.4 7.1 10.8
-3
x 2.9 6.0 9.0
Cape American beachgrass 2 4.0 6.7 8.8
14 2.7 6.6 10.3
-3
x 3.3 6.6 9.5
Hatteras beachgrass 3 2.7 6.9 10.7
13 2.3 6.8 9.8
x 2.5 6.9 10.2
Bitter panicum (Hatteras) 4 3.3 3.0 3.7
8 3.1 4.9 5.0
x 3.2 4.0 4.3
Hatteras beachgrass plus 5 2.3 4.8 7.3
Bitter panicum (Hatteras) 113 2.6 5.4 8.4
x 2.4 5.1 7.9
Bitter panicum (Hatteras) plus 6 3.3 5.6 7.7
Sea oats (Drum Inlet) 103 1.7 6.7 9.7
x 2.5 6.2 8.7
Hatteras beachgrass plus 7 2.6 6.3 7.2
Bitter panicum (Hatteras) plus 9 2.8 6.4 9.2
Sea oats (Drum Inlet) x 2.7 6.4 8.2

1. Based on two elevational cross sections for each of two replicates
per treatment.
2. Planting established in March 1973.
3. Treatment mean.

NJ - 327 American beachgrass

i-i Planting width
'I6. 4 12. I16. '23. NA . k '. W. W . 11. h
Cape American beachgrass

9. ..e C32. 19. N20. '2. N21. V2 . '6 H. e.
Hatteras beachgrass

a ~ ~~~~~~~~~~~~~~~~~~~~~. *.M----

Bitter panicum S13 -

9.6 era bU.Se p i.; . u. biter he.ne.cu. he

Hatteras beachgrass plus bitter p anicumnpu o~f

'16 S. W ~ . 130. 14. 1. '. H.

F~~~~itter 16pManicun cross sectioats

inamteras aboecgru mlsbteraniupw sea ot
level (Sa Oforsee
treatments~~~$2 at ru
I~~nle. 17 o 95

U.~~3

of sand accumulation. Based on the 1975 profiles, oceanside and
sound side dune slopes were most gentle in the American beachgrass
treatments; the sound side slope was steeper in the other treatments,
all of which included bitter panicum. Dune side slopes were steepest
in the Hatteras beachgrass plus bitter panicum plus sea oats treatment.

IV. SUMMARY AND CONCLUSIONS

Single culm transplants of bitter panicum can be planted in an
inland nursery, and with routine cultivation and fertilization, can
yield a supply of transplants for field planting at the end of the
first growing season. A tenfold increase in number of culms was
obtained at the end of the first growing season at Clayton, with an
additional 2.5-fold increase by the end of the second growing season.
The plants should be separated into single culm transplants after
digging, dipped in a clay slurry, and packaged in reinforced paper to
prevent desiccation. About 2 man-hours are required to dig and process
1,000 transplants for field planting. This is about twice the time
required to process an equal amount of American beachgrass transplants.

Bitter panicum has the potential to stabilize foredunes and inland
sandy areas. On the high sandy site at Duck, bitter panicum
contributed more toward stabilizing the site than American beachgrass
or sea oats. However, the American beachgrass planting stock may not
have been as vigorous as generally encountered. Although bitter panicum
can stabilize an area where relatively little sand is moving, such as
the Duck site, the species was more vigorous and spread more at the
foredune site at Drum Inlet where moderate amounts of sand were
accumulating.

Production of new shoots by bitter panicum plants buried in a 15-
centimeter furrow was higher than transplants planted in the conventional
upright manner at Duck. However, most of the buried transplants at
Drum Inlet were covered by 45 centimeters of sand and unable to grow.
Transplants should be planted in the conventional manner in areas
accumulating sand, but may be buried in a furrow in nursery plantings
and in areas not accumulating much sand. Recent observations suggest
that a furrow planting technique which allows the tip end of the
transplant to protrude above the sand, may be as good as upright
planting, even in areas accumulating sand.

On the foredune planting site at Drum Inlet, each of three
selections of American beachgrass accumulated over five times more
sand than bitter panicum in a 24-month period. Sand accumulations in
mixed species plantings of bitter panicum with American beachgrass
and sea oats over this period of time were more comparable with that
of American beachgrass alone. Both American beachgrass and sea oats
were more efficient sand trappers than bitter panicum.

Cross section profiles indicated that American beachgrass dunes
moved seaward more rapidly and had more gentle side slopes than
bitter panicum dunes. These findings and other observations suggest
that American beachgrass dunes can repair themselves more rapidly
following storm attack than dunes with bitter panicum or sea oats.

The length of the growing season, and the width and number of
leaves per unit area may be factors related to differential sand
accumulation by the three dune grasses tested. The leaves of bitter
panicum are wider and generally fewer per unit area than those of
either American beachgrass or sea oats. Therefore, bitter panicum
may not be as effective at trapping sand. The relatively short (May
to October) growing season of bitter panicum compared to the
relatively long one (February to November) for American beachgrass
at this latitude may be one of the reasons for not accumulating as
much sand as American beachgrass. The growing season of sea oats
coincides closely with that of bitter panicum; other factors, such
as leaf width and density, may be responsible for the differential-
sand trapping between the two species. Since bitter panicum has a
longer growing season at a more southerly latitude, it is probably
a better dune builder farther south.

Sand accumulation and dune profile data suggest that bitter
panicum should not be used in monospecific plantings to build dunes
along the North Carolina coast. The results indicate that the mixed
species planting is almost as good at dune building as monospecific
stands of American beachgrass. These mixed species plantings are
ecologically more desirable because of the insect, disease, and
physiological problems associated with American beachgrass at this
latitude, In a mixed species planting of American beachgrass, bitter
panicum, and sea oats, a dune can be built primarily by the sand
trapping potentials of American beachgrass and sea oats; when American
beachgrass begins dying out, it can rapidly be replaced by the other
two native grasses to stabilize the area. The principal values of
bitter panicum are in stabilizing sandy coastal areas and in mixed
species plantings to build and stabilize coastal dunes in the
southeastern United States.

LITERATURE CITED

CAMPBELL, W.V., and FUZY, E.A., "Survey of the Scale Insect Effect on
American Beach Grass," Shore and Beach, Vol. 40, No. 1, Apr. 1972,
pp. 18-19.

DAHL, B.E., et al., "Construction and Stabilization of Coastal Foredunes
with Vegetation; Padre Island, Texas," MP 9-75, U.S. Army, Corps of
Engineers, Coastal Engineering Research Center, Fort Belvoir, Va.,
Sept. 1975.

GAFFNEY, F.B., and DUELL, R.W., "Registration of Cape American Beachgrass,"
Crop Science, Vol. 14, No. 5, Sept.-Oct. 1974, p. 777.

LUCAS, L.T., et al., "Marasmius Blight, a New Disease of American Beach-
grass," Plant Disease Reporter, Vol. 55, No. 7, July 1971, pp. 582-585.

PALMER, P.G., "A Biosystematic Study of the Panicum amarum - P. amarulum
complex (Gramineae)," Brittonia, Vol. 27, No. 2, Apr.-June 1975,
pp. 142-150.

SENECA, E.D., "Germination and Seedling Response of Atlantic and Gulf
Coasts Populations of Uniola paniculata," American Journal of Botany,
Vol. 59, No. 3, Mar. 1972, pp. 290-296.

WOODHOUSE, W.W., Jr., and HANES, R.E., "Dune Stabilization with Vegetation
on the Outer Banks of North Carolina," TM-22, U.S. Army, Corps of
Engineers, Coastal Engineering Research Center, Washington, D.C., Aug.
1967.

WOODHOUSE, W.W., Jr., SENECA, E.D., and COOPER, A.W., "Use of Sea Oats
for Dune Stabilization in the Southeast," Shore and Beach, Vol. 36,
No. 2, Oct. 1968, pp. 15-21.

PREVIOUS PUBLICATIONS PUBLISHED
By J
THE CENTER FOR MARINE AND COASTAL STUDIES

Wave-Current Force Spectra, C. C. Tung and N. E. Huang, Report No. 72-2,
December, 1972.

A Survey of North Carolina Beach Erosion by Air Photo Methods, H. E. Wahls,
Report No. 73-1, May, 1973.

Sediment Movement in Tubbs Inlet,'North Carolina, Robert P. Masterson, Jr.,
Jerry L. Machemehl and Victor V. Cavaroc, Jr., Report No. 73-2,
June, 1973.

Influence of Current On Some Statistical Properties of Waves, C. C. Tung
and N. E. Huang, Report No. 73-3, December, 1973.

CTD Sensors, Specific Conductance and the Determination of Salinity,
C. E. Knowles, Report No. 73-3, August, 1973.

Planning for North Carolina's Coastal Inlets - An Analysis of the Present
Process and Recommendations for the Future, William S. Tilley,
Report No. 73-4, September, 1973.

A Preliminary Study of Storm-Induced Beach Erosion for North Carolina,
C. E. Knowles and Jay Langfelder and Richard McDonald, Report
No. 73-5, October, 1973.

A Historical Review of Some of North Carolina's Coastal Inlets, Jay
Langfelder, Tom French, Richard McDonald and Richard Ledbetter,
Report No. 74-1, January, 1974.

Statistical Properties of Kinematics and Dynamics of a Random Gravity
Wave Field, C. C. Tung, Report No. 74-2, June, 1974.

A New Technique of Beach Erosion Control, Tom French, Jerry L. Machemehl
and N. E. Huang, Report No. 74-3, June, 1974.

Citizen Participation in North Carolina's Coastal Area Management Program,
Steve Tilley, Report No. 74-4, June, 1974.

An Experimental Study of Scour Around Marine Foundations Due to
Oscillatory Waves and Undirectional Currents, Greg N. Abad and
Jerry L. Machemehl, Report No. 74-5, September, 1974.

Proceedings of A Conference on Coastal Management, Report No. 74-6,
September, 1974.

Statistical Properties of Fluid Motion and Fluid Force in A Random
Wave Field, Keikhosrow Pajouhi and C. C. Tung, Report No. 75-1,
May, 1975

Previous Publications Published Cont'd. Page 2

A Numerical Method for Solutions of Systems of Non-Linear Algebraic
Equations , John M. Klinck and Leonard J. Pietrafesa, Report No.
75-2, July, 1975.

Wave-Current Interactions in Water of Variable Depths , A. M. Radwan,
C. C. Tung and N. E. Huang, Repbrt No. 75-3, August, 1975.

Conference Proceedings Energy From The Oceans Fact or Fantasy?
Jerome Kohl, Report No. 76-1, UNC-SG-76-04, January, 1976.

Lonq Waves Trapped by the Cape Fear Continental Shelf Topography:
A Model Study of Their Propagation Characteristics and Circula-
tion Patterns , David A. Brooks, Report No. 76-2, July, 1976.

A Comparative Study of Three Methods of Inhibiting Scour Around A
Vertical Circular Cylinder, David M. Rooney and Jerry L. Machemehl,
Report No. 76-3, September, 1976.
A Flow Study of Drum Inlet, North Carolina, Paul R. Blankinship,
Report No. 76-4, UNC-SG-76-13 November, 1976

Dune Stabilization with Panicum amarum Along the North Carolina Coast,
E. D. Seneca, W. W. Woodhouse, Jr., and S. W. Broome, Report No.
77-1, UNC-SG-77-03, February, 1977.