Plant World
1914

NOTES ON THE ECOLOGY OF SAND DUNE PLANTS
by
Edward B. Couch
at
University of Southern California
Los Angeles, California


The dunes studied are those at Peck's Manhattan Beach, between Redondo and Venice, California. They are practically undisturbed, and therefore lend themselves readily to safe investigation of their flora. These dunes rise to a height of 150 feet above sea level in a horizontal distance of three-quarters of a mile and descend abruptly 75 feet in about 100 feet of horizontal distance. The physiography is referred to as windward slopes, as summits, or as leeward slopes the configuration of the dunes having been determined by the sea winds.

Quadrat counts covering the dunes were made in March 1913, each quadrat being 10 meters square.

It is seen that the dominant plant in the first three quadrats [1,2,3] is Gaertneria, [Ambrosia chamissonis] which is the pioneer plant to encroach on moving sand. It establishes itself and is followed by Abronia umbellata in more or less protected places. As Abronia umbellata is secondary in the first three quadrats and dominant in the fourth it seems to rank second to Gaertneria as a sand binding plant.

In the fourth quadrat [4] Abronia umbellata is the dominant plant with Eriogonum [Eriogonum parvifolium] and Lupinus as secondaries. Gaertneria [Ambrosia chamissonis] has lost its place and become a relict perhaps of former formations or is of accidental occurrence.

Quadrat number five [5] shows Adenostoma [Ericameria ericoides] as dominant and Abronia umbellata and Cheiranthus [Erysimum insulare suffratescens] as secondaries. Adenostoma [Ericameria ericoides] appears suddenly and in so doing rather upsets the series of dominants and secondaries. It however is peculiar to the summit and leeward slopes and occurs just as markedly as the quadrat count indicates. It does not occur on the windward slope. It is possible that Eriogonum [Eriogonum parvifolium] should also be named as a secondary in this quadrat.

Quadrat six [6] gives Cheiranthus [Erysimum insulare suffratescens] as dominant by numbers and Adenostoma [Ericameria ericoides] and Eriogonum [Eriogonum parvifolium] as secondaries. The size of the plants however place them in reverse order.

In quadrat seven [7] the most conspicuous plant of the dunes in dominance is Lupinus. [Lupinus chamissonis] The land is so nearly occupied that to name a secondary would be stretching the meaning to apply to mere numbers.

The two kinds of competition exist, that between plants and their environment and that between plants themselves. In general the competition on the windward slope is environmental that of the summit a combination of environmental and vegetative and that of the leeward slope mainly vegetative. In both cases where the competition is greatest the number of species is the least. In case of environmental competition the plants do not cover the surface of the soil, but in the case of vegetative competition the surface is covered in proportion as the competition is close. In other words, open formation occurs on the windward slope and slightly so on the summit, while closed formations are the rule on the leeward slope and at the foot of the dune on that side. Gaertneria [Ambrosia chamissonis] and Abronia umbellata seem to be the most successful in the environmental competition and Lupinus [Lupinus chamissonis] in plant competition. The regions giving the greatest number of species in the counts seem to be where there is an intermediate stage in competition and stabilization. It will be noted that the greatest number species occurs in counts taken on or near the summit of the dune. This is peculiar to dune formations. The combination of plant and vegetative competition is caused by the constant of sand and the tendency toward complete ecesis. The existence of this double condition tends to permit the gathering of representatives of all the species on the dunes near the summit excepting Abronia maritima which is limited to within about one-quarter mile from the sea.

The September aspect of the dune is very different from that of the spring. Most of the plants are in a drought resisting condition. Those flourishing in September are Eremocarpus [Croton californicus], Sphaerostigma [Camissonia cheiranthifolia var. suffriticosa], Eriogonum[Eriogonum parvifolium]. The rest of the plants that made such a showing in the spring appear dead but still remain rooted for next season's growth. The leaves and stems of those growing are grayish in color and largely tomentose, a condition peculiar to the drought resisting plants of the dunes. The leaves of Eriogonum [Eriogonum parvifolium] are more revolute than in the spring, thereby reducing the synthetic and transpiring surface.

New dune regions where the above plants have not grown show the order of succession to be given as above. In evidence of this the fact may be stated that the owner of the sand spit connecting the mainland with Coronado near San Diego, California, sowed seeds of Abronia umbellata and [Ambrosia chamissonis] on the barren spit and after two years all the plants that occur on the dunes are present in the same relations as have been given in the quadrats above.




AFTERWORD
by
Robert Jan "Roy" van de Hoek
Biologist - Geographer - Naturalist - Archaeologist
Ballona Institute
322 Culver Boulevard, Suite 317
Playa del Rey, CA 90293
Email: ballonainstitute@yahoo.com
Phone: (310)821-9045

2004

Natural History of a Geography of Hope Via a Website
Seaside Heliotrope


More than 90 years ago, Edward Couch studied and wrote about the native plant ecology of the coastal sand dunes of Los Angeles County. His article, published in Plant World in 1914 is a classic today, and this magazine is the antecedent periodical to the science periodical Ecology that is published today by the Ecological Society of America. Edward Couch conducted his research in Manhattan Beach, where this sand dune habitat is nearly obliterated today in Manhattan Beach except at Sand Dune Park and could be restored at the adjacent California National Guard property, now covered in iceplant.

The early research by Edward Couch is not only important as a historical document related to the development of the science of Ecology, the fields of Conservation Biology, Environmental History, Historical Ecology, and Ecological Restoration will find this early classic report as essential and vital to doing "genuine" restoration of sand dunes on the coast of Los Angeles County. The data and some of the conclusions drawn by Edward Couch are useful beyond Manhattan Beach. For example, the data can be used for "genuine" restoration in Playa del Rey at the Toes "Sunset" Beach sand dune and the Ballona sand dune, the Los Angeles Airport sand dune, Hyperion sand dune fragments, El Segundo Chevron Refinery sand dune fragments, and at coastal sand dune fragments in Hermosa Beach, Redondo Beach, Torrance, Santa Monica, and Venice (Los Angeles).

In 2005, the Los Angeles County sand dune ecosystem studied by Edward Couch in 1913 is mostly developed with expensive coastal homes and businesses. This classic study of dune perennial vegetation is fortunate indeed, so much so that Edward Couch needs to be considered prescient for studying these sand dunes and that Edward Couch was affiliated with a university, that being University of Southern California (USC) as indicated by the affiliation beside his name. In the early days of the Ecological Society of America (ESA), prominent professors of biology were officers in ESA. Approximately 20 years later, another scientist from USC would study the sand dunes of Los Angeles County, just north of Manhattan Beach at the future location of LAX Airport. Her name was Edith Purer, and her professor advisor/mentor were also officers of the ESA, so that we see a continuity of interest by USC in ecology, coastal sand dunes, and student education.

Fortunately, a growing cultural movement has appeared that is interested in preserving and restoring natural ecosystems across the USA, and also across the earth. In California and in Los Angeles, the movement is growing too. As an example, even though so much sand dune habitat has been lost, a societal movement to save the last remnants of this ecosystem parkland is occurring. In Los Angeles County, several cities are beginning to connect their sand dune and coastal strand ecosystems together. A draft conservation scientific plan has been assembled. In essence, there is a renaissance occurring for the restoration of coastal sand dune and coastal strand that once stretched from Torrance to Santa Monica in Los Angeles County.

Perhaps the most important and significant feature of the research by Edward Couch is that his report of 90+ years ago can be used to guide us in the direction of "true" and "genuine" restoration. Currently, throughout the restoration efforts of coastal southern California, nearly every effort has been a failure due to using the "wrong" native plants. These mistakes are supported naively and ignorantly by state agencies with government funding. The reasons are complex but involve both politics by major corporations and landscape architects. These entities lack scientific understanding and awareness of what genuine native plants are for coastal southern California.

The list of plants by Edward Couch in his study is an excellent guide of the species to utilize but they must be deciphered still further for nomenclatural name changes, some misidentifications, and a comparison to photographs in his report. Furthermore, there needs to be a linkage to restoration of the fauna, not the the mere hope that animals will return if native plants are used. In nearly every situation, there will need to be a "planting" of the animals as well. Zoologists and conservation biologists actually refer to the restoration of animals as translocation and is a form of recovery, and can also be called animal restoration. And if this kind of animal restoration is not completed, no project can be termed genuine restoration.

About 20 years after the study of Edward Couch, a complementary investigation by another USC researcher named Edith Purer occurred in the early 1930s. She studied several plants in excruciating detail on the El Segundo Sand Dune for her graduate work toward a PhD, after moving here from Chicago, where she had just completed a Masters Degree. She studied at the dominant University of Chicago School of Ecology of the early 1920s. She had been tempted to do a sand dune study by virtue of the fact that she observed sand dunes around the shores of Lake Michigan near Chicago at the Indiana Dunes National Park. Her sand dune investigation is a classic in ecology and so are her later studies into vernal pools and salt marshes of San Diego County. She quotes the studies of Edward Couch in her own investigation of the El Segundo Sand Dune.

Although the study by Edward Couch and later by Edith Purer were focused on just a portion of the Los Angeles County sand dunes, their results are applicable to the entire dune system of Los Angeles County.

Their studies focused on plants, but there are animals that occur in sand dunes too. Fortunately, there were studies done in the 1930s by both entomologists and vertebrate zoologists so that we have a good idea of the original fauna too. Some of these animals are rare animals known to be associated with this sand dune complex. These faunal elements include several birds (Loggerhead Shrike is one example), reptiles (Silvery Legless Lizard), and butterflies such as the El Segundo Blue. The University of California at Berkeley, via Jerry Powell, resulted in further studies of coastal sand dunes of Los Angeles County with a focus on insects.

Hopefully, the last remaining remnants of the coastal sand dunes of Los Angeles County can be saved. These last sand dune and coastal strand ecosystems stretch from Santa Monica to Venice to Playa del Rey to El Segundo to Manhattan Beach to Hermosa Beach to Redondo Beach to Torrance. This is a true "geography of hope." The real difficulty and challenge will be to do "GENUINE" restoration. This study by Edward Couch that was published in 1914, now 90+ years ago, will be vitally important as a source document for "GENUINE" restoration. For this reason I have labored to bring this article back-into-print in association with the Ballona Institute. The Ballona Institute has already conducted numerous field investigations and even some actual ecological restoration to recover the "GENUINE" flora and fauna of the Los Angeles County Sand Dune.


SELECTED WEB PAGES
Wandering Skipper Butterfly at Malibu Lagoon

Malibu Lagoon & Golf: Another Photo

Malibu Lagoon & Golf: Another View

Heliotrope Wildlings