Salt Spray Distribution and Its Impact on Vegetation Zonation on Coastal Dunes: a Review

Coastal dunes are very dynamic systems, particularly where the coast is rising as a result of isostatic rebound. In those environments, succession proceeds from plants highly tolerant to sand accumulation, salt spray, and low nutrient availability to less disturbance-tolerant and stress-tolerant, more nutrient-demanding, and supposedly more competitive species. In the subarctic, the regional climate exacerbates the stresses imposed by local abiotic conditions on the dunes. I hypothesized that facilitation would be particularly significant on the foredune of subarctic coastal dune systems because of intense stresses (local and regional) and frequent disturbance in the form of sand deposition. Belowground and aboveground plant biomass was sampled at three different periods during the 1990 growing season along transects perpendicular to the shoreline on a coastal dune system in subarctic Quebec (Canada). The three herbaceous perennials found on the foredune (Honckenya peploides, Elymus mollis, and Lathyrus japonicus) were segregated in time during the growing season and in space along the topographical gradient. The biomass of Honckenya, the first species encountered as one progresses from the upper part of the beach towards the foredune ridge, was not correlated to substrate physicochemistry. However, the biomass of Elymus and that of Lathyrus, the next two species to appear along the flank of the foredune, were related to pH, Mg, Na, and Cl (negatively), and to P and Ca (positively). These results suggest variable linkages between substrate physicochemistry and plant species along the foredune, possibly in relation to species-specific tolerance for abiotic conditions and requirements for substrate resources or to microscale influence of the plants themselves on substrate physicochemistry. Removal experiments carried out over 2 years revealed only one significant unidirectional interaction between these three species along the topographical gradient, and little plant control over abiotic variables (e.g., soil temperature, wind velocity, and photosynthetically active radiation). Early primary succession on subarctic coastal dunes (and elsewhere) appears to be under the control of strong limiting abiotic conditions. As plants slowly gain more control over the physical environment, interspecific interactions (positive and negative) may become more significant. Key words: Elymus mollis, facilitation, Honckenya peploides, inhibition, Lathyrus japonicus, removal experiment, succession, tolerance.

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Trade-off between growth ability and stress tolerance in Leymus mollis (Poaceae) along a subarctic coastal dune sequence in northern Quebec

Canadian Journal of Botany ◽

10.1139/b02-073 ◽

2002 ◽

Vol 80 (8) ◽

pp. 869-874 ◽

Cited By ~ 5

Author(s):

Gilles Houle

Keyword(s):

Growth Rate ◽

Salt Stress ◽

Stress Tolerance ◽

Relative Growth Rate ◽

Salt Spray ◽

Perennial Grass ◽

Coastal Dunes ◽

Relative Growth ◽

Trade Off ◽

Leymus Mollis

Several environmental factors vary with distance from the shoreline on coastal dunes. For instance, salinity, salt spray, and sand movement decrease but nutrient and water availability increase from the foredune to the stabilized dunes. Plants colonizing the upper beach and the foredune are thus exposed to more severe abiotic stresses than those on the stabilized dunes. Although community composition changes progressively from the upper beach to the stabilized dunes, some species persist through the sequence. For example, on the coastal dunes of subarctic Quebec, Leymus mollis (Trin.) Hara (Poaceae), a perennial grass that colonizes the upper beach and the foredune, persists onto older stabilized dunes. Under controlled conditions, the response of L. mollis ramets from different habitats along the dune sequence to various saline conditions was examined. It was expected that ramets from the upper beach and the foredune, where substrate salinity is typically higher, salt spray more important, and saltwater intrusion more frequent, to better support salinity stress. Ramets from the upper beach and the foredune had a higher relative growth rate (RGR) but were, in fact, less tolerant to salt stress than those from the stabilized dune. Because sand accumulation is higher on the upper beach and the foredune, a higher RGR may be favored there to the detriment of a higher sensitivity to salt stress. The salt tolerance of stabilized dune ramets may be the expression of a more generalized stress-tolerance strategy as suggested by low RGR and high leaf nutrient concentration.Key words: embryo dune, foredune, leaf turnover, relative growth rate (RGR), salt stress, stabilized dune, tolerance, trade-off.

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Bryophytes in Mediterranean coastal dunes: ecological strategies and distribution along the vegetation zonation

Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology ◽

10.1080/11263504.2017.1418452 ◽

2018 ◽

Vol 152 (5) ◽

pp. 1141-1148 ◽

Cited By ~ 6

Author(s):

Valeria Murru ◽

Michela Marignani ◽

Alicia T. R. Acosta ◽

Annalena Cogoni

Keyword(s):

Coastal Dunes ◽

Ecological Strategies ◽

Vegetation Zonation

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Vegetation zonation on a Natal coastal sand-dune system in relation to salt spray and soil salinity

South African Journal of Botany ◽

10.1016/s0022-4618(16)30144-9 ◽

1983 ◽

Vol 2 (1) ◽

pp. 46-51 ◽

Cited By ~ 9

Author(s):

F.A. Donnelly ◽

N.W. Pammenter

Keyword(s):

Soil Salinity ◽

Sand Dune ◽

Salt Spray ◽

Coastal Sand Dune ◽

Dune System ◽

Vegetation Zonation ◽

Coastal Sand

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Salt spray and soil salinity

The Biology of Coastal Sand Dunes ◽

10.1093/oso/9780198570356.003.0013 ◽

2009 ◽

Author(s):

M. Anwar Maun

Keyword(s):

Plant Growth ◽

Plant Species ◽

Soil Salinity ◽

Seedling Survival ◽

Salt Spray ◽

Coastal Dunes ◽

High Amplitude ◽

Salt Crystals ◽

High Turbulence ◽

Spilling Breakers

Salt spray is an important abiotic stress that affects plant and other biotic communities in the vicinity of sea coasts. Salt stress refers only to excess of ions in the environment, but along sea coasts it specifically involves increased amounts of Na+ and Cl− ions. Anyone who has visited a sea coast on windy days has experienced the landward movement of salt in the form of salt spray. Salisbury (1805) reported details of a marine storm in England following gale force winds from the east for one week. He writes: ‘On the 14th of January 1803, I observed an east window of my house, which had been cleaned a few days before, covered on the outside with an apparent hoar frost.’ Chemical analysis showed that it was salt from salt spray that had been deposited on plants, buildings and other objects. In spring of that year he made two observations: (i) plant taxa showed differential tolerance to salt spray and (ii) injury was more pronounced on the windward than the leeward sides of plants. Salt spray acts as a strong environmental stress and populations of biotic organisms have evolved traits that allow them to tolerate the effects of salt. The salt crystals also act as condensation nuclei in the air and damage plants by abrasion during wind storms. However, salt spray may also be beneficial because it improves plant growth by providing some essential nutrients. Many researchers have examined the role of salt spray on survival, distribution and growth form of plant species. In this chapter the effects of salt spray and soil salinity on seed germination, seedling survival and plant growth will be examined. Symptoms of injury to plants, mechanisms of salt tolerance and comparisons between plant species native to the coastal dunes will also be discussed. Three factors—wind speed, wave amplitude and wind direction—influence the formation of salt spray. Waves of high amplitude produce four basic types of breakers: surging, collapsing, plunging and spilling. The steepest waves with high turbulence create spilling breakers with a bore accompanied by large quantities of small foam bubbles.

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Zonation of vegetation along a burial gradient on the leeward slopes of Lake Huron sand dunes

Canadian Journal of Botany ◽

10.1139/b04-163 ◽

2005 ◽

Vol 83 (2) ◽

pp. 227-236 ◽

Cited By ~ 40

Author(s):

Jeffery P Dech ◽

M Anwar Maun

Keyword(s):

Community Composition ◽

Plant Community ◽

Plant Communities ◽

Sand Dunes ◽

Salt Spray ◽

Coastal Dunes ◽

Causative Factor ◽

Lake Huron ◽

Plant Community Composition ◽

Species Importance

The zonation of coastal dune plant communities from the beach to their inland margin is recognized worldwide; however, the cause of this pattern remains controversial because of the covariance of several environmental factors, such as sand burial, salt spray, and microclimate, along a gradient perpendicular to the shoreline. To minimize the confounding influence of this complex shoreinland gradient and determine the direct effects of burial on plant community composition, we examined stands along a burial gradient that extended parallel to the Lake Huron coastline, produced by variable blowout activity amongst a series of parabolic dunes comprising the second ridge inland from the coast. We used the point-quarter method and 1 m × 1 m plots to quantify overstorey and understorey plant communities in each parabolic dune stand and determined species importance, here defined as the sum of density, frequency, and dominance for the overstorey and the sum of frequency and dominance only for the understorey. Correspondence analyses of the species importance dune stand matrices elucidated a pattern of plant community composition on the primary ordination axis that was strongly related to an index of burial activity (r2 = 0.40 and 0.87 for the overstorey and understorey, respectively). Burial was associated with changes in species richness and diversity, shifts in dominant species, and species replacement based on burial tolerance across the gradient. These data support the hypothesis that burial in sand dunes is a major causative factor of zonation, which can extend beyond the foredunes and include communities of woody species.Key words: coastal dunes, vegetation, zonation, woody plants, burial.

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Morphological Differences in Lignotubers of Eucalyptus intermedia R.T. Bak. And E. signata F. Muell. Associated With Different Stages of Podzol Development on Coastal Dunes, Cooloola, Queensland

Australian Journal of Botany ◽

10.1071/bt9870301 ◽

1987 ◽

Vol 35 (3) ◽

pp. 301 ◽

Cited By ~ 10

Author(s):

J Walker ◽

CH Thompson ◽

CJ Lacey

Keyword(s):

Water Status ◽

Salt Spray ◽

Soil Nutrient ◽

Coastal Dunes ◽

Nutrient Status ◽

Fire Regimes ◽

Nutrient Supply ◽

Dune System ◽

Factors Affecting ◽

Coastal Margin

The sandmass at Cooloola comprises a series of overlapping aeolian dune systems that extend in age from the present back more than 100 000 years. Podzols are the dominant soils, forming a sequence from rudimentary through to giant forms, according to age. The lignotuber morphology of Eucalyptus signata and E. intermedia was examined within each dune system across the chronosequence, at sites in which most factors affecting plant growth (available soil water status, drainage, light, temperature, fire regimes, exposure to wind and/or salt spray) other than a declining soil nutrient supply were similar. Three lignotuber morphologies were identified: (1) a single-stemmed (SS) form; (2) a multi-stemmed (MS) form with stems originating from a lignotuber only slightly larger than a main stem; and (3) a multi-stemmed plate-like form (MSP) with individual stems separated and growing from a plate-like lignotuber. Multi-stemmed forms of the two eucalypts occur along the coastal margin and on the most nutrient- poor dunes; at all other sites single-stemmed forms are dominant. The most nutrient-poor site had only MS and MSP forms, whilst in sheltered areas the coastal margin had SS individuals. We conclude that in the Cooloola sandmass the development of multi-stemmed forms in both E. signata and E. intermedia may be induced by a variety of factors, including very low nutrient status, but the multi-stemmed plate-like form of E. intermedia is most likely a response to an exceptionally low nutrient supply.

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Physical, Chemical, and Crystallographic Characterization of Anodic Coatings on High Strength Aluminum Base Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100093146 ◽

1976 ◽

Vol 34 ◽

pp. 636-637

Author(s):

R. E. Herfert ◽

N. T. McDevitt

Keyword(s):

Sulfuric Acid ◽

Salt Spray ◽

High Strength ◽

Environmental Stability ◽

Anodic Films ◽

Sodium Dichromate ◽

Corrosion Resistant ◽

Aerospace Applications ◽

Bond Strengths ◽

Adhesive Bonded Joints

Durability of adhesive bonded joints in moisture and salt spray environments is essential to USAF aircraft. Structural bonding technology for aerospace applications has depended for many years on the preparation of aluminum surfaces by a sulfuric acid/sodium dichromate (FPL etch) treatment. Recently, specific thin film anodizing techniques, phosphoric acid, and chromic acid anodizing have been developed which not only provide good initial bond strengths but vastly improved environmental durability. These thin anodic films are in contrast to the commonly used thick anodic films such as the sulfuric acid or "hard" sulfuric acid anodic films which are highly corrosion resistant in themselves, but which do not provide good initial bond strengths, particularly in low temperature peel.The objective of this study was to determine the characteristics of anodic films on aluminum alloys that make them corrosion resistant. The chemical composition, physical morphology and structure, and mechanical properties of the thin oxide films were to be defined and correlated with the environmental stability of these surfaces in humidity and salt spray. It is anticipated that anodic film characteristics and corrosion resistance will vary with the anodizing processing conditions.

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