Dune Plant Research Articles

Coastalplain Honeycombhead, Balduina angustifolia

Coastalplain honeycombhead is found in beach dunes, coastal grasslands, and scrub throughout Florida and into Alabama and Mississippi. It is a prolific flower and seed producer that attracts numerous pollinators, including the gulf fritillary butterfly. Interestingly, the endemic, solitary, and ground-dwelling coastal plain Hesperapis (Hesperapis oraria), also known as Balduina bee, is completely dependent on the coastalplain honeycombhead for survival, only emerging from the ground a few weeks each year in September to October to collect pollen and nectar (Hunsburger 2013). This bee only occurs on barrier islands and peninsulas in the northern Gulf of Mexico (Hunsburger 2013) and is particularly vulnerable to climate-change-driven sea-levelrise and habitat fragmentation.https://edis.ifas.ufl.edu/sg163
 Note: This fact sheet is also available as a chapter in a comprehensive manual titled Dune Restoration and Enhancement for the Florida Panhandle, Please see the manual for more information about other useful and attractive native plants for dunes and for further information about restoration and preservation techniques.

False Rosemary, Conradina canescens

False rosemary is found on the backsides of foredunes, on all sides of backdunes, and inland in scrub communities. False rosemary is killed by fires but will reseed to an area in the absence of further disturbance. It is endemic to west Florida and Alabama, contributes to beach mouse habitat, and attracts many pollinators.https://edis.ifas.ufl.edu/sg167
 Note: This fact sheet is also available as a chapter in a comprehensive manual titled Dune Restoration and Enhancement for the Florida Panhandle, Please see the manual for more information about other useful and attractive native plants for dunes and for further information about restoration and preservation techniques.

Gopher Apple, Geobalanus oblongifolius Synonym: Licania michauxii

Gopher apple occurs from the lower Florida peninsula northward to South Carolina westward to Louisiana in coastal dunes, sandhills, and disturbed areas such as roadsides. Gopher apple gets its name because gopher tortoises, along with other small mammals, eat their fruit. Gopher apple is an ideal groundcover for a coastal landscape with well-draining soil and a low pH (Gilman 2014).https://edis.ifas.ufl.edu/sg169
 Note: This fact sheet is also available as a chapter in a comprehensive manual titled Dune Restoration and Enhancement for the Florida Panhandle, Please see the manual for more information about other useful and attractive native plants for dunes and for further information about restoration and preservation techniques

Woody Goldenrod, Chrysoma pauciflosculosa

Woody goldenrod is found in beach dunes, scrub, and sandhill plant communities. It occurs in the Panhandle ofFlorida and more broadly in the southeastern United States west to Mississippi and northeast to North Carolina. This plant may leach chemicals into the soil that inhibit seed germination of gulf bluestem (Schizachyrium scoparium var. scoparium) (Fischer et al. 1994). Woody goldenrod is an underused landscape plant with a prolific fall color from flowers that attract numerous pollinators.https://edis.ifas.ufl.edu/sg165
 Note: This fact sheet is also available as a chapter in a comprehensive manual titled Dune Restoration and Enhancement for the Florida Panhandle, Please see the manual for more information about other useful and attractive native plants for dunes and for further information about restoration and preservation techniques.

Coastal Sand Frostweed, Crocanthemum arenicola Synonym: Helianthemum arenicola

Coastal sand frostweed is found on beach dunes, scrub, and sandhills. It is endemic to the Florida Panhandle, Mississippi, and Alabama coastal counties. After Hurricane Katrina, coastal sand frostweed became the plant with highest frequency on stable dunes on Horn Island, Mississippi (Lucas and Carter 2013).https://edis.ifas.ufl.edu/sg168
 Note: This fact sheet is also available as a chapter in a comprehensive manual titled Dune Restoration and Enhancement for the Florida Panhandle, Please see the manual for more information about other useful and attractive native plants for dunes and for further information about restoration and preservation techniques.

Determining Change in Coastal Barrier Island Dune Vegetation Following a Decade of Nitrogen Fertilization

ABSTRACT Day, F.P.; Adams, E.C.; Gibala-Smith, L.A.; Graziani, D.J.; McMillan, B.; Sedghi, N.; Shafer, J., and Smith, M., 2018. Determining change in coastal barrier island dune vegetation following a decade of nitrogen fertilization. Nitrogen deposition from agricultural and industrial sources is a threat to terrestrial biodiversity, and impacts are likely to be greatest in nitrogen-deficient systems. The results of a 10 year fertilization treatment on nitrogen-deficient coastal barrier island dunes and the decade following cessation of fertilizer application are reported here. The study objective was to determine the resilience of the dune plant communities. Would these communities return to their former state in terms of density, species composition, and species diversity after nitrogen additions ended, and if so, how rapid was their recovery? Plant density by species and species diversity were determined over a 20 year period from permanent plots established on three different-aged dunes on a Virginia...

Biological assessment of dune restoration in south Texas

A dune restoration program was initiated by the City of South Padre Island, Texas in 2010 consisting primarily of plantings of Sea Oats, Uniola paniculata, and Bitter Panicum, Panicum amarum, and has continued annually thereafter. These restoration efforts were evaluated by comparing selected metrics of ecosystem structure and function among reference and restoration plots ranging in age (time after planting) from 2 to 5 years. Plant and animal communities were examined using a combination of quadrat sampling, funnel traps, pit-falls, and sweep nets. Soil organic content and soil electrical conductivity were also measured. Dune volumes and heights were calculated using a 2013 Lidar DEM. Plant communities were similar across 2 and 4 year-old plots but differed markedly among 2 and 5 year-old plots and between all restoration plots and undisturbed reference plots. After 5 years, restoration plots had 15 plant species, while reference plots had 19. Animal communities followed a similar trend in which all restoration plots differed from the reference plots with the exception of 5 year-old plots which were similar. More time seems necessary for restored dunes to accumulate soil organic matter at levels similar to natural dunes which is still about three times higher. There was a significant positive correlation between plot age and dune heights. These results suggest the native dune plant revegetation as implemented by the City of South Padre Island from 2010 to 2015 is successful in fostering plant and animal community succession and potentially increasing coastal resiliency.

Patterns of phylogenetic community structure of sand dune plant communities in the Yucatan Peninsula: the role of deterministic and stochastic processes in community assembly

ABSTRACTBackground: Tropical sand dunes are ideal systems for understanding drivers of community assembly as dunes are subject to both deterministic and stochastic processes. However, studies that evaluate the factors that mediate plant community assembly in these ecosystems are few.Aims: We evaluated phylogenetic community structure to elucidate the role of deterministic and stochastic processes in mediating the assembly of plant communities along the north of the Yucatan Peninsula, Mexico.Methods: We used plastid genetic markers to evaluate phylogenetic relationships in 16 sand-dune communities. To evaluate the role of climate in shaping plant community structure we carried out linear regressions between climatic variables and mean phylogenetic distance. We estimated the Net Relatedness Index and Nearest Taxon Index to identify ecological processes mediating community assembly.Results: Observed phylogenetic structure was not different from random, suggesting that stochastic processes are the major determinants of community assembly. Climate was slightly correlated with phylogenetic diversity suggesting that abiotic environment plays a minimal role in community assembly.Conclusions: Random assembly appears to be the primary factor structuring the studied sand dune plant communities. Environmental filters may represent a secondary factor contributing to the observed phylogenetic structure. Thus, both processes may act simultaneously to mediate the assembly of sand-dune plant communities.

Natural risks and vulnerabilities of dynamic coastal dune landscapes

Set in the Habitats Directive as priority habitat, fixed dunes with herbaceous vegetation (grey dunes) occur around the coasts of Europe. As a part of many coastal dune systems these habitats are especially complex and low resilience and need special attention from the conservation and management perspectives. Nearly a decade we have studied representative examples of fixed dunes in Estonia. Due to growing anthropogenic pressure and ongoing global changes it is vital to distinguish the changes and analyse general trends of development of grey dunes. The selected sites Keibu (located on the NW coast of mainland Estonia) and Ruhnu (located on the eastern coast of Ruhnu Island) are representative examples in Estonia, with a coverage of a geographical range and ecological variation. Both sites are part of conservation and monitoring areas. In each site, we have compiled a landscape profile to visualize the topography, vegetation and soils. he study was carried out on perpendicular to shoreline landscape profiles in order to express the full spectrum of coastal dune plant communities and surface deposits from shores towards inland. Both, natural and human impacts have been considered in the assessment of changes in the structure and functioning of the grey dunes in Estonia. The results show that changes in dune landscapes can be rapid, especially on sandy beaches due to stronger storm surges in recent decades. The inland areas are more affected by human activity and the changes there are well reflected. The gradual loss of open sandy habitats on the sites is evident during the last 100 years and show the overall development trends of dynamic coastal dune landscapes. This study has proven that these areas need permanent observation to assess the level of changes. It is vital to contribute to the decision making processes concerning their optimal use and conservation needs to maintain their resilience.

Context-dependent crypsis: a prey's perspective of a color polymorphic predator.

Many animals use body coloration as a strategy to communicate with conspecifics, prey, and predators. Color is a trade-off for some species, since they should be visible to conspecifics but cryptic to predators and prey. Some flower-dwelling predators, such as crab spiders, are capable of choosing the color of flowers where they ambush flower visitors and pollinators. In order to avoid being captured, visitors evaluate flowers visually before landing. The crab spider Mecaphesa dubia is a polymorphic species (white/purple color morphs), which inhabits the flower heads of a dune plant, Palafoxia lindenii. Using full-spectrum photography of spiders and flowers, we evaluated how honeybees perceived the spiders at different distances. Using visual modeling, we obtained the chromatic and achromatic contrasts of the spiders on flower heads as perceived by honeybees. Purple morphs were found mainly on the receptacle area and white morphs were equally likely to be found in the flowers and receptacle. According to theoretical modeling, white morphs were visible to honeybees from a distance of 10cm in receptacle area but appeared to be cryptic in the flower area. Purple morphs were cryptic on the receptacle and less so when they were on the flowers. Spiders on flower heads are predicted to be more easily detected by honeybees using chromatic contrast. Our study shows that the conspicuousness of flower dwelling spiders to honeybees depends on the color morph, the distance of observation, and the position of spider on the flower head.

Restoring the natural functional capacity of coastal dune ecosystems: Utilising research records for New Zealand littoral refurbishment as a proxy for analogous global responses

Aggregated results from twenty years of community-engaged assiduous restoration of severely degraded coastal littoral systems in New Zealand (NZ) reveal numerous fundamental and substantive natural improvements to dune form, function, and storm resilience. This is accomplished by simple, low-cost exclusive utilisation of the variably threatened local indigenous dune plant species. These valuable and innovative enhancements succeed countless decades of cascading consequences from numerous impacts instigated by historic (and frequently continuing) damaging effects on those previously natural coastal dune ecosystems – impacts that subsequently induced problematic littoral retreat – the true root cause of prevailing coastal erosion. The durable reversals were often generated in less than two decades, contemporaneously with adverse storm surge and sea level rise conditions. Research reveals many global dune ecosystems are afflicted with analogous normalised degradation and erosion difficulties, with the earliest active circumvention recorded in sixteenth century Denmark (McKelvey 1999). Historic plus current pressures such as coastal settlement impacts and continuing agricultural use of dunelands similarly threaten numerous global littoral margins, alongside recent concerns regarding the compounding effects of climate change. Successful, affordable, diligent dune restoration work pioneered in NZ has extensive benefits for other nations experiencing similarly challenging attrition on degraded coastal zones. Persuasive data is presented to validate the numerous persistently accrued benefits of this cost-effective and enduring coastal adaptation response.

Landscape pattern and plant biodiversity in Mediterranean coastal dune ecosystems: Do habitat loss and fragmentation really matter?

AbstractAimHabitat fragmentation and loss are two of the most important factors driving current biodiversity decline. Nonetheless, the relationship between biodiversity and landscape patterns appears more complex than generally expected, depending on the species and communities involved. We aim to enrich knowledge concerning the relationship between plant diversity and landscape patterns along linear landscapes, such as Mediterranean coastal dunes. A dedicated buffering method considering multiple nested extents was developed for sampling linear landscapes (e.g. coastal or fluvial), which traditionally present a challenge for standard round or square sampling buffering approaches.LocationTyrrhenian coast of central Italy.MethodsBased on a database of plant community plots and functional traits from field measurements, for each plot we calculated taxonomic (TD) and functional (FD) diversity, which was further decomposed in functional evenness (FDeven) and mean trait dispersion (FDdisp). Relying on a land‐cover map, we computed a set of landscape metrics describing habitat loss, fragmentation and direct human disturbance at multiple extents around each plot. Diversity measures (TD, FD, FDeven and FDdisp) were then related to the landscape metrics at different scales via linear mixed‐effect models.ResultsOverall, the relationship between plant species diversity and landscape patterns was weak. We observed different responses of TD, FD, FDeven and FDdisp, which only emerged at fine‐medium scales. TD decreased with habitat loss and disturbance, while FD only with disturbance. FDeven decreased in more fragmented areas, while FDdisp was not affected by the selected landscape parameters.Main conclusionsLike other transitional areas, coastal strand and dune ecosystems exhibit steep gradients in biotic and environmental factors, are dynamic in location, and could be among the earliest to be affected by environmental drivers. However, the response of Mediterranean coastal dune plant diversity to habitat loss and fragmentation is weak. For these reasons, we propose that these plant communities are adapted to the ever‐changing nature of the coastal environment and consequently to changes in landscape pattern.

Spatial patterns of species diversity in sand dune plant communities in Yucatan, Mexico: importance of invasive species for species dominance patterns

Background: Coastal ecosystems in Mexico remain understudied in spite of their ecological, economic and conservation value and are being impacted by human activities along the coast. Knowledge on spatial patterns of plant species distribution that helps preserve these fragile ecosystems is crucial.Aims: We evaluated differences in species richness, species diversity and species dominance patterns in 16 plant communities as well as the degree to which differences were driven by climatic conditions in sandy dunes in Yucatán. We evaluated the importance of invasive species in mediating patterns of species diversity and species dominance patterns.Results: We found wide variation in plant species richness, species diversity and species dominance patterns among communities that stems from broad climatic differences along dune systems. Invasive plants represent almost one-third of total species richness and seem to be drastically changing the species dominance patterns in these communities.Conclusions: Regional climatic differences along the Yucatán north coast seems to be a major driver of plant diversity and species composition. Our findings suggest that invasive plants have successfully colonised and spread along the coast over the past 30 years. Even though invasive species do not alter spatial patterns of species diversity, they are becoming more dominant with potential detrimental consequences for native plants.

Halomonas malpeensis sp. nov., isolated from rhizosphere sand of a coastal sand dune plant.

A Gram-stain-negative, aerobic, non-endospore-forming organism, isolated from the rhizosphere sand of a coastal sand dune plant was studied for its taxonomic position. On the basis of 16S rRNA gene sequence similarity comparisons, strain YU-PRIM-29T was grouped within the genus Halomonas and was most closely related to Halomonas johnsoniae (97.5 %). The 16S rRNA gene sequence similarity to other Halomonas species was <97.5 %. Strain YU-PRIM-29T grew optimally at 28 °C (growth range, 10-36 °C), at a pH of 7-9 (growth range, pH 5.5-12.0) and in the presence of 0.5 to 5 % (w/v) NaCl (growth up to 20 % NaCl). The fatty acid profile from whole-cell hydrolysates supported the allocation of the strain to the genus Halomonas. The fatty acids C18 : 1ω7c and C16 : 0 were found as major compounds, followed by the hydroxylated fatty acid C12 : 0 3-OH. The quinone system consisted predominantly of ubiquinone Q-9. The polar lipid profile was composed of the major lipids diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. In the polyamine pattern, spermidine was the predominant compound. The DNA G+C content was 64.8 mol%. In addition, the results of physiological and biochemical tests also allowed phenotypic differentiation of strain YU-PRIM-29T from its closest-related species. Hence, YU-PRIM-29T represents a new species of the genus Halomonas, for which we propose the name Halomonas malpeensis sp. nov., with YU-PRIM-29T (=LMG 28855T=CCM 8737T) as the type strain.

Consequences of multiple mating-system shifts for population and range-wide genetic structure in a coastal dune plant.

Evolutionary transitions from outcrossing to selfing can strongly affect the genetic diversity and structure of species at multiple spatial scales. We investigated the genetic consequences of mating-system shifts in the North American, Pacific coast dune endemic plant Camissoniopsis cheiranthifolia (Onagraceae) by assaying variation at 13 nuclear (n) and six chloroplast (cp) microsatellite (SSR) loci for 38 populations across the species range. As predicted from the expected reduction in effective population size (Ne ) caused by selfing, small-flowered, predominantly selfing (SF) populations had much lower nSSR diversity (but not cpSSR) than large-flowered, predominantly outcrossing (LF) populations. The reduction in nSSR diversity was greater than expected from the effects of selfing on Ne alone, but could not be accounted for by indirect effects of selfing on population density. Although selfing should reduce gene flow, SF populations were not more genetically differentiated than LF populations. We detected five clusters of nSSR genotypes and three groups of cpSSR haplotypes across the species range consisting of parapatric groups of populations that usually (but not always) differed in mating system, suggesting that selfing may often initiate ecogeographic isolation. However, lineage-wide genetic variation was not lower for selfing clusters, failing to support the hypothesis that selection for reproductive assurance spurred the evolution of selfing in this species. Within three populations where LF and SF plants coexist, we detected genetic differentiation among diverged floral phenotypes suggesting that reproductive isolation (probably postzygotic) may help maintain the striking mating-system differentiation observed across the range of this species.

Environmental change in the terrestrial vegetation of Bermuda: Revisiting Harshberger (1905)

In June of 1905 the pioneer ecologist John W. Harshberger visited Bermuda to investigate sand dune plants, survey the main plant formations and collect herbarium specimens. His specimens and observations are of significant value as a baseline to understand the extraordinary ecological change due to plant invasion that the island has experienced over the last 100 years. His observations on the vegetation types of Bermuda are contained in a six-page summary of a talk that he gave to the Academy of Natural Sciences of Philadelphia. He divided the terrestrial vegetation of the island into eight types. While five of these, mangrove swamp, salt marsh, brackish marsh, cliff rock, and sand dune, have vegetation that is lightly invaded and still recognizable from his descriptions, three others, cedar forest, limestone sinks forest, and scrub, have been altered by invasive plants beyond recognition except in a few small nature reserves that are actively managed against invasives. The seed rain from the introduced starling feeding on the fruits of invasive plants is heavy and ubiquitous. Any conservation of terrestrial vegetation now requires weeding against invasives in perpetuity, a “conservation treadmill” that needs to be budgeted for and carefully applied if conservation is to succeed.

Distribution of alien species along sand dune plant communities zonation

Background and purpose: For a fairly long period, Velika plaža in Ulcinj, Montenegro has been considered to be one of the best-preserved sites with psammophilous vegetation along the Adriatic coast. In recent years, however, this area has been significantly transformed as a result of various human disturbances (e.g., a non-sustainable approach to touristic development, illegal dumping, sand exploitation etc.), and has become prone to alien plant invasions. We made a transect survey to assess the presence of alien species in the psammophilous communities.Materials and methods: In order to make a survey of the present state of plant life on Velika plaža, its floristic composition and zonation of plant communities, 20 transects were set perpendicular to the coast, regularly every 500 m. Quadrats (2 x 2 m) were laid contiguously in the form of a belt transect starting from the area with the first colonizing plants towards the end of the sand dune system with forest vegetation. This resulted in a matrix of 1124 plots and 196 species (15 alien and 181 native), on which multivariate analysis was performed.Results: Nine plant communities were detected, arranged in zonation from sea to inland. All of them were characterised by the presence of alien species. The least affected was the plant community dominated by Cladium mariscus, while the most affected ones were dominated by Scirpoides holoschoenus and Tripidium ravennae. Psammophilous vegetation is less affected by alien species than wetland communities. Foredunes are dominated by Xanthium orientale ssp. italicum, while Oenothera species are predominant on stable dunes.Conclusions: Sand dunes are a highly invaded ecosystem, with changed plant communities, so conservation measures should be considered.

Does enemy damage vary across the range of exotic plant species? Evidence from two coastal dune plant species in eastern Australia.

Release from natural enemies is often cited as a key factor for understanding the success of invasive plant species in novel environments. However, with time invasive species will accumulate native enemies in their invaded range, with factors such as spread distance from the site of introduction, climate and leaf-level traits potentially affecting enemy acquisition rates. However, the influence of such factors is difficult to assess without examining enemy attack across the entire species' range. We tested the significance of factors associated with range expansion (distance from source population and maximum population density), climatic variables (annual temperature and rainfall) and leaf-level traits [specific leaf area (SLA) and foliar nitrogen concentration] in explaining variation in enemy damage across multiple populations of two coastal invasive plants (Gladiolus gueinzii Kunze and Hydrocotyle bonariensis Lam.) along their entire introduced distribution in eastern Australia. We found that for H. bonariensis, amount of foliar damage increased with distance from source population. In contrast, for G. gueinzii, probability and amount of foliar damage decreased with decreasing temperature and increasing rainfall, respectively. Our results show that patterns of enemy attack across species' ranges are complex and cannot be generalised between species or even range edges.

Impacts of Invasive Phragmites australis on Diamondback Terrapin Nesting in Chesapeake Bay

The range expansion of exotic plant species, including the invasive reed Phragmites australis, causes widespread structural and functional changes to coastal ecosystems along the Atlantic and Gulf Coasts of North America. Native estuarine species, such as the diamondback terrapin (Malaclemys terrapin), are at risk of adverse effects from rapid habitat changes due to exotic invasions. Diamondback terrapins currently face population threats including by-catch mortality in crab pots, predation, and habitat loss, and populations may continue to suffer if deleterious plant invasions into preferred nesting habitats are left unchecked. We examined the extent to which Phragmites affects nesting of a breeding population of diamondback terrapins at Fisherman Island National Wildlife Refuge on the eastern shore of Virginia, where Phragmites has recently expanded into known areas of terrapin nesting. With data collected from the 2015 nesting season, we quantified the extent to which Phragmites shading could impact nest incubation temperature and determined how Phragmites density impacts the risk of rhizome invasion into nests. We conclude that Phragmites cover greater than 50% would decrease incubation temperatures of terrapin nests sufficiently to produce predominantly male hatchlings. Phragmites cover had no observed effect on root growth into simulated nests, but cover by other dune plant species explained observed trends in root growth. These results suggest that terrapins may be negatively impacted by Phragmites expansion into open nesting sites. Breeding site fidelity exhibited by terrapins and other estuarine species could limit the ability of their populations to adjust to rapid coastal expansion of invasive plant species.

Flora en playas y dunas costeras de México

Antecedentes y Objetivos: Se presenta el primer listado florístico de las playas y dunas costeras de México, actualizado y respaldado por ejemplares de herbario.Métodos: Se revisaron 14 herbarios nacionales y extranjeros. Se sobrepuso una retícula de 2 × 2 km al mapa de la costa y de las dunas costeras de México para referir todos los registros que corresponden a 2180 sitios con 12,419 ejemplares de plantas. Se calcularon índices de diversidad, similitud, diversidad taxonómica y redundancia.Resultados clave: La flora registrada consta de 153 familias, 897 géneros y 2075 especies de plantas vasculares, las cuales representan 9.5% de la flora vascular de México. Las cinco colecciones con índices de redundancia altos IR≥0.7 son los herbarios de la Universidad Nacional Autónoma de México (MEXU, IR=0.9), del Centro de Investigación Científicas de Yucatán (CICY, IR=0.8), y los del Centro de Investigaciones Biológicas del Noroeste (HCIB), el Instituto de Ecología, A.C. (XAL) y el del Museo de Historia Natural de San Diego (SD), cada uno con un IR de 0.7. Se reconocen cinco regiones florísticas que corresponden a los mares de México. El Pacífico Norte tiene mayor diversidad taxonómica y el Pacífico Sur menor diversidad taxonómica. El Golfo de California, Golfo de México y Mar Caribe tienen diversidades taxonómicas similares. Las especies con más registros son Trianthema portulacastrum (165), Croton punctatus (107), Echites umbelllatus (106) e Ipomoea pes-caprae (90). Por el carácter de ecotono de las dunas costeras, la mayoría de las especies se comparten con los tipos de vegetación vecinos (selvas, matorrales, y humedales como las marismas y manglares).Conclusiones: Esta primera lista de la flora en playas y dunas de México es la base para múltiples estudios florísticos regionales y locales, biogeográficos, y ecológicos; además, que será importante para su uso en temas de impacto ambiental y manejo costero.