Ammophila Breviligulata Research Articles

Draft Genome Sequence of the Plant Growth-Promoting Sphingobium sp. Strain AEW4, Isolated from the Rhizosphere of the Beachgrass Ammophila breviligulata.

ABSTRACTSphingobium sp. strain AEW4 is a novel isolate from rhizosphere soil attached to the root of the American beachgrass Ammophila breviligulata. The genomic sequence consisted of 4,678,518 bp and 4,428 protein-coding sequences. Here we report the draft genome sequence of this strain and some initial insights on its plant growth-promoting capabilities.

Mechanisms of surviving burial: Dune grass interspecific differences drive resource allocation after sand deposition

AbstractSand dunes are important geomorphic formations of coastal ecosystems that are critical in protecting human populations that live in coastal areas. Dune formation is driven by ecomorphodynamic interactions between vegetation and sediment deposition. While there has been extensive research on responses of dune grasses to sand burial, there is a knowledge gap in understanding mechanisms of acclimation between similar, coexistent, dune‐building grasses such as Ammophila breviligulata (C3), Spartina patens (C4), and Uniola paniculata (C4). Our goal was to determine how physiological mechanisms of acclimation to sand burial vary between species. We hypothesize that (1) in the presence of burial, resource allocation will be predicated on photosynthetic pathway and that we will be able to characterize the C3 species as a root allocator and the C4 species as leaf allocators. We also hypothesize that (2) despite similarities between these species in habitat, growth form, and life history, leaf, root, and whole plant traits will vary between species when burial is not present. Furthermore, when burial is present, the existing variability in physiological strategy will drive species‐specific mechanisms of survival. In a greenhouse experiment, we exposed three dune grass species to different burial treatments: 0 cm (control) and a one‐time 25‐cm burial to mimic sediment deposition during a storm. At the conclusion of our study, we collected a suite of physiological and morphological functional traits. Results showed that Ammophila decreased allocation to aboveground biomass to maintain root biomass, preserving photosynthesis by allocating nitrogen (N) into light‐exposed leaves. Conversely, Uniola and Spartina decreased allocation to belowground production to increase elongation and maintain aboveground biomass. Interestingly, we found that species were functionally distinct when burial was absent; however, all species became more similar when treated with burial. In the presence of burial, species utilized functional traits of rapid growth strategy, although mechanisms of change were interspecifically variable.

Identification of the fungal endophyte of Ammophila breviligulata (American beachgrass) as Epichloë amarillans.

The grass Ammophila breviligulata (American beachgrass) is known to host an endophyte of the genus Epichloë. Based on morphological characteristics it was originally identified as Acremonium typhinum var. ammophilae and is currently designated as Epichloë typhina var. ammophilae. However, the Epichloë species has not previously been identified based on DNA sequence data. Based on phylogenetic placement of beta-tubulin and translation elongation factor 1-alpha DNA sequences the endophyte is identified as a member of E. amarillans rather than E. typhina.

Literature-based latitudinal distribution and possible range shifts of two US east coast dune grass species (Uniola paniculata and Ammophila breviligulata)

Literature-based latitudinal distribution and possible range shifts of two US east coast dune grass species (Uniola paniculata and Ammophila breviligulata)

Nonhost neighborhood increases biocontrol weevil damage to the nontarget, federally threatened Pitcher's thistle (Cirsium pitcheri)

Studies that monitor the intensity of biocontrol insect damage on target and nontarget hosts in the field often consider the effects of neighboring vegetation that serve as acceptable alternative hosts. Whether nonhost neighboring plants can also influence damage to hosts has received less attention. The nonnative, seed-eating weevil Larinus planus has been distributed as a biocontrol agent for weedy thistles in the U.S., but also attacks native thistles including the federally threatened Cirsium pitcheri. To test the hypothesis that nonhost Ammophila breviligulata grass neighbors increase susceptibility of C. pitcheri to L. planus damage, we clipped the neighboring vegetation within a 1 m radius around focal C. pitcheri, and assessed weevil infestation in flower heads of plants with clipped or unclipped neighbors. We also examined elevational effects by surveying weevil presence along an environmental gradient and comparing infestation rates between primary and secondary dune habitats with intact neighboring vegetation. Larinus planus infestation was more prevalent at low than at high dune elevations. At low elevations, clipping neighboring vegetation surrounding C. pitcheri significantly decreased the proportion of flower heads infested by weevils. Grasses may aid L. planus dispersal to C. pitcheri hosts and/or provide a refuge from environmental stress or natural enemies. Our results highlight two factors that predict L. planus attack, as well as areas of the dune on which to focus Cirsium pitcheri management or weevil control efforts. More broadly, our results suggest that nonhost neighboring vegetation may be an important factor determining the intensity of damage by invasive and biocontrol insects.

Topography, vegetation cover and below ground biomass of spatially constrained and unconstrained foredunes in New Jersey, USA

Space for dunes is often limited in developed areas, placing increased importance on human efforts to aid dune-building. This study assesses how different management strategies influence dune topography, surface cover and below ground biomass of vegetation on four dune segments in New Jersey in two successive years. Two segments are evolving without human actions, one with a cover of native vegetation (Ammophila breviligulata) and one with an invasive exotic (Carex kobomugi). Two segments are in developed areas and are maintained using sand fences, vegetation plantings and bulldozers; one of these segments uses bulldozers to bury a seawall.The foredunes evolving naturally are wider than foredunes in the developed segments and have more topographic variability alongshore. Foredunes in the developed segments are narrower because sand blown or washed landward is recycled. The naturally evolving A. breviligulata dune segment had the sparsest vegetation cover; the segment maintained mainly by sand fences and vegetation plantings had the densest cover. The crest of developed dunes can be higher than the crest of natural dunes with the same vegetation type and similar beach widths, but sediment volume may be restricted if the dune cannot migrate inland. Planting programs hasten dune accretion and are especially valuable on the dune ramp following wave erosion. Species dependent on mobile dunes can be favored where landward infrastructure is not threatened; species dependent on stable dunes can be favored in developed areas. Dune veneers placed over seawalls are temporary, but seawalls can favor evolution of stable-dune species landward of them.

The Role of Beach Nourishment on the Success of Invasive Asiatic Sand Sedge

Abstract Beach nourishment, or artificial addition of sediment to a beach, a common practice for rebuilding beaches for recreation and storm protection, can have positive or negative effects on the flora and fauna of dune communities. There has been little work exploring the consequences of nourishment on the impacts of invasive plant species that thrive on dunes. In this study, we explored the impacts of nourishment on the invasiveness of Carex kobomugi (Asiatic Sand Sedge) in secondary dune communities composed primarily of Ammophila breviligulata (American Beachgrass) and Solidago sempervirens (Seaside Goldenrod) at 3 study sites at Island Beach State Park in New Jersey, testing the hypothesis that nourishment promotes sedge invasion. Dune communities were subjected to 5 burial depth treatments in ∼15-cm increments ranging from 0 (control) to 60 cm (∼24 inches) burial. Growth responses were monitored by quantifying emergent individuals and by harvesting all aboveground biomass at the end of the season....

Emergent interactions influence functional traits and success of dune building ecosystem engineers

Dune building processes are affected by interactions between the growth of ecosystem engineering dune grasses and environmental factors associated with disturbance such as sand burial and sea spray. Research investigating how species interactions influence dune community structure and functional trait responses in high abiotic stress environments is minimal. We investigated how species interactions influence the functional trait responses of three dominant dune grasses to common abiotic stressors. We performed a multi-factorial greenhouse experiment by planting three common dune grasses (Ammophila breviligulata Fern., Uniola paniculata L. and Spartina patens Muhl.) in different interspecific combinations, using sand burial and sea spray as abiotic stressors. Sand burial was applied once at the beginning of the study. Sea spray was applied three times per week using a calibrated spray bottle. Morphological functional trait measurements (leaf elongation, maximum root length, aboveground biomass and belowground biomass) were collected at the end of the study. The experiment continued from May 2015 to August 2015. Species interactions between A. breviligulata and U. paniculata negatively affected dune building function traits of A. breviligulata, indicating that interactions with U. paniculata could alter dune community structure. Furthermore, A. breviligulata had a negative interaction with S. patens, which decreased S. patens functional trait responses to abiotic stress. When all species occurred together, the interactions among species brought about coexistence of all three species. Our data suggest that species interactions can change traditional functional trait responses of dominant species to abiotic stress.

Leaf endophytic fungus interacts with precipitation to alter belowground microbial communities in primary successional dunes.

Understanding interactions between above- and belowground components of ecosystems is an important next step in community ecology. These interactions may be fundamental to predicting ecological responses to global change because indirect effects occurring through altered species interactions can outweigh or interact with the direct effects of environmental drivers. In a multiyear field experiment (2010-2015), we tested how experimental addition of a mutualistic leaf endophyte (Epichloë amarillans) associated with American beachgrass (Ammophila breviligulata) interacted with an altered precipitation regime (±30%) to affect the belowground microbial community. Epichloë addition increased host root biomass at the plot scale, but reduced the length of extraradical arbuscular mycorrhizal (AM) fungal hyphae in the soil. Under ambient precipitation alone, the addition of Epichloë increased root biomass per aboveground tiller and reduced the diversity of AM fungi in A. breviligulata roots. Furthermore, with Epichloë added, the diversity of root-associated bacteria declined with higher soil moisture, whereas in its absence, bacterial diversity increased with higher soil moisture. Thus, the aboveground fungal mutualist not only altered the abundance and composition of belowground microbial communities but also affected how belowground communities responded to climate, suggesting that aboveground microbes have potential for cascading influences on community dynamics and ecosystem processes that occur belowground.

Differential response of barrier island dune grasses to species interactions and burial

Barrier islands are at the forefront of storms and sea-level rise. High disturbance regimes and sediment mobility make these systems sensitive and dynamic. Island foredunes are protective structures against storm-induced overwash that are integrally tied to dune grasses via biogeomorphic feedbacks. Shifts in dune grass dominance could influence dune morphology and susceptibility to overwash, altering island stability. In a glasshouse study, two dune grasses, Ammophila breviligulata and Uniola paniculata, were planted together and subjected to a 20 cm burial to quantify morphological and physiological responses. Burial had positive effects on both plants as indicated by increased electron transport rate and total biomass. Ammophila breviligulata performance declined when planted with U. paniculata. Uniola paniculata was not affected when planted with A. breviligulata but did have higher water use efficiency and nitrogen use efficiency. Planted in mixture, differential reallocation of biomass occurred between species potentially altering resource acquisition further. As U. paniculata migrates into A. breviligulata dominated habitat and A. breviligulata performance diminishes, biotic interactions between these and other species may affect dune formation and community structure. Our study emphasizes the importance of studying biotic interactions alongside naturally occurring abiotic drivers.

A species effect on storm erosion: Invasive sedge stabilized dunes more than native grass during Hurricane Sandy

Summary Vegetation and biogeomorphology are highly coupled in beach dune systems, but plant species effects on abating storm erosion are largely unexplored. We quantified coastal dune erosion from Hurricane Sandy (October 2012) as a function of pre‐storm system characteristics – dune height, beach width and dominant vegetation stabilizing dunes (native Ammophila breviligulata or invasive Carex kobomugi) at Island Beach State Park, New Jersey, USA. We assessed dune erosion using a combination of pre‐ and post‐Sandy aerial image spatial analyses in ArcGIS and GPS field mapping. Our two erosion metrics are novel, macroscale 2D surface area changes and Dune Crest Transgression, the later of which is measured at the microscale (1 m−1) and analysed using a mixed model incorporating spatial autocorrelation. We document a species‐specific effect on collision erosion. Although C. kobomugi reduces native diversity and abundance, it may be beneficial for coastal protection, as dunes fronted and stabilized by C. kobomugi suffered less erosion than those dominated by A. breviligulata under the same abiotic conditions. Dune height and beach width were equal for species prior to the storm and therefore do not account for or confound differences in erosion. Similarly, traditional calculations of erosion with volumetric loss confer these results. Synthesis and applications. This is the first study to show a species effect on coastal dune erosion. Native Ammophila breviligulata stabilized dune stretches suffered more erosion from Hurricane Sandy than complimentary invasive Carex kobomugi stretches, contradicting anecdotal reports that foredunes stabilized by a shorter statured species are more prone to erosion. This study highlights the importance of vegetation for dune stability and management using two novel metrics for erosion. Our erosion metrics are related to volumetric loss, can be monitored and calculated by managers with or without remote sensing, and can be applied to other systems. Discussions on coastal management of dunes as habitats and protective buffers must include vegetation and the results of this study suggest that not all species are equal with regard to their ability to combat storm erosion. Multidisciplinary studies with applied implications will grow increasingly important as storms continue to grow more frequent, severe and unpredictable with climate change.

Glomeromycetes from the Magdalen Islands archipelago: analyzing diversity and meta-community structure in a sand-dune ecosystem

This report presents the first survey and analysis of the arbuscular mycorrhizal fungi community associated with Ammophila breviligulata Fernald (American beachgrass), of the Magdalen Islands archipelago, Quebec. Of the 36 selected harvesting sites, a total of 180 sand samples were collected from the rhizosphere of American beachgrass. Analyses were performed on the original sand samples and root and sand trap cultures. Of the 34 spore-morphotypes found, 31 belonged to glomoid spore species. Of the field sand samples, 72% contained the spores of Glomeromycetes and subsequent trap cultures increased this percentage to 84%. Of the 34 species, 29 were found sporulating in indigenous sand samples at harvest time, and only five additional species were recovered from root and sand trap pot culturing. Among the more generalist species were Rhizoglomus irregulare and G. sp4, which were found in 19 sites, Rhizoglomus aggregatum and Corymbiglomus tortuosum (found in 17 sites), Funneliformis mosseae and G. sp3 (found in 15 sites). This meta-community of Glomeromycetes is shown to have significant nestedness, indicating that fungal taxa that are more frequent in the whole archipelago are also more abundant locally. Some species pairs are shown to display significant negative associations in their patterns of co-occurrence. The relevance of these results for arbuscular mycorrhizal fungal community assembly and dynamics is discussed.

Responses of native plant populations on an unprotected beach to disturbance by storm-induced overwash events

Extreme climatic events disturb plant communities, altering species composition, and abundance. For herbaceous populations on coastal beaches, responses to disturbance are often spatially heterogeneous and depend on species’ life history. This study documents the effects of two overwash events, caused by Hurricane Irene in August 2011 and Superstorm Sandy in October 2012, on the abundance of native species on a low-lying, unprotected beach on Staten Island, New York, USA. Temporary plots (33 cm diameter) spaced at 3-m intervals along 30-m transects perpendicular to shoreline, were used in September 2007, 2011, 2012, and 2013 to survey lower (0–9 m), middle (12–21 m), and upper (24–30 m) regions of the same beach. The same procedure was used to quantify seedling recruitment in spring (May) after each overwash. Complex changes in density the year after each overwash were specific for distinct beach regions and depended on species’ life history. Rhizomatous perennial grasses (Ammophila breviligulata and Panicum amarum) maintained or increased ramet populations, possibly stimulated by sand deposition on the middle and upper beach. The first overwash was early enough in the growing season to permit subsequent seed production during autumn, and seedling recruitment occurred for three native annuals (Cenchrus tribuloides, Heterotheca subaxillaris, and Triplasis purpurea), and the tall perennial Solidago sempervirens the next spring. The second overwash was later in autumn and probably removed seeds from the site and/or deeply buried the seeds of two annuals (Cenchrus and Heterotheca) which did not recruit seedlings the next spring. Triplasis seedlings were abundant in a blowout on the lower beach. Given more frequent storms and sea-level rise in the future, it becomes imperative to maintain an assemblage of native plant species with diverse life histories when restoring coastal beaches.

Plant–fungal symbiosis affects litter decomposition during primary succession

Microbial symbionts of plants can affect decomposition by altering the quality or quantity of host plant tissue (substrate) or the micro‐environment where decomposition occurs (conditioning). In C3 grasses, foliar fungal endophytes (Clavicipitaceae) can increase plant resistance to drought and/or produce alkaloids that reduce herbivory – effects that may also influence host litter composition and subsequent litter decomposition. We studied the effect of the endophyte Epichloë sp. on litter decomposition in the Great Lakes dunes (USA) using a reciprocal design altering endophyte presence/absence in both American beachgrass Ammophila breviligulata substrate (litter bags) and its conditioning of the decomposition microenvironment. Symbiont treatments were crossed with rain‐out shelters that altered growing season precipitation. The first year of decomposition, senesced leaf substrate from A. breviligulata with Epichloë decomposed 21% faster than endophyte‐free substrate. By the third year, conditioning by live symbiotic plants reduced cumulative decomposition by 33% compared to plots planted with endophyte‐free plants. Of the traits we examined – litter quantity, C:N ratio, mineral composition, fungal colonization, and carbon chemistry – increased litter quantity via greater tiller production was the primary trait shift associated with endophyte symbiosis. Epichloë in A. breviligulata litter also altered litter nitrogen decomposition dynamics, as evidenced by lower nitrogen and protein content in decomposed tissue from plants that hosted the endophyte. Differences in initial litter quality and subsequent colonization by saprotrophic fungi were ruled out as key drivers. Altered precipitation had negligible effects on decomposing processes in the dunes. Grass–Epichloë symbiosis altered nutrient cycling through increasing the rate of litter decomposition when present in the litter and through reducing litter decomposition by conditioning the decomposition microenvironment. Epichloë are widespread symbionts of grasses. Thus, their effects on decomposition could be an important, but often overlooked, driver of nutrient cycling in grass‐dominated ecosystems.

Beachgrass invasion in coastal dunes is mediated by soil microbes and lack of disturbance dependence

AbstractBiological invasions are a threat to ecological communities and ecosystems, yet understanding the processes that mediate invasion and the environmental contexts in which these processes are important remains a challenge. In this study, we investigated how disturbance and biotic interactions with pathogens and microbial symbionts mediate invasion of American beachgrass (Ammophila breviligulata) in early‐ and late‐successional coastal dune habitats. First, we tested the effect of disturbance on biomasses of two exotic beachgrass species (the invading A. breviligulata and the established A. arenaria) and a native beachgrass (Elymus mollis) by growing plants with and without a disturbance manipulation in early‐ and late‐successional habitats. We quantified root colonization by fungal symbionts and infection by plant‐parasitic nematodes to determine the effect of potential mutualists and pathogens on plant biomass. Second, we tested whether soil microbes associated with the established A. arenaria mediated A. breviligulata invasion by inoculating potted plants with microbes from early‐ and late‐successional habitat. We found no effect of disturbance on biomass of the invading A. breviligulata or native E. mollis, whereas A. arenaria biomass increased when grown with disturbance. Colonization by arbuscular mycorrhizal fungi and by fungal endophytes were poor predictors of plant biomass, and plant‐parasitic nematodes were infrequently observed. Microbe addition increased belowground biomass of A. breviligulata, but not A. arenaria, compared to control treatments. Overall, our results suggest that A. breviligulata invasion in both the early‐ and late‐successional habitat is mediated by its lack of disturbance dependence and positive effects of soil microbes. These results have important implications for other primary successional systems and contribute to our understanding of how ecological contexts influence invasion processes.

Density-dependent resource selection by a terrestrial herbivore in response to sea-to-land nutrient transfer by seals.

Sea-to-land nutrient transfers can connect marine food webs to those on land, creating a dependence on marine webs by opportunistic species. We show how nitrogen, imported by gray seals, Halichoerus grypus, and traced through stable isotope (δ15 N) measurements in marram grass, Ammophila breviligulata, significantly alters foraging behavior of a free-roaming megaherbivore (feral horses, Equus ferus caballus) on Sable Island, Canada. Values of δ15 N correlated with protein content of marram and strongly related to pupping-seal densities, and positively influenced selective foraging by horses. The latter was density dependent, consistent with optimal foraging theory. We present the first demonstration of how sea-to-land nutrient transfers can affect the behavioral process of resource selection (resource use relative to availability) of terrestrial consumers. We hypothesize that persistence of horses on Sable Island is being facilitated by N subsidies. Our results have relevance to advancing theory on trophic dynamics in island biogeography and metaecosystem ecology.

Above vs. belowground plant biomass along a barrier island: Implications for dune stabilization

Coastal regions are inherently and increasingly vulnerable and geomorphologically unstable, yet are invaluable economic and residential hubs. Dunes are dynamic buffers to erosion and the most natural, economical, and effective defense for coastal communities. Vegetation is integral to dune structure as it facilitates accretion and stabilization. Differences in the vegetation and root density likely translate to variability in coastal erosion prevention, but this notion has been largely unconsidered. We directly compared stabilizing factors, depth and density, of the root systems of two dominant mid-Atlantic dune plant species, native American beach grass (Ammophila breviligulata) and invasive Asiatic sand sedge (Carex kobomugi). Despite high plant density, C. kobomugi is targeted for removal in restoration efforts as its roots are assumed to provide less effective stabilization than A. breviligulata. We collected 30 cores and hand dug 14 A. breviligulata ramets at Island Beach State Park, New Jersey to examine biomass, root:shoot ratios, and root density. C. kobomugi had a more extensive root system with a root:shoot ratio of 11.36:1 compared to 1.62:1 for A. breviligulata. Similarly, cores 60 cm deep and 7.6 cm wide were sufficient to attain fully intact A. breviligulata roots, which did not extend deeper than 40 cm, but insufficient for C. kobomugi roots which extended beyond the sampling system vertically and horizontally. Scaling these findings to m−2, aboveground biomass is relatively equal, but C. kobomugi had over 700% more root mass m−2 than A. breviligulata. These results have strong implications for dune management. The root system of C. kobomugi may be better adapted to stabilize dunes and thus protect coastal areas during small and large-scale perturbations than previously supposed. This is a unique situation whereby the creation of monocultures will hyperstabilize dunes and make them more resistant to erosion at the cost of reduced biodiversity within the framework of resiliency.

Genetic Structure of Native and Restored Populations of American Beachgrass (Ammophila breviligulataFern.) along the New Jersey Coast

ABSTRACT Slaymaker, D.H.; Peek, M.S.; Wresilo, J.; Zeltner, D.C., and Saleh, Y.F., 2015. Genetic structure of native and restored populations of American beachgrass (Ammophila breviligulata Fern.) along the New Jersey coast. Ammophila breviligulata Fern. (American beachgrass) is planted extensively along the Atlantic coast of North America and in the Great Lakes region to stabilize damaged and constructed coastal dunes. Most A. breviligulata restorations are planted with a single cultivar for rapid dune stabilization. Restoration practice, however, is increasingly focused on maintaining native genetic diversity and restoring ecological services and function. We used intersimple sequence repeat (ISSR) markers to characterize the genetic structure of four native and four restored A. breviligulata populations along the coast of New Jersey on the northeastern Atlantic coast of the United States. Native populations had high levels of genotypic diversity for a clonal species, whereas restored populations on con...

Greenhouse Growth of Native American Beachgrass (Ammophila breviligulata) and Invasive Asiatic Sand Sedge (Carex kobomugi) Under Competition

Worldwide, dunes buffer peripheral coastal areas from destructive abiotic elements of erosion and storms. Vegetation is a major element of these systems as roots bind sand and thereby, stabilize dunes and shoots promote dune growth. The dunes of the Mid-Atlantic U.S. are stabilized by two alpha species that compete for space and resources-native American Beachgrass (Ammophila breviligulata) and invasive Asiatic Sand Sedge (Carex kobomugi). Despite the importance of these species, today many of the biological and physiological factors underpinning their competition remain poorly understood. Therefore, we conducted a 7 week greenhouse competition study with transplanted A. breviligulata and C. kobomugi ramets. We manipulated substrate amount and salt spray as treatments in a factorial-designed greenhouse experiment. Despite ample acclimation prior to testing and appropriate abiotic conditions throughout, we had very low survivorship for both species. This was especially true for C. kobomugi, which may be largely intolerant of wet substrate conditions. We performed microscopy to begin to understand the morphological and physiological differences that could have drive differences in our survival rates. Our results provide information useful for the design and uses of future attempts at conducting coastal vegetation transplant studies.

Fungal symbiosis and precipitation alter traits and dune building by the ecosystem engineer, Ammophila breviligulata.

Ecosystem engineer species influence their community and ecosystem by creating or altering the physical structure of habitats. The function of ecosystem engineers is variable and can depend on both abiotic and biotic factors. Here we make use of a primary successional system to evaluate the direct and interactive effects of climate change (precipitation) and fungal endophyte symbiosis on population traits and ecosystem function of the ecosystem engineering grass species, Ammophila breviligulata. We manipulated endophyte presence in A. breviligulata in combination with rain-out shelters and rainfall additions in a factorial field experiment established in 2010 on Lake Michigan sand dunes. We monitored plant traits, survival, growth, and sexual reproduction of A. breviligulata from 2010-2013, and quantified ecosystem engineering as the sand accumulation rate. Presence of the endophyte in A. breviligulata increased vegetative growth by up to 19%, and reduced sexual reproduction by up to 46% across all precipitation treatments. Precipitation was a less significant factor than endophyte colonization for A. breviligulata growth. Reduced precipitation increased average leaf number per tiller but had no other effects on plant traits. Changes in A. breviligulata traits corresponded to increases in sand accumulation in plots with the endophyte as well as in plots with reduced precipitation. Sand accumulation is a key ecosystem function in these primary successional habitats, and so microbial symbiosis in this ecosystem engineer could lead to direct effects on the value of these dune habitats for humans.