Australian Species Research Articles

Alpine plants are on the move: Quantifying distribution shifts of Australian alpine plants through time

AbstractAimAlpine plant species’ distributions are thought to have been shifting to higher elevations in response to climate change. By moving upslope, species can occupy cooler and more suitable environments as climate change warms their current ranges. Despite evidence of upslope migration in the northern hemisphere, there is limited evidence for elevational shifts in southern hemisphere plants. Our study aimed to determine if alpine plants in Australia have migrated upslope in the last 2 to 6 decades.LocationKosciuszko National Park, NSW, Australia.MethodsWe collated historic occurrence data for 36 Australian alpine plant species from herbarium specimens and historic field observations and combined these historic data with modern occurrence data collected in the field.ResultsEleven of the thirty‐six species had shifted upslope in mean elevation and four species showed downslope elevational shifts. The rate of change for upslope shifts varied between 4 and 10 m per year and the rate of change for most downslope shifts was between 4 and 8 m per year, with one species shifting downslope at a high rate of 18 m per year. Additionally, some species showed shifts upward in their upper range edge and/or upward or downward shifts in their lower range edge. Five species also showed range contractions in the difference between their lower and upper range edges over time, while two showed range expansions. We found no significant differences in elevational shifts through time among herbaceous dicotyledons, herbaceous monocotyledons and shrubs.Main ConclusionsPlant elevational shifts are occurring rapidly in the Australian alpine zone. This may allow species to persist under climate change. However, if current warming trends continue, several species within the Australian alpine zone will likely run out of suitable habitat within a century.

Observations of oviposition behaviour in the long‐tailed waspMegalyra fasciipennisWestwood, 1832 (Hymenoptera: Megalyridae)

AbstractMegalyridae is a small family of mostly Southern Hemisphere parasitoid wasps, with the females of some species having ovipositors up to eight times their body length. The largest genus,Megalyra, is represented by 22 Australian species. Despite the conspicuous morphology of females, the biology of this family is relatively poorly known, with few published field observations. We opportunistically observed a femaleMegalyra fasciipennisWestwood, 1832, in urban bushland in south‐western Sydney, New South Wales, and extensively describe our observations of oviposition behaviour. Although our observations are largely consistent with historical accounts of oviposition in this species, we also describe previously unreported behaviours such as abdominal rotation. We speculate thatM. fasciipennisemploys both chemoreception and passive vibration detection to find hosts inside wood and note the importance of urban habitat and standing dead trees for preserving biodiversity.

Pastures and Climate Extremes: Impacts of Cool Season Warming and Drought on the Productivity of Key Pasture Species in a Field Experiment.

Shifts in the timing, intensity and/or frequency of climate extremes, such as severe drought and heatwaves, can generate sustained shifts in ecosystem function with important ecological and economic impacts for rangelands and managed pastures. The Pastures and Climate Extremes experiment (PACE) in Southeast Australia was designed to investigate the impacts of a severe winter/spring drought (60% rainfall reduction) and, for a subset of species, a factorial combination of drought and elevated temperature (ambient +3°C) on pasture productivity. The experiment included nine common pasture and Australian rangeland species from three plant functional groups (C3 grasses, C4 grasses and legumes) planted in monoculture. Winter/spring drought resulted in productivity declines of 45% on average and up to 74% for the most affected species (Digitaria eriantha) during the 6-month treatment period, with eight of the nine species exhibiting significant yield reductions. Despite considerable variation in species’ sensitivity to drought, C4 grasses were more strongly affected by this treatment than C3 grasses or legumes. Warming also had negative effects on cool-season productivity, associated at least partially with exceedance of optimum growth temperatures in spring and indirect effects on soil water content. The combination of winter/spring drought and year-round warming resulted in the greatest yield reductions. We identified responses that were either additive (Festuca), or less-than-additive (Medicago), where warming reduced the magnitude of drought effects. Results from this study highlight the sensitivity of diverse pasture species to increases in winter and spring drought severity similar to those predicted for this region, and that anticipated benefits of cool-season warming are unlikely to be realized. Overall, the substantial negative impacts on productivity suggest that future, warmer, drier climates will result in shortfalls in cool-season forage availability, with profound implications for the livestock industry and natural grazer communities.

An integrated approach to assessing abiotic and biotic threats to post‐fire plant species recovery: Lessons from the 2019–2020 Australian fire season

AbstractAimExisting abiotic and biotic threats to plant species (e.g., disease, drought, invasive species) affect their capacity to recover post‐fire. We use a new, globally applicable framework to assess the vulnerability of 26,062 Australian plant species to a suite of active threats after the 2019–2020 fires.LocationAustralia.Time period2019–2020.Major species studiedPlants.MethodsSpatial data for existing threats and information on species‐level susceptibility were combined with estimates of the extent of range burnt in southern Australia (> 22°S) to assign species against 10 criteria into vulnerability categories (high, medium, low, none, data deficient). We explore in detail results for three threats (drought, disease, feral animals), highlighting where impacts from multiple threats ranked high vulnerability may compound to reduce post‐fire recovery.ResultsAnalysis of the full suite of 10 vulnerability criteria, which encompass a broad range of threats, revealed large numbers of species vulnerable to poor post‐fire recovery from one or more different hazards (high vulnerability: 1,243 species; medium vulnerability: 2,450 species). Collectively, 457 plant species that burnt extensively (> 50%) across their range are highly vulnerable to poor recovery due to exposure to pre‐fire drought conditions (235 species), disease (186 species), or feral animals (97 species). Of these 457 species, 61 are vulnerable to more than one of these three threats, highlighting how a suite of interacting hazards can impact plant recovery after fire.Main conclusionsWhile fire can renew plant populations by stimulating recruitment and resetting competitive interactions, the presence of existing threats in post‐fire landscapes jeopardizes recovery. The simultaneous impact of multiple threats that impact recovery can create a suite of hazards that contribute to declines and, potentially, extinction. Our method for rapid post‐fire vulnerability assessment can be applied to large numbers of plant species or other biota in fire affected regions globally.

Nitrogen concentration and physical properties are key drivers of woody tissue respiration.

Despite the critical role of woody tissues in determining net carbon exchange of terrestrial ecosystems, relatively little is known regarding the drivers of sapwood and bark respiration. Using one of the most comprehensive wood respiration datasets to date (82 species from Australian rainforest, savanna and temperate forest), we quantified relationships between tissue respiration rates (Rd) measured in vitro (i.e. 'respiration potential') and physical properties of bark and sapwood, and nitrogen concentration (Nmass) of leaves, sapwood and bark. Across all sites, tissue density and thickness explained similar, and in some cases more, variation in bark and sapwood Rd than did Nmass. Higher density bark and sapwood tissues had lower Rd for a given Nmass than lower density tissues. Rd-Nmass slopes were less steep in thicker compared with thinner-barked species and less steep in sapwood than in bark. Including the interactive effects of Nmass, density and thickness significantly increased the explanatory power for bark and sapwood respiration in branches. Among these models, Nmass contributed more to explanatory power in trunks than in branches, and in sapwood than in bark. Our findings were largely consistent across sites, which varied in their climate, soils and dominant vegetation type, suggesting generality in the observed trait relationships. Compared with a global compilation of leaf, stem and root data, Australian species showed generally lower Rd and Nmass, and less steep Rd-Nmass relationships. To the best of our knowledge, this is the first study to report control of respiration-nitrogen relationships by physical properties of tissues, and one of few to report respiration-nitrogen relationships in bark and sapwood. Together, our findings indicate a potential path towards improving current estimates of autotrophic respiration by integrating variation across distinct plant tissues.

Phylogeny, diversification, and biogeography of a hemiclonal hybrid system of native Australian freshwater fishes (Gobiiformes: Gobioidei: Eleotridae: Hypseleotris)

BackgroundCarp gudgeons (genus Hypseleotris) are a prominent part of the Australian freshwater fish fauna, with species distributed around the western, northern, and eastern reaches of the continent. We infer a calibrated phylogeny of the genus based on nuclear ultraconserved element (UCE) sequences and using Bayesian estimation of divergence times, and use this phylogeny to investigate geographic patterns of diversification with GeoSSE. The southeastern species have hybridized to form hemiclonal lineages, and we also resolve relationships of hemiclones and compare their phylogenetic placement in the UCE phylogeny with a hypothesis based on complete mitochondrial genomes. We then use phased SNPs extracted from the UCE sequences for population structure analysis among the southeastern species and hemiclones.ResultsHypseleotris cyprinoides, a widespread euryhaline species known from throughout the Indo-Pacific, is resolved outside the remainder of the species. Two Australian radiations comprise the bulk of Hypseleotris, one primarily in the northwestern coastal rivers and a second inhabiting the southeastern region including the Murray–Darling, Bulloo-Bancannia and Lake Eyre basins, plus coastal rivers east of the Great Dividing Range. Our phylogenetic results reveal cytonuclear discordance between the UCE and mitochondrial hypotheses, place hemiclone hybrids among their parental taxa, and indicate that the genus Kimberleyeleotris is nested within the northwestern Hypseleotris radiation along with three undescribed species. We infer a crown age for Hypseleotris of 17.3 Ma, date the radiation of Australian species at roughly 10.1 Ma, and recover the crown ages of the northwestern (excluding H. compressa) and southeastern radiations at 5.9 and 7.2 Ma, respectively. Range-dependent diversification analyses using GeoSSE indicate that speciation and extinction rates have been steady between the northwestern and southeastern Australian radiations and between smaller radiations of species in the Kimberley region and the Arnhem Plateau. Analysis of phased SNPs confirms inheritance patterns and reveals high levels of heterozygosity among the hemiclones.ConclusionsThe northwestern species have restricted ranges and likely speciated in allopatry, while the southeastern species are known from much larger areas, consistent with peripatric speciation or allopatric speciation followed by secondary contact. Species in the northwestern Kimberley region differ in shape from those in the southeast, with the Kimberley species notably more elongate and slender than the stocky southeastern species, likely due to the different topographies and flow regimes of the rivers they inhabit.

New Australian Utricularia taxa published since Allen Lowrie’s Magnum Opus

At the time of completion of Magnum Opus by the end of 2013, the genus Utricularia L. (Lentibulariaceae) contained approximately 240 monographed species worldwide, with 66 of these found in Australia. This paper will provide a brief treatment of the newly described and reinstated Australian Utricularia species and subspecies since Lowrie’s seminal work, Carnivorous Plants of Australia, Magnum Opus.

Refined taxon sampling discloses new quinone patterns and relationships among Sundews (Drosera, Droseraceae)

In a screening of 43 accessions of predominantly Australian sundew species (Drosera), naphthoquinones were detected convincingly for the first time in D. section Lasiocephala (D. petiolaris group, or ‘wooly sundews’), where these metabolites remain restricted to a minority of four closely related species. Great chemical similarity across the large geographic range confirms a close phylogenetic affinity between taxa of the D. peltata species group (of D. section Ergaleium, from tropical and Eastern Asia to New Zealand). Drosera barrettiorum (D. section Arachnopus) is chemically confirmed as a close relative of D. hartmeyerorum. The recently described species D. margaritacea in the same section is chemically different from the morphologically close D. finlaysoniana. Quinone data for African and South American sundews (D. sections Drosera, Ptycnostigma and Brasilianae) shed further light on the affinities between these taxonomically challenging plants.

In vitro Cytotoxic Properties of Crude Polar Extracts of Plants Sourced from Australia

Numerous commercial pharmaceuticals – including anticancer, antiviral, and antidiabetic drugs have been developed from traditional plant-derived medicines. There are approximately 25,000 species of flora occurring in Australia, which are adapted to a range of harsh environments, and hence a plethora of novel compounds are still awaiting research in the context of their medicinal properties. The current study therefore aimed to develop a systematic protocol for screening plants with potential cytotoxicity. Many studies have found polar compounds such as caffeic acid, coumaric acid, chlorogenic acid, quercetin, anthocyanins, hesperidin, kaempferol, catechin, ellagic acid, and saponins to be the bioactive components responsible for the therapeutic effects. The total phenolic content (TPC) and antioxidant capacity (FRAP) of methanolic extracts of selected plants was first determined. A high correlation between the TPC values and FRAP values of the plant polar extracts were evident. Cell viability of the cancer cell lines were assessed using the MTS assay. Cells subjected to Pittosporum angustifolium Lodd. extracts at concentration of 250 µg·mL −1 showed no viable cells, comparable to cisplatin (a chemotherapy medication) used as a positive control (10 µg·mL −1 ). Some promising inhibitory effects were also seen with Murrya koenigii flower and leaves at concentration of 250 µg·mL −1 , with only 43.46% and 63.88% cell viability, respectively. In contrast, extracts of Citrus hystrix (leaves) and Sygyzium australe (stamen) showed higher percentage cell viabilities (around 82–93%) at same concentrations. The phenolic profile of P. angustifolium B extracts demonstrating greater peak intensity and dominant peaks were tentatively identified as chlorogenic acid, p-coumaric acid, caffeic acid, t-ferulic acid and rutin. The Australian species Pittosporum angustifolium was the most cytotoxic against HeLa and HT29 cells comparing to the other plant extracts tested. A HPLC profile of the P. angustifolium extract also showed an array of promising therapeutic phenolic compounds. Future work will aim to fractionate and isolate novel compounds from this species and test their bioactivity.

New Australian Nepenthes taxa published since Allen Lowrie’s Magnum Opus

Allen Lowrie supported three Nepenthes species, N. mirabilis, N. rowaniae, and N. tenax in Magnum Opus and this treatment remained the accepted protocol until 2016, when a fourth Australian species was described, Nepenthes parvula G.W.Wilson & S.Venter.

Cannibalism and intraguild predation between endemic and introduced coccidophagous lady beetles (Coleoptera: Coccinellidae)

AbstractThe Chilocorini lady beetles Tenuisvalvae notata (Mulsant) and Cryptolaemus montrouzieri Mulsant are important biological control agents being able to share their habitat and compete for their preferred prey, mealybugs. Whereas T. notata is native to South America, C. montrouzieri is an Australian species introduced in Brazil in a biological control program of mealybugs. This work investigated the cannibalism and intraguild predation between these species in the absence of prey. To test for intraguild predation, one individual larva (instars 1–4) from each species was confined for 24 h with another larva of the same instar or the next instar, in a total of 10 combinations. In addition, we measured predation of T. notata adults upon eggs, larvae, pre‐pupae and pupa of C. montrouzieri, and vice versa. Cannibalism within the species was also tested across adults, larvae and eggs. Results showed asymmetric interactions in favour of C. montrouzieri, which acted as intraguild predator more than 80% of the time when paired with larvae of T. notata either of the same or different instar. In addition, C. montrouzieri adults preyed more upon larvae and eggs of T. notata than the contrary. There was no intraguild predation upon pre‐pupae and pupae. Cannibalism was high upon eggs and first instar larvae of T. notata (89.5% and 65%) and C. montrouzieri (100% and 55%), respectively. Therefore, the exotic C. montrouzieri outcompeted the native T. notata and could become a threat to this endemic species in areas of simultaneous occurrence and under prey scarcity. Thus, the interactions between these lady beetles could affect the success of biological control of mealybugs.

Thermal responses of some Australian cicadas (Insecta: Hemiptera: Cicadidae)

We determine the thermal responses for 22 species from 16 genera, nine tribes and two subfamilies of Australian cicadas. Thermal responses are related to habitat and possibly to behavior. The thermal responses of the Australian species show convergent patterns to the cicadas in similar environments in Africa, Europe, North America, and South America. The study illustrates that similar evolutionary pressures select for similar thermal adaptation regardless of geographic locality or species phylogeny.

Reproductive and leaf morpho-anatomy of the Australian alpine podocarp and comparison with the Australis subclade

ABSTRACT Podocarpus lawrencei (Mountain Plum Pine) is an endemic Australian conifer species and morphologically, ecologically, and genetically close to P. nivalis, P. gnidioides, P. totara, P. acutifolius, and P. laetus. The reproductive biology and seed cone morpho-anatomy of P. lawrencei and the Australis subclade is not well understood. This study describes the detailed reproductive morpho-anatomy of P. lawrencei and compares it with these related species of Australis subclade. Seed cone reproductive developmental stages, morpho-anatomical features of the seed cones and leaf were investigated using histology, light, and scanning electron microscopy. Seed cone initiates with a terminal bud in late July, and the reproductive cycle takes 1 or more than 1 year (12–16 months) to complete. The ovule is inverted and ovule inversion is present. The reproductive cycle of this group of podocarps takes more than 1 year to complete. The seed cone of P. lawrencei has a fused non-fleshy epimatium (green-brown seed) with a brightly coloured reddish receptaculum. The seed cone shows morphological and anatomical similarity with P. nivalis in particular and no significant morpho-anatomical difference with other Australis subclade species. The brightly coloured fleshy cones of Australis subclade suggest frugivory and zoochory for dispersal of seeds. More extensive population genetic studies are required to evaluate the genetic structure, diversification, and historical biogeography of Australis subclade. This study provides a primary base from which to evaluate the genetic structure of all the species in this clade.

Juncus sarophorus, a native Australian species, tolerates and accumulates PFOS, PFOA and PFHxS in a glasshouse experiment

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) have been identified as emerging contaminants of public health concern. With PFAS now detected globally in a wide range of environments, there is an urgent need for effective remedial treatment solutions at the field scale. Phytoremediation presents a potential remediation strategy for PFAS that would allow efficient and cost-effective remediation at large scales. This study examined the potential for the Australian native wetland plant Juncus sarophorus to tolerate, take up, and accumulate PFOS, PFOA and PFHxS. A 190-day glasshouse experiment was conducted, in which 0, 10 and 100 μg/L each of PFOS, PFOA and PFHxS were used to irrigate J. sarophorus in potted soil. The results suggest that J. sarophorus has a high tolerance to PFAS and is effective at accumulating and transferring PFHxS and PFOA from soils to above ground biomass. Together with its high growth rate, J. sarophorus appears to be, in principle, a suitable candidate for phytoextraction of short-chained PFAS compounds. It is, however, less efficient at uptake of PFOS, owing to the long chain-lengths of this compound and PFOSs' ability to sorb effectively to soils. The total accumulated PFAS mass at the end of the experiment was ~2000 μg/kg biota(wet weight) and ~170 μg/kg biota(wet weight) for soils irrigated with 100 μg/L and 10 μg/L for each PFAS compound, translating into overall PFAS removal rates of 11% and 9%.

Variation in density, but not morphology, of cutaneous sensilla among body regions in nine species of Australian geckos.

Skin sense organs, cutaneous sensilla, are a well-known feature of the integument of squamate reptiles and particularly geckos. They vary widely in morphology among species and are thought to be mechanosensitive, associated with prey capture and handling, tail autotomy and placement of the adhesive toepads in pad-bearing species. Some authors suggest that they may also sense abiotic environmental features, such as temperature or humidity. Here, we describe the morphology and distribution of cutaneous sensilla among body regions of nine Australian gecko species, in four genera. We hypothesised that if sensilla morphology was distinct, or sensilla density high, around the mouth, on the tail and on extremities, sensilla were likely used for these direct tactile functions. We found that sensilla morphology was uniform among body regions within species, but varied among species, while sensilla densities varied among species and body regions. In all species studied, sensilla density was highest on the labials and the dorsal tail scales and low on the feet, head and body, providing strong support for the hypothesis that sensilla serve tactile mechanoreceptive functions for prey capture and handling and for predator avoidance, but not for toepad placement. We suggest sensilla density may be explained by mechanoreception, whereas structure may be influenced by other factors.

Investigating Antimicrobial Characteristics/Advantages of Australian Wood Species for Use in Food Packaging—A Feasibility Study

The antimicrobial characteristics of Australian commercial timber species were studied using a direct screening method and two different microorganisms. The effectiveness of timber samples was compared with plastic and paper samples during an incubation period of 24 h at 37 °C. The initial data with E. coli and S. aureus showed no difference in performance between the plastic and paper samples and the softwood samples tested. Hardwood samples, however, showed an inhibition zone when tested with S. Aureus. The data showed similar trends of inhibition zones developed for sterilised and non-sterilised samples of spotted gum and shining gum species. The observed data showed promising antimicrobial characteristics for both veneer and solid samples of hardwood species. Further studies investigating the type of extractives, their role in antimicrobial characteristics and differences in the type of surface exposed to the microbial contamination from the point of view of timber’s anatomical properties are proposed.

ОСОБЕННОСТИ ФУНКЦИОНАЛЬНОГО СОСТОЯНИЯ РЕГУЛЯТОРНЫХ МЕХАНИЗМОВ КВАЛИФИЦИРОВАННЫХ СПОРТСМЕНОВ РАЗНЫХ ВИДОВ СПОРТА

Представлены результаты исследования вариабельности сердечного ритма квалифицированных спортсменов различных видов спорта (циклических, игровых, единоборств). Оценка полученных результатов проведена методами спектрального и временного анализа. Определены особенности срочной (по результатам ортостатической пробы) и долговременной адаптации регуляторных механизмов, возникающих в результате продолжительных занятий представленными видами спорта. У гандболистов отмечено повышение роли симпатического отдела ВНС и признаки централизации регуляции сердечного ритма. У представителей циклических видов спорта отмечается равновесие в деятельности отделов ВНС, устойчивое в условиях ортопробы. У спортсменов, занимающихся единоборствами, отмечается сбалансированность ВНС, но нагрузка вызывает активное включение симпатического отдела.

Grouped SPME Comparison of Floral Scent as a Method of Unlocking Phylogenetic Patterns in Volatiles

Global crop production rate has exceeded the availability of pollination services provided by managed honeybees, and habitat loss remains a key factor in the loss of wild pollinators. Revegetation of agricultural land and wild pollination may provide a solution; however, the collection of floral trait data that are correlated to pollinator preferences remains an under studied and complex process. Here, we demonstrate a method for scent analysis, ordination [non-metric dimensional scaling (NMDS)], and clustering outputs that provides a fast and reproducible procedure for a broad grouping of flora based on scent and unlocking characteristic inter-floral patterns. We report the floral profiles of 15 unstudied native Australian plant species and the extent to which they match the commonly cultivated seed crops of Daucus carota L and Brassica rapa L. Through solid-phase microextraction (SPME) paired with gas chromatography–mass spectrometry (GC-MS), we identify a set of inter-family shared, common floral volatiles from these plant species as well as unique and characteristic patterns.

Can slowing the rate of water temperature decline be utilized to reduce the impacts of cold water pollution from dam releases on fish physiology and performance?

Cold water pollution (CWP) is caused by releases of unseasonably cold water from large, thermally stratified dams. Rapid and prolonged decreases in water temperature can have depressive effects on the metabolism, growth and swimming performance of fish. However, it is unknown if reducing the rate of temperature decrease could mitigate these negative effects by allowing thermal acclimation/acclimatization to occur. This study investigated the rate of temperature decrease as a potential CWP mitigation strategy in juvenile Murray cod Maccullochella peelii. M. peelii were exposed to a gradual, intermediate or rapid temperature decrease from 24 to 14°C. Energetic costs, locomotor performance, growth and survival were measured to determine if the initial thermal regime affected the thermal acclimation capacity of M. peelii. Cold exposure had significant acute and lasting depressive effects regardless of the rate of temperature decrease, although M. peelii showed varying degrees of thermal compensation in swimming performance and metabolism after 8 weeks of exposure to low temperatures. The short‐term effects of CWP‐like reductions in temperature are significant, but over time M. peelii can offset some of the depressive effects of CWP through thermal plasticity. This study highlights the importance of understanding physiological responses of fish to inform management and conservation. We conclude that rate of water temperature decline cannot be used to mitigate the sublethal effects of CWP on juvenile M. peelii but may still be useful for managing the negative effects in other native Australian fish species.

Profiling the cell walls of seagrasses from A (Amphibolis) to Z (Zostera)

BackgroundThe polyphyletic group of seagrasses shows an evolutionary history from early monocotyledonous land plants to the marine environment. Seagrasses form important coastal ecosystems worldwide and large amounts of seagrass detritus washed on beaches might also be valuable bioeconomical resources. Despite this importance and potential, little is known about adaptation of these angiosperms to the marine environment and their cell walls.ResultsWe investigated polysaccharide composition of nine seagrass species from the Mediterranean, Red Sea and eastern Indian Ocean. Sequential extraction revealed a similar seagrass cell wall polysaccharide composition to terrestrial angiosperms: arabinogalactans, pectins and different hemicelluloses, especially xylans and/or xyloglucans. However, the pectic fractions were characterized by the monosaccharide apiose, suggesting unusual apiogalacturonans are a common feature of seagrass cell walls. Detailed analyses of four representative species identified differences between organs and species in their constituent monosaccharide composition and lignin content and structure. Rhizomes were richer in glucosyl units compared to leaves and roots. Enhalus had high apiosyl and arabinosyl abundance, while two Australian species of Amphibolis and Posidonia, were characterized by high amounts of xylosyl residues. Interestingly, the latter two species contained appreciable amounts of lignin, especially in roots and rhizomes whereas Zostera and Enhalus were lignin-free. Lignin structure in Amphibolis was characterized by a higher syringyl content compared to that of Posidonia.ConclusionsOur investigations give a first comprehensive overview on cell wall composition across seagrass families, which will help understanding adaptation to a marine environment in the evolutionary context and evaluating the potential of seagrass in biorefinery incentives.