Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 725
Filtrar
1.
Sci Total Environ ; 942: 173805, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-38848917

RESUMO

BACKGROUND: Seagrass meadows are among the most abundant marine coastal ecosystems in the world. The wide variety of species, a worldwide distribution with overall high abundance, and especially their high productivity make them a plausible nature-based blue carbon solution to mitigate atmospheric CO2 levels. In the Mediterranean Basin, the endemic angiosperm Posidonia oceanica plays a remarkable role as a marine habitat provider in shallow waters through its vertical growth and as a carbon sink storing allochthonous carbon and biomass underneath the meadows. OBJECTIVES: Here, we assess the capacity of a pristine meadow to oxygenate the water column in the coastal area of the Balearic Islands through an evaluation of the metabolic rates in the benthic compartment as well as the resulting oxygen concentrations in the pelagic compartment. METHODS: Gross primary production (GPP), respiration (R), and net community production (NCP) are determined from dissolved oxygen (DO) measurements using two different calculation methods: a model developed for this purpose is used for data obtained from water column sensors and benthic multiparametric sensors, whereas the mass balance of measured DO is used to calculate the metabolic rates inside benthic chambers. RESULTS: The meadow at our study site was characterised as a net autotrophic ecosystem throughout the year. Oxygen productivity was significantly higher in the benthic compartment than in the water column and followed clear seasonal patterns, with enhanced productivity during spring. NOVELTY: This work shows the key role of a healthy Posidonia oceanica ecosystem as a water column oxygenator by comparing primary production using three different sampling strategies. The potential of the seagrass as climate change mitigator and its importance for the Mediterranean coasts should be considered in future coastal planning strategies.


Assuntos
Alismatales , Oxigênio , Oxigênio/análise , Oxigênio/metabolismo , Ecossistema , Espanha , Monitoramento Ambiental , Biomassa , Água do Mar/química
2.
Mar Pollut Bull ; 203: 116435, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38772171

RESUMO

The Posidonia oceanica (L.) Delile 1813 banquette provides precious ecosystem services for Mediterranean beach nourishment and protection, representing an important way of energy transfer through marine-coastal habitats. It is surprising to note how it is poorly investigated, especially concerning its double role as potential sink and source of chemicals. In particular, few studies exist about the metal (loid)s occurrence and no data are available on emerging contaminants, such as Rare Earth Elements (REEs). The present research investigated for the first time the concentrations of twenty-eight metal(loid)s and fifteen REEs in a well-structured banquette along the Italian coast (Central Tyrrhenian Sea) showing that (i) metal(loid)s and REEs occur in banquettes, with higher relative concentrations of some metal(loid)s (B, Sr, Mn, Fe, Al, Zn) and REEs (Ce, Y, La, Nd) with no statistically significant seasonal variations; (ii) Posidonia banquettes may represent an interesting biological model for chemicals monitoring.


Assuntos
Alismatales , Monitoramento Ambiental , Metais Terras Raras , Poluentes Químicos da Água , Metais Terras Raras/análise , Poluentes Químicos da Água/análise , Metais/análise , Itália , Ecossistema
3.
Sci Total Environ ; 937: 173523, 2024 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-38797423

RESUMO

Seagrass meadows are globally recognized as critical natural carbon sinks, commonly known as 'blue carbon'. However, seagrass decline attributed to escalating human activities and climate change, significantly influences their carbon sequestration capacity. A key aspect in comprehending the impact of seagrass decline on carbon sequestration is understanding how degradation affects the stored blue carbon, primarily consisting of sediment organic carbon (SOC). While it is widely acknowledged that seagrass decline affects the input of organic carbon, little is known about its impact on SOC pool stability. To address this knowledge, we examined variations in total SOC and recalcitrant SOC (RSOC) at a depth of 15 cm in nine seagrass meadows located on the coast of Southern China. Our findings revealed that the ratio of RSOC to SOC (RSOC/SOC) ranged from 27 % to 91 % in the seagrass meadows, and the RSOC/SOC increased slightly with depth. Comparing different seagrass species, we observed that SOC and RSOC stocks were 1.94 and 3.19-fold higher under Halophila beccarii and Halophila ovalis meadows compared to Thalassia hemprichii and Enhalus acoroides meadows. Redundancy and correlation analyses indicated that SOC and RSOC content and stock, as well as the RSOC/SOC ratio, decreased with declining seagrass shoot density, biomass, and coverage. This implies that the loss of seagrass, caused by human activities and climate change, results in a reduction in carbon sequestration stability. Further, the RSOC decreased by 15 %, 29 %, and 40 % under unvegetated areas compared to adjacent Halophila spp., T. hemprichii and E. acoroides meadows, respectively. Given the anticipated acceleration of seagrass decline due to climate change and increasing coastal development, our study provides timely information for developing coastal carbon protection strategies. These strategies should focus on preserving seagrass and restoring damaged seagrass meadows, to maximize their carbon sequestration capacity.


Assuntos
Sequestro de Carbono , Carbono , Mudança Climática , Sedimentos Geológicos , Sedimentos Geológicos/química , China , Carbono/análise , Monitoramento Ambiental , Hydrocharitaceae , Alismatales
4.
Mar Pollut Bull ; 203: 116394, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38705001

RESUMO

Seagrasses are marine flowering plants that create critical coastal ecosystems and are threatened by warming. Clonal expansion is generally the dominant strategy for meadow recovery, while sexual reproduction strongly differs among species (e.g., monoecious and diecious species, some creating seed banks, viviparous seedlings). In 2022, the Western Mediterranean underwent unprecedented warming, and, associated with it, we observed flowering (100 %) across 11 Posidonia oceanica meadows in Mallorca, Balearic Islands. Furthermore, 64 % of the sites also exhibited pseudovivipary, an extremely rare phenomenon in angiosperms whereby plantlets replace sexual reproductive structures, producing clones of the maternal plant. Our results support the notion that P. oceanica flowering and pseudovivipary (genetically confirmed) are triggered by warming, never before being pseudovivipary reported across multiple sites in a marine plant. Considering the negative impacts that warming can have on seagrasses, existence of widespread pseudovivipary is a critical aspect to consider for understanding mechanisms of resilience in seagrasses.


Assuntos
Alismatales , Alismatales/fisiologia , Flores , Ecossistema , Reprodução , Temperatura Alta
5.
J Environ Manage ; 359: 121008, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38703654

RESUMO

Despite the high potential of seagrass restoration to reverse the trend of marine ecosystem degradation, there are still many limitations, especially when ecosystems are severely degraded. In particular, it is not known whether restoring polluted ecosystems can lead to potentially harmful effects associated with contaminant remobilisation. Here, we aimed to investigate the role of P. oceanica transplanted from a pristine meadow to a polluted site (Augusta Bay, Italy, Mediterranean Sea) in two seasons of the year, as a sink or source of trace elements to the environment. The main results showed i) higher accumulation of chromium (Cr), copper (Cu) and total mercury (THg) in plants transplanted in summer than in winter, as well as an increase in Cr and THg in plants from sites with higher trace element loads; ii) an increase in leaf phenolics and a decrease in rhizome soluble carbohydrates associated with As and THg accumulation, suggesting the occurrence of defence strategies to cope with pollution stress; iii) a different partitioning of trace elements between below- and above-ground tissues, with arsenic (As) and Cr accumulating in roots, whereas Cu and THg in both roots and leaves. These results suggest that P. oceanica transplanted to polluted sites can act as both a sink and a source, sequestering trace elements in the below-ground tissues thus reducing their bioavailability, but also potentially remobilising them. However, the amount of trace elements potentially exported from P. oceanica to the environment through transfer into food webs via leaves and detritus appeared to be low under the specific conditions of the study site. Although further research into seagrass restoration of polluted sites would improve current knowledge to support effective ecosystem-based coastal management, the benefits of restoring polluted sites through seagrass transplantation appear to outweigh the potential costs of inaction over time.


Assuntos
Alismatales , Ecossistema , Oligoelementos , Oligoelementos/análise , Mar Mediterrâneo , Poluentes Químicos da Água , Itália , Arsênio/análise
6.
Mar Pollut Bull ; 204: 116515, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38796990

RESUMO

The increase of marine heat waves (MHWs) occurrence is exacerbated in Mediterranean Sea and temperature resilience-enhancing strategies on key species, such as the seagrass Posidonia oceanica, need to be investigated. "Priming" describes a stimulus that prepares an organism for an improved response to upcoming environmental changes by triggering a memory that remains during a lag-phase. The aim of this study, conducted in Sardinia (Italy), was to investigate whether the development of thermo-primed P. oceanica seedlings is affected by a field simulated MHW depending on the duration of the lag-phase. After the thermo-priming stimulus, seedlings had a 0, 7 or 14 days lag-phase and after that, for each lag-phase group, half of the seedlings experienced a simulated MHW (the other half served as controls). Some other seedlings did not experience either the priming stimulus or the lag-phase. Results did not show any evidence of a memory triggered by the priming stimulus, but they highlighted the importance of an acclimation phase before the highest temperature: seedlings that experienced a gradual increase of temperature had a higher number of leaves and shorter leaf necrosis length compared to seedlings that had a lag-phase between two heat events. Regardless the priming stimulus, MHWs slowed down the development of the leaf and root length. Considering the increase of temperature fluctuations, testing different intensities of priming and different length of lag-phase is necessary to provide information about the adaptive success of the species.


Assuntos
Alismatales , Plântula , Alismatales/fisiologia , Plântula/crescimento & desenvolvimento , Temperatura Alta , Itália , Mar Mediterrâneo , Aclimatação , Folhas de Planta
7.
Mar Environ Res ; 198: 106499, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38640690

RESUMO

Determining the proximity of ecosystems to tipping points is a critical yet complex task, heightened by the growing severity of climate change and local anthropogenic stressors on ecosystem integrity. Spatial Early Warning Signals (EWS) have been recognized for their potential in preemptively signaling regime shifts to degraded states, but their performance in natural systems remains uncertain. In this study, we investigated the performance of 'recovery length' - the spatial extent of recovery from a perturbation - and spatial EWS as early warnings of regime shifts in Posidonia oceanica meadows. Our experimental approach involved progressively thinning the P. oceanica canopy, from 0 to 100%, at the edge of a dead-matte area - a structure formed by dead P. oceanica rhizomes and colonized by algal turfs - to promote the propagation of algal turfs. We calculated recovery length as the distance from the dead-matte edge to the point where algal turfs colonized the canopy-thinned region. Our results showed a linear increase in recovery length with canopy thinning, successfully anticipated the degradation of P. oceanica. While spatial skewness decline with increased canopy degradation, other spatial EWS, such as Moran correlation at lag-1, low-frequency spatial spectra, and spatial variance, were ineffective in signaling this degradation. These findings underscore the potential of recovery length as a reliable early warning indicator of regime shifts in marine coastal ecosystems.


Assuntos
Alismatales , Mudança Climática , Ecossistema , Alismatales/fisiologia , Monitoramento Ambiental
8.
Mar Environ Res ; 197: 106464, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38583356

RESUMO

Seagrass meadows are biodiversity hotspots for invertebrate species including decapods. Understanding the drivers of species abundance, richness and diversity of decapod assemblages is crucial for the conservation of such hotspots, but how drivers act across multiple spatial scales remains unexplored. Here we describe the decapod assemblages of Posidonia oceanica seagrass meadows and assess the influence of attributes from three increasing spatial scales (habitat, landscape, and geographical levels) on the assemblages' structure and composition, as well as the variability partitioning among each one of these levels. Overall, geographical level attributes (i.e., inlet aperture, confinement) affected the most the decapod assemblages, while we only found a modest contribution from habitat (e.g., detritus biomass, sediment organic matter) and landscape attributes (e.g., fragmentation). We suggest that decapod assemblages are driven by the interaction of multiple processes occurring at different scales and other highly stochastic phenomena such as larval dispersion and recruitment.


Assuntos
Alismatales , Decápodes , Animais , Ecossistema , Biodiversidade , Biomassa
9.
Sci Rep ; 14(1): 8360, 2024 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-38600271

RESUMO

Seagrasses are undergoing widespread loss due to anthropogenic pressure and climate change. Since 1960, the Mediterranean seascape lost 13-50% of the areal extent of its dominant and endemic seagrass-Posidonia oceanica, which regulates its ecosystem. Many conservation and restoration projects failed due to poor site selection and lack of long-term monitoring. Here, we present a fast and efficient operational approach based on a deep-learning artificial intelligence model using Sentinel-2 data to map the spatial extent of the meadows, enabling short and long-term monitoring, and identifying the impacts of natural and human-induced stressors and changes at different timescales. We apply ACOLITE atmospheric correction to the satellite data and use the output to train the model along with the ancillary data and therefore, map the extent of the meadows. We apply noise-removing filters to enhance the map quality. We obtain 74-92% of overall accuracy, 72-91% of user's accuracy, and 81-92% of producer's accuracy, where high accuracies are observed at 0-25 m depth. Our model is easily adaptable to other regions and can produce maps in in-situ data-scarce regions, providing a first-hand overview. Our approach can be a support to the Mediterranean Posidonia Network, which brings together different stakeholders such as authorities, scientists, international environmental organizations, professionals including yachting agents and marinas from the Mediterranean countries to protect all P. oceanica meadows in the Mediterranean Sea by 2030 and increase each country's capability to protect these meadows by providing accurate and up-to-date maps to prevent its future degradation.


Assuntos
Alismatales , Ecossistema , Humanos , Efeitos Antropogênicos , Mudança Climática , Inteligência Artificial , Tecnologia de Sensoriamento Remoto , Mar Mediterrâneo
10.
Waste Manag ; 181: 101-113, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38603994

RESUMO

Significant quantities of Posidonia oceanica deposit on some beaches and coastlines every year, which generates high costs associated with the disposal of this waste. Pyrolysis may be an adequate way for its valorization. However, it would imply to know how the process takes place and if the removal of its natural detrital inorganic matter (epiphytes, marine salt and sand) is necessary, which are the objectives of this research. Pyrolysis by thermogravimetry-mass spectrometry was carried out on both the washed and unwashed samples. During this waste pyrolysis, the following occurs: (i) the high alkali metal chloride content promotes fragmentation reactions of carbohydrates and O formation, which increases HCOOH intensities at temperatures between 250 and 360 °C; (ii) from 500 °C to 650 °C, Fe2O3 and decomposition of carbonates seem to be involved in reactions that produce O release and steam and CO2 reforming of hydrocarbons and oxygenated organic compounds with H2 generation; (iii) from 650 °C to 750 °C, Fe2O3, high alkali metal content and carbonate decomposition generate char gasification, an increase in O release, SO2 capture and HCOOH formation. In general, the abundance of inorganic matter (chlorides, carbonates, etc.) minimizes the release of various compounds during pyrolysis, including SO2 and HCl, while increasing HCOOH production. Thus, this high content of inorganic matter may represent an advantage for its pyrolysis, producing value-added chemical products with a reduced environmental impact. Therefore, this study may be the starting point for defining the optimal pyrolysis conditions for this waste valorisation.


Assuntos
Alismatales , Pirólise , Dióxido de Enxofre , Alismatales/química , Dióxido de Enxofre/química , Ácido Clorídrico/química , Termogravimetria , Oxigênio/química
11.
Plant Physiol Biochem ; 210: 108614, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38626655

RESUMO

Heat-priming improves plants' tolerance to a recurring heat stress event. The underlying molecular mechanisms of heat-priming are largely unknown in seagrasses. Here, ad hoc mesocosm experiments were conducted with two Mediterranean seagrass species, Posidonia oceanica and Cymodocea nodosa. Plants were first exposed to heat-priming, followed by a heat-triggering event. A comprehensive assessment of plant stress response across different levels of biological organization was performed at the end of the triggering event. Morphological and physiological results showed an improved response of heat-primed P. oceanica plants while in C. nodosa both heat- and non-primed plants enhanced their growth rates at the end of the triggering event. As resulting from whole transcriptome sequencing, molecular functions related to several cellular compartments and processes were involved in the response to warming of non-primed plants, while the response of heat-primed plants involved a limited group of processes. Our results suggest that seagrasses acquire a primed state during the priming event, that eventually gives plants the ability to induce a more energy-effective response when the thermal stress event recurs. Different species may differ in their ability to perform an improved heat stress response after priming. This study provides pioneer molecular insights into the emerging topic of seagrass stress priming and may benefit future studies in the field.


Assuntos
Alismatales , Transcriptoma , Alismatales/genética , Alismatales/metabolismo , Transcriptoma/genética , Especificidade da Espécie , Resposta ao Choque Térmico/genética , Resposta ao Choque Térmico/fisiologia , Regulação da Expressão Gênica de Plantas , Mar Mediterrâneo , Temperatura Alta
12.
Mar Pollut Bull ; 202: 116274, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38564819

RESUMO

In the context of limiting global warming, the seagrass Posidonia oceanica (L.) gained the centrality of several international climate change mitigation projects being the most effective carbon storage sink among Mediterranean seagrasses. To assess and monitor the change of environmental conditions and economic values of natural resources, the present study moves from the insights of the System of Environmental-Economic Accounting - Ecosystem Accounting to assess the economic value of the carbon sequestration and storage capacity of the Mediterranean-endemic seagrass P. oceanica at the Tremiti Islands Marine Protected Area. The economic value is compared across: i. the reference study by Pergent-Martini et al.; ii. the ecological condition-based approach; and iii. the unit value transfer. Based on the obtained outcomes, an ecosystem-based approach would prevent biases in the accounting of the ecosystem-service provision capacity of P. oceanica and help the policy maker to implement adequate public investment policies to mitigate its overall degradation.


Assuntos
Alismatales , Sequestro de Carbono , Ecossistema , Mar Mediterrâneo , Conservação dos Recursos Naturais , Mudança Climática , Monitoramento Ambiental/métodos
13.
Mar Environ Res ; 197: 106488, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38593646

RESUMO

Studies focusing on patterns of spatial variation in marine soft-bottom assemblages suggest that variability is mainly concentrated at small spatial scale (from tens of centimeters to few meters), but there is still a lack of knowledge about the consistency of this spatial pattern across habitats and seasons. To address this issue, we quantified the variability in the structure of macrozoobenthic assemblages and in the abundance of dominant macroinvertebrate species in the Mellah Lagoon (Algeria) at three spatial scales, i.e., Plot (meters apart), Station (10's m apart) and Site (kms apart) scale, in Ruppia maritima (Ruppia) beds and unvegetated sediments (Unvegetated), and in two dates in winter and two dates in summer 2016. Spatial variability of the most dominant bivalve Mytilaster marioni varied significantly between habitats, but consistent across the two seasons, with a more heterogeneous distribution in Ruppia than in Unvegetated at the Station scale. Furthermore, a second-order interaction among the hierarchical nature of spatial variability, season and habitat emerged for the assemblage structure. Spatial variability between habitats varied significantly in winter, with the largest variation at the Plot scale in Unvegetated and more heterogenous assemblages at the Plot and Site scales than at the Station scale in Ruppia, but did not vary in summer when most of the variance was at the Site scale. We demonstrate that the scales of influence of the processes operating in the Mellah Lagoon are contingent on the specific habitat and/or period of the year at which the study was conducted, highlighting the importance of examining all these sources of variation simultaneously to increase the accuracy of explanatory models derived from the observed patterns in sedimentary environments.


Assuntos
Alismatales , Biodiversidade , Animais , Estações do Ano , Invertebrados , Ecossistema
14.
Mar Drugs ; 22(3)2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38535471

RESUMO

The aim of the present study was to investigate the use of Posidonia oceanica for making products beneficial for human health. Firstly, we demonstrated that the antioxidant defense (i.e., SOD and APX activity) of P. oceanica's living leaves (LP) has low efficacy, as they partly neutralize the produced H2O2. However, high H2O2 levels led LP to produce, as a response to oxidative stress, high phenolic content, including chicoric acid, p-coumaric acid, caftaric acid, trans-cinnamic and rutin hydrate, as shown by UHPLC-DAD analysis. In addition, LP extracts inhibited intestinal cancer cell proliferation. Moreover, P. oceanica's beach casts consisting of either Wet 'Necromass' (WNP) or Dry 'Necromass' (DNP) were used for preparing extracts. Both DNP and WNP exhibited antioxidant and antiproliferative activities, although lower as compared to those of LP extracts. Although both P. oceanica's meadows and beach casts are considered priority habitats in the Mediterranean Sea due to their high ecological value, legislation framework for beach casts forbidding their removal is still missing. Our results suggested that both LP and DNP could be utilized for the production of high-added value products promoting human health, provided that a sustainability management strategy would be applied for P. oceanica's meadows and beach casts.


Assuntos
Alismatales , Antioxidantes , Humanos , Peróxido de Hidrogênio , Estresse Oxidativo , Intestinos , Transformação Celular Neoplásica
15.
Environ Pollut ; 348: 123814, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38499170

RESUMO

In the coastal environment, a large amount of microplastics (MPs) can accumulate in the sediments of seagrass beds. However, the potential impact these pollutants have on seagrasses and associated organisms is currently unknown. In this study, we investigated the differences in MPs abundance and composition (i.e., shape, colour and polymer type) in marine sediments collected at different depths (-5 m, -15 m, -20 m) at two sites characterized by the presence of Posidonia oceanica meadows and at one unvegetated site. In the vegetated sites, sediment samples were collected respectively above and below the upper and lower limits of the meadow (-5 m and -20 m), out of the P. oceanica meadow, and in the central portion of the meadow (-15 m). By focusing on the central part of the meadow, we investigated if the structural features (i.e. shoots density and leaf surface) can affect the amount of MPs retained within the underlying sediment and if these, in turn, can affect the associated benthic communities. Results showed that the number of MPs retained by P. oceanica meadows was higher than that found at the unvegetated site, showing also a different composition. In particular, at vegetated sites, we observed that MPs particles were more abundant within the meadow (at - 15 m), compared to the other depths, on unvegetated sediment, with a dominance of transparent fragments of polypropylene (PP). We observed that MPs entrapment by P. oceanica was accentuated by the higher shoots density, while the seagrass leaf surface did not appear to have any effect. Both the abundance and richness of macrofauna associated with P. oceanica rhizomes appear to be negatively influenced by the MPs abundance in the sediment. Overall, this study increases knowledge of the potential risks of MPs accumulation in important coastal habitats such as the Posidonia oceanica meadows.


Assuntos
Alismatales , Microplásticos , Plásticos , Meio Ambiente , Ecossistema , Alismatales/química , Mar Mediterrâneo
16.
Mar Environ Res ; 197: 106443, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38507985

RESUMO

Natural disturbances can produce a mosaic of seagrass patches of different ages, which may affect the response to herbivory. These pressures can have consequences for plant performance. To assess how seagrass patch age affects the response to herbivory, we simulated the effect of herbivory by clipping leaves of Halodule wrightii in patches of 2, 4 and 6 years. All clipped plants showed ability to compensate herbivory by increasing leaf growth rate (on average 4.5-fold). The oldest patches showed resistance response by increasing phenolic compounds (1.2-fold). Contrastingly, the concentration of phenolics decreased in the youngest patches (0.26-fold), although they had a similar leaf carbon content to controls. These results suggest that younger plants facing herbivory pressure reallocate their phenolic compounds towards primary metabolism. Results confirm the H. wrightii tolerance to herbivory damage and provides evidence of age-dependent compensatory responses, which may have consequences for seagrass colonization and growth in perturbed habitats.


Assuntos
Alismatales , Herbivoria , Ecossistema , Alismatales/fisiologia , Plantas , Folhas de Planta/metabolismo
17.
J Environ Manage ; 357: 120744, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38552518

RESUMO

Restoration of coastal ecosystems, particularly those dominated by seagrasses, has become a priority to recover the important ecosystem services they provide. However, assessing restoration outcomes as a success or failure remains still difficult, probably due to the unique features of seagrass species and the wide portfolio of practices used on transplanting actions. Here, several traits (maximum leaf length, number of leaves, leaf growth rate per shoot, and leaf elemental carbon and nitrogen contents) of transplanted seagrass Posidonia oceanica were compared to reference meadows in five sites of Western Mediterranean Sea in which restoration were completed in different times. Results have evidenced the resilience of transplanted P. oceanica shoots within a few years since restoration, as traits between treatments changed depending on the elapsed time since settlement. The highlighted stability of the restoration time effect suggests that the recovery of the plants is expected in four years after transplanting.


Assuntos
Alismatales , Resiliência Psicológica , Ecossistema , Mar Mediterrâneo
18.
Sci Rep ; 14(1): 5888, 2024 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-38467723

RESUMO

Among marine ecosystems globally, those in the Mediterranean Sea, are facing many threats. New technologies are crucial for enhancing our understanding of marine habitats and ecosystems, which can be complex and resource-intensive to analyse using traditional techniques. We tested, for the first time, an integrated multi-platform approach for mapping the coastal benthic habitat in the Civitavecchia (northern Latium, Italy) coastal area. This approach includes the use of an Unmanned Surface Vehicle (USV), a Remote Operated Vehicle (ROV), and in situ measurements of ecosystem functionality. The echosounder data allowed us to reconstruct the distribution of bottom types, as well as the canopy height and coverage of the seagrass Posidonia oceanica. Our study further involved assessing the respiration (Rd) and net primary production (NCP) rates of P. oceanica and its associated community through in situ benthic chamber incubation. By combining these findings with the results of USV surveys, we were able to develop a preliminary spatial distribution model for P. oceanica primary production (PP-SDM). The P. oceanica PP-SDM was applied between the depths of 8 and 10 m in the studied area and the obtained results showed similarities with other sites in the Mediterranean Sea. Though in the early stages, our results highlight the significance of multi-platform observation data for a thorough exploration of marine ecosystems, emphasizing their utility in forecasting biogeochemical processes in the marine environment.


Assuntos
Alismatales , Ecossistema , Mar Mediterrâneo , Itália
19.
Sci Rep ; 14(1): 6218, 2024 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-38486018

RESUMO

Posidonia oceanica meadows are the most productive coastal ecosystem in the Mediterranean. Posidonia oceanica seeds are enclosed in buoyant fleshy fruits that allow dispersal. Many fruits eventually strand on beaches, imposing a remarkable energy cost for the plant. This study aims to assess whether stranded seeds retain functional reproductive potential under a variety of environmental conditions. First, we measured the possibility that seeds could be returned to the sea, by tagging fruits and seeds. Second, we quantified the effect of air, sun and heat exposure on the viability and fitness of stranded fruits and naked seeds. The results showed that on average more than half of fruits and seeds are returned to the sea after stranding events and that fruits significantly protect from desiccation and loss of viability. Furthermore, in fruits exposed to the sun and in naked seeds, seedlings development was slower. This study indicates that a significant portion of stranded P. oceanica fruits have a second chance to recruit and develop into young seedlings, relieving the paradox of large energy investment in seed production and apparent low recruitment rate. Additionally, we provide practical indications for seed collection aimed at maximizing seedling production, useful in meadow restoration campaigns.


Assuntos
Alismatales , Frutas , Ecossistema , Sementes , Plântula
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...