17 research outputs found

    Ventilation Systems in Wetland Plant Species

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    Molecular oxygen and carbon dioxide may be limited for aquatic plants, but they have various mechanisms for acquiring these gases from the atmosphere, soil, or metabolic processes. The most common adaptations of aquatic plants involve various aerenchymatic structures, which occur in various organs, and enable the throughflow of gases. These gases can be transferred in emergent plants by molecular diffusion, pressurized gas flow, and Venturi-induced convection. In submerged species, the direct exchange of gases between submerged above-ground tissues and water occurs, as well as the transfer of gases via aerenchyma. Photosynthetic O2 streams to the rhizosphere, while soil CO2 streams towards leaves where it may be used for photosynthesis. In floating-leaved plants anchored in the anoxic sediment, two strategies have developed. In water lilies, air enters through the stomata of young leaves, and streams through channels towards rhizomes and roots, and back through older leaves, while in lotus, two-way flow in separate air canals in the petioles occurs. In Nypa Steck palm, aeration takes place via leaf bases with lenticels. Mangroves solve the problem of oxygen shortage with root structures such as pneumatophores, knee roots, and stilt roots. Some grasses have layers of air on hydrophobic leaf surfaces, which can improve the exchange of gases during submergence. Air spaces in wetland species also facilitate the release of greenhouse gases, with CH4 and N2 O released from anoxic soil, which has important implications for global warming

    Distribution of the macrophyte communities in the Danube reflects river serial discontinuity

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    The Danube is the second-longest river in Europe that is subjected to various man-made alterations, including those related to hydro-power plants. We surveyed and analyzed the presence and abundance of macrophytes in the main channel from 2582 river kilometers (rkm) to 171 rkm. We also assessed selected habitat parameters in the sampled river stretches. Sixty-eight different plant species were recorded along the entire course. Among neophytes, we found Elodea nuttallii, E. canadensis, Vallisneria spiralis and Azolla filiculoides. Based on similarity analysis, we distinguished 15 plant communities, most of which were defined as associations, which were classified into 5 alliances and represented three vegetation classes, namely vegetation of rooted hydrophytes Potamogetonetea, the vegetation of pleustophytes Lemnetea and vegetation of marshes Phragmitetea. The number and abundance of plant species, as well as plant communities recorded in single stretches, varied along the course. Canonical correspondence analysis (CCA) revealed that environmental parameters explained 21% of plant species composition. CCA runs with neophytes explained 41% of the variance, and current velocity, water transparency, species number and bank structure were significant variables. The present study revealed that the free-running sections of the river are poor in number and abundance of plant species, whereas impounded reaches mainly show an opposite result

    The combined effect of water limitation and UV-B radiation on common and tartary buckwheat

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    The effects of elevated UV-B radiation and water limitation have been evaluated in terms of the biochemical, physiological, morphological and productivity responses of common buckwheat (Fagopyrum esculentum Moench) and tartary buckwheat (Fagopyrum tataricum Gaertn.). Research was carried out under semi-controlled conditions. Common and tartary buckwheat were exposed to UV-B radiation and water limitation in different combinations. Photosynthetic pigments, UV-absorbing compounds, potential and effective photochemical efficiency, stomatal conductance, plant morphology and biomass production were monitored. The negative effect of elevated UV-B radiation on growth parameters in common buckwheat was highly significant in watered plants but less pronounced in plants exposed to water limitation. However, in tartary buckwheat UV-B radiation mitigated the negative effects of water limitation, resulting in increased biomass production

    Saving lives and saving the planet: The readiness of Ireland's healthcare manufacturing sector for the circular economy

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    Healthcare manufacturing is one of the leading creators of single-use products in Ireland and accounts for 11% of waste generated. Industry and businesses can play a significant role in tackling unsustainable production and consumption levels. Circular Economy (CE) practices could play a major role in the sustainability of health care and medical device manufacturing. This study aimed to develop an understanding of the current state of these company s readiness for the Circular Economy. An online survey was carried out with key employees in this industry to understand their perception of CE and what might drive more circular models. This study found that there was very little knowledge of CE within this industry. Despite this, some aspects of CE had been implemented, driven by cost saving initiatives. The barriers to implementation identified included a lack of prioritization and funding to develop more sustainable models of production. It was also found that financial assistance (e.g. grants) together with policy and legislation could unlock opportunities to develop a more circular model. This study adds to the limited empirical literature on CE barriers and opportunities to manufacturing organisations operating in Ireland.peer-reviewed2021-09-1
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