Ecosystem (Spain)

Coastal tidal wetlands and estuaries play important roles in the global carbon budget by contributing to the net withdrawal of CO 2 from the atmosphere. We quantified the linkages between terrestrial and oceanic systems, marsh-to-bay carbon exchange, and the uptake of CO 2 from the atmosphere in the wetland-dominated Plum Island Sound (MA, USA) and Duplin River (GA, USA) estuaries. The C budgets revealed that autotrophic marshes [primary production:ecosystem respiration (P:R) ~1.3:1] are tightly coupled to heterotrophic aquatic systems (P:R ~0.6:1). Levels of marsh gross primary production are similar in these systems (865 ± 39 and 768 ± 74 gC m −2 year −1 in Plum Island and the Duplin, respectively) even though they are in different biogeographic provinces. In contrast to inputs from rivers and coastal oceans, tidal marshes are the dominant source of allochthonous matter that supports heterotrophy in aquatic systems. Dissolved inorganic carbon (DIC) exported from marshes to the coastal ocean was a major flux pathway in the Duplin River; however, there was no evidence of DIC export from Plum Island marshes and only minor export to the ocean. Burial was a sink for 53% of marsh net ecosystem production (NEP) on Plum Island, but only 19% of marsh NEP in the Duplin. Burial was the dominant blue carbon sequestration pathway at Plum Island, whereas in the Duplin, DIC and organic carbon export to the ocean were equally important. Regional- and continental-scale C budgets should better reflect wetland-dominated systems to more accurately characterize their contribution to global CO 2 sequestration.

This study was aimed to understand the difference in forest transpiration between slope positions, and to separate the contributions of main influencing factors, for improving the accuracy of forest transpiration estimation at slope scale by up-scalin

This study highlights the potential of aquariums as research platforms for bioacoustic research. Aquariums provide access to a wide variety of fish species, offering unique opportunities to characterize their acoustic features in controlled settings. In particular, we present a preliminary description of the acoustic characteristics of Myripristis jacobus, a soniferous species in the Holocentridae family, within a controlled environment at a zoological facility in the Canary Islands, Spain. Using two HydroMoth 1.0 hydrophones, we recorded vocalizations of the blackbar soldierfish in a glass tank, revealing a pulsed sound type with a peak frequency around 355 Hz (DS 64), offering a more precise characterization than previously available. The vocalizations exhibit two distinct patterns: short sequences with long pulse intervals and fast pulse trains with short inter-pulse intervals. Despite some limitations, this experimental setup highlights the efficacy of cost-effective methodologies in public aquariums for initial bioacoustic research. These findings contribute to the early stages of acoustic characterization of coastal fishes in the western central Atlantic, emphasizing the value of passive acoustic monitoring for ecological assessments and conservation efforts. Moreover, this study opens new avenues for considering the acoustic environment as a crucial factor in the welfare of captive fish, an aspect that has largely been overlooked in aquarium management.

Achieving high-fidelity image transmission through turbid media is a significant challenge facing both the AI and photonic/optical communities. While this capability holds promise for a variety of applications, including data transfer, neural endoscopy, and multi-mode optical fiber-based imaging, conventional deep learning methods struggle to capture the nuances of light propagation, leading to weak generalization and limited reconstruction performance. To address this limitation, we investigated the non-locality present in the reconstructed images and discovered that conventional deep learning methods rely on specific features extracted from the training dataset rather than meticulously reconstructing each pixel. This suggests that they fail to effectively capture long-range dependencies between pixels, which are crucial for accurate image reconstruction. Inspired by the physics of light propagation in turbid media, we developed a global attention mechanism to approach this problem from a broader perspective. Our network harnesses information redundancy generated by peculiar non-local features across the input and output fiber facets. This mechanism enables a two-order-of-magnitude performance boost and high fidelity to the data context, ensuring an accurate representation of intricate details in a pixel-to-pixel reconstruction rather than mere loss minimization.

The use of wavefront shaping has found extensive application to develop ultra-thin endoscopic techniques based on multimode optical fibers (MMF), leveraging on the ability to control modal interference at the fiber’s distal end. Although several techniques have been developed to achieve MMF-based laser-scanning imaging, the use of short laser pulses is still a challenging application. This is due to the intrinsic delay and temporal broadening introduced by the fiber itself, which requires additional compensation optics on the reference beam during the calibration procedure. Here we combine the use of a supercontinuum laser and an internal reference-based wavefront shaping system to produce focused spot scanning in multiple planes at the output of a step-index multimode fiber, without the requirement of a delay line or pulse pre-compensation. We benchmarked the performances of internal vs external reference during calibration, finding that the use of an internal reference grants better focusing efficiency. The system was characterized at different wavelengths, showcasing the wavelength resiliency of the different parameters. Lastly, the scanning of focal planes beyond the fiber facet was achieved by exploiting the chromato-axial memory effect.

Coastal sprawl is among the main drivers of global degradation of shallow marine ecosystems. Among artificial substrates, quarry rock can have faster recruitment of benthic organisms compared to traditional concrete, which is more versatile for construction. However, the factors driving these differences are poorly understood. In this context, this study was designed to compare the intertidal and subtidal benthic and epibenthic assemblages on concrete and artificial basalt boulders in six locations of Madeira Island (northeastern Atlantic, Portugal). To assess the size of the habitat, the shorelines in the study area were quantified using satellite images, resulting in >34 % of the south coast of Madeira being artificial. Benthic assemblages differed primarily between locations and secondarily substrates. Generally, assemblages differed between substrates in the subtidal, with lower biomass and abundance in concrete than basalt. We conclude that these differences are not related to chemical effects (e.g., heavy metals) but instead to a higher detachment rate of calcareous biocrusts from concrete, as surface abrasion is faster in concrete than basalt. Consequently, surface integrity emerges as a factor of ecological significance in coastal constructions. This study advances knowledge on the impact and ecology of artificial shorelines, providing a baseline for future research towards ecological criteria for coastal protection and management.

Abstract Water hyacinth, a plant considered highly invasive, is globally recognized for its detrimental impact on tropical freshwater ecosystems and economies. Its biology, sexual and asexual propagations, short life-cycle and abundant seed production, makes it difficult to control. Although physical removal is the common intervention, our current study in Lake Tana, Ethiopia, revealed its ineffectiveness. Despite a massive removal campaign that initially eliminated 75% (~ 1,271 ha) of water hyacinth in November-December 2020, we here show that the plant rebounded within a year, surpassing pre-intervention levels by 18%. Through SWOT analysis of various interventions, we show that short-term interventions are neither effective nor sustainable. Our analysis suggests that its proliferation in freshwaters is primarily driven by eutrophication rather than traditional mechanisms of invasion. We propose a sustainable solution centered around improving water quality through continuous removal of water hyacinth, utilizing phytoremediation to extract nutrients, and implementing catchment management to minimize nutrient influx.

Abstract Ancient bacteria largely lived and flourished as free-living cells till the rise of eukaryotes triggered their adaptation to a new habitat: the intracellular milieu. Rickettsiales bacteria are the most prevalent intracellular microorganisms discovered and the culprits behind some of mankind’s worst pestilential diseases. Here, we show that intracellularity is not a defining feature of the group and describe the eco-evolutionary processes that transformed harmless free-living bacteria into obligate intracellular symbionts and parasites. We found that the evolution of free-living lineages towards enhanced cross-feeding interactions with microbial eukaryotes trapped them in a nutritional bind to their trophic partners. We discovered that the oldest Rickettsiales lineages are the closest relatives to modern eukaryotes and are enriched in proteins predicted to have been present in the mitochondrial ancestor. This study not only opens avenues for the detection and surveillance of emerging diseases but also expands our understanding of the origins of complex life.One-Sentence SummaryCross-feeding interactions shaped Rickettsiales genomic architectures along the parasite/free-living spectrum

Abstract. Quantification of land surface-atmosphere fluxes of carbon dioxide (CO2) fluxes and their trends and uncertainties is essential for monitoring progress of the EU27+UK bloc as it strives to meet ambitious targets determined by both international agreements and internal regulation. This study provides a consolidated synthesis of fossil sources (CO2 fossil) and natural sources and sinks over land (CO2 land) using bottom-up (BU) and top-down (TD) approaches for the European Union and United Kingdom (EU27+UK), updating earlier syntheses (Petrescu et al., 2020, 2021b). Given the wide scope of the work and the variety of approaches involved, this study aims to answer essential questions identified in the previous syntheses and understand the differences between datasets, particularly for poorly characterized fluxes from managed ecosystems. The work integrates updated emission inventory data, process-based model results, data-driven sectoral model results, and inverse modeling estimates, extending the previous period 1990–2018 to the year 2020 to the extent possible. BU and TD products are compared with European National Greenhouse Gas Inventories (NGHGIs) reported by Parties including the year 2019 under the United Nations Framework Convention on Climate Change (UNFCCC). The uncertainties of the EU27+UK NGHGI were evaluated using the standard deviation reported by the EU Member States following the guidelines of the Intergovernmental Panel on Climate Change (IPCC) and harmonized by gap-filling procedures. Variation in estimates produced with other methods, such as atmospheric inversion models (TD) or spatially disaggregated inventory datasets (BU), originate from within-model uncertainty related to parameterization as well as structural differences between models. By comparing NGHGIs with other approaches, key sources of differences between estimates arise primarily in activities. System boundaries and emission categories create differences in CO2 fossil datasets, while different land use definitions for reporting emissions from Land Use, Land Use Change and Forestry (LULUCF) activities result in differences for CO2 land. The latter has important consequences for atmospheric inversions, leading to inversions reporting stronger sinks in vegetation and soils than are reported by the NGHGI. For CO2 fossil emissions, after harmonizing estimates based on common activities and selecting the most recent year available for all datasets, the UNFCCC NGHGI for the EU27+UK accounts for 3392 ± 49 Tg CO2 yr-1 (926 ± 13 Tg C yr-1), while eight other BU sources report a mean value of 3340 [3238,3401] [25th,75th percentile] Tg CO2 yr-1 (948 [937,961] Tg C yr-1). The sole top-down inversion of fossil emissions currently available accounts for 3800 Tg CO2 yr-1 (1038 Tg C yr-1), a value close to that of the NGHGI, but for which uncertainty estimates are not yet available. For the net CO2 land fluxes, during the most recent five-year period including the NGHGI estimates, the NGHGI accounted for -91 ± 32 Tg C yr-1 while six other BU approaches reported a mean sink of -62 [-117,-49] Tg C yr-1 and a 15-member ensemble of dynamic global vegetation models (DGVMs) reported -69 [-152,-5] Tg C yr-1. The five-year mean of three TD regional ensembles combined with one non-ensemble inversion of -73 Tg C yr-1 has a slightly smaller spread (0th–100th percentile of [-135,45] Tg C yr-1), and was calculated after removing land-atmosphere CO2 fluxes caused by lateral transport of carbon (crops, wood trade and inland waters) resulting in increased agreement with the the NGHGI and bottom-up approaches. Results at the sub-sector level (Forestland, Cropland, Grassland) show generally good agreement between the NGHGI and sub-sector-specific models, but results for a DGVM are mixed. Overall, for both CO2 fossil and net CO2 land fluxes, we find current independent approaches are consistent with the NGHGI at the scale of the EU27+UK. We conclude that CO2 emissions from fossil sources have decreased over the past 30 years in the EU27+UK, while large uncertainties on net uptake of CO2 by the land surface prevent trend identification. In addition, a gap on the order of 1000 Tg C yr-1 between CO2 fossil emissions and net CO2 uptake by the land exists regardless of the type of approach (NGHGI, TD, BU), falling well outside all available estimates of uncertainties. However, uncertainties in top-down approaches to estimate CO2 fossil emissions remain uncharacterized and are likely substantial. The data used to plot the figures are available at https://doi.org/10.5281/zenodo.7365863.