This study investigates the spatio-temporal, trait-based distribution and functioning of Posidonia oceanica meadows in the Mediterranean Sea, utilizing benthic chambers to upscale ecosystem services predictions. Posidonia meadows are critical for marine biodiversity, nutrient cycling, and carbon sequestration. We conducted in-situ metabolic measurements of Posidonia meadows in the northern Tyrrhenian Sea, integrating these with remote sensing data to develop predictive models of key metabolic traits under current and future climate scenarios. The Net Community Production (NCP) was used to assess community metabolism, constructing Thermal Performance Curves (TPC) for Posidonia habitat. Results showed that Posidonia meadows exhibit autotrophic metabolism year-round, with optimal performance at 23°C and upper thermal limits at 35°C. Spatial predictions indicated seasonal variations in metabolic performance, with significant future changes due to rising temperatures. Our findings highlight the essential role of Posidonia meadows in providing ecosystem services, such as oxygen production, CO₂ absorption, and carbon fixation, which are projected to increase under moderate warming scenarios. However, the meadows may face performance declines during the warmest periods, particularly in the central-western Mediterranean, potentially impacting local fisheries and ecosystem stability. This study underscores the need for conservation efforts to preserve Posidonia habitats, integrating high-resolution data into ecosystem management strategies to mitigate climate change impacts. By providing a comprehensive understanding of the metabolic responses of Posidonia meadows to varying temperature regimes, this research contributes to the broader effort of forecasting the ecological consequences of global warming on marine ecosystems. It also emphasizes the importance of adaptive management strategies that can enhance the resilience of these vital habitats, ensuring the sustained provision of their ecosystem services in the face of environmental change.

The endemic seagrass of the Mediterranean Sea Posidonia oceanica forms extensive beds, considered among the most complex and productive marine ecosystems. They are also defined as priority habitats by the European Community Directive 92/43 on the Conservation of Natural Habitats and of Wild Fauna and Flora.

The balance between primary production and remineralization governs the cycle of these ecosystems, especially considering that most of their production plays a role as necromass. The fate this necromass may endure is highly variable. Indeed, once being shed from the original bed, the destination of the dead biomass depends on the major driving forces acting on the bed (e.g., hydrodynamic characteristics and coastline conformation). Consequently, the necromass is exported towards other locations, leading to the formation of deposits both offshore (the neglected “maceration sites”) and onshore (the so-called “banquettes”). They both constitute an important carbon stock and a source for detrital food webs, also providing valuable ecosystem services (e.g., sediment retention and protection from coastal erosion).

In this study, we investigated the fate of the primary production in a P. oceanica bed off the Ischia Island (Southern Italy). Three different compartments were considered: (i) the living bed, (ii) the maceration site, and (iii) the banquette.

The aim was firstly to assess and quantify the associated carbon pools (gC m-3). Furthermore, the purpose was also to investigate and possibly to determine their fluxes among the three different compartments using ecosystem accounting.

Beside the well-known importance of the living seagrass beds, results shed light on the key role of the overlooked necromass of Posidonia oceanica in the blue carbon cycle.

The interactions between abiotic and biotic components within ecosystems generate functions that provide a wide range of ecosystem services vital for human well-being. The ecosystem services provided by coastal and marine ecosystems are increasingly recognized, especially for highly productive habitats such as mangrove forests and seagrass beds. However, some key vegetated ecosystems, like rhodolith beds, remain overlooked. Rhodolith beds are biogenic calcareous habitats formed by the aggregation of unattached, non-geniculate coralline algae. These beds are distributed worldwide and, due to their 3D structural complexity, host a high biodiversity of benthic microalgae, fleshy macroalgae, zoobenthos, and fishes, also of commercial interest. Rhodolith beds are also relevant in the blue carbon cycle through their role in carbon sequestration and carbonate production, even if their real contribution to climate regulation has still to be deeply understood. Indeed, although several studies address the functional role of rhodolith beds, there is an urgent need to link this knowledge to the supply of ecosystem services. This study aims to provide an overview of rhodolith bed ecosystem services according to the CICES classification (i.e., provisioning, regulation and maintenance, and cultural), also investigating supporting services (i.e., ecological functions) for their crucial role in generating all the other ecosystem services. Rhodolith beds are vulnerable to various anthropogenic threats on both global (e.g., climate change) and local (e.g., fishing) scale. Consequently, negative impacts on rhodolith beds may undermine their ability to provide these essential services. In this scenario, it is crucial to assess how the ecosystem services provided by rhodolith beds are changing in response to global environmental changes. This overview will offer useful insights for the management and conservation of these important yet vulnerable marine ecosystems.

Trees and green spaces are crucial elements for urban quality of life. Beyond their presence and abundance, species diversity and urban distribution of city trees are also important. These characteristics help to inform the status of urban ecosystems, ecosystems services supply, and management. They also serve as inputs in ecological models supporting decision-making on urban tree management and ecosystem services. Here, we aim to map and analyze tree species, age, morphological characteristics and diversity attributes in the municipality of Milan in relation to contextual factors, and to assess whether there are variations. We used a dataset of public trees provided by Milan municipality. Analyses were conducted city-wide and partitioning Milan into a uniform grid. Particular attention was paid to assess whether there were significant differences between trees within and outside parks. Among other aspects, we identified dominant species, calculated indices of species diversity and similarity and studied age and size trends by tree species. In terms of dominant species, differences emerged between trees within parks and outside parks. For example, Quercus trees are only predominant in parks, mainly in the form of young individuals; in contrast, Platanus x acerifolia is mainly found outside parks, and composed of most individuals that are over 30 years old. DBH versus age plots confirmed that there is a linear growth relationship for most species, indicating continuous growth. In contrast, crown diameter versus age plots show an unnatural saturation, especially clear in trees outside parks, which plausibly results from established management practices. These findings provide insights into the current distribution of public trees in Milan and provide in situ allometric relationships for several species’ morphological attributes. This information could be useful to inform future planning and management actions, as well as ecological models supporting such actions aimed at enhancing urban ecosystem and biodiversity conditions.