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Abstract: The xylem and phloem anatomy of co-existing tree species provides valuable information on how different tree species face climate change and adjust their vascular structure to local weather conditions. We examined and compared annual ring widths and conduit size in earlywood and early phloem in Fraxinus ornus, Quercus pubescens and Ostrya carpinifolia in a sub-Mediterranean site in the period 2019–2021. The selected xylem and phloem traits were correlated with monthly weather conditions (precipitation and temperature). We found that phloem increment widths and conduits in earlywood and early phloem in the studied tree species showed different trends in terms of interannual variability and in relation to local weather conditions. In F. ornus, May conditions affected xylem traits, while June conditions phloem traits. In Q. pubescens, winter and March precipitation was related to phloem development. In O. carpinifolia, xylem ring width was positively correlated with June precipitation, while early phloem conduits were negatively affected by April temperature. Only two consistent patterns were detected across the species and years studied: wider xylem increments compared to phloem increments, and wider earlywood vessels compared to early phloem sieve tubes. Statistically significant differences were observed among species across all years for the size of xylem and phloem conduits and the hydraulic conductivity of earlywood vessels, which indicates great differences in the calculated hydraulic conductivity among the tree species. To summarize, hydraulic conductivity of earlywood vessels in Q. pubescens was on average for all three years 10.4 -times and 114-times larger than in F. ornus and O. carpinifolia, respectively. High interannual variability and species-specific sensitivity of xylem and phloem traits to precipitation and temperature confirm high plasticity and different radial growth strategies of the studied tree species to ensure optimal functioning under local weather conditions.
Keywords: manna ash, pubescent oak, European hop-hornbeam, earlywood, early phloem, wood anatomy, sub-Mediterranean
Published in DiRROS: 12.02.2026; Views: 35; Downloads: 12
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Abstract: Sorrento Peninsula, together with an outpost at the top of the Picentini Mountains, is rich in local endemics and has been well studied from a taxonomical perspective. The vegetation is instead poorly known, particularly the plant assemblages of rock cliffs. In this paper, we present the phytosociological insights on cliff-dwelling communities of rocky ranges in the top of Sorrento Peninsula (600-1800 m a.s.l.). We carried out 28 relevés (8 already published) and conducted multivariate analyses to classify the vegetation. We analysed the bioclimatic context of the relevés with Rivas-Martínez indexes and carried out a comparison with other rock vegetation from the Central Mediterranean. We found three clusters that we classified into 2 associations, one of which is further divided into two sub-associations (Globulario neapolitanae-Loniceretum stabianae typicum Fanelli et al. 2020; Globulario neapolitanae-Loniceretum stabianae globularietosum neapolitanae subass. nova; Diantho virginei-Seselietum polyphylli ass. nova). We refer this vegetation to a new alliance, Lonicerion stabianae all. nova, distinguished from the other rock vegetation of the Central Mediterranean because develops in an intermediate range between the mediterranean, temperate and weakly continental climate. Sorrento Peninsula and the cliffs at the top of Picentini Mountains are characterised by endemic cliff vegetation, rich in exclusive taxa. We suggest that it represents a distinct phytogeographical sector in the context of the Italian Peninsula.
Keywords: casmophytic vegetation, Mediterranean, phytogeography, rock vegetation, Southern Italy, syntaxonomy
Published in DiRROS: 23.01.2026; Views: 182; Downloads: 84
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Abstract: Marine ecosystems are healthy with a high degree of biodiversity. Assessing how factors affect spatial and temporal patterns of biodiversity is an essential task for the Ecosystem Based Management approach. In this work, we investigated the effect of fisheries disturbance and ocean variables in determining α- and β-diversity of Mediterranean demersal assemblages. Generalized additive mixed models were used to explain the spatio-temporal variability of diversity indices from 2014 to 2020 in three Mediterranean subregions as a function of covariates. An in-depth analysis also made it possible to decouple the effects of bottom trawling from the other covariates. The results show that several fishing activities and environmental variables influence biodiversity, but the direction of change depends on the subregion considered. Bottom trawling instead has a quasi-linear erosion effect on α- and β-diversity in all areas. Valuable commercial species and threatened rays and sharks importantly characterized the sites with low fishing impact. Results are a step towards the development of conservation and management strategies, particularly in the context of the Marine Strategy.
Keywords: biodiversity, fishing, Mediterranean sea, marine strategy
Published in DiRROS: 28.10.2025; Views: 361; Downloads: 150
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Abstract: Mediterranean brown algal forests, dominated by Cystoseira sensu lato species, are undergoing widespread decline due to the cumulative effects of anthropogenic pressure and climate-related stressors. Restoration efforts increasingly rely on ex situ cultivation and outplanting of seedlings, yet early developmental stages often suffer from low survival and growth rates. This study investigated the potential of algal extracts to enhance the seedling development and survival in two canopy-forming species, Gongolaria barbata and Ericaria crinita. We tested extracts from a cyanobacterium (Trichormus variabilis), two microalgae (Desmodesmus sp. and Cylindrotheca closterium), and a commercial macroalgal formulation (AlgatronCifo®) at varying concentrations under controlled mesocosm conditions. Seedling performance was significantly influenced by extract type, and target species identity. Notably, a low-concentration Desmodesmus sp. extract (0.07 mg mL− 1 ) improved survival and growth, whereas T. variabilis exerted an inhibitory effect on G. barbata. AlgatronCifo® did not outperform Desmodesmus sp. extract in promoting seedling development. These findings suggest that specific extracts from green microalgae could improve protocols for the early stages of restoration, offering a scalable tool for rehabilitating degraded marine forests. However, the results underscore the importance of species-specific optimization and the need for in situ validation of biostimulant-based restoration approaches.
Keywords: Cystoseira s.l., seaweed biostimulants, microalgal extracts, seedling development, restoration, Mediterranean sea
Published in DiRROS: 22.09.2025; Views: 405; Downloads: 196
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Keywords: biodiversity, phytoplankton, zooplankton, expert group, Mediterranean Sea
Published in DiRROS: 15.04.2025; Views: 651; Downloads: 0
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