Search results for " ECOLOGIA"
showing 10 items of 756 documents
Ocean acidification as a driver of community simplification via the collapse of higher-order and rise of lower-order consumers
2017
AbstractIncreasing oceanic uptake of CO2 is predicted to drive ecological change as both a resource (i.e. CO2 enrichment on primary producers) and stressor (i.e. lower pH on consumers). We use the natural ecological complexity of a CO2 vent (i.e. a seagrass system) to assess the potential validity of conceptual models developed from laboratory and mesocosm research. Our observations suggest that the stressor-effect of CO2 enrichment combined with its resource-effect drives simplified food web structure of lower trophic diversity and shorter length. The transfer of CO2 enrichment from plants to herbivores through consumption (apparent resource-effect) was not compensated by predation, becaus…
Happy birthday Hydrobiologia! 70 years young and still growing…
2018
Hydrobiologia started its existence in March 1948 by publishing a first volume of 476 pages, and already then focused on the biology and ecology of aquatic organisms. After 70 years, the focus of the journal is still similar, but the diversity of approaches increased during the seven decades of its existence. To celebrate the 70 years of Hydrobiologia, we here address some emerging trends in the history of publications in Hydrobiologia.
Influence of ambient temperature on the photosynthetic activity and phenolic content of the intertidal Cystoseira compressa along the Italian coastli…
2019
Understanding the physiological responses of intertidal seaweeds to environmental factors is fundamental to characterize their local physiological adaptation and success in the face of climate change. We measured the photosynthetic activity and the total phenolic content of the intertidal alga Cystoseira compressa and explored their relationship with latitude or local ambient air and seawater temperatures. Our results show that, when submerged, the photosynthetic activity of C. compressa showed values typical for non-stressed thalli, and the seawater temperatures found across sites explained the variability of these values. We observed a decrease in the photosynthetic activity of C. compres…
Past cover modulates the intense and spatially structured natural regeneration of woody vegetation in a pastureland
2020
Made available in DSpace on 2020-12-12T02:34:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-01 Università degli Studi di Palermo Ministero dell’Istruzione, dell’Università e della Ricerca Vegetation natural regeneration after agricultural abandonment is changing the landscape patterns in many areas worldwide. However, the expansion rate, spatio-temporal dynamics, and the role of past vegetation cover in shaping such patterns are still barely quantified in fine and meso scales. Here, we aim to quantify the expansion rate and assess the spatio-temporal patterns and the effects of past cover on natural woody vegetation cover increase. We sampled woodland and shrubland cover from …
Different invasibility of permanent and temporary waterbodies in a semiarid Mediterranean Island
2019
Nonindigenous species (NIS) represent a threat to aquatic biodiversity worldwide. However, freshwater ecosystems in drylands are potentially more prone to biological invasions than those located in temperate regions because of the higher number of artificial waterbodies generally occurring in these areas, which might act as invasion hubs for NIS. We review the available information about NIS in Sicilian waterbodies, discuss the role exerted by artificial lakes and ponds in facilitating the establishment of NIS in arid and semiarid areas, and compare the invasibility of permanent and temporary waterbodies in drylands. Artificial waterbodies increase the target-area effect for dispersers and …
Geospatial modelling and map analysis allowed measuring regression of the upper limit of Posidonia oceanica seagrass meadows under human pressure
2018
Abstract Marine coastal ecosystems are facing structural and functional changes due to the increasing human footprint worldwide, and the assessment of their long-term changes becomes particularly challenging. Measures of change can be done by comparing the observed ecosystem status to a purposely defined reference condition. In this paper, a geospatial modelling approach based on 2D mapping and morphodynamic data was used to predict the natural position of the upper limit (i.e., the landward continuous front) of Posidonia oceanica seagrass meadows settled on soft bottom. This predictive model, formerly developed at the regional spatial scale, was here applied for the first time at the Medit…
Decomposition rate and invertebrate colonization of seagrass detritus along a hydrodynamic gradient in a Mediterranean coastal basin: The Stagnone di…
2019
International audience; Seagrass leaf litter decomposition is a key component of marine carbon flow driven by both biotic and abiotic factors, including water movement. In this study, we analyse Posidonia oceanica litter decomposition and invertebrate colonization in three sites with different hydrodynamics in a coastal basin. Litterbags were put on the sea bed along a gradient of distance from the open sea, implying a different level of water exchange. Leaf litter mass loss and carbon and nitrogen concentration were analysed, and density and biomass of benthic invertebrates colonizing litterbags were recorded after 3, 7, 14, 47, 101, 152 and 221 days. Results showed that in the most shelte…
Seagrass meadows at the extreme of environmental tolerance: the case ofPosidonia oceanicain a semi-enclosed coastal lagoon
2009
Atoll-like structures of the endemic Mediterranean seagrass Posidonia oceanica were encountered in the innermost area of the Stagnone di Marsala, a semi-enclosed coastal lagoon along the western coasts of Sicily. The area is characterized by limited water exchange with the open sea and by a marked seasonal variation of water salinity and temperature, reaching beyond the theoretical tolerance limits of the species. In the present study we determined the genetic composition of the atoll-like structures, as well as the growth performance and flowering rate of these stands. We also assessed whether and to what extent the atoll-like structures are genetically isolated from plants growing in mead…
Microplastics and the functional traits of fishes: A global meta‐analysis
2021
Over the years, concern about the effects of microplastics has grown. Here, we answered the main question “What are the impacts of microplastics on the functional traits of fish species?” through a meta-analysis. The general impact of microplastic exposure on the functional traits of fishes and specifically on eight variables, namely, behaviour, development, fecundity, feeding, growth, health, hatching and survival was explored. Subgroup analyses were performed to detect correlations between the impact of microplastics and the following factors: species, life stage, habitat, water column habitat, day of exposure to microplastics and microplastic size, type and shape. A meta-regression analy…
An energy budget for the subtidal bivalve Modiolus barbatus (Mollusca) at different temperatures
2011
Clearance rates, respiration rates and food absorption efficiencies of the commercially interesting subtidal bivalve Modiolus barbatus were measured at different temperatures under laboratory conditions and scope for growth calculated. Clearance rates were highest at temperatures from 20 °C to 28 °C, whereas respiration rate was maximal at 9 °C and minimal at 26 °C. Highest mean values of absorbed energy occurred at 20 °C and 26 °C. Scope for growth trend had negative values at 9 °C, 15 °C and 28 °C and positive values at temperatures 20 °C and 26 °C. The profitable thermal window for M. barbatus to have energy sufficient for growth and reproduction corresponded to <5 months per year. Seawa…