134 research outputs found

    Lichen and lichenicolous fungal communities tested as suitable systems for the application of cross-taxon analysis

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    Lichens are outstanding examples of fungal symbioses, forming long-lived structures, the lichen thalli in which a multiplicity of other microorganisms are hosted. Among these, microfungi seem to establish diverse trophic relationships with their lichen hosts. The most specialised of these fungi are the parasitic lichenicolous fungi. of which the diversity has hardly been explained as a proxy for the diversity of lichen species. Here, we used an exemplar dataset of a well-studied alpine lichen community composed of 63 lichen and 41 lichenicolous fungal species and tested it to verify the strength of the co-occurrences of the two species groups with predictive co-correspondence analyses. The results showed that the distribution of lichen abundances affect the abundance and variation of lichenicolous fungi and support our hypothesis to use lichens as surrogate for lichenicolous fungi in the surrogacy analysis

    A simplified framework for fast and reliable measurement of leaf turgor loss point

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    Drought tolerance shapes the distribution of plant species, and it is mainly determined by the osmotic potential at full turgor (\u3c00) and the water potential at turgor loss point (\u3a8tlp). We provide a simplified framework for \u3c00 and \u3a8tlp measurements based on osmometer determination of \u3c00 (\u3c00_osm). Specifically, we ran regression models to i) improve the predictive power of the estimation of \u3c00 from \u3c00_osm and morpho-anatomical traits; ii) obtain the most accurate model to predict \u3a8tlp on the basis of the global relationship between \u3c00 and \u3a8tlp. The inclusion of the leaf dry matter content (LDMC), an easy-to-measure trait, in the regression model improved the predictive power of the estimation of \u3c00 from \u3c00_osm. When \u3c00_osm was used as a simple predictor of \u3a8tlp, discrepancies arose in comparison with global relationship between \u3c00 and \u3a8tlp. \u3a8tlp values calculated as a function of the \u3c00 derived from \u3c00_osm and LDMC (\u3c00_fit) were consistent with the global relationship between \u3c00 and \u3a8tlp. The simplified framework provided here could encourage the inclusion of mechanistically sound drought tolerance traits in ecological studies

    Shift in proximate causes of mortality for six large migratory raptors over a century

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    Delayed maturity and low reproductive rate make raptors naturally sensitive to high mortality rates, yet a wide variety of human-related threats negatively affect their population dynamics and persistence over time. We modelled the variability in the proximate causes of mortality associated with six species of large migratory raptors characterized by different ecological traits. We tested the hypothesis that species-specific mortality signals occur owing to differential exposure to threats in space and time. We relied on an unprecedently large dataset of ring (band) recovery (31269 records) over a period of > 100 years. Our findings suggested that mortality of these birds has declined dramatically since the late 1970s. We found species-specific seasonal patterns of mortality, with higher mortality rates during early life-stages. For Black Kite, Common Buzzard, and Osprey, mortality increased with distance travelled and decreased with distance from migratory bottlenecks. Human-related mortality was higher than natural mortality (47% vs 5.6%), but after 1979 indirect anthropogenic factors increased, while direct ones decreased. Raptors showed differential specific exposure to mortality causes (direct human: Honey Buzzard, Marsh Harrier; indirect human: Common Buzzard, Black Kite; direct and indirect human: Osprey; natural: Montagu\u2019s Harrier). Conservation efforts and international laws have helped lower mortality caused directly by humans, but new emerging human-related threats are impacting migratory raptors and call for advanced conservation efforts. In a fast-changing world, anticipating future threats is key to stemming losses and boosting future preservation

    Make it simpler: alien species decrease functional diversity of coastal plant communities

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    Questions: 1) Are there differences in abundance-weighted functional trait values between native and alien species in coastal plant communities? 2) Which functional traits are associated with a higher level of invasion in these communities? 3) Do functional diversity patterns differ between native and alien species? 4) Is alien species occurrence linked to small-scale functional homogenization effects on the resident native species? Location: N-Adriatic coastal ecosystems (Marano and Grado lagoon, Friuli Venezia Giulia region, Italy) Methods: We sampled coastal vegetation within two habitats (foredunes and saltmarshes) along 9 belt transects in two sampling sites. Plant species richness and abundance were assessed in 128 plots along with a suite of plant functional traits. We tested for differences in CWMs between native and alien species within the two habitats, and a Linear Mixed Model (LMMs) provided insights on traits fostering the invasion success among alien species. To check for potential functional homogenization driven by alien species invasion, we explored functional diversity patterns of native and alien species (alpha and beta functional diversity) and the relationship between alpha functional diversity and alien cover. Results: Alien species had lower functional diversity than natives and were characterized by lower leaf construction costs coupled with lower drought resistance and higher water transport efficiency. The most abundant aliens were the ones minimizing carbon investment for leaf construction. In addition, we also found evidence for small-scale functional homogenization driven by alien invasion. Conclusions: Our results suggested that native species adopt a resource conservative strategy whereas alien species are characterized by a higher resource acquisition capacity (i.e. acquisitive strategy). Our data also confirmed that alien species are less functionally diverse than natives, Functional diversity of coastal plant communities potentially driving the community towards small-scale functional homogenization, resulting in a loss of species and a reduction in the functional space

    Forensic botany as a useful tool in the crime scene: report of a case

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    The ubiquitous presence of plant species makes forensic botany useful for many criminal cases. Particularly, bryophytes are useful for forensic investigations because many of them are clonal and largely distributed. Bryophyte shoots can easily become attached to shoes and clothes and it is possible to be found on footwear, providing links between crime scene and individuals. We report a case of suicide of a young girl happened in Siena, Tuscany, Italia. The cause of traumatic injuries could be ascribed to suicide, to homicide, or to accident. In absence of eyewitnesses who could testify the dynamics of the event, the crime scene investigation was fundamental to clarify the accident. During the scene analysis, some fragments of Tortula muralis Hedw. and Bryum capillare Hedw were found. The fragments were analyzed by a bryologists in order to compare them with the moss present on the stairs that the victim used immediately before the death. The analysis of these bryophytes found at the crime scene allowed to reconstruct the accident. Even if this evidence, of course, is circumstantial, it can be useful in forensic cases, together with the other evidences, to reconstruct the dynamics of events

    Drivers of distance‐decay in bryophyte assemblages at multiple spatial scales: Dispersal limitations or environmental control?

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    Questions: Despite the increasing scientific interest in distance decay of compositional similarity in ecology, the scale dependence of geographical versus environmental control on distance decay of biological communities has not been properly addressed so far. The present work highlights the relative importance of niche-based processes versus dispersal limitations on distance decay patterns of epilithic bryophyte assemblages at different spatial scales. Location: Serra de Sintra, central Portugal. Methods: We adopted a nested sampling design with 32 selected sampling sites in each of which two clusters, each with five rocks, were surveyed. Each cluster was characterized by a set of 15 macroscale variables, which were divided into environmental and anthropogenic. For each rock eight microscale variables were recorded. Partial Mantel tests were used to assess the relative importance of geographical and environmental distance on community dissimilarity for each grain size (site, cluster, rock). Quantile regressions were used to describe the decay patterns of community similarity with respect to geographical and environmental distances. Ordination analyses and variation partitioning techniques were applied to assess the pure and shared effects of measured variables on bryophyte community composition. Results: Environmental distance based upon macroscale predictors was significantly correlated to community similarity, while no significant correlation was found for ecological distance calculated for microscale predictors, except at the largest grain size. The decrease of community similarity with geographical and environmental distance was thus consistently strengthened with increasing sample grain. Compositional variation was best explained by anthropogenic variables. Conclusions: The relative importance of environmental versus geographical distance on compositional similarity in epilithic bryophyte communities varies with the spatial scale of the predictors and with the sample grain. The decrease of similarity with increasing distance is related to changes in habitat features, especially those driven by human disturbance, while it is weakly affected by variations in substrate features.info:eu-repo/semantics/publishedVersio

    The Impact of Beehive Proximity, Human Activity and Agricultural Intensity on Diptera Diversity in a Mediterranean Mosaic of Agroecosystems, with a Focus on Pest Species

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    Diptera with their participation in pollination, significantly contribute to the maintenance of plant diversity, and they also have great potential for assessing habitat health and preserving it. A decline in their abundance and diversity has been recorded worldwide as a consequence of biotic, abiotic and anthropic alterations. Besides pollinators, these orders also include agricultural and forestry pests, which are a threat to cultivated and wild plants having great economic importance. Many pests have escaped from their native area, and it is important to monitor their spread to implement sustainable means of control. Our study provides baseline information on Diptera and Vespidae diversity in the Mediterranean mosaic of agroecosystems, giving information on the importance of human influence on insect diversity. We carried out an insect inventory in Istria, Croatia, using a set of traps placed in the proximity of beehives. This study was also important in determining the presence of pests and newly introduced species. A total of 94 species belonging to 24 families were recorded—7 important agricultural pests of Diptera and 17 new records for Croatia. The correlation between species diversity and environmental and anthropogenic factors leads to the conclusion that total insect species richness, pest richness, and first findings depend on human activities. The number of honeybee colonies negatively correlated with species richness, while anthropic influence positively affected total and pest species richness
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