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Pattern di variazione spaziale in comunità biotiche appenniniche: modelli teorici e implicazioni conservazionistiche
Get PDFThe Apennines are characterized by the presence of a double stress gradient, with lowlands subject to high temperatures and pronounced aridity in summer, and high altitudes to very low temperatures in winter. This double stress gradient is expected to represent a strong environmental filter for biological communities. To test this hypothesis, we investigated how various aspects of plant communities, such as their functional traits, biogeographical groups, biological forms, and ecological preferences, varied with elevation in mountain areas of the Abruzzi Region. We also studied the influence of floral diversity and elevation (which reflects the environmental filtering mainly exerted by temperature) on butterfly communities. We also discussed the possible role of botanical gardens as sites to promote butterfly conservation (butterfly gardens) in natural areas. Finally, we used lichens to investigate the impact of air pollutants produced by the post-seismic reconstruction works in the city of L’Aquila, whose urban-rural gradient follows the elevational gradient. The study of plant functional traits showed that, as expected according to the double stress gradient hypothesis, the lowest and the highest elevations were the most selective. Also, the interspecific variation in plant traits was more important than the intraspecific one, a result of particular interest given the increasing impact of the climate change on mountains. The study of the biogeographical composition (chorotypes) of plant communities highlighted a prevalence of European and Euro-Asiatic species at intermediate elevations because of their preference for temperate climates, while Mediterranean species were strongly filtered by elevation, being particularly sensitive to the decrease of temperature. The analysis of biological forms showed that phanerophytes and geophytes prevailed at intermediate elevations occupied by beech woods, whereas hemicryptophytes increased with elevation due to their greater ability to cope with harsh environmental conditions at high elevations. Chamaephytes exhibited a U-shaped pattern due to their ability to cope with the harsh conditions at the two extremes of the gradient (strong aridity in the lowlands and intense cold on the mountaintops, respectively). The study of plant ecological preferences showed that the thermophilic character of the plant communities decreased with increasing elevation. At the extremes of the gradient (where open environments prevailed) plant communities were dominated by species that prefer sunny places and are capable of surviving on poor and dry soils, while communities at intermediate elevations (where forests prevailed) were dominated by species associated with shady places and which prefer rich and moist soils. The analysis of the relationships between butterfly and floral diversity (number of plant species with flowers at least potentially usable by butterflies) showed that plant richness was a much stronger predictor of butterfly abundance than elevation, while its effect on butterfly diversity was less important. This supports the hypothesis that butterflies are mainly generalist nectarivores, with availability of nectar sources and elevation acting in an opposite way on butterfly diversity. Our work on the use of botanical gardens as a tool for butterfly conservation allowed the development of a project that can represent a reference model to promote awareness of insect conservation, disseminate scientific knowledge, and perform research, also through citizen science programs. Finally, the study of lichens as bioindicators of air quality showed that lichen diversity decreased towards the center of the city of L'Aquila due to the atmospheric pollution produced by demolition and reconstruction works. This research suggests that lichens can be profitably used for air quality evaluation in other rural contexts subject to rapid urban expansion
Disentangling the role of inter and intraspecific trait variations in plant community assembly processes
No full textThe analysis of functional trait variation in plant assemblages along environmental gradients may provide fundamental information to understand community assembly. Differences in trait dominance among assemblages, commonly expressed by the community-weighted mean, can arise from either the intraspecific variability alone, a change in species composition (species turnover, that is, interspecific variation), or, most often, a combination of these two sources of variation. Although differences among plant communities in response to environmental changes are mostly due to interspecific variations, there is increasing evidence that intraspecific variation may also play an important role. Disentangling the relative contribution of inter and intraspecific variation is particularly useful to investigate the relative importance of “internal” and “external” filters in shaping plant community responses to the environment, and hence to understand community assembly. Investigating the magnitude of the inter and intraspecific sources of variation may be useful to shed light on community resistance, since a low intraspecific variability indicates low capabilities of plant communities to adapt to environmental changes. Inter and intraspecific variations along gradients can occur in the same direction (positive covariance) or in opposite directions (negative covariance). Positive covariation indicates that the environmental factors that favor the occurrence of plant species with some particular traits also favor the same traits at the individual level, whereas negative covariation indicates that individuals with trait values that deviate most from the predominant species-mean trait values have some selective advantage at the local scale. Investigating intraspecific variation may be difficult because of the large number of measures that must be taken, yet assessing its role for multiple traits is of pivotal importance in community ecology
Use of lichens to evaluate the impact of post- earthquake reconstruction activities on air quality: a case study from the city of L'Aquila
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Community structure of tenebrionid beetles in the Ulan Buh Desert (Inner Mongolia, China) (Coleoptera: Tenebrionidae)
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Use of Lichens to Evaluate the Impact of Post-Earthquake Reconstruction Activities on Air Quality: A Case Study from the City of L’Aquila
Get PDFSIMPLE SUMMARY: Lichens are a symbiotic association of fungi and algae. As few lichen species can tolerate high levels of pollution, they are widely used for air-quality monitoring. In this study, we used the Lichen Diversity Value (LDV), an index based on the diversity of lichens living on trees, to evaluate the effects of the reconstruction activities occurring in the city of L’Aquila after the 2009 earthquake that largely destroyed the city centre. We tested if the values of the LDV index changed along the urban–rural gradient in response to the presence of air pollutants produced by reconstruction works. We also used a rapid analytical technique (Energy-Dispersive X-ray Spectroscopy—EDS) to detect the main pollutants accumulated in the lichens. We found that the LDVs increased from the city centre towards suburban areas. The EDS analysis revealed a massive presence of aluminium and silicon (used in the manufacture of concrete) in the more central areas. Our study suggests that the LDV index can be profitably used to monitor air quality in urban areas subject to building demolition and reconstruction, and that EDS may be applied to lichen samples for the rapid detection of the main pollutants associated with these activities. ABSTRACT: Lichens are widely used as bioindicators of air quality because of their ability to absorb chemical pollutants. We used the Lichen Diversity Value (LDV) index to assess the effects of the urban reconstruction activities in the city of L’Aquila ten years after the 2009 earthquake on air quality. Sampling was conducted from the city centre (still mostly under reconstruction and closed to traffic) to suburban areas (where reconstruction is minimal). We tested if the LDV index varied with distance from the city centre because of the presence of air pollutants produced by reconstruction works. We also used Energy-Dispersive X-ray Spectroscopy (EDS) to detect the main pollutants accumulated in the sampled lichens. The LDV increased from the city centre towards suburban areas. EDS revealed high concentrations of pollutants related to demolition and reconstruction activities, such as aluminium and silicon (used in the manufacture of concrete), in the more central areas. These results suggest that the LDV index can be a useful tool to monitor air quality, even on a small scale, and in urban environments subject to building demolition and reconstruction. Moreover, EDS could represent a good preliminary analytical technique to identify the air pollutants associated with all of these activities
Using Botanical Gardens as Butterfly Gardens: Insights from a Pilot Project in the Gran Sasso and Monti Della Laga National Park (Italy)
Get PDFButterfly gardens are green spaces designed as places where butterflies can feed, mate, and rest. Here, we present some perspectives on the possible use of botanical gardens in natural areas as butterfly gardens to promote insect conservation through science dissemination and citizen science activities. We explored this possibility with a project developed in the Botanical Garden of the Gran Sasso and Monti della Laga National Park (Italy). We found an extremely high butterfly richness as a result of favorable conditions which can be common in botanical gardens. To promote awareness of insect conservation in the general public and citizen science activities, we have installed within the garden several posters illustrating the butterfly fauna of the park, the species that visitors can easily observe, and the importance of butterfly conservation. Using this case study, we provided reflections and guidelines for the realization and management of butterfly gardens in already existing botanical gardens, especially in natural areas. The realization of butterfly gardens in protected areas to promote awareness of insect conservation, as well as to perform scientific research (namely insect monitoring), may help to ensure that insects will exert a pivotal role in expanding the global network of protected areas under the Post-2020 Global Biodiversity Framework
Activity density of carabid beetles along an urbanisation gradient
Get PDFSeveral works have investigated the impact of urbanisation on carabid activity density using urban-rural gradients. Such works compared activity density recorded from green spaces located in different parts of a city and assigned to categories of increasing urban intensity, which poses two problems: (1) since the gradient is divided into categories, it is impossible to model continuous variations in biotic responses, and (2) sites representative of different urbanisation levels are not true segments of the same ecological continuum. To surpass these problems, we modelled variations in carabid activity density along an urban-rural transect within a single green space extending from the city centre of Rome to rural environments. Carabids were sampled by pitfall traps from sites distributed along the entire gradient. We used breakpoint regressions to model how (1) carabid activity density, (2) carabids/beetles ratio, (3) carabids/insects ratio and (3) carabids/arthropods ratio varied along the gradient. As already observed for various organisms in urban environments, we found that activity density of carabids and their contribution to the abundance of beetles, insects and arthropods, peaked in the middle of the gradient. This supports the intermediate disturbance hypothesis, according to which moderate urbanisation may favour diversity by increasing habitat heterogeneity.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Macroecology of Dung Beetles in Italy
Get PDFThe Italian fauna includes about 170 species/subspecies of dung beetles, being one of the richest in Europe. We used data on dung beetle distribution in the Italian regions to investigate some macroecological patterns. Specifically, we tested if species richness decreased southward (peninsula effect) or northward (latitudinal gradient). We also considered the effects of area (i.e., the species–area relationship), topographic complexity, and climate in explaining dung beetle richness. Finally, we used multivariate techniques to identify biotic relationships between regions. We found no support for the peninsula effect, whereas scarabaeines followed a latitudinal gradient, thus supporting a possible role of southern areas as Pleistocene refuges for this group of mainly thermophilic beetles. By contrast, aphodiines were more associated with cold and humid climates and do not show a distinct latitudinal pattern. In general, species richness was influenced by area, with the Sardinian fauna being however strongly impoverished because of its isolation. Faunal patterns for mainland regions reflect the influence of current ecological settings and historical factors (Pleistocene glaciations) in determining species distributions. © 2024 by the authors.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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