Is landscape of fear of macroinvertebrate communities a major determinant of mesopredator and prey activity?

Macroinvertebrate foragers play an important role on the trophic structures of freshwater environments, and multiple trophic levels occur among macroinvertebrate communities providing very interesting scenarios for testing scientific hypotheses. One of the most intriguing aspect to understand is the role played by the landscape of fear (LOF) on macrobenthos density and activity. With this pilot study we wanted to test if LOF at the macrobenthos community levels plays a role in determining the density of both prey and mesopredators. During two consecutive years, we evaluated, with both day and night surveys, the density of two mesopredator triclad species and of one detritivore prey crustacean species, and we compared them to the number of respective predators occurring in the macroinvertebrate community. LOF levels at the macroinvertebrate community did not reduce the abundance of the target taxa. One of the triclad species was instead positively related to the levels of LOF assessed for it on the basis of the available knowledge. The broad implication of the research is that the abundance of freshwater macroinvertebrates is not mainly linked to the predation risk at the community level, suggesting that also for researches on macrobenthos LOF analyses should take in consideration the role of top predators

International Gravity Field Service (IGFS)

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A shared database of underground utility lines for 3D mapping and GIS applications

For the purpose of facility management it is very important to have detailed and up-to-date databases of underground utility lines, but such data are not always available with adequate accuracy. Hence, the need of collecting and organizing suitable information on underground services is a fundamental issue when dealing with urban data. Besides, by analyzing the process of designing and laying new underground infrastructures it is possible to implement an efficient and cost-effective approach to integrate and update existing maps by exploiting the surveying required for the installation of new facilities. It is also important to underline that collecting all the data in a unique integrated database (and GIS) gives the possibility to share (at least at a local level) the cartographic and thematic information for an optimal management of underground networks. In this paper, a database (DB) model for archiving the underground lines data is presented. The structure of the DB has been designed by following the standard methodology for the modelling of a relational DB, going through successive phases and originating the external, conceptual and logical model. Finally, preliminary tests have been carried on for parts of the DB to verify quality parameters

On the connection of the Ecuadorian Vertical Datum to the IHRS

In this work, the determination of the discrepancy between the Ecuadorian Vertical Datum (EVD) and the International Height Reference System (IHRS) is presented. The vertical offset was estimated at the EVD based on the fixed geodetic boundary value problem approach. The focus of the experiment was the determination of the anomalous potential in the EVD, which in turn enable determination of the respective geopotential value. Taking a geopotential space-based approach, two estimates of the EVD offset with respect to the IHRS were obtained that amount to −1.51 and −1.61m2/s2

The stenoendemic cave-dwelling planarians (Platyhelminthes, Tricladida) of the Italian Alps and Apennines: Conservation issues

Despite being a fundamental component of biodiversity, several highly diverse taxa of aquatic invertebrates are still poorly known and poorly considered in protection programs. This is the case especially of several invertebrate species that inhabit groundwater. In this environment, invertebrates play significant roles in ecosystem services closely connected to the usefulness of these systems for human welfare and survival. The groundwater biodiversity of continental Italy is largely unknown and its importance is neglected in national and regional legislation. One of the most poorly studied groups of Italian groundwater fauna are planarians (Platyhelminthes, Tricladida). Most known species are endemic to small, single karst areas or a single cave, their geographic range never having been investigated in detail after the original description. The aims of this study are i) to provide the first conservation assessment of cave-dwelling planarians in the Italian Alps and Apennines, whose status is at present Not Evaluated in IUCN categories and ii) to evaluate which environmental constraints, including potential threats, possibly affect the occurrence of the species within different cave systems. Our results suggest that most of the cave-dwelling planarian species of continental Italy are threatened by water pollution and habitat destruction/alteration; moreover, datasets underline that there is a considerable conservation issue concerning stenoendemic planarians that may involve other cave-dwelling invertebrates with narrow geographic ranges. Generally, the underground habitat of most surveyed species appears to be deeply compromised and changed since the first species description

OFFSET EVALUATION OF THE ECUADORIAN VERTICAL DATUM RELATED TO THE IHRS

Considering the definition of the International Height Reference System (IHRS) in the geopotential space (Resolution 1/2015, International Association of Geodesy - IAG), among the present main objectives of the international geodetic community is the materialization of IHRS around the world. One fundamental task for this is the offset determination of each national vertical datum related to the IHRS. In this manuscript we establish the relationship between the Ecuadorian Vertical Datum (EVD) and the IHRS in the geopotential space following the foundations of the Resolution 1/2015 IAG. Gravity data, heights from the Ecuadorian Fundamental Vertical Network, Global Geopotential Models and Digital Elevation Models were used in the computations. Based on the Least Squares Collocation method, empirical covariance functions and spectral decomposition techniques, we realized the modelling of the geopotential in the study region (4° x 4° centered in the La Libertad tide gauge, Ecuador). Based on the referred approaches, we solved the free Geodetic Boundary Value Problem for determining the discrepancy of the EVD related to the IHRS. An offset of approximately 29 cm ± 3 cm was estimated for the W0 - W0i relation when the GO_CONS_GCF_2_DIR_R5 model was used in the modeling of the medium and long wavelengths of the terrestrial gravity field, and approximately 43 cm ± 3 cm when the EIGEN6C4 model was used

Tectonic Deformation in the Tyrrhenian : A Novel Statistical Approach to Infer the Role of the Calabrian Arc Complex

We apply the statistical procedure proposed by Barzaghi et al. (2014) to determine model uncertainty for the purpose of classifying different geophysical models that simulate tectonic deformation in the Mediterranean. For each predictive geophysical model, a covariance model is established based on 500 randomly chosen parameter combinations. Using the covariance function, model prediction uncertainty is derived from parameter uncertainties. Velocities predicted through geophysical models have been compared with GPS-derived velocities by means of a 2 statistic analysis, and these results are used to classify different models by rheology. The results indicate that including the obtained model covariance within the comparative analysis facilitates the ability to discriminate among geophysical models. When this methodology is applied to analyze the tectonic deformation in the Mediterranean, models that account for granite and granulite composition in the upper and lower crust, respectively, more effectively predict the velocity field of the study area

Do Salamanders Limit the Abundance of Groundwater Invertebrates in Subterranean Habitats?

Several species of surface salamanders exploit underground environments; in Europe, one of the most common is the fire salamander (Salamandra salamandra). In this study, we investigated if fire salamander larvae occurring in groundwater habitats can affect the abundance of some cave-adapted species. We analyzed the data of abundance of three target taxa (genera Niphargus (Amphipoda; Niphargidae), Monolistra (Isopoda; Sphaeromatidae) and Dendrocoelum (Tricladida; Dedrocoelidae)) collected in 386 surveys performed on 117 sites (pools and distinct subterranean stream sectors), within 17 natural and 24 artificial subterranean habitats, between 2012 and 2019. Generalized linear mixed models were used to assess the relationship between target taxa abundance, fire salamander larvae occurrence, and environmental features. The presence of salamander larvae negatively affected the abundance of all the target taxa. Monolistra abundance was positively related with the distance from the cave entrance of the sites and by their surface. Our study revealed that surface salamanders may have a negative effect on the abundance of cave-adapted animals, and highlited the importance of further investigations on the diet and on the top-down effects of salamanders on the subterranean communities

Detection of non-consumptive effects of predation and intraspecific aggression in fire salamander larvae: Environmental issues

The identification of injury causes may reveal important insights on the factors that influence intra and interspecific predation pressures. In this study we evaluated the proportion of injuries occurring in fire salamander larvae (Salamandra salamandra) in caves and epigean springs to understand the factors determining non-consumptive effects that may affect larval survival. We surveyed 25 sites (13 cave pools, 12 spring pools) during the day. We applied two consecutive removal samplings to collect fire salamander larvae and examined every removed larva to detect if it had injuries and we evaluated the proportion of the injured larvae on the total number of collected larvae. For each site we recorded different environmental variables including predator occurrence and prey density. The proportion of injured larvae was significantly linked only to predators occurrence. Our results show that interspecific predation pressure is a major source of non-consumptive effects that may affect larval survival Overall, our study underlines the role that environmental features may play on the non-consumptive effects of selective pressures that affect larval survival. Predator occurrence determines the levels of non-consumptive effects and larval survival across their developmental cycle. These results deriving from a field survey could furnish useful insights for further experimental studies