Diatom community biodiversity in an Alpine protected area: a study in the Maritime Alps Natural Park

As part of the "All Taxa Biodiversity Inventories" (ATBIs) coordinated by the European Distributed Institute of Taxonomy (EDIT), we analysed diatom communities colonizing different habitats of the Valasco Valley (Maritime Alps Natural Park). The aim of this research was to shed light on the diatom richness in an Alpine context through i) the collection of data concerning diatom communities inhabiting an unexplored watershed of the Maritime Alps Natural Park, including all of the most important aquatic habitats (comparison among river, springs and peat bogs) and assemblages (epilithic and epiphytic diatom communities); ii) analysis of the main environmental factors driving the development of diatom communities in different habitats. We completed a list of 174 diatom taxa. In general, river samples were poorer in terms of species richness than spring and peat bog ones, probably due to the selective role of the fast flow, while springs sheltered the highest biodiversity of the Valasco Valley. Peat bog communities were mainly composed of acidophilous taxa, sometimes planktonic and forming colonies. Epilithic and epiphytic samples did not show significant differences in terms of composition and biodiversity, even though it was statistically possible to identify indicator species for each assemblage. The study also highlighted the presence of several taxa included in the German Red List as endangered or decreasing, especially in the epiphytic samples. Since the water nutrient level and substrate geology were similar among habitats, the main environmental factors shaping Valasco diatom communities were water velocity and pH

Recent findings regarding non-native or poorly known diatom taxa in north-western Italian rivers

Diatoms of the major rivers of North-Western Italy were investigated to highlight the presence of species of particular ecological interest but not as yet recorded. The survey area included streams belonging to seven different hydroecoregions (HERs) with a wide range of physical characteristics. Between 2008 and 2010, 200 samples were taken for the study of the diatom community composition, while a larger set of samples was examined to determine the presence or absence of the nuisance diatom species Didymosphenia geminata (Lyngbye) Schmidt. A specific field study was performed in two rivers characterized by persistent blooms of this species to evaluate the effects of its proliferation on the benthic communities. D. geminata was present in almost 20% of the samples. From a comparison with published data, we can confirm that D. geminata has recently been expanding its ecological range, as it has been found also in mesotrophic lowlands water. In some instances the formation of massive proliferation has been recorded. The calculation of autecological values confirmed its preference for oligotrophic waters with low mineral content and organic loading, although with a wider ecological amplitude than recorded in the first studies on this species. Another four taxa of particular interest were detected: Achnanthidium subhudsonis (Hustedt) Kobayasi (in 15 sites), Cymbella tropica Krammer (11 sites), Mayamaea cahabaensis Morales and Manoylov (2 sites) and Reimeria uniseriata Sala, Guerrero and Ferrario (18 sites). The first three species must be considered new records for Northern Italy. A. subhudsonis and C. tropica reached up to 20% relative abundance. From the analysis of their distribution and autecological values, we can assert that A. subhudsonis and M. cahabaensis show a preference for high values of nitrogen, this latter preferring also quite high values of total phosphorus. C. tropica prefers intermediate values of nitrogen nutrients and R. uniseriata is the least demanding species in terms of water quality. All the taxa studied have a wide ecological range, confirming their potential invasive behaviour. Finally, considerations are provided with respect to Italian and European historical data in order to understand whether these species can be considered non-indigenous and/or bloom forming, in the study area. The results may help improve the process of ecological classification of water bodies in the seven HERs, and the water protection actions introduced by the Water Framework Directive (2000/60)

Comparison of Polyethylene Bubble Wrap and Corrugated Cardboard Traps for Sampling Tree-Inhabiting Spiders

In this paper, we studied the use of polyethylene bubble wrap and corrugated cardboard bark traps to sample spiders inhabiting tree trunks, with special reference to test whether they function the same way despite the differences in the spider community imposed by the different tree species and surroundings and times of sampling. The survey was carried out from July 1997 to July 1998 in Turin, Italy, in a green urban area on three poplars and four American basswoods. Differences between the two methods were tested in terms of abundance, diversity, dominance, mean body length of specimens, and proportion of juveniles, calculating Spearman's correlations. Three-factor analysis of variance, multiresponse permutation procedure, and indicator species analysis were used for further analysis. Results obtained by the two traps were correlated following a similar trend over sampling time. Bubble polyethylene seemed to be more effective than corrugated cardboard at trapping higher number of specimens. The dimension and total amount of interstices and the different microhabitat conditions of temperature and humidity seemed to be the main factors influencing spider composition in terms of the selected variables. On the basis of our results, polyethylene bark traps are recommended for sampling spiders living on trees. It is important to consider seasonality in experimental design, autumn being the period with the highest abundance of spiders but a lower level of diversity

Suggestions for diatom-based monitoring in intermittent streams

Over the last decades, river lentification processes and droughts have been dramatically spreading worldwide, due to global and local drastic changes due to human activities. Under this scenario, the evaluation of physical disturbance caused by intermittency and droughts has become more and more relevant. In this research, we compare samples collected in Mediterranean streams following both traditional and experimental approaches with the aim of understanding if diatom indices calculated from a new sampling strategy could provide additional information for the physical disturbance assessment. Moreover, we also evaluated the response of functional metrics. Our results demonstrated that even though an enhanced sampling method better reflects hydrological disturbance than the traditional one, diatom indices do not detect it. Conversely, functional traits proved to be important metrics for the hydrological disturbance assessment. In particular, benthic diatom chlorophyll a showed significantly lower values in sections more subject to droughts. With respect to ecological guilds, the motile taxa proved to be linked to depositional areas, which resulted important microhabitats (MHs) to be explored in rivers affected by lentification. Including different MHs in the sampling process improves the information we can obtain from the analysis of the diatom community and presents important implications in documenting species distribution and autecology

Towards modelling beef cattle management with Genetic Programming

Abbona, F., Vanneschi, L., Bona, M., & Giacobini, M. (2020). Towards modelling beef cattle management with Genetic Programming. Livestock Science, 241, 1-12. [104205]. https://doi.org/10.1016/j.livsci.2020.104205Among the Italian Piemontese Beef Breedings, the yearly production of calves weaned per cow, that is the calves that survive during the period of 60 days following birth, is identified as the main target expressing the performance of a farm. modeling farm dynamics in order to predict the value of this parameter is a possible solution to investigate and highlight breeding strengths, and to find alternatives to penalizing factors. The identification of such variables is a complex but solvable task, since the amount of recorded data among livestock is nowadays huge and manageable through Machine Learning techniques. Besides, the evaluation of the effectiveness of the type of management allows the breeder to consolidate the ongoing processes or, on the contrary, to adopt new management strategies. To solve this problem, we propose a Genetic Programming approach, a white-box technique suitable for big data management, and with an intrinsic ability to select important variables, providing simple models. The most frequent variables encapsulated in the models built by Genetic Programming are highlighted, and their zoological significance is investigated a posteriori, evaluating the performance of the prediction models. Moreover, two of the final expressions selected only three variables among the 48 given in input, one of which is the best performing among GP models. The expressions were then analyzed in order to propose a zootechnical interpretation of the equations. Comparisons with other common techniques, including also black-box methods, are performed, in order to evaluate the performance of different type of methods in terms of accuracy and generalization ability. The approach entailed constructive and helpful considerations to the addressed task, confirming its key-role in the zootechnical field, especially in the beef breeding management.authorsversionpublishe

A GP approach for precision farming

Abbona, F., Vanneschi, L., Bona, M., & Giacobini, M. (2020). A GP approach for precision farming. In 2020 IEEE Congress on Evolutionary Computation, CEC : 2020 Conference Proceedings (pp. 1-8). [9185637] (2020 IEEE Congress on Evolutionary Computation, CEC 2020 - Conference Proceedings). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/CEC48606.2020.9185637Livestock is increasingly treated not just as food containers, but as animals that can be susceptible to stress and diseases, affecting, therefore, the production of offspring and the performance of the farm. The breeder needs a simple and useful tool to make the best decisions for his farm, as well as being able to objectively check whether the choices and investments made have improved or worsened its performance. The amount of data is huge but often dispersive: it is therefore essential to provide the farmer with a clear and comprehensible solution, that represents an additional investment. This research proposes a genetic programming approach to predict the yearly number of weaned calves per cow of a farm, namely the measure of its performance. To investigate the efficiency of genetic programming in such a problem, a dataset composed by observations on representative Piedmontese breedings was used. The results show that the algorithm is appropriate, and can perform an implicit feature selection, highlighting important variables and leading to simple and interpretable models.authorsversionpublishe