No abstract

From the beginning of the last century, the expansion of the ski industry has significantly altered Alpine environments.The aim of this research was to study the impacts of forest ski-pistes on small mammals by assessing (i) whether ski-pistes were used or avoided and (ii) whether they acted as ecological barriers to local movements.Two ski-developed valleys of the Western Italian Alps were considered. Most of the fieldwork occurred in the Sessera Valley (Piedmont), a minor part was carried out in the Ayas valley (Aosta Valley).In the main study site three capture-mark-recapture studies on core species were carried out to assess habitat use (one study) and the capability of crossing ski-pistes (two studies: spontaneous crossing and individual translocation). Two radiotracking surveys of the most vagile species, the fat dormouse, were carried out to locate home ranges and resting sites in relation to ski-pistes.In the habitat use experiment, virtually all individuals (245 out of 249) were captured outside the skipiste. In the spontaneous crossing test, recaptures of marked individuals showed they moved on one side of the ski-piste only, and never crossed it. However, in translocation experiments, 18.6% of translocated individuals were able to cross the ski-piste and come back to the original forest patch.Fat dormice maintained home ranges on one side of the ski-piste and they never crossed it. Resting sites were mostly underground, between rocks, boulders and in rocky crevices, never in the ski-piste.Our study clearly suggests that forest ski-pistes represent a habitat loss and are ecological, semipermeable barriers to small mammals. To mitigate habitat loss and make movements between forest patches easier, a possible management intervention could be maintaining a partial shrub cover or adding woody debris, both relatively easy methods for ski areas to implement in order to maintain small mammal communities.

High-quality pollen is a prerequisite for plant reproductive success. Pollen viability and sterility can be routinely assessed using common stains and manual microscope examination, but with low overall statistical power. Current automated methods are primarily directed towards the analysis of pollen sterility, and high throughput solutions for both pollen viability and sterility evaluation are needed that will be consistent with emerging biotechnological strategies for crop improvement. Our goal is to refine established labelling procedures for pollen, based on the combination of fluorescein (FDA) and propidium iodide (PI), and to develop automated solutions for accurately assessing pollen grain images and classifying them for quality. We used open-source software programs (CellProfiler, CellProfiler Analyst, Fiji and R) for analysis of images collected from 10 pollen taxa labelled using FDA/PI. After correcting for image background noise, pollen grain images were examined for quality employing thresholding and segmentation. Supervised and unsupervised classification of per-object features was employed for the identification of viable, dead and sterile pollen. The combination of FDA and PI dyes was able to differentiate between viable, dead and sterile pollen in all the analysed taxa. Automated image analysis and classification significantly increased the statistical power of the pollen viability assay, identifying more than 75,000 pollen grains with high accuracy (R2 = 0.99) when compared to classical manual counting. Overall, we provide a comprehensive set of methodologies as baseline for the automated assessment of pollen viability using fluorescence microscopy, which can be combined with manual and mechanized imaging systems in fundamental and applied research on plant biology. We also supply the complete set of pollen images (the FDA/PI pollen dataset) to the scientific community for future research.

Hazel (Corylus avellana L.) and black alder (Alnus glutinosa (L.) Gaertn.) are important sources of airborne pollen and represent an allergen threat during the flowering period. Researches on airborne pollen concentrations in both species are useful in allergology, as well as for fruit production for hazel. The aims of the present study were: (1) to investigate the relationships between environmental conditions and the airborne pollen concentration of hazel and black alder during the flowering period by correlation and multiple regression analysis and (2) to predict the pollen season start (PSS) by using a sequential model, in order to obtain a helpful tool in allergology and hazel cultivation. In this study, the applied method defines the pollen season as the period in which 90 % of the total season's catch occurred, using a data set of 18 years (1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014). The relationships between daily meteorological parameters (temperature, humidity, rainfall and wind speed) during the 14-day period that precedes the PSS and the PSS of hazel and black alder (day of the year) were investigated. The results showed that mean temperature and the number of rainy days before the PSS are the main factors influencing PSS for both taxa. Moreover, the chilling and heat needed to break dormancy were estimated in order to predict the PSS of both species. Different years and different thresholds of temperature and chill days were used to calibrate and validate the model. Keywords Black alder _ Chilling units _ Hazel _ Pollen season start _ Sequential models