Distribution of the nurse species Pycnophyllum molle J. Rémy and P. weberbaueri Muschl. in the Andean dry puna (Arequipa district-Southern Peru): role of topographic/soil variability and disturbance regime

The dry Puna is the widest pastoral ecosystem of the tropical alpine Andes, characterized by harsh environmental conditions (long and intense drought stress periods and un-fertile soils) and grazed by wild and domestic camelids. In these conditions, facilitation is of key importance in plant diversity conservation. Indeed, facilitation is a positive plant-plant interaction by which the so called nurse species provide environmental amelioration of harsh conditions and/or refuge to other plants (beneficiary species), which otherwise might fail to establish. The research aims were to understand which ecological variables affect the distribution of the potential nurse cushion species Pycnophyllum molle J. Remy and P. weberbaueri Muschl., and if these species are affected by grazing disturbance. The study area (4000-4900 m a.s.l.) is located in the southern Peruvian Andes. Data of species cover, topographic and soil features, besides type of disturbance were collected along transects. We used canonical redundancy analysis to understand the relations between the cover of the two Pycnophyllum species and the above mentioned constraining variables. Results indicate that both the Pycnophyllum species grow on sandy loam, moderately acid soils, with low organic matter and very poor nitrogen content, and avoid high disturbance intensities. molle is more sensitive than P weberbaueri to disturbance, and grows on relatively more fertile soils, also at higher altitudes and on steeper slopes characterized by greater rockiness

Evidence of Facilitation Cascade Processes as Drivers of Successional Patterns of Ecosystem Engineers at the Upper Altitudinal Limit of the Dry Puna

Facilitation processes constitute basic elements of vegetation dynamics in harsh systems. Recent studies in tropical alpine environments demonstrated how pioneer plant species defined as "ecosystem engineers" are capable of enhancing landscape-level richness by adding new species to the community through the modification of microhabitats, and also provided hints about the alternation of different ecosystem engineers over time. Nevertheless, most of the existing works analysed different ecosystem engineers separately, without considering the interaction of different ecosystem engineers. Focusing on the altitudinal limit of Peruvian Dry Puna vegetation, we hypothesized that positive interactions structure plant communities by facilitation cascades involving different ecosystem engineers, determining the evolution of the microhabitat patches in terms of abiotic resources and beneficiary species hosted. To analyze successional mechanisms, we used a "space-for-time" substitution to account for changes over time, and analyzed data on soil texture, composition, and temperature, facilitated species and their interaction with nurse species, and surface area of engineered patches by means of chemical analyses, indicator species analysis, and rarefaction curves. A successional process, resulting from the dynamic interaction of different ecosystem engineers, which determined a progressive amelioration of soil conditions (e.g. nitrogen and organic matter content, and temperature), was the main driver of species assemblage at the community scale, enhancing species richness. Cushion plants act as pioneers, by starting the successional processes that continue with shrubs and tussocks. Tussock grasses have sometimes been found to be capable of creating microhabitat patches independently. The dynamics of species assemblage seem to follow the nested assemblage mechanism, in which the first foundation species to colonize a habitat provides a novel substrate for colonization by other foundation species through a facilitation cascade process

Short communication: Effects of summer rainfall variations on sheep body state and farming sustainability in sub-Mediterranean pastoral systems

In sub-Mediterranean climate the grassland aboveground phytomass production peaks in late spring and drops in summer, when the decrease of the pasture feed value may lead to the worsening of the animal welfare. Our goal was to define the summer rainfall values leading to a decrease of semi-extensive farming system sustainability in sub-Mediterranean regions. Summer rainfall variations reflect in the aboveground phytomass production and on the sheep body state. Differences of body condition score (BCS) among years were significant in late summer, which is the mating period for sheep. In the driest year the BCS of end August drops down to 2.1, largely below the value considered sufficient to ensure the animal breeding/milking performances (2.5). Reduction of summer rainfall greater than 15–20% compared to the normal average value (thus less than expected by the scenario of climate change) might be detrimental for semi-extensive rearing sustainability in sub-Mediterranean climate

How modifications of forage features related to inter-annual rainfall variations affect sheep morpho-physiological characteristics

The sub-Mediterranean climate, mostly characterising the mountain regions sited all around the Mediterranean basin, is a variant of the Temperate bioclimate, characterised by winter cold stress and summer drought stress, the intensity and duration of which depend on the elevation gradient and land form factors. Models for the sub-Mediterranean regions indicate a strong increase of summer dry conditions and a more marked inter-seasonal and interannual variability, with maximum changes in summer and minimum changes in winter. We aimed to assess the interplay among plant community characteristics, inter-annual climatic variations and sheep morpho-physiological features to model the responses of sub- Mediterranean pastoral systems to climate change and management modification. We tested the hypothesis that the inter-annual climatic variability affects grassland productivity and feed value with different intensity (depending on slope angle and aspect) and causes variations in sheep rumen features (epithelium keratinisation degree) and animal body state estimated by means of Body Condition Score (BCS) method. We postulated that there is a significant correlation among grassland features, rumen characteristics and animal body state. Results showed that in the sub-Mediterranean climate increased summer drought stress negatively affects forage quantity and quality, and that type and direction of changes are quite different from those reported for both Mediterranean and Temperate regions. In particular, the most negatively affected plant communities were those of productive habitats, which also undergo a strong decrease of the summer forage re-growth ability. These habitats are foundational for the sustainability of extensive sheep farming in sub- Mediterranean mountains, since those of south-facing slopes are normally fully dry in summer. Grasslands of south-facing slopes are more affected by the decrease of latespring/ summer rainfall variation, and by the seasonal rainfall patterns. Changes in forage features, and in particular the increasing fibre amount led to increase the rumen keratinisation. When the degree of keratinisation increases, the absorptive ability decreases, so we can infer that drought intensification reflects in a sheep's lessened ability to absorb nutrients because of increases in the rumen keratinisation degree, negatively affecting also the animal body state. Differences of BCS among years were significant in late summer, which is the mating period for sheep. In the driest year the end-August BCS drops down largely below the value considered sufficient to ensure the animal breeding/milking performances. Reduction of summer rainfall greater than 15–20% compared to the normal average value might be detrimental for semi-extensive rearing sustainability in sub- Mediterranean climate

An updated checklist of the vascular flora of Montagna di Torricchio State Nature Reserve (Marche, Italy)

This study aims to increase floristic knowledge of Marche by means of a survey in the Montagna di Torricchio State Nature Reserve (central Italy). The Reserve, located in the central Apennines, covers about 3.2 km2 at altitudes ranging from 820 to 1,491 m a.s.l. It has been owned and managed as a strict reserve by the University of Camerino since 1970: all the anthropic activities ceased about 50 years ago, except for a minimal area where mowing and cattle grazing are still allowed. The floristic list consists of 789 specific and subspecific taxa belonging to 81 families and 352 genera. Two species are new for Italy (Taraxacum calocarpum and T. pulchrifolium) and 14 for Marche regional flora. Compared to previous floristic studies, we found 127 more taxa but we showed a certain stability in the life-form spectrum, suggesting limited effects of dynamic processes related to climate and land-use changes. The negligible number of alien species (11) is probably related to the limitations to anthropic activities in the Reserve. The occurrence of taxa never recorded for Italy and Marche highlights the floristic value of the Reserve for species conservation in the central Apennines

MIRTO: an open-source robotic platform for education

This paper introduces the MIddlesex RoboTic platfOrm (MIRTO), an open-source platform that has been used for teaching First Year Computer Science students since the academic year 2013/2014, with the aim of providing a physical manifestation of Software Engineering concepts that are often delivered using only abstract or synthetic case studies. In this paper we provide a detailed description of the platform, whose hardware specifications and software libraries are all released open source; we describe a number of teaching usages of the platform, report students’ projects, and evaluate some of its aspects in terms of effectiveness, usability, and maintenance