Alessandra Gorlier

Developing an Adaptive Management approach to prescribed burning: a long-term heathland conservation experiment in north-west Italy

Calluna vulgaris-dominated heathlands are globally important habitats and extremely scarce outside of north- west Europe. Rotational fire, grazing and cutting by local farmers were dominant features of past heathland management throughout Europe but have been abandoned, altering the historical fire regime and habitat structure. We briefly review research on Calluna heathland conservation management and provide the background and methodology for a long-term research project that will be used to define prescribed fire regimes in combination with grazing and cutting, for management of Calluna heathlands in north-west Italy. We outline the ecological and research issues that drive the fire experiment, making explicit the experimental design and the hypotheses that will be tested. We demonstrate how Adaptive Management can be used to inform decisions about the nature of fire prescriptions where little formal knowledge exists. Experimental plots ranging from 600 to 2500 m 2 are treated according to one of eight alternative treatments (various combinations of fire, grazing and cutting), each replicated four times. To date, all treatments have been applied for 4 years, from 2005 to 2008, and a continuation is planned. Detailed measurement of fire characteristics is made to help interpret ecological responses at a microplot scale. The results of the experiment will be fed back into the experimental design and used to inform heathland management practice in north-west Italy.

Use of mineral mix supplements to modify the grazing patterns by cattle for the restoration of sub-alpine and alpine shrub-encroached grasslands

Throughout the last decades, agricultural abandonment in European mountain areas has caused changes in traditional livestock management with consequences for semi-natural grassland use and vegetation. In the Western Italian Alps, continuous extensive grazing has become the simplest and the most common system for managing large cattle herds. As a result, limited grazing in many rugged locations has led to an extensive shrub-encroachment of semi-natural grasslands in the sub-alpine and alpine belts. A study was conducted to assess if the provision of mineral mix supplements (MMS): (1) increases the use of steep and shrub-encroached locations by beef cows, and (2) helps restore meso-eutrophic grassland vegetation around supplement-deployment sites. During the summer grazing season, MMS were placed within 10 steep and shrub-encroached areas in two adjacent pastures (364 and 366 ha), and 12 cows were tracked with GPS collars. For each supplement site, a paired control site was identified, and vegetation surveys were performed in the surrounding areas of both sites. Placement of MMS increased the use of areas within 12 m of supplement locations compared with corresponding control areas. Cattle use of areas within 100 m of the MMS sites was also greater than expected by chance. The use by cattle, associated with trampling, grazing and faecal deposition, reduced the cover of shrubs and oligotrophic herbaceous species and increased the average nutrient N-value and forage pastoral value of the new vegetation types established around MMS sites 2 years after their use by cattle. Strategic placement of MMS appears to be a sustainable practice to restore sub-alpine and alpine shrub-encroached grasslands. Nevertheless these results must be considered preliminary as a longer period is needed to evaluate the long-term effectiveness of this practice for the restoration of semi-natural grasslands.

Implementation of a rotational grazing system with large paddocks changes the distribution of grazing cattle in the south-western Italian Alps

Continuous grazing systems (CGS) are still widely used for managing cattle herds in the south-western Alps. Recently, Pastoral Plans have been used as a policy tool to improve grazing management. Rotational grazing systems (RGS) with large paddocks (i.e. ~100 ha on average) and stocking rate adjustments based on recommended levels calculated from vegetation surveys have been implemented through Pastoral Plans to improve the uniformity of grazing. A case study was conducted to compare grazing distribution patterns of beef cows during the summer under CGS and RGS on sub-alpine and alpine pastures within Val Troncea Natural Park in the south-western Alps of Italy. Cows were tracked with global positioning system collars at 15-min intervals under both CGS and RGS. Cattle distribution patterns were aggregated in both grazing systems, but in the RGS concentration of grazing was less clustered and the selection of vegetation communities was more homogeneous than in CGS. Under CGS, cows were attracted (P   0.05) high pastoral value, and they avoided areas farther from water (P < 0.05). Similar to CGS, cows under RGS were attracted (P < 0.05) to salt and avoided (P < 0.05) steep slopes. In the RGS, cows used steeper slopes and areas farther from salt and water in the second half of the grazing period within a paddock compared with the first half, which likely explains the improvement in uniformity of grazing with RGS. Our findings indicate that Pastoral Plans that combine appropriate stocking levels and RGS are valid policy and management tools that have the potential to improve grazing distribution on rough sub-alpine and alpine pastures in the south-western Alps.

Electronic Nose analysis of milk from cows grazing on two different Alpine vegetation types.

The nutritional distinctiveness of pasture-fed dairy products is mainly influenced by the transfer of specific chemical compounds from the grass to the milk and by their effect on rumen microflora and animal metabolism. Thus, the pasture-fed origin has to be objectively proven, using fast and reproducible analytical methods applied to finished products, in order to protect consumers against potential frauds. In this work, Electronic Nose patterns of Alpine milks produced by cows grazing Trifolium alpinum and Festuca nigrescens pasture types have been examined, in order to test the potential use of this device for routine control analyses of the botanical origin of milk and dairy products. The data have been treated with different multivariate analyses (MANOVA, LDA) and chemometrics (MPLS). The results allow a very good classification of the milks, according to the two treatments. Such results demonstrate that this device could be successfully applied to PDO dairy products food chain as a tool for the determination of their dietary origin.

Plant species selection by sheep in semi-natural dry grasslands extensively grazed in the south-western Italian Alps

Sheep can have an important role in the conservation of abandoned and shrub- and tree-encroached, semi-natural dry grasslands because their feeding behaviour is known to affect plant diversity and structure. Nevertheless, little information is available about feeding preferences of sheep at the sward-patch scale and about the effects of stocking density on their selectivity. Consequently, we investigated plant-species selection by sheep managed with a low-intensity grazing, examining the influence of stocking density and plant species abundance by means of vegetation surveys and animal GPS tracking. Sheep grazed a graminoid-dominated, semi-natural dry grassland (Festuco–Brometea) in Piedmont Region, north-west Italy. Plant species, classified into graminoids, suffruticose forbs, and herbaceous forbs, were selected with a different intensity by sheep, which preferred graminoids over suffruticose and herbaceous forbs. Plant species showing a high consumption ratio (CR), i.e. the level of selection of plant species (CR >10%), were mostly graminoids (e.g. Bromus erectus, Koeleria vallesiana and Stipa pennata). Furthermore, Carex species were also noticeably selected, in particular C. humilis, whereas spiny species and those with a rosette or prostrate forms were rarely grazed. The heterogeneity of stocking density over the pasture allowed testing of the relationships between stocking density and CR. For many species, the higher the stocking density, the higher was the CR, regardless of the abundance of dominant neighbouring species. Results suggest that sheep under low-intensity grazing conditions exert a specific plant-species selection in abandoned dry grasslands. By regulating the stocking density through the management of grazing sheep, it may be possible to condition the consumption of certain plant species, with medium–long-term effects on the botanical composition.

Species-rich Nardus stricta grasslands host a higher vascular plant diversity on calcareous than on siliceous bedrock

Background: Species-rich Nardus stricta grasslands are a priority habitat for conservation in Europe. They typically occur on siliceous substrates and less frequently are found on calcareous bedrock. Aims: The present paper aimed to identify the environmental factors (i.e. bedrock type, topographic, and climatic factors) that are related with community diversity and to assess if differences in plant diversity between N. stricta communities on calcareous and siliceous bedrock occur. We hypothesised that Nardus grasslands on calcareous bedrock hosted a higher vascular plant diversity than those on siliceous bedrock. Methods: Based on 579 vegetation surveys carried out in the south-western Alps, we assessed vascular plant diversity (species richness, Shannon diversity, and Pielou’s equitability index) of species-rich Nardus grasslands and compared it between N. stricta communities on calcareous and siliceous bedrock. Results: Elevation was identified as the main factor related to species composition, while species diversity was mostly related to mean annual precipitation and bedrock type. Species richness, Shannon diversity, and Pielou’s equitability index were higher within the communities on calcareous rather than on siliceous bedrock and a total of 89 and 34 indicator species were detected, respectively. Conclusions: Based on our results, we suggest to protect primarily, as a habitat of priority interest, N. stricta grasslands on calcareous substrates for the higher vascular plant diversity hosted.

Evaluation of hygiene and safety criteria in the production of a traditional Piedmont cheese

Traditional products and related processes must be safe to protect consumers’ health. The aim of this study was to evaluate microbiological criteria of a traditional Piedmont cheese, made by two different cheese producers (A and B). Three batches of each cheese were considered. The following seven samples of each batch were collected: raw milk, milk at 38°C, curd, cheese at 7, 30, 60, 90 days of ripening. During cheese making process, training activities dealing with food safety were conducted. Analyses regarding food safety and process hygiene criteria were set up according to the EC Regulation 2073/2005. Other microbiological and chemical-physical analyses [lactic streptococci, lactobacilli, pH and water activity (Aw)] were performed as well. Shiga-toxin Escherichia coli, aflatoxin M1 and antimicrobial substances were considered only for raw milk. All samples resulted negative for food safety criteria; Enterobacteriaceae, E.coli and coagulase-positive staphylococci (CPS) were high in the first phase of cheese production, however they decreased at the end of ripening. A high level of CPS in milk was found in producer A, likewise in some cheese samples a count of >5 Log CFU/g was reached; staphylococcal enterotoxins resulted negative. The pH and Aw values decreased during the cheese ripening period. The competition between lactic flora and potential pathogen microorganisms and decreasing of pH and Aw are considered positive factors in order to ensure safety of dairy products. Moreover, training activities play a crucial role to manage critical points and perform corrective action. Responsible application of good manufacturing practices are considered key factors to obtain a high hygienic level in dairy products.