Suchergebnisse

The Vaia Storm had a significant impact on forests and on the related sector in North-Eastern Italy, considerably influencing forest management and the wood supply chain. Five years after the event, on October 30th 2023 in the Aula Magna of the Agripolis campus of the University of Padua, young researchers from the TESAF and DAFNAE Departments presented their results from ongoing research on windthrow and related cascade disturbances (e.g. bark beetle outbreaks). In the first part of the day, contributions from the various regions (Friuli-Venezia Giulia, Lombardy, Veneto) and the autonomous provinces (Bolzano/Bozen and Trento) were presented, with an update on the post-event management experiences and problems. In the second part, the projects financed by the University of Padua were presented (VAIAFRONT of TESAF and the "Young Researchers for Vaia" initiative), followed by talks delivered by doctoral students and research fellows who presented the main results relating to the research conducted on the Vaia storm. The problem was addressed from different points of view and with a multidisciplinary approach, analyzing aspects related to silviculture and forest ecology, mechanization and forest uses, entomology, hydrology, geomatics and the socio-economic context. Given the interest of the topics covered, here we report the summary of the contributions presented by the young researchers, with the hope that this will encourage the exchange of knowledge and provide inspiration for further collaborations and in-depth studies.

European coniferous forests are currently threatened by bark beetles (e.g. Ips typographus) because of an increasing incidence of triggering factors, such as drought and windstorms. Furthermore, such natural disturbances are expected to increase in terms of magnitude and frequency due to climate change, and thus interacting with each other. Here, we present a particular case study in the Southern Italian Alps (Gares, Canale d'Agordo, Belluno), in which wind disturbance interacts with an ongoing outbreak of I. typographus, probably associated with an extended drought in the previous three years. By combining remote sensing and field surveys, we spatially reconstructed the bark beetle attack in the period 2015-2021, which includes the Vaia windstorm in October 2018. Although the windstorm occurred in an expanding phase of the bark beetle outbreak, attacks on standing trees did not occur during the first year after the windstorm but were observed two years later. Our findings suggest that an overlap of a large availability of wind felled trees with an incipient outbreak of I. typographus resulted in an immediate decrease of standing trees mortality in the year following the storm. However, the fallen trees worked as a hidden sink for the beetle population, which in the following years massively attacked the standing trees that survived the storm.

Diapause development is a complex process involving several eco-physiological phases. Understanding these phases, especially diapause termination, is vital for interpreting the life history of many insect species and for developing suitable predictive models of population dynamics. The pine processionary moth is a major defoliator of pine and a vertebrate health hazard in the Mediterranean region. This species can display either univoltine or semivoltine development, with a pupal diapause extending from a few months to several years, respectively. Although the ecological and applied importance of diapause is acknowledged, its physiological regulation in either case remains obscure. In the present study, we characterize pre-termination, termination and post-termination phases of pupae developing as univoltine or remaining in prolonged diapause. Changes in metabolic activity are monitored continuously using thermocouples, comprising a novel method based on direct calorimetry, and periodically by use of O-2 respirometry. The two methods clearly detect diapause termination in both types of pupae before any visible morphological or behavioural changes can be observed. Univoltine individuals are characterized by an increase in metabolic activity from pre-termination through to termination and post-termination, ultimately resulting in emergence. Remarkably, a synchronous termination is observed in individuals that enter prolonged diapause instead of emerging; however, in these pupae, the increased metabolic activity is only transient. The present study represents a starting point toward understanding the eco-physiology of diapause development processes in the pupae of the pine processionary moth.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers the plant health risks posed by the following commodities: (i) dormant and free of leaves 1-year-old bare rooted plants and (ii) free of leaves 1-year-old liners of Ficus carica imported from Israel, taking into account the available scientific information, including the technical information provided by Israel. The relevance of any pest for this opinion was based on evidence following defined criteria. Four EU quarantine pests, Euwallacea fornicatus, Hypothenemus leprieuri, Scirtothrips dorsalis and Spodoptera frugiperda, and 11 EU nonregulated pests fulfilled all relevant criteria and were selected for further evaluation. For these pests, the risk mitigation measures proposed in the technical dossier from Israel were evaluated separately for bare rooted plants and for liners, taking into account the possible limiting factors. For these pests, an expert judgement was given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The estimated degree of pest freedom varied among the pests evaluated. Aonidiella orientalis and Russellaspis pustulans were the most frequently expected pests on the imported bare rooted plants, and Scirtothrips dorsalis on liners. The Expert Knowledge Elicitation indicated, with 95% certainty, that between 9,585 and 10,000 bare rooted plants per 10,000 would be free of Aonidiella orientalis and Russellaspis pustulans and between 9,456 and 10,000 liners per 10,000 would be free of Scirtothrips dorsalis.