Sound absorption by tree bark

Scattering of sound waves by trunks is a main physical factor leading to sound pressure level reduction by tree belts, and it has been shown before that the absorbing properties of the trunks are relevant in this respect. However, detailed information on bark absorption is currently very scarce. Therefore, laboratory experiments were conducted with an impedance tube to measure the bark’s sound absorption of various tree species, including characterizations of bark thickness, roughness, tree age and moss coverage. Preliminary measurements were made to come to a reproducible sample handling procedure. The measurements show that the absorption (at normal incidence) is generally below 0.1 for the species considered and rather frequency independent below 1 kHz. There are statistically significant differences in the averaged absorption between species. Overall, the barks of conifers absorb sound slightly better than in case of broadleaved species. The most relevant visual predictor for the sound absorption of bark is its roughness. Interestingly, moss grown barks provide a strong increase in absorption in the frequency range up to 800 Hz. Especially in dense tree belts, bark absorption might have an influence on the final noise shielding performance

Simple identification tools in FishBase

Simple identification tools for fish species were included in the FishBase information system from its inception. Early tools made use of the relational model and characters like fin ray meristics. Soon pictures and drawings were added as a further help, similar to a field guide. Later came the computerization of existing dichotomous keys, again in combination with pictures and other information, and the ability to restrict possible species by country, area, or taxonomic group. Today, www.FishBase.org offers four different ways to identify species. This paper describes these tools with their advantages and disadvantages, and suggests various options for further development. It explores the possibility of a holistic and integrated computeraided strategy

Molecular methods for the diagnosis and characterization of phytopathogenic fungi of quarantine concern or causing emerging plant diseases

In the context of molecular techniques applied to Plant Pathology, this Ph.D. thesis has pursued the following major objectives: i) to develop new diagnostic protocols for fungal pathogens; ii) to study the metabolic and physiological effects determined by new and emerging fungal pathogens; iii) to contribute to develop management strategies of diseases caused by quarantine and/or emerging fungi on plant species typical of the Mediterranean region. To fulfill these objectives, the following specific studies have been developed: • “Fusarium circinatum an emergent and quarantine pathogen of pine worldwide: its detection and its interaction with Phytophthora species (P. cambivora and P. parvispora) on Pinus radiata seedlings.” This study has been developed by two different lines of research: “Transferability of PCR-based diagnostic protocols: An international collaborative case study assessing protocols targeting the quarantine pine pathogen, Fusarium circinatum.” In this study, different protocols for the molecular diagnosis of F. circinatum were compared and validated for the first time in 23 laboratories spread across Europe, South Africa and Chile, in the framework of the international collaborative study funded by COST Action FP1406 “Pine pitch canker - Strategies for management of Gibberella circinata in greenhouses and forests - PINESTRENGTH ''. The protocol tested by the Laboratory of Molecular Plant Pathology of the Department of Agriculture, Food and Environment (Di3A) of the University of Catania were: (i) Real-time PCR by Lamarche et al. 2015 and (ii) real-time PCR by Luchi et al. 2018. Results from the two tested protocols were illustrated in Ioos et al (2019), Scientific Reports 2019, 9, 8195. DOI: 10.1038 / s41598-019-44672-8. “Co-infections by Fusarium circinatum and Phytophthora spp. on Pinus radiata, a case study of complex interactions in the Pine pitch canker disease.” This study investigated i. the phenotypic response of pine to the infective process and ii. the relative expression levels of genes of plant encoding for pathogenetic-related proteins and antifungal secondary metabolites. Results obtained in this research showed that the phenotypic response of pine to the simultaneous action of the aforementioned pathogens it is manifested by an increasing of the severity of the symptoms at the early stages of the infection, allowing then to speculate that Phytophthora spp. can realistically contribute to the severity of the disease. Results from gene expression suggest that a real synergic effect as the result of the effects of both pathogens it is not clearly evident. • “Scabby canker caused by Neofusicoccum batangarum (Botryosphaeriaceae), an emergent disease of Opuntia ficus-indica in minor islands around Sicily: identification of the causal agent and characterization of both its phytotoxic metabolites and the genetic variability of its local population.” The specific objectives of this study were the following: i) determine the geographical distribution of the disease; ii) characterize N. batangarum isolates obtained from symptomatic plants of prickly pear in the smaller islands of Sicily; iii) check whether the range of potential host plants of this phytopathogenic fungus includes other Mediterranean species that could act as alternative hosts or as inoculation 'reservoir'; iv) determine the ability of N. batangarum to produce phytotoxic secondary metabolites (phytotoxins) in culture, which can play an active role in the pathogenesis of the disease; v) chemically identify the phytotoxins extracted from N. batangarum liquid filtrates and determine their phytotoxic effects on the host plant as well as on non-host plant species. In cross-pathogenicity tests, N. batangarum isolated from Opuntia ficus-indica plants was able to reproduce disease symptoms on the host plant and also infect other plant species. The fungus artificially inoculated by wounding induced cancers on several hosts. This result indicates that the pathogen has a very wide range of potential hosts. Six phytotoxins were obtained and identified from Neofusicoccum batangarum culture filtrates: (-) - (R) ‐mellein (1); (±) ‐botriisocoumarin A (2); (-) - (3R, 4R) - and (-) - (3R, 4S) ‐4 hydroxymelline (3 and 4); (-) - terpestacin (5); and (+) - 3,4 ‐ dihydro - 4,5,8 - trihydroxy - 3 - methylisocoumarin, renamed (+) - neoisocoumarin (6). All six metabolites have been shown to have phytotoxic activity on both the host and non-host plants. The most active compounds proved to be (±) ‐botriisocoumarin A (2), (-) - terpestacin (5) and (+) - neoisocoumarin (6). Results from this study are part of two scientific publications: Masi, Mt. et al., Toxins 2020, 12, 126. DOI: 10.3390 / toxins12020126 and Aloi, F. et al., Mediterranean Phytopathology 2020, 59 (2): 269-284. DOI: 10.14601 / Phyto-11225. • “Identification of Neofusicoccum parvum (Botryosphaeriaceae) as the causative agent of gummy cankers of lemon (Citrus × limon) trees.” This study was aimed at identifying the causative agent of the observed disease. Neofusicoccum parvum, in the family Botryosphaeriaceae, was identified as the causal agent of bot gummosis of lemon (Citrus x limon) trees, in the two major lemon-producing areas in Italy. Gummy cankers on trunk and scaffold branches of mature trees were the most typical disease symptoms. Neofusicoccum parvum was the sole fungus constantly and consistently isolated from the canker bark of symptomatic lemon trees. It was identified on the basis of morphological characters and the phylogenetic analysis of three loci, i. e. the internal transcribed spacer of nuclear ribosomal DNA (ITS) as well as the translation elongation factor 1-alpha (TEF1) and β-tubulin (TUB2) genes. The pathogenicity of N. parvum was demonstrated by wound inoculating two lemon cultivars, ‘Femminello 2kr’ and ‘Monachello’, as well as citrange (C. sinensis x Poncirus trifoliata) ‘Carrizo’ rootstock. In artificial inoculations, the fungus was very aggressive on lemons and weakly virulent on citrange, consistently with symptoms observed in the field as a consequence of natural infections. This is the first report of N. parvum, both in a wide and in a strict taxonomic sense, as a pathogen of lemon in Italy. • “Characterization of Alternaria species associated with heart rot of pomegranate fruit.” This study was aimed at identifying Alternaria species associated with heart rot disease of pomegranate fruit in southern Italy and characterizing their mycotoxigenic profile. A total of 42 Alternaria isolates were characterized. They were obtained from pomegranate fruits with symptom of heart rot sampled in Apulia and Sicily and grouped into six distinct morphotypes based on macro- and microscopic features. According to multi-gene phylogenetic analysis, including internal transcribed spacer (ITS), translation elongation factor 1-α (EF-1α), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and a SCAR marker (OPA10-2), 38 isolates of morphotypes 1 to 5 were identified as A. alternata, while isolates of morphotype 6, all from Sicily, clustered within the A. arborescens species complex. In particular, isolates of morphotype 1, the most numerous, clustered with the ex-type isolate of A. alternata, proving to belong to morphotype alternata. No difference in pathogenicity on pomegranate fruits was found between isolates of A. alternata and A. arborescens and among A. alternata isolates of different morphotypes. The toxigenic profile of isolates varied greatly: in vitro, all 42 isolates produced tenuazonic acid and most of them other mycotoxins including alternariol, alternariol monomethyl ether, altenuene and tentoxin. • “Shoot dieback of citrus, a new disease caused by Colletotrichum species.” This study was aimed at identifying the Colletotrichum species associated with twig and shoot dieback of citrus, a new disease occurring in the Mediterranean region and also reported as emerging in California. Overall, 119 Colletotrichum isolates were characterized. They were recovered from symptomatic trees of sweet orange, mandarin and mandarin-like during a survey of citrus groves in Albania and Sicily (southern Italy). The isolates were grouped into two distinct morphotypes. The grouping of isolates was supported by phylogenetic sequence analysis of two genetic markers, the internal transcribed spacer regions of rDNA (ITS) and β-tubulin (TUB2). The groups were identified as Colletotrichum gloeosporioides and C. karstii, respectively. The former accounted for more than 91% of isolates, while the latter was retrieved only occasionally in Sicily. Both species induced symptoms on artificially wound inoculated twigs. C. gloeosporioides was more aggressive than of C. karstii. Winds and prolonged drought were the factor predisposing to Colletotrichum twig and shoot dieback. This is the first report of C. gloeosporioides and C. karstii as causal agents of twig and shoot dieback disease in the Mediterranean region and the first report of C. gloeosporioides as a citrus pathogen in Albania

Developing a Pedagogy for Reducing ‘Plant Blindness’

Despite human dependence on them, inattention to plants or plant blindness is a well–known phenomenon in urban societies. This thesis investigates the efficacy of a suite of novel teaching approaches for botany with adults and children and considers how these published research–based resources can contribute to a pedagogy for reducing plant blindness, in conjunction with the existing literature. This research was based on a mixed methods design using knowledge tests, questionnaires and interviews. It focused on two themes: novel methods for learning taxonomy (digital keys, mnemonics, drawing and game–playing) and drama–based methods for learning reproduction and classification. The literature review examined the characteristics of plant blindness and its impacts on teaching and learning. The fundamental cause of plant blindness was shown to be diminished experience with plants in urban societies which leads to low interest in plants compared to animals. A majority of pedagogic studies were based on learning with live plants, many of which were inquiry-based learning. Half the studies included outdoor learning and half used digital learning approaches. A content analysis of published research using themes based on theories of embodied cognition, memory and positive affect found the textual data to be evenly distributed across all three themes. The pedagogic approaches promoted learning through elaborative techniques, instructional tools with high usability, multimedia experiences and emotional wellbeing. Drawing and keys favoured observation over other perceptual modes, whereas drama facilitated multisensory experience. The research identified physical and cognitive factors that may assist or impede learning. A theoretical contribution of the research was the application of memory theory to learning taxonomy, advancing our understanding of how the design of keys and mnemonics may assist retention. Drama studies enhanced our understanding of children’s attitudes to plants and how a brief intervention may address these

Plants, food and the repurposing of urban nature: the geographies of foraging and landscape in London

An increasingly common sight in London is people seeking out and collecting the uncultivated, unattended and altogether unintended plants growing wild in the multifarious spaces of the city. “Urban foraging”, as it has been termed and observed in other geographies, can be read as a reflection of various concerns. It may be an expression of hipster gentrification, a radical reclamation of communal space, a re-finding of lost flavours and traditions, a reflection of a city diverse with cultural plant uses, or a shared desire to reconnect with nature, both spiritual and material. This research uses the figuration of “urban foraging” to plot a path through the uneven social and material landscapes of food, nature and the city. In so doing, it examines what foraging might tell us about the material affordances of the city, how we do or might differently feed ourselves, how urban space is designed and governed, and the alternatives politics, performance and possibilities of urban nature. Drawing upon a year of mixed-method field work in London, including participant observation with urban pickers and foragers, interviews with a range of actors, archival and visual resources, and autoethnographic walking and learning, it offers a qualitative account of the activities in question and the city more broadly. The research builds on existing work concerned with urban gathering practices in North American cities, and nascent research from other geographies, applying some of this insight to the situated histories, ecologies and knowledges at work in London. While political ecologies, and urban political ecologies, provide a valuable theoretical basis for addressing issues of access to nature, the status of the urban forest, and different epistemic traditions, urban foraging reveals a more complex picture. Looking towards “relational materialist” thinking, it helps reimagine food as a contingent event—a becoming— replete with ontological uncertainty. At the same time, it undermines stable readings of the food system by re-inscribing moments of human-plant encounter with affective meaning, bearing implications for efforts to recalibrate urban foodscapes and food-ways. The thesis attends to the various facets and ‘affordances’ of urban foraging in London, including the praxis of walking and mobility, botanical encounter and knowledge, culture and memory, the history and (re)emergence of the urban commons, and the importance of how language and etymology intertwine themselves in all of these. Fundamentally, the research offers an interpretation of urban foraging as a form of figurative and literal “poaching”— to borrow the term from De Certeau—and means through which to make sense of the city, which unsettles the increasingly numerous representations of London as an ecologically coherent entity. In so doing, it also reveals a performative element that invokes varying visions of rurality connecting the city, at least symbolically, with temporally and geographically distant spaces. Rather than the revival of culturally or historically ‘authentic’ practices, urban foraging—through the enactment of varied ethnobotanical knowledge and skill—is contributing to the emergence of novel cultures of urban nature. As such, these plant collection practices bear implications for how the city’s green spaces are conceived and managed

Invasive Species in Forests and Rangelands of the United States

This open access book describes the serious threat of invasive species to native ecosystems. Invasive species have caused and will continue to cause enormous ecological and economic damage with ever increasing world trade. This multi-disciplinary book, written by over 100 national experts, presents the latest research on a wide range of natural science and social science fields that explore the ecology, impacts, and practical tools for management of invasive species. It covers species of all taxonomic groups from insects and pathogens, to plants, vertebrates, and aquatic organisms that impact a diversity of habitats in forests, rangelands and grasslands of the United States. It is well-illustrated, provides summaries of the most important invasive species and issues impacting all regions of the country, and includes a comprehensive primary reference list for each topic. This scientific synthesis provides the cultural, economic, scientific and social context for addressing environmental challenges posed by invasive species and will be a valuable resource for scholars, policy makers, natural resource managers and practitioners