Recent research has indicated an increase in the likelihood and impact of tree failure. The potential for trees to fail relates to various biomechanical and physical factors. Strikingly, there seems to be an absence of tree risk assessment methods supported by observations, despite an increasing availability of variables and parameters measured by scientists, arborists and practitioners. Current urban tree risk assessments vary due to differences in experience, training, and personal opinions of assessors. This stresses the need for a more objective method to assess the hazardousness of urban trees. The aim of this study is to provide an overview of factors that influence tree failure including stem failure, root failure and branch failure. A systematic literature review according to the PRISMA guidelines has been performed in databases, supported by backward referencing: 161 articles were reviewed revealing 142 different factors which influenced tree failure. A meta-analysis of effect sizes and p-values was executed on those factors which were associated directly with any type of tree failure. Bayes Factor was calculated to assess the likelihood that the selected factors appear in case of tree failure. Publication bias was analysed visually by funnel plots and results by regression tests. The results provide evidence that the factors Height and Stem weight positively relate to stem failure, followed by Age, DBH, DBH squared times H, and Cubed DBH (DBH3) and Tree weight. Stem weight and Tree weight were found to relate positively to root failure. For branch failure no relating factors were found. We recommend that arborists collect further data on these factors. From this review it can further be concluded that there is no commonly shared understanding, model or function available that considers all factors which can explain the different types of tree failure. This complicates risk estimations that include the failure potential of urban trees.
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In this Smart Forests Radio episode in conversation with tree-ring researcher Ute Sass Klaassen at Van Hall Larenstein and Wageningen University & Research, and multi-species geographer Clemens Driessen at Wageningen University & Research. Their research illustrates different more-than-human approaches to engaging with seemingly slower entities like trees and snails by using digital technology. Ute discusses in this podcast how sensors enable the analysis of the interaction between tree vitality and climate change, such as rate of growth and water transport in stems. To obtain a fuller picture of how trees react to extreme climate events, she explores ways to combine remotely sensed data from drones and satellites with data from tree sensors. Clemens shares an artistic design research project, Unwhorl, developed in collaboration with Mari Bastashevski and Sam Lavinge, which visualises the traces snails leave as they interact with an iPad.
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Today’s internet has become like Deleuze’s societies of control, media scholars argue. The network’s invisible infrastructure, with near global reach, has amplified hierarchies, and is owned, exploited and surveilled by internet, advertising, and data-analytics companies, and by state security institutions. With the digital data produced by the often banal and quotidian activities of millions of internet users – or dividuals – a monopoly of a handful of Tech Giants accumulate massive amounts of wealth, and influence. The world wide web, various media scholars contend, has degenerated to a serpent’s coil. This article argues that the rhizomatic Wood Wide Web provides a basis from which to rethink today’s debate on the present and future of the internet, and challenges a predominant understanding of the societies control. Beneath our feet and beyond our perception, a subterranean meshwork of trees, mushrooms and fungi forms an ecology of trans-species solidarity, singularities, and creative, collaborative interactivity that could carry us outside the entrapments of the supposed totality of the societies of control.What can the World Wide Web learn from the Wood Wide Web?
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The carbon sink capacity of tropical forests is substantially affected by tree mortality. However, the main drivers of tropical tree death remain largely unknown. Here we present a pan-Amazonian assessment of how and why trees die, analysing over 120,000 trees representing > 3800 species from 189 long-term RAINFOR forest plots. While tree mortality rates vary greatly Amazon-wide, on average trees are as likely to die standing as they are broken or uprooted—modes of death with different ecological consequences. Species-level growth rate is the single most important predictor of tree death in Amazonia, with faster growing species being at higher risk. Within species, however, the slowest-growing trees are at greatest risk while the effect of tree size varies across the basin. In the driest Amazonian region species-level bioclimatic distributional patterns also predict the risk of death, suggesting that these forests are experiencing climatic conditions beyond their adaptative limits.These results provide not only a holistic pan-Amazonian picture of tree death but largescale evidence for the overarching importance of the growth–survival trade-off in driving tropical tree mortality.
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While Amazonian forests are extraordinarily diverse, the abundance of trees is skewed strongly towards relatively few ‘hyperdominant’species. In addition to their diversity, Amazonian trees are a key component of the global carbon cycle, assimilating and storing morecarbon than any other ecosystem on Earth. Here we ask, using a unique data set of 530 forest plots, if the functions of storing andproducing woody carbon are concentrated in a small number of tree species, whether the most abundant species also dominate carboncycling, and whether dominant species are characterized by specific functional traits.
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In human-controlled environments, areas of wild plants are 'translated' into cultivated landscapes to accommodate social, cultural and economic needs. This article explores indoor, agricultural and (sub)urban landscape in the Netherlands, focusing on the use of plants both indoors and outdoors, and reveals anthropocentric, instrumental and unsustainable practices. The article also presents suggestions for alternative, more ethical and sustainable ways of relating to plants in the Netherlands and beyond. https://www.ecologicalcitizen.net/article.php?t=wilderness-plastic-plants-how-might-get-back-wildness https://www.linkedin.com/in/helenkopnina/
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The relation between IT and value is a complex and disputed one. Many studies are not decisive in their results. This paper presents an overview of approaches to the quest for value and identifies the qualities of and issues with each approach. It adds several new insights, including whats missing from most approaches: taking into account the nature of the investment. From this notion a conceptual model to select the most appropriate valuation approach is developed.
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The adaptation of urbanised areas to climate change is currently one of the key challenges in the domain of urban policy. The diversity of environmental determinants requires the formulation of individual plans dedicated to the most significant local issues. This article serves as a methodic proposition for the stage of retrieving data (with the PESTEL and the Delphi method), systemic diagnosis (evaluation of risk and susceptibility), prognosis (goal trees, goal intensity map) and the formulation of urban adaptation plans. The suggested solution complies with the Polish guidelines for establishing adaptation plans. The proposed methodological approach guarantees the participation of various groups of stakeholders in the process of working on urban adaptation plans, which is in accordance with the current tendencies to strengthen the role of public participation in spatial management. https://doi.org/10.12911/22998993/81658
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Global climate change is resulting in a wide range of biotic responses, including changes in diel activity and seasonal phenology patterns, range shifts polewards in each hemisphere and/or to higher elevations, and altered intensity and frequency of interactions between species in ecosystems.Oak (Thaumetopoea processionea) and pine (T. pityocampa) processionary moths (hereafter OPM and PPM, respectively) are thermophilic species that are native to central and southern Europe. The larvae of both species are gregarious and produce large silken ‘nests’ that they use to congregate when not feeding. During outbreaks, processionary caterpillars are capable of stripping foliage from theirfood plants (oak and pine trees), generating considerable economic damage. Moreover, the third to last instar caterpillars of both species produce copious hairs as a means of defence against naturalenemies, including both vertebrate and invertebrate predators, and parasitoids. These hairs contain the toxin thaumetopoein that causes strong allergic reactions when it comes into contact with humanskin or other membranes. In response to a warming climate, PPM is expanding its range northwards, while OPM outbreaks are increasing in frequency and intensity, particularly in northern Germany,the Netherlands, and southern U.K., where it was either absent or rare previously. Here, we discuss how warming and escape from co-evolved natural enemies has benefitted both species, and suggest possible strategies for biological control.
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