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.
MULTIFILE
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?
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.
MULTIFILE
Worldwide, coral reefs are rapidly declining due to increased sea water temperatures and other environmental stresses (Figure 1). To counter the extinction of major coral reef building species on the island of Bonaire, the non-profit organization Reef Renewal Foundation Bonaire is restoring degraded reef sites using corals that are grown in local nurseries. In these nurseries, corals are propagated on artificial trees using fragmentation. After 6-8 months of growth in the nursery, the corals are transplanted to degraded reef sites around the island. Over the years more than 21.000 corals have been outplanted to reef restoration sites in this way. These corals show high survivorship under natural reef conditions but remain under threat by environmental disturbances, such as increased water temperatures, diseases, and competition with macroalgae. A promising intervention to increase reef persistence and resilience is to manipulate the coral-associated microbiome. At present, the composition of the microbiome in nursery-reared and outplanted corals on Bonaire is unknown. The aim of the current project is to identify and isolate naturally occurring beneficial bacteria that may stimulate the resilience of these corals. Our key objectives are: 1) to assess the presence of functionally beneficial bacteria in corals in nursery and restoration sites on Bonaire using metagenomic screening. 2) to design culture strategies to isolate these functionally beneficial bacteria. In the future, a selection of these beneficial bacteria can be applied to the corals to increase their resilience against environmental disturbances.
Gebouwen blijven lang (gemiddeld 50 jaar) in functie. Desondanks wordt circulariteit van gebouwen vaak gelijk gesteld aan herbruikbaarheid van de toegepaste materialen na sloop. Door de aanscherpende functionele eisen is het moeilijk om de bouwmaterialen die bij sloop of verbouwing vrijkomen één-op-één te hergebruiken. Deze materialen voldoen niet meer aan de huidige eisen en worden veelal gerecycled om de materialen/grondstoffen in de kringloop te houden. Als hergebruik van afzonderlijke bouwmaterialen moeilijk is dan wordt het interessant om te onderzoeken of de levensduur van een gebouw in z’n totaliteit kan worden opgerekt: door te streven naar bijvoorbeeld levensduren van 100 jaar en meer. In de leidraad Circulair Ontwerpen van CB’23, een platform dat onderzoek doet naar circulariteit in de gebouwde omgeving, worden onder meer overmaat en koestering als randvoorwaarden voor een langere levensduur genoemd. Door het gebouw te over-dimensioneren kan het gemakkelijker andere functies in zich opnemen. Koestering gaat over waardering van de gebruikers voor een gebouw. Uit het literatuuronderzoek dat met een KIEM-subsidie is uitgevoerd, blijken gebouwen met royale en aansprekende entrees en die uitgevoerd zijn in zorgvuldig gedetailleerde materialen die mooi verouderen hiervoor in aanmerking te komen: materialen als beton, natuursteen en baksteen – dure materialen met relatief hoge schaduwkosten. Het consortium, bestaande uit architectenbureaus, bouwfysische en constructieve adviesbureaus, opdrachtgevers, ontwikkelaars en koepelorganisatie/kennisplatform NEVAP wil het onderzoek naar gebouwen die lang in functie kunnen blijven, doorzetten. Het architectonische en theoretische onderzoek naar gebouwen met lange levensduren wordt uitgebreid, maar het onderzoek gaat zich vooral richten op de vraag hoe deze gebouwen technisch en financieel gerealiseerd kunnen worden. De onderzoeksvraag is hierbij : ‘Op welke manieren kan de levensduur van gebouwen worden verlengd om waardeverlies van gebouw en gebruikte materialen te voorkomen waarbij niet alleen rekening wordt gehouden met architectonische en (gebruiks-)technische, maar ook met financiële en milieutechnische randvoorwaarden?’
In the Netherlands, the theme of transitioning to circular food systems is high on the national agenda. The PBL Netherlands Environmental Assessment Agency has stressed that commuting to circular food chains requires a radical transformation of the food chain where (a) natural resources must be effectively used and managed (soil, water, biodiversity, minerals), (b) there must be an optimum use of food by reducing (food) waste . . ., (c) less environmental pressure, and (d) an optimum use of residue streams. The PBL also recognizes that there should be room for tailored solutions and that it is important to establish a benchmark, to be aware of impacts in the production chain and the added value of products. In the line of circular food systems, an integrated nature-inclusive circular farming approach is needed in order to develop a feasible resource-efficient and sustainable business models that brings shared value into the food chain while invigorating the rural areas including those where agricultural vacancy is occurring. Agroforestry is an example of an integrated nature-inclusive circular farming. It is a multifunctional system that diversifies and adapts the production while reducing the carbon footprint and minimizing the management efforts and input costs; where trees, crops and/or livestock open business opportunities in the food value chains as well as in the waste stream chains. To exploit the opportunities that agroforestry as an integrated resource-efficient farming system adds to the advancement towards (a) valuable circular short food chains, (b) nature-based entrepreneurship (nature-inclusive agriculture), and (c) and additionally, the re-use of abandoned agricultural spaces in the Overijssel province, this project mobilizes the private sector, provincial decision makers, financers and knowledge institutes into developing insights over the feasible implementation of agroforestry systems that can bring economic profit while enhancing and maintaining ecosystem services.
