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Mistletoes have a fraught public relations history. Vilified as toxic tree-killing weeds, they have long been targeted for removal by arborists and forest managers concerned with tree health. Research on mistletoe ecology has revealed their positive influence on diversity and community structure via complex networks of interactions. In areas where mistletoe has traditionally been removed, managers are now asking whether these parasitic plants can return on their own or whether they should be reintroduced. To evaluate the practicalities of mistletoe restoration, we inoculated 28 London plane trees Platanus * acerfolia (Aiton) Willd. in inner Melbourne with creeping mistletoe Muellerina eucalyptoides (DC.) Barlow, a locally rare species. Branch dimensions and aspect had no discernible effect on germination or seedling emergence, but trees where access to possums (Trichosurus vulpecula (Kerr, 1792) and Pseudocheirus peregrinus (Boddaert, 1785)) was restricted were 30% more likely to host seedlings. Five years after inoculation, seven mistletoes successfully established on five trees, with two mistletoes bearing fruit. Communications with residents and city users elicited positive feedback, catalysing four additional inoculation trials in urban and forest settings elsewhere. In addition to representing a cost-effective means of enhancing habitat values, mistletoe restoration is useful for addressing open questions about mistletoe ecology and educating the community about the functional roles these parasitic plants play. Key words: Muellerina, Loranthaceae, direct seeding, reintroduction, urban ecology, Introduction Mistletoes are a diverse and widespread group of aerial hemiparasites that have often been regarded as problematic by foresters and arborists, customarily removed as part of routine maintenance operations [...]

As keystone structures in urban ecosystems, trees are critical to addressing many of the current livability, health, and environmental challenges facing cities. Every day, trees are removed from urban landscapes as part of routine management. These tree removals are an opportunity for implementing manipulative experiments to directly measure the social and ecological functions of trees. Here we review the kinds of tree removals that commonly occur in cities, assess the relevant opportunities that arise for research–practice partnerships, and discuss the challenges posed when implementing experiments of this nature. We argue that experimental studies on the routine removal of urban trees will improve and expand the mechanistic understanding of how trees support biodiversity and human well‐being in cities beyond current knowledge, which is largely based on correlative studies. Finally, we highlight the opportunity for experiments to be co‐designed by scientists and urban land managers, and how "learning while doing" can generate tangible research impacts and improve urban forest decision making. [ABSTRACT FROM AUTHOR]

Experimentally manipulating urban tree abundance and structure can help explore the complex and reciprocal interactions among people, biodiversity and the services urban forests provide to humans and wildlife.In this study we take advantage of scheduled urban tree removals to experimentally quantify the benefits that urban trees provide to humans and wildlife. Specifically, we aim to understand how trees affect: (1) bird and mammal abundance and diversity, as well as an ecological process (predation); and (2) people's perception responses, such as the importance that people assign to the trees, wildlife and the site.We designed two independent Before‐after‐control‐impact (BACI) experiments based on two sites where tree removals were occurring (impact sites): an urban park and a residential street, both located in the Greater Melbourne Area, Australia. We selected three control sites for each impact site, or four per experiment. Ecological data were collected through field surveys, and social data on people's perceptions through intercept questionnaires among park and street users. Data were analysed using a GLMMs to determine the combined effect of time (before and after) and treatment (impact and controls).At the urban park, the abundance of nectarivorous birds and possums both declined by 62% following tree removal, while invertebrate predation increased by 82.1%. The level of importance people assigned to the urban park and to the trees at the site decreased after tree removal, and people's attitudes towards tree planting became more positive, meaning more people wanted to plant more trees at the site.None of these changes were observed in the street experiment where fewer and smaller trees were removed, suggesting that effects may be highly specific to context, where factors such as tree volume, diversity and arrangement influence the magnitude of social–ecological effects observed.By demonstrating the social–ecological effect of removing urban trees, we provide evidence that urban trees provide critical habitat to urban wildlife and are perceived as an important aspect of the human experience of urban nature. Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

A multitude of factors is promoting rapid road expansion globally, including a quest for valuable resources such as timber, minerals, oil and arable land, and initiatives to increase regional trade, [...], The number and extent of roads will expand dramatically this century (1). Globally, at least 25 million kilometres of new roads are anticipated by 2050; a 60% increase in the total length of roads over that in 2010. Nine-tenths of all road construction is expected to occur in developing nations (1), including many regions that sustain exceptional biodiversity and vital ecosystem services. Roads penetrating into wilderness or frontier areas are a major proximate driver of habitat loss and fragmentation, wildfires, overhunting and other environmental degradation, often with irreversible impacts on ecosystems (2-5). Unfortunately, much road proliferation is chaotic or poorly planned (3,4,6), and the rate of expansion is so great that it often overwhelms the capacity of environmental planners and managers (2-7). Here we present a global scheme for prioritizing road building. This large-scale zoning plan seeks to limit the environmental costs of road expansion while maximizing its benefits for human development, by helping to increase agricultural production, which is an urgent priority given that global food demand could double by mid-century (8,9). Our analysis identifies areas with high environmental values where future road building should be avoided if possible, areas where strategic road improvements could promote agricultural development with relatively modest environmental costs, and 'conflict areas' where road building could have sizeable benefits for agriculture but with serious environmental damage. Our plan provides a template for proactively zoning and prioritizing roads during the most explosive era of road expansion in human history.