Saddles and Barrier in Landscapes of Generalized Search Operators

Barrier trees are a convenient way of representing the structure of complex combinatorial landscapes over graphs. Here we generalize the concept of barrier trees to landscapes defined over general multi-parent search operators based on a suitable notion of topological connectedness that depends explicitly on the search operator. We show that in the case of recombination spaces, path-connectedness coincides with connectedness as defined by the mutation operator alone. In contrast, topological connectedness is more general and depends on the details of the recombination operators as well. Barrier trees can be meaningfully defined for both concepts of connectedness

Coming down from the trees: is terrestrial activity in Bornean orangutans natural or disturbance driven?

The orangutan is the world's largest arboreal mammal, and images of the red ape moving through the tropical forest canopy symbolise its typical arboreal behaviour. Records of terrestrial behaviour are scarce and often associated with habitat disturbance. We conducted a large-scale species-level analysis of ground-based camera-trapping data to evaluate the extent to which Bornean orangutans Pongo pygmaeus come down from the trees to travel terrestrially, and whether they are indeed forced to the ground primarily by anthropogenic forest disturbances. Although the degree of forest disturbance and canopy gap size influenced terrestriality, orangutans were recorded on the ground as frequently in heavily degraded habitats as in primary forests. Furthermore, all age-sex classes were recorded on the ground (flanged males more often). This suggests that terrestrial locomotion is part of the Bornean orangutan's natural behavioural repertoire to a much greater extent than previously thought, and is only modified by habitat disturbance. The capacity of orangutans to come down from the trees may increase their ability to cope with at least smaller-scale forest fragmentation, and to cross moderately open spaces in mosaic landscapes, although the extent of this versatility remains to be investigated

"Edible" urban forests as part of inclusive, sustainable cities

Feeding an increasingly urban population and ensuring the economic and social well-being of urban dwellers will be the primary challenge for cities in coming decades. The impacts of climate change are expected to slow down urban economic growth, exacerbate environmental degradation, increase poverty and erode urban food security. Many cities are on a quest for more sustainable urbanization pathways that will enable effective responses to the increasing socio-economic and environmental challenges they face. In the search to \u201cmake cities and human settlements inclusive, safe, resilient and sustainable\u201d (Sustainable Development Goal 11 in the United Nations Sustainable Development Agenda 2030), interest is increasing in growing local food. Edible green infrastructure, mainly in the form of urban food forests and trees (referred to here generally as urban food forests and also sometimes as tree-based edible landscaping), can help address a range of problems caused by rapid and unplanned urbanization, such as food scarcity, poverty, the deterioration of human health and well-being, air pollution, and biodiversity loss. The use of edible plants in urban and peri-urban forestry varies among cities and is influenced by historical, cultural and socio-economic factors. Overall, it has tended to be neglected in modern cities. This article explores the potential of urban and peri-urban forests as sources of food and the role that urban food forests can play in fostering sustainable cities

‘Pushing on through transparencies’ : H.D.’s shores and the creation of new space

‘If she could have gone to Point Pleasant, listened to the sea, everything would come right… escape through barriers…’ (H.D., HERmione). Shorelines and natural borders recur throughout H.D.’s work; Atlantic coasts and English coasts in her prose, Greek islands and deconstructed dreamscapes in her poetry, even riverbanks and animal cages in her work with Pool Films. In this essay, I examine the way in which H.D.’s shores construct “new spaces” in which H.D. tests the definitions and boundaries of conventional society, including the break between “elsewhere” and “here” in the imaginations of the novel HERmione, the space between beauty and ugliness in the coastal wildflower poems of Sea Garden, and the construction of a space in which man and nature are unified in ‘Oread’. Hidden in these spaces are implications for H.D.’s dealings with androgyny and gender, and a vision for a more unified natural world and environmental poetic.peer-reviewe

Peoples’ use of, and concerns about, green space networks: A case study of Birchwood, Warrington New Town, UK

Cultural services provided by green space networks and in particular leisure and recreational opportunities are central to the quality of life of those living in urban areas. However, the literature concerned with green space networks has mainly focussed on planning aspects rather than on recreational use. The aim of this study was to evaluate the recreational use of, and concerns about, a naturalistic green space network. The case study location was the naturalistic woodland framework in Birchwood, Warrington, UK, known as Birchwood Forest Park. Non-participant observation and content analysis of local archives were used to collect quantitative and qualitative data. Birchwood Forest Park was used more for leisure activities (52.8%, N = 1,825; i.e. recreation, sports or play) than for utilitarian purposes (47.2%, N = 1,825; i.e. as walking or cycling thoroughfare). However, utilitarian walking (30%, N = 1,825) was the most frequent type of activity observed. The maintenance of the naturalistic woodland framework was the most frequent concern mentioned in the local archives (33.3%, N = 234). This case study suggests that the recreational patterns in, as well as peoples’ concerns about, naturalistic urban landscapes may be a factor of high quality maintenance and associated local aesthetic and cultural perceptions. In developing, planning or managing comprehensive urban green space networks it is important to ensure that natural looking scenes are well maintained and that the local community is culturally connected to such scenes

Sustainable deathstyles? The geography of green burials in Britain

In the context of a wider literature on ‘deathscapes’, we map the emergence of a new mode of burial and remembrance in Britain. Since a ‘green’ burial ground was established in Carlisle in 1993, sites for so-called ‘green, ‘natural’ or ‘woodland’ funerals have proliferated. There are now over 270 such sites in Britain. Drawing on a postal and email survey sent to all managers/owners and visits to 15 green burial grounds (enabling observations and semi-structured interviews with their managers), we chart their growth, establishment and regulation and describe the landscapes associated with them. This requires, and leads to, wider reflections on nature, capital, consumption, culture and the body

Emergent Landscape: Urban Shadow Space, Illuminated

This study defines a new approach to the transformation of unmaintained land within cities, or urban shadow space. Although urban shadow space can offer a place of free expression for the community and spontaneous vegetative growth within a city, it is often dismissed as blighted land by public authority. This study maximizes existing opportunities of these spaces, illuminating a realm of the city that is currently dark to the public eye. A proposed set of guidelines is utilized in the creation of three alternative designs that illustrate the emergent landscape, a sensitively designed, evolving landscape that encourages user interaction with the site. These guidelines and the results of their application are intended to assist design professionals who wish to move beyond the typical “clean and green” strategy currently employed by many municipalities to embrace a site’s existing characteristics