Nonlethal management of baboons on the urban edge of a large metropole

2020 ◽  
Vol 82 (8) ◽  
Author(s):  
Angela C. Doorn ◽  
M. J. O'Riain
Keyword(s):  
2018 ◽  
Vol 40 (6) ◽  
pp. 555 ◽  
Author(s):  
Tamer Khafaga ◽  
Greg Simkins ◽  
David Gallacher

Urban developments affect neighbouring ecosystems in multiple ways, usually decreasing native biodiversity. Arabian arid rangeland was studied to identify the primary causes of biodiversity variation. Al Marmoum is a 990km2 area on the urban edge of Dubai, designated for ecological ‘enhancement’ and outdoor recreational use. The area lacks historical biodiversity data, but is thought to be primarily influenced by Arabian camel (Camelus dromedarius Linnaeus, 1758) herbivory. Perennial floral and faunal diversity was assessed at 54 sites. Counts of reintroduced ungulates (Arabian oryx Oryx leucoryx (Pallas, 1777), Arabian gazelle Gazella gazella cora (C.H. Smith, 1827) and sand gazelle G.subgutturosa marica (Thomas, 1897)) were made at 79 separate sites. Correlations of observed biodiversity with substrate type, anthropogenic structures, and ungulate distribution were assessed. Native biodiversity was substantially higher in north-north-west locations near recreational facilities, with the most likely cause being differential browsing pressure. Camel browsing faced greater communal regulation in the north-north-west, whereas oryx and gazelles congregated at feed points in the south-south-east that were farther from human activity. Arid rangeland in this socioecological landscape exhibits greater natural biodiversity at the urban fringe. Human activity reduces ungulate density, enabling a greater diversity of perennial flora, which then attracts non-ungulate fauna. Anthropogenic features can therefore offer conservation value in landscapes where ungulate populations are artificially elevated.


2010 ◽  
Vol 16 (2) ◽  
pp. 92 ◽  
Author(s):  
Peter Smith ◽  
Judy Smith

Urban edge effects can have an adverse impact on native flora and fauna in the adjoining bushland. We surveyed edge effects at sites in the Blue Mountains where the urban area is separated from bushland by a perimeter road. Common edge effects included weed invasion, physical disturbance of the vegetation and soil, incidental rubbish, dumped rubbish, dumped plant material, tree felling/lopping/ringbarking and visits from domestic dogs. Uncommon edge effects included recent hazard reduction burns, bushrock collection, and poor tree health (dieback not associated with fires). The maximum extent of obvious edge effects (all types combined) varied between sites, from 9 m to 60 m from the edge of the road. At most sites (77%), edge effects were restricted to distances of 40 m or less into the bushland, but a significant number of sites (23%) had more extensive edge effects. Sites with extensive weed invasion were associated with older housing, suggesting that weed invasion will increase over time at sites adjacent to younger housing. Weed invasion frequently extended further than 60 m into the bushland along drainage lines and tracks, especially the former, but these were not included in the measurements. Edge effects were more extensive on flatter topography than downslope of housing, apparently because the former is subject to more intensive use by local residents. The actions of local residents have a major influence on edge effects, and are responsible for much of the variability observed between sites. The findings of this study are consistent with previous studies of edge effects around Sydney and elsewhere. Based on the results of the study, we recommend that a buffer of native vegetation at least 60 m wide should be retained around significant flora and fauna habitats to protect them from edge effects. Additional management actions are required to control vegetation degradation along drainage lines.


Author(s):  
Rachel Sari-Dewi Murray ◽  
Sam Kebbell ◽  
Martin Bryant

Supervisors: Sam Kebbell, Martin Bryant This design-led research project addresses the rapid environmental degradation and socioeconomic decline to which many of New Zealand's low-lying swampland regions have succumbed. The research critiques existing settlement patterns, investigating innovative urban forms that work dually to reactivate the wetland environments while increasing population density to levels required for public systems to function sustainably and vitally. The design project identifies a squared-off urban conservation wetland, transforming it into a new Wetland Square: a civic heart of the region’s natural and cultural heritage. A Market Pier is also proposed, extending from the urban edge of the town square towards the central wetland lagoon. The research rethinks traditional land conservation practice in New Zealand’s settled regional landscapes, stressing architecture’s responsibility to reconcile urban, ecological and cultural heritage systems to ensure environmental and community resilience in the regional landscape.


2020 ◽  
Vol 12 (22) ◽  
pp. 3810
Author(s):  
Xiuxiu Chen ◽  
Feng Zhang ◽  
Zhenhong Du ◽  
Renyi Liu

An accelerating trend of global urbanization accompanying various environmental and urban issues makes frequently urban mapping. Nighttime light data (NTL) has shown great advantages in urban mapping at regional and global scales over long time series because of its appropriate spatial and temporal resolution, free access, and global coverage. However, the existing urban extent extraction methods based on nighttime light data rely on auxiliary data and training samples, which require labor and time for data preparation, leading to the difficulty to extract urban extent at a large scale. This study seeks to develop an unsupervised method to extract urban extent from nighttime light data rapidly and accurately without ancillary data. The clustering algorithm is applied to segment urban areas from the background and multi-scale spatial context constraints are utilized to reduce errors arising from the low brightness areas and increase detail information in urban edge district. Firstly, the urban edge district is detected using spatial context constrained clustering, and the NTL image is divided into urban interior district, urban edge district and non-urban interior district. Secondly, the urban edge pixels are classified by an adaptive direction filtering clustering. Finally, the full urban extent is obtained by merging the urban inner pixels and the urban pixels in urban edge district. The proposed method was validated using the urban extents of 25 Chinese cities, obtained by Landsat8 images and compared with two common methods, the local-optimized threshold method (LOT) and the integrated night light, normalized vegetation index, and surface temperature support vector machine classification method (INNL-SVM). The Kappa coefficient ranged from 0.687 to 0.829 with an average of 0.7686 (1.80% higher than LOT and 4.88% higher than INNL-SVM). The results in this study show that the proposed method is a reliable and efficient method for extracting urban extent with high accuracy and simple operation. These imply the significant potential for urban mapping and urban expansion research at regional and global scales automatically and accurately.


Acta Tropica ◽  
2020 ◽  
Vol 206 ◽  
pp. 105441 ◽  
Author(s):  
Adam Hendy ◽  
Eduardo Hernandez-Acosta ◽  
Bárbara Aparecida Chaves ◽  
Nelson Ferreira Fé ◽  
Danielle Valério ◽  
...  

2021 ◽  
Vol 36 (5) ◽  
pp. 391-410
Author(s):  
Alison Todes ◽  
Jennifer Houghton

Urban peripheral growth takes diverse forms, including the development of new economic centralities, raising questions about access to employment for residents, especially in contexts where unemployment is high and economies are shifting towards more skilled and service-related employment. This article explores two case studies of residents’ experience of access to employment close to economic centralities on the urban edge in South Africa: the growing northern eThekwini area (Durban), which has developed major retail and office complexes since the 1990s and more recently a new airport and industrial spaces, and a declining industrial decentralisation point established in the 1980s on the eastern edge of the City of Tshwane (Pretoria). It shows the severe impact of industrial decline in the Tshwane case, but while unemployment is less in northern eThekwini, access to employment for low-income residents in these areas is still very limited and constrained. Experiences are however differentiated, suggesting a complexity of outcomes. The cases point to the vulnerability of these economic centralities to economic change and the limits of new developments on the urban periphery to addressing unemployment. These findings have implications for the current advocacy of ‘new cities’ in economic contexts such as South Africa.


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