scholarly journals Disentangling urban habitat and matrix effects on wild bee species

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2729 ◽  
Author(s):  
Leonie K. Fischer ◽  
Julia Eichfeld ◽  
Ingo Kowarik ◽  
Sascha Buchholz
Keyword(s):  
Urban Areas ◽  
Large Scale ◽  
Matrix Effects ◽  
Urban Environments ◽  
Urban Habitat ◽  
Anthropogenic Pressure ◽  
Wild Bees ◽  
Study Region ◽  
Rural Landscapes ◽  
Wild Bee

In face of a dramatic decline of wild bee species in many rural landscapes, potential conservation functions of urban areas gain importance. Yet effects of urbanization on pollinators, and in particular on wild bees, remain ambiguous and not comprehensively understood. This is especially true for amenity grassland and extensively managed wastelands within large-scale residential housing areas. Using Berlin as a study region, we aimed to investigate (a) if these greenspaces are accepted by wild bee assemblages as foraging habitats; (b) how assemblage structure of bees and individual bee species are affected by different habitat (e.g., management, flower density) and urban matrix variables (e.g., isolation, urbanization); and (c) to what extent grassland restoration can promote bees in urban environments. In summer 2012, we collected 62 bee species belonging to more than 20% of the taxa known for Berlin. Urbanization significantly affected species composition of bees; 18 species were affiliated to different levels of urbanization. Most bee species were not affected by any of the environmental variables tested, and urbanization had a negative effect only for one bee species. Further, we determined that restoration of diverse grasslands positively affected bee species richnesss in urban environments. We conclude that differently structured and managed greenspaces in large-scale housing areas can provide additional foraging habitats and refuges for pollinators. This supports approaches towards a biodiversity friendly management within urban regions and may be of particular importance given that anthropogenic pressure is increasing in many rural landscapes.

The Use of Social Media for Urban Planning

2019 ◽  
pp. 1049-1070
Author(s):  
Fabian Neuhaus
Keyword(s):  
Social Media ◽  
Big Data ◽  
Urban Areas ◽  
Large Scale ◽  
Urban Environments ◽  
Data Systems ◽  
User Management ◽  
Social Nature ◽  
User Data ◽  
Use Of Social Media

User data created in the digital context has increasingly been of interest to analysis and spatial analysis in particular. Large scale computer user management systems such as digital ticketing and social networking are creating vast amount of data. Such data systems can contain information generated by potentially millions of individuals. This kind of data has been termed big data. The analysis of big data can in its spatial but also in a temporal and social nature be of much interest for analysis in the context of cities and urban areas. This chapter discusses this potential along with a selection of sample work and an in-depth case study. Hereby the focus is mainly on the use and employment of insight gained from social media data, especially the Twitter platform, in regards to cities and urban environments. The first part of the chapter discusses a range of examples that make use of big data and the mapping of digital social network data. The second part discusses the way the data is collected and processed. An important section is dedicated to the aspects of ethical considerations. A summary and an outlook are discussed at the end.

scholarly journals Conducting Household Surveys on Reproductive Health in Urban Settings: Lessons From Karachi, Pakistan

2020 ◽  
Author(s):  
Mir Baz Khan ◽  
Sidrah Nausheen ◽  
Imtiaz Hussain ◽  
Kristy Hackett ◽  
Zahra Kaneez ◽  
...  
Keyword(s):  
Reproductive Health ◽  
Urban Areas ◽  
Large Scale ◽  
Urban Environments ◽  
Lessons Learned ◽  
Geographical Information ◽  
Health Study ◽  
Computer Assisted ◽  
Household Surveys ◽  
Technical Problems

Abstract Background: Data collection is the most critical stage in any population health study and correctly implementing fieldwork enhances the quality of collected information. However, even the most carefully planned large-scale household surveys can encounter many context-specific issues. This paper reflected on our research team’s recent experiences of conducting surveys for a quasi-experimental evaluation of a reproductive health program in urban areas of Karachi, Pakistan. Methods: The study followed a three-stage random sampling design. Result: This paper has described the issues that were encountered around technical problems related to geographical information system (GIS) usage and computer assisted personal interviews (CAPI), household listing, interviewing respondents on sensitive topics and their expectations, and other field related concerns such as ensuring privacy etc. during the survey.Conclusion: The papers has also underscored on lessons learned from this process and presented some potential solutions for conducting future household surveys in similar urban environments.

scholarly journals A VOXEL-BASED METADATA STRUCTURE FOR CHANGE DETECTION IN POINT CLOUDS OF LARGE-SCALE URBAN AREAS

2018 ◽  
Vol IV-2 ◽  
pp. 97-104
Author(s):  
J. Gehrung ◽  
M. Hebel ◽  
M. Arens ◽  
U. Stilla
Keyword(s):  
Change Detection ◽  
Urban Areas ◽  
Laser Scanning ◽  
Large Scale ◽  
Point Clouds ◽  
Urban Environments ◽  
Detection Methods ◽  
Planar Surfaces ◽  
Occupancy Grids ◽  
Speed Up

Mobile laser scanning has not only the potential to create detailed representations of urban environments, but also to determine changes up to a very detailed level. An environment representation for change detection in large scale urban environments based on point clouds has drawbacks in terms of memory scalability. Volumes, however, are a promising building block for memory efficient change detection methods. The challenge of working with 3D occupancy grids is that the usual raycasting-based methods applied for their generation lead to artifacts caused by the traversal of unfavorable discretized space. These artifacts have the potential to distort the state of voxels in close proximity to planar structures. In this work we propose a raycasting approach that utilizes knowledge about planar surfaces to completely prevent this kind of artifacts. To demonstrate the capabilities of our approach, a method for the iterative volumetric approximation of point clouds that allows to speed up the raycasting by 36 percent is proposed.

scholarly journals Devising Urban Biodiversity Habitat Provision Goals: Ecosystem Services Analysis

Forests ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 391 ◽  
Author(s):  
Maibritt Pedersen Zari
Keyword(s):  
Ecosystem Services ◽  
Ecosystem Service ◽  
Service Provision ◽  
Urban Areas ◽  
Urban Environments ◽  
Comparative Case Study ◽  
Urban Habitat ◽  
Urban Green ◽  
Analysis Methodology ◽  
Negative Environmental Impact

This paper employs a unique ecosystem services analysis methodology to evaluate how cities could support or generate ecosystem services. Ecosystem services analysis can provide quantifiable goals for urban ecological regeneration that are determined by the site-specific ecology and climate of an urban area. In this research, the ecosystem service of habitat provision is the key focus. The role of urban green space and urban forests is crucial within this. Setting ambitious targets for urban ecological performance and ecosystem services provision is of great importance due to the large negative environmental impact that cities currently have on ecosystems and, therefore, ecosystem service provision, and because healthier ecosystems enable humans to better adapt to climate change through creating potentials for increased resilience. A comparative case study analysing the ecosystem service of habitat provision in two existing urban environments with similar climates (Cfb according to the Köppen Climate Classification System) but in different parts of the world, namely Wellington, New Zealand and Curitiba, Brazil, was conducted to examine how the ecosystem services analysis concept can used to devise urban habitat provision goals. The paper concludes that, although achieving habitat provision goals derived from ecosystem services analysis in urban areas is likely to be difficult, determining quantitative site- and climate-specific staged goals could enable urban design professionals to increase the effectiveness of conservation and regeneration efforts in terms of ecosystem service provision from urban green and blue spaces.

The Use of Social Media for Urban Planning

2014 ◽  
pp. 113-134 ◽  
Author(s):  
Fabian Neuhaus
Keyword(s):  
Social Media ◽  
Big Data ◽  
Urban Areas ◽  
Large Scale ◽  
Urban Environments ◽  
Data Systems ◽  
User Management ◽  
Social Nature ◽  
User Data ◽  
Use Of Social Media

User data created in the digital context has increasingly been of interest to analysis and spatial analysis in particular. Large scale computer user management systems such as digital ticketing and social networking are creating vast amount of data. Such data systems can contain information generated by potentially millions of individuals. This kind of data has been termed big data. The analysis of big data can in its spatial but also in a temporal and social nature be of much interest for analysis in the context of cities and urban areas. This chapter discusses this potential along with a selection of sample work and an in-depth case study. Hereby the focus is mainly on the use and employment of insight gained from social media data, especially the Twitter platform, in regards to cities and urban environments. The first part of the chapter discusses a range of examples that make use of big data and the mapping of digital social network data. The second part discusses the way the data is collected and processed. An important section is dedicated to the aspects of ethical considerations. A summary and an outlook are discussed at the end.

scholarly journals Road to ruin: Herbivory in a common tropical weed (Turnera subulata) along a rural-urban gradient

2020 ◽  
Author(s):  
Antonio C. de Andrade ◽  
L. Ruth Rivkin
Keyword(s):  
Urban Areas ◽  
Plant Defence ◽  
Impervious Surface ◽  
Urban Environments ◽  
Urban Habitat ◽  
Elevated Concentration ◽  
List Type ◽  
Urban Gradient ◽  
Pollution Levels ◽  
Positive Effects

AbstractUrbanization is associated with numerous changes to the biotic and abiotic environment, many of which degrade biodiversity. For example, cities often have increased pollution levels that harm wildlife. Nevertheless, the elevated concentration of some gases can fertilize urban plants, with concomitant positive effects on herbivore populations that could select defence phenotypes in plants. However, actual evidence supporting increased herbivory in urban environments remains scarce and contradictory. Giving the gaps in our knowledge, particularly in tropical cities, we evaluate herbivory on Turnera subulata, a common weed, along a rural-urban gradient in Joao Pessoa, Brazil. We expected higher rates of herbivory in urban areas and we predicted these populations to evolve cyanogenesis. We quantified herbivory and screened for cyanogenesis in 32 populations (617 plants) along the urbanization. Our results show that urban populations had significantly higher herbivory rates than rural populations. The likelihood of herbivory was positively correlated to increased amount of impervious surface, although there was no difference in amount of leaf loss to herbivory. Despite elevated herbivory, we found no evidence for the evolution of cyanongenesis in any of the populations. Habitat loss, predator release, and nutrient enrichment likely act in concert to benefit of leaf-eating arthropods, influencing the herbivory patterns observed in our study.HIGHLIGHTSHigher arthropod herbivory in cities can drive the evolution of urban plant defenceWe found increased herbivory in urban habitat, mostly by lace bugsWe found a significant positive effect of impervious surface on herbivoryExtensive impervious surfaces and stressful urban environment facilitate herbivory, but do not lead to the expression of HCN, a antiherbivore defense chemical

The fancy city life: Kuhl's pipistrelle, Pipistrellus kuhlii, benefits from urbanisation

2015 ◽  
Vol 42 (7) ◽  
pp. 598 ◽  
Author(s):  
Leonardo Ancillotto ◽  
Alessandra Tomassini ◽  
Danilo Russo
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Urban Environments ◽  
Urban Habitat ◽  
Urban Habitats ◽  
Wild Mammals ◽  
City Life ◽  
Ecological Flexibility ◽  
Major Process

Context Urbanisation is often regarded as a major threat to global biodiversity. Although wildlife is frequently affected by urbanisation, some species may actually benefit from it. Bats are among the commonest wild mammals in human-modified areas, and some species seem particularly well suited to exploit urban habitats where they find roosting and foraging opportunities. Aims We investigated habitat selection around roosts of synurbic Kuhl’s pipistrelles, Pipistrellus kuhlii, in Italy. Methods We measured the effects of the amount of urban habitat on bat reproductive timing and success in human-modified environments. Key results We found that P. kuhlii selects roosts surrounded by areas featuring urban habitats, especially those subject to urban development. Colonies in cities and suburbs advanced parturition time and produced more pups than those in rural areas. Permanent water sources and artificial lights in the surrounding habitats also seemed to favour the species reproductive success, particularly in developing urban areas. Conclusions Our results showed that this bat benefits from urbanisation and provided new insights on the effects of this major process on animal ecology and conservation in urban environments. Implications Although the ecological flexibility and positive response to urbanisation of P. kuhlii may help explain its recent range expansion, the role of climate change as a potential driver of this process has yet to be tested.

scholarly journals Assessing trends in rat populations in urban and non-urban environments in the Netherlands

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Miriam Maas ◽  
Tamara Helsloot ◽  
Katsuhisa Takumi ◽  
Joke van der Giessen
Keyword(s):  
The Netherlands ◽  
Urban Areas ◽  
Large Scale ◽  
Low Cost ◽  
Urban Environments ◽  
Local Municipalities ◽  
Term Monitoring ◽  
Insight Into ◽  
Large Municipality

Abstract Rats in urban areas pose health risks as they can transmit various zoonotic pathogens. Monitoring rat populations in urban areas is therefore a key determinant in risk assessments for taking adequate control and preventive measures. However, large-scale and long-term monitoring of rat populations is labor-intensive and time consuming. The aim of this study was to develop a low-cost and low-time- consuming method to gain insight into the trends of rat populations in urban and non-urban environments in the Netherlands, and to identify potential drivers of these trends. From 2014 to 2018, local municipalities or their pest control organizations voluntarily submitted quarterly overviews of rat nuisance reports in urban areas. For non-urban areas, a nationwide record of reported bycatch species from the muskrat control was used to assess a potential trend. To identify potential drivers of observed trends, employees of nine municipalities were interviewed. Rat nuisance reports from 25 municipalities were analyzed. An increasing trend in rat nuisance reports was observed in 12, a decreasing trend in 3 and no trend in 10 municipalities. In non-urban areas, no trend in the bycatch of rats was detected. The increase in rat nuisance reports was associated with a large municipality resident size. No consistent drivers could be identified, but potential drivers were discussed in the interviews. Although it was not possible to quantify their influence on the rat population trends seen, they provide direction for future studies on drivers of rat populations.

scholarly journals Implementing Nature-Based Solutions in Rural Landscapes: Barriers Experienced in the PHUSICOS Project

2021 ◽  
Vol 13 (3) ◽  
pp. 1461
Author(s):  
Anders Solheim ◽  
Vittoria Capobianco ◽  
Amy Oen ◽  
Bjørn Kalsnes ◽  
Turid Wullf-Knutsen ◽  
...  
Keyword(s):  
Urban Areas ◽  
Large Scale ◽  
Practical Implementation ◽  
Horizon 2020 ◽  
Rural Landscapes ◽  
Rural Settings ◽  
Main Barrier ◽  
Risk Reducing ◽  
The Eu

Nature-based solutions (NBS) are becoming increasingly important in both the EU and individual countries’ political agendas, as a sustainable means to reduce the risk posed by hydrometeorological hazards. However, as the use of NBS is increasing, a number of barriers regarding their practical implementation also become apparent. A number of review studies have summarized and classified barriers, mainly in urban settings. PHUSICOS is a Horizon 2020 Innovation Action to demonstrate the use of NBS in rural and mountain landscapes. Large-scale demonstrator case sites with several sub-projects are established in Italy, Norway and in the French and Spanish Pyrenees. The present paper describes the project’s NBS measures and their experienced barriers, some of which have resulted in full cancellation of the planned interventions. Many of the barriers experienced in rural settings have the same root causes as the ones described from urban areas, and the main barrier-creating mechanisms are institutional factors, resistance among stakeholders and technical and economic issues. The key element, however, is the lack of knowledge about the ability of NBS to deliver a series of co-benefits in addition to their risk-reducing effects and that long-term thinking is required to see the effect of many of these co-benefits.

scholarly journals Building Extraction from Very High Resolution Stereo Satellite Images Using OBIA and Topographic Information

2020 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Minakshi Kumar ◽  
Ashutosh Bhardwaj
Keyword(s):  
High Resolution ◽  
Urban Areas ◽  
Large Scale ◽  
Decision Rules ◽  
Urban Environments ◽  
Fuzzy Rules ◽  
Building Extraction ◽  
Digital Elevation ◽  
Elevation Model ◽  
Very High

The availability of very high resolution (VHR) satellite imagery (<1 m) has opened new vistas in large-scale mapping and information management in urban environments. Buildings are the most essential dynamic incremental factor in the urban environment, and hence their extraction is the most challenging activity. Extracting the urban features, particularly buildings using traditional pixel-based classification approaches as a function of spectral tonal value, produces relatively less accurate results for these VHR Imageries. The present study demonstrates building extraction using Pleiades panchromatic (PAN) and multispectral stereo satellite datasets of highly planned and dense urban areas in parts of Chandigarh, India. The stereo datasets were processed in a photogrammetric environment to obtain the digital elevation model (DEM) and corresponding orthoimages. DEM’s were generated at 0.5 m and 2.0 m from stereo PAN and multispectral datasets, respectively. The orthoimages thus generated were segmented using object-based image analysis (OBIA) tools. The object primitives such as scale parameter, shape, textural parameters, and DEM derivatives were used for segmentation and subsequently to determine threshold values for building fuzzy rules for building extraction and classification. The rule-based classification was carried out with defined decision rules based on object primitives and fuzzy rules. Two different methods were utilized for the performance evaluation of the proposed automatic building approach. Overall accuracy, correctness, and completeness were evaluated for extracted buildings. It was observed that overall accuracy was higher (>93%) in areas having larger buildings and that were sparsely built-up as compared to areas having smaller buildings and being densely built-up.

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