scholarly journals Bee Guilds’ Responses to Urbanization in Neotropics: A Case Study

Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 365
Author(s):  
Sônia Guimarães Alves ◽  
Maria Cristina Gaglianone
Keyword(s):  
City Planning ◽  
Trophic Specialization ◽  
Explanatory Variables ◽  
Wild Bee ◽  
Nesting Site ◽  
Green Areas ◽  
Bee Diversity ◽  
Eusocial Bees ◽  
Bee Communities

The consequent deforestation of urban sprawl is one of the causes of the decline of wild bee communities. In this context, urban green areas (UGA) may play an important role and constitute refuge areas for bees. This study analyzed the influence of UGA conditions and their surroundings in bee guilds’ responses in a medium-sized Brazilian city (Campos dos Goytacazes, RJ). The bees were sampled for 12 months (2017–2018) in 12 UGAs, and bee abundance and species richness were evaluated in guilds considering: nesting behavior, nesting site, and trophic specialization. We used as explanatory variables conditions of UGAs—the number of trees (NT), diameter at breast height (DBH), flower cover (FC), plant richness (PR), percentage of paving (PV)—and of their surroundings—paving (SPV) and the number of buildings (NB). Results showed 80% of eusocial bees, 82% nest in cavities, and 99% were generalists. FC, DBH, and NB mainly explained the responses of different guilds in study areas from all explanatory variables. Thus, this study confirms different responses associated with bee guilds’ attributes. In order to conserve bee diversity, city planning must include more green areas with large flower covers and avoid long corridors of high buildings that can impact bee dispersion.

Postharvest Bee Diversity is High but Declines Rapidly with Stand Age in Regenerating Douglas-Fir Forest

2021 ◽  
Author(s):  
James W Rivers ◽  
Matthew G Betts
Keyword(s):  
Distinct Species ◽  
Douglas Fir ◽  
Floral Resources ◽  
Stand Age ◽  
Managed Forests ◽  
Wild Bee ◽  
Bee Diversity ◽  
Key Driver ◽  
Bee Communities

Abstract Concerns about long-term pollinator declines have made assessing bee communities a priority in nonagricultural ecosystems, including managed forests. We assessed wild bee communities in Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) stands one to 15 years after clearcut harvest in western Oregon, USA, testing the hypothesis that bee diversity would be high initially and then decline with time-dependent reductions in floral resources. We captured 2,009 individual bees that represented 67 distinct species/morphospecies in 20 genera and five families. Asymptotic estimators of bee diversity representing Shannon and Simpson diversity were greater in communities during the second half of the early seral period, indicating older early seral stands were less diverse and contained more common and dominant bee species. In addition, observed species richness and bee abundance peaked at approximately three years postharvest and declined thereafter by 20% and 30% per year, respectively. Because floral resources declined in concert with reductions in bee diversity as stands aged, food appears to be a key driver of forest bee communities. Our results indicate that postharvest Douglas-fir stands supported a diversity of bees, including important crop pollinators, but their value to bees was restricted to a relatively short window at the beginning of the early seral period.

scholarly journals The bee fauna of an Atlantic coastal plain tidal marsh community in Southern New England, USA

2019 ◽  
pp. 1-34 ◽  
Author(s):  
Tracy A. Zarrillo ◽  
Kimberly A. Stoner
Keyword(s):  
New England ◽  
Alien Plants ◽  
Atlantic Coastal Plain ◽  
Wild Bees ◽  
Southern New England ◽  
Wild Bee ◽  
Bee Diversity ◽  
Conservation Concern ◽  
Abundance And Diversity ◽  
Bee Communities

 With growing evidence of changes in local abundance, geographical range, and species diversity of wild bees, it is imperative to document wild bee communities in representative habitats throughout North America. The Connecticut shoreline has historically been subject to many natural and anthropogenic disturbances, and there is a lack of baseline data regarding bee biodiversity in Connecticut’s maritime habitats. In this study, we characterize the wild bee fauna of a discrete maritime habitat in Connecticut, USA, and examine salt-marsh, beach dune, and coastal scrub bee communities adjacent to Long Island Sound. Patterns found are discussed in relation to recent coastal surveys in New England. Biweekly surveys were conducted at Grass Island (Guilford, CT) over a two-year period (2011-2012) using pan traps and effort-based (timed) net collecting from flowers. A total of 3928 individual bees were collected, representing five families, 18 genera and at least 80 species. Floral records for 374 individuals resulted in associations of 35 bee species with 19 species of flowers. Seventy percent of the bees captured in the net survey were visiting alien plants, with the exotic Rosa rugosa Thunb. having the highest level of bee diversity and relative abundance. The total number of bee species collected in this survey represents approximately 23% of the known Connecticut fauna, including four specialists associated with coastal and wetland habitats. The abundance and diversity of bees visiting alien plants on Grass Island, as well as the occurrence of these sand specialists, may prove to be of conservation concern as the Connecticut shoreline continues to be altered.  

IMF Stabilization Programs, Policy Conduct and Macroeconomic Outcomes: A Case Study of Pakistan

2006 ◽  
Vol 11 (1) ◽  
pp. 35-62
Author(s):  
Nawaz A. Hakro ◽  
Wadho Waqar Ahmed
Keyword(s):  
Current Account ◽  
Inflation Rate ◽  
Current Account Balance ◽  
Macroeconomic Policies ◽  
Explanatory Variables ◽  
Fiscal Balance ◽  
Macroeconomic Impacts ◽  
The Individual ◽  
The Imf

This study is designed to assess the macroeconomic performance of fund-supported programs, and the sequencing and ordering of macroeconomic policies in the context of the Pakistan economy. The generalized evaluation estimator technique has been used to assess the macroeconomic impacts of the IMF supported programs. GDP growth, inflation rate, current account balance, fiscal balance and unemployment are used as the target variables in order to gauge economic performance during the program years. The vector of policy variables (that might have been adopted in the absence of programs) and the vector of foreign exogenous variables are also taken as explanatory variables in the model, so that the individual effect of the IMF supported programs could be assessed. The result suggests that as the IMF prescriptions were applied, the current account balance has worsened, the unemployment rate has significantly increased, and the inflation rate has increased during the years of fund-supported programs. Only the budget balance has shown signs of improvement. Furthermore an inadequate sequencing of reforms has contributed to the further worsening of the economic scenario during the program period.

Influence of Nesting Characteristics on Health of Wild Bee Communities

2020 ◽  
Vol 65 (1) ◽  
pp. 39-56 ◽  
Author(s):  
Alexandra Harmon-Threatt
Keyword(s):  
Climate Change ◽  
Nest Site ◽  
Site Conditions ◽  
Wild Bees ◽  
Nesting Biology ◽  
Habitat Disturbances ◽  
Wild Bee ◽  
Growth Development ◽  
Bee Communities ◽  
Nest Initiation

Nest site availability and quality are important for maintaining robust populations and communities of wild bees. However, for most species, nesting traits and nest site conditions are poorly known, limiting both our understanding of basic ecology for bee species and conservation efforts. Additionally, many of the threats commonly associated with reducing bee populations have effects that can extend into nests but are largely unstudied. In general, threats such as habitat disturbances and climate change likely affect nest site availability and nest site conditions, which in turn affect nest initiation, growth, development, and overwintering success of bees. To facilitate a better understanding of how these and other threats may affect nesting bees, in this review, I quantify key nesting traits and environmental conditions and then consider how these traits may intersect with observed and anticipated changes in nesting conditions experienced by wild bees. These data suggest that the effects of common threats to bees through nesting may strongly influence their survival and persistence but are vastly understudied. Increasing research into nesting biology and incorporating nesting information into conservation efforts may help improve conservation of this declining but critical group.

scholarly journals Multi-Criteria, Co-Evolutionary Charging Behavior: An Agent-Based Simulation of Urban Electromobility

2021 ◽  
Vol 12 (1) ◽  
pp. 18
Author(s):  
Lennart Adenaw ◽  
Markus Lienkamp
Keyword(s):  
Urban Areas ◽  
City Planning ◽  
User Behavior ◽  
Transport Sector ◽  
Simulation Framework ◽  
Agent Based Simulation ◽  
Agent Based ◽  
Charging Station ◽  
Spatio Temporal

In order to electrify the transport sector, scores of charging stations are needed to incentivize people to buy electric vehicles. In urban areas with a high charging demand and little space, decision-makers are in need of planning tools that enable them to efficiently allocate financial and organizational resources to the promotion of electromobility. As with many other city planning tasks, simulations foster successful decision-making. This article presents a novel agent-based simulation framework for urban electromobility aimed at the analysis of charging station utilization and user behavior. The approach presented here employs a novel co-evolutionary learning model for adaptive charging behavior. The simulation framework is tested and verified by means of a case study conducted in the city of Munich. The case study shows that the presented approach realistically reproduces charging behavior and spatio-temporal charger utilization.

scholarly journals Mining Vehicle Trajectories to Discover Individual Significant Places: Case Study using Floating Car Data in the Paris Region

2021 ◽  
pp. 036119812199550
Author(s):  
Danyang Sun ◽  
Fabien Leurent ◽  
Xiaoyan Xie
Keyword(s):  
Large Scale ◽  
City Planning ◽  
Human Mobility ◽  
Work Place ◽  
Trajectory Data ◽  
Floating Car Data ◽  
Vehicle Trajectories ◽  
Activity Types ◽  
Paris Region

In this study we discovered significant places in individual mobility by exploring vehicle trajectories from floating car data. The objective was to detect the geo-locations of significant places and further identify their functional types. Vehicle trajectories were first segmented into meaningful trips to recover corresponding stay points. A customized density-based clustering approach was implemented to cluster stay points into places and determine the significant ones for each individual vehicle. Next, a two-level hierarchy method was developed to identify the place types, which firstly identified the activity types by mixture model clustering on stay characteristics, and secondly discovered the place types by assessing their profiles of activity composition and frequentation. An applicational case study was conducted in the Paris region. As a result, five types of significant places were identified, including home place, work place, and three other types of secondary places. The results of the proposed method were compared with those from a commonly used rule-based identification, and showed a highly consistent matching on place recognition for the same vehicles. Overall, this study provides a large-scale instance of the study of human mobility anchors by mining passive trajectory data without prior knowledge. Such mined information can further help to understand human mobility regularities and facilitate city planning.

Bike your City: Planning and Designing Cycling Infrastructure in the Urban Environment

2021 ◽  
Author(s):  
◽  
Jack J. Jiang
Keyword(s):  
Urban Environment ◽  
Traffic Congestion ◽  
City Planning ◽  
Environment Design ◽  
Mode Of Transport ◽  
Design Case Study ◽  
Architecture And Design ◽  
Graphical Design ◽  
The City

<p>Cycling is a memory of the past for most of us, the lack of support from the authorities on the cycling infrastructure made it difficult to attract people to cycle in the city. Urban sprawl, traffic congestion, car dependency, environmental pollution and public health concerns have pressured cities around the world to consider reintegrating cycling into the urban environment.  Design as a research method was utilised to investigate the effectiveness of design methodology and workflow for cycling infrastructure from an architecture and design perspective. Using Wellington City as a design case study, this research aimed to improve the legibility, usability and the image of cycling as a mode of transport in the city. To achieve this, a customisable graphical design framework and branding strategies were developed to structure and organise the design components within cycling infrastructure. The findings from the iterative design processes were visualised through the appropriate architectural and presentation conventions.  This research provided an unique architectural perspectives on the issues of cycling infrastructure; the results would support the transportation advisers and urban planners to further the development and integration of cycling, as a viable mode of transport, within the city.</p>

Reliability-based covariate analysis for complex systems in heterogeneous environment: Case study of mining equipment

2018 ◽  
Vol 233 (4) ◽  
pp. 593-604
Author(s):  
Amin Moniri-Morad ◽  
Mohammad Pourgol-Mohammad ◽  
Hamid Aghababaei ◽  
Javad Sattarvand
Keyword(s):  
Complex Systems ◽  
Cox Regression ◽  
Reliability Evaluation ◽  
Distribution Functions ◽  
Heterogeneous Environment ◽  
Mining Equipment ◽  
Data Set ◽  
Explanatory Variables ◽  
The Impact

Operational heterogeneity and harsh environment lead to major variations in production system performance and safety. Traditional probabilistic model is dealt with time-to-event data analysis, which does not have the capability of quantifying and simulation of these types of complexities. This research proposes an integrated methodology for analyzing the impact of dominant explanatory variables on the complex system reliability. A flexible parametric proportional hazards model is developed by focusing on standard parametric Cox regression model for reliability evaluation in complex systems. To achieve this, natural cubic splines are utilized to create a smooth and flexible baseline hazards function where the standard parametric distribution functions do not fit into the failure data set. A real case study is considered to evaluate the reliability for multi-component mechanical systems such as mining equipment. Different operational and environmental explanatory variables are chosen for the analysis process. Research findings revealed that precise estimation of the baseline hazards function is a major part of the reliability evaluation in heterogeneous environment. It is concluded that an appropriate maintenance strategy potentially mitigate the equipment failure intensity.

scholarly journals Improving Habitat Quality at the Local and Landscape Scales Increases Wild Bee Assemblages and Associated Pollination Services in Apple Orchards in China

2021 ◽  
Vol 9 ◽  
Author(s):  
Panlong Wu ◽  
Piaopiao Dai ◽  
Meina Wang ◽  
Sijie Feng ◽  
Aruhan Olhnuud ◽  
...  
Keyword(s):  
Management Practices ◽  
Ground Cover ◽  
Agricultural Landscapes ◽  
Wild Bees ◽  
Natural Habitats ◽  
Pollination Services ◽  
Wild Bee ◽  
Wide Range ◽  
Bee Diversity ◽  
Landscape Scales

Bees provide key pollination services for a wide range of crops. Accumulating evidence shows the effect of semi-natural habitats at the landscape level and local management practices on bee diversity in fields. However, most of the evidence is derived from studies in North America and Europe. Whether this paradigm is applicable in China, which is characterized by smallholder-dominated agricultural landscapes, has rarely been studied. In this study, we aimed to investigate how bee diversity affected apple production, and how landscape and local variables affected bee diversity and species composition on the Northern China Plain. The results showed that bees significantly increased apple fruit set compared to bagged controls. Wild bee diversity was positively related to apple seed numbers. Higher seed numbers reduced the proportion of deformed apples and thus increased fruit quality. Wild bee abundance was positively correlated with flowering ground cover, and both the abundance and species richness of wild bees were positively affected by the percentage of semi-natural habitats. We conclude that apple quality can benefit from ecological intensification comprising the augmentation of wild bees by semi-natural habitats and flowering ground cover. Future pollination management should therefore reduce the intensification level of management at both the local and landscape scales.

scholarly journals SUSTAINING THE CULTURAL VITALITY OF URBAN PUBLIC MARKETS: A Case Study of Pasar Payang, Malaysia

2016 ◽  
Vol 10 (1) ◽  
pp. 228 ◽  
Author(s):  
Khalilah Zakariya ◽  
Zumahiran Kamarudin ◽  
Nor Zalina Harun
Keyword(s):  
City Planning ◽  
Local Economy ◽  
Local Identity ◽  
Cultural Participation ◽  
Structured Interviews ◽  
Public Markets ◽  
Cultural Aspects ◽  
Public Market ◽  
The City

The development of a public market in the city planning is pivotal in supporting the growth of the local economy. The market is also a place where the culture of the locals evolves daily. However, the unique qualities of the market are vulnerable to the redevelopment process. This study examines the cultural aspects of Pasar Payang in Terengganu, Malaysia, as one of the well-known markets among the locals and the tourists, which will soon be redeveloped. The aim of this paper is to identify the tangible and intangible qualities of the market, so that it can sustain its cultural qualities in the future. The methods adopted for this study comprise of conducting a survey among 497 visitors, and semi-structured interviews among 19 market vendors. The findings reveal that the cultural vitality of the market can be sustained by strengthening its local identity through its products and culture, providing spaces that can facilitate tourist activities and cultural participation, and enhancing the development of the local businesses.

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