scholarly journals Dancing bees evaluate agricultural forage resources as inferior to central urban land

Author(s):  
Ash E. Samuelson ◽  
Roger Schürch ◽  
Ellouise Leadbeater

AbstractRecent evidence suggests that flower-rich areas within cities could play an important role in pollinator conservation, but direct comparison of agricultural and urban areas has proved challenging to perform over large scales. Here we use the waggle dances of honeybees (Apis mellifera L.) to evaluate floral resource availability over the entire season at deeply urban or agricultural sites. Through analysis of 3378 dances that were performed over two years by 20 colonies in SE England, we show that foraging trip distance is consistently lower at urban sites across the entire season, implying a higher availability of forage in heavily urbanized areas. Urban bees also collected nectar with a higher mean sugar content. From the self-reported perspective of a generalist pollinator, the modern agricultural landscapes that we studied provided insufficient and transient resources relative to heavily urbanised areas, which may represent important refuges within an impoverished landscape.

Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 807
Author(s):  
Simone Valeri ◽  
Laura Zavattero ◽  
Giulia Capotorti

In promoting biodiversity conservation and ecosystem service capacity, landscape connectivity is considered a critical feature to counteract the negative effects of fragmentation. Under a Green Infrastructure (GI) perspective, this is especially true in rural and peri-urban areas where a high degree of connectivity may be associated with the enhancement of agriculture multifunctionality and sustainability. With respect to GI planning and connectivity assessment, the role of dispersal traits of tree species is gaining increasing attention. However, little evidence is available on how to select plant species to be primarily favored, as well as on the role of landscape heterogeneity and habitat quality in driving the dispersal success. The present work is aimed at suggesting a methodological approach for addressing these knowledge gaps, at fine scales and for peri-urban agricultural landscapes, by means of a case study in the Metropolitan City of Rome. The study area was stratified into Environmental Units, each supporting a unique type of Potential Natural Vegetation (PNV), and a multi-step procedure was designed for setting priorities aimed at enhancing connectivity. First, GI components were defined based on the selection of the target species to be supported, on a fine scale land cover mapping and on the assessment of land cover type naturalness. Second, the study area was characterized by a Morphological Spatial Pattern Analysis (MSPA) and connectivity was assessed by Number of Components (NC) and functional connectivity metrics. Third, conservation and restoration measures have been prioritized and statistically validated. Notwithstanding the recognized limits, the approach proved to be functional in the considered context and at the adopted level of detail. Therefore, it could give useful methodological hints for the requalification of transitional urban–rural areas and for the achievement of related sustainable development goals in metropolitan regions.


Author(s):  
Glenn Vorhes ◽  
Ernest Perry ◽  
Soyoung Ahn

Truck parking is a crucial element of the United States’ transportation system as it provides truckers with safe places to rest and stage for deliveries. Demand for truck parking spaces exceeds supply and shortages are especially common in and around urban areas. Freight operations are negatively affected as truck drivers are unable to park in logistically ideal locations. Drivers may resort to unsafe practices such as parking on ramps or in abandoned lots. This report seeks to examine the potential parking availability of vacant urban parcels by establishing a methodology to identify parcels and examining whether the identified parcels are suitable for truck parking. Previous research has demonstrated that affordable, accessible parcels are available to accommodate truck parking. When used in conjunction with other policies, adaptation of urban sites could help reduce the severity of truck parking shortages. Geographic information system parcel and roadway data were obtained for one urban area in each of the 10 Mid America Association of Transportation Officials region states. Area and proximity filters were applied followed by spectral analysis of satellite imagery to identify candidate parcels for truck parking facilities within urban areas. The automated processes created a ranked short list of potential parcels from which those best suited for truck parking could be efficiently identified for inspection by satellite imagery. This process resulted in a manageable number of parcels to be evaluated further by local knowledge metrics such as availability and cost, existing infrastructure and municipal connections, and safety.


Author(s):  
Lauren Lynch ◽  
Madeline Kangas ◽  
Nikolas Ballut ◽  
Alissa Doucet ◽  
Kristine Schoenecker ◽  
...  

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1708
Author(s):  
Yeon-Moon Choo ◽  
Sang-Bo Sim ◽  
Yeon-Woong Choe

The annual average rainfall in Busan area is increasing, causing frequent flooding of Busan’s Suyeong and Oncheon rivers. Due to the increase in urbanized areas and climate change, it is difficult to reduce flood damage. Therefore, new methods are needed to reduce urban inundation. This study models the effects of three flood reduction methods involving Oncheon River, Suyeong River, and the Hoedong Dam, which is situated on the Suyeong. Using EPA-SWMM, a virtual model of the dam and the rivers was created, then modified with changes to the dam’s height, the installation of a floodgate on the dam, and the creation of an underground waterway to carry excess flow from the Oncheon to the Hoedong Dam. The results of this study show that increasing the height of the dam by 3 m, 4 m, or 6 m led to a 27%, 37%, and 48% reduction in flooding, respectively, on the Suyeong River. It was also found that installing a floodgate of 10 × 4 m, 15 × 4 m, or 20 × 4 min the dam would result in a flood reduction of 2.7% and 2.9%, respectively. Furthermore, the construction of the underground waterway could lead to an expected 25% flood reduction in the Oncheon River. Measures such as these offer the potential to protect the lives and property of citizens in densely populated urban areas and develop sustainable cities and communities. Therefore, the modifications to the dam and the underground waterway proposed in this study are considered to be useful.


2016 ◽  
Vol 76 (4) ◽  
pp. 888-897 ◽  
Author(s):  
L. R. C. C. Xavier ◽  
F. Scherner ◽  
D. C. Burgos ◽  
R. C. Barreto ◽  
S. M. B. Pereira

Abstract Population growth in urban areas changes freshwater ecosystems, and this can have consequences for macrophyte communities as can be seen in the municipalities that border the Capibaribe River, Pernambuco, Brazil. This study reports the effects of urbanization on the composition and structure of macrophyte communities in areas along that river. The following urbanized and non-urbanized sampling sites were chosen: Sites 1 and 2 (municipality of Santa Cruz do Capibaribe), Sites 3 and 4 (municipality of Toritama), and Sites 5 and 6 (metropolitan region of Recife). These sites were visited every two months from January to July 2013 to observe seasonal variation (wet and dry seasons). Thirty-one species were identified. Generally, the non-urbanized sites had a higher number of species. Multivariate analyses indicated significant overall differences between urbanized and non-urbanized areas (R = 0.044; p < 0.001) and between seasons (R = 0.018; p < 0.019). Owing to the large variation in physical, chemical, and biological characteristics between urbanized and non-urbanized areas, we found that urbanization significantly influenced the floristic composition and structure of macrophyte communities.


Author(s):  
Giuseppe Aliperti ◽  
Silvia Sarti

The increasing number of metropolitan areas worldwide suggests to more in-depth investigate metropolitan neighbourhoods in order to explain the complex social dynamics emerging in these new contexts. As a matter of fact, the majority of the existing studies on spatial justice provided analyses and investigations focused on metropolitan settings. However, the issue of spatial justice also involves smaller urban areas and further research is needed in that sense. Our investigation analyses a case study of urban gardening that has been developed with the aim of valorising the central neighbourhood of an Italian mid-size city through proposing participatory planning interventions and requalification of urban sites. The urban gardening initiative has included several actors within the process of implementation. The investigated group of people potentially subjected to the spatial injustice is formed by the residents and the local retailers. A comparison between different stakeholders’ perspectives is provided in order to measure the positive and negative impacts of the initiative on the local community.


2019 ◽  
Vol 19 (18) ◽  
pp. 11843-11864 ◽  
Author(s):  
Huizheng Che ◽  
Xiangao Xia ◽  
Hujia Zhao ◽  
Oleg Dubovik ◽  
Brent N. Holben ◽  
...  

Abstract. Multi-year observations of aerosol microphysical and optical properties, obtained through ground-based remote sensing at 50 China Aerosol Remote Sensing Network (CARSNET) sites, were used to characterize the aerosol climatology for representative remote, rural, and urban areas over China to assess effects on climate. The annual mean effective radii for total particles (ReffT) decreased from north to south and from rural to urban sites, and high total particle volumes were found at the urban sites. The aerosol optical depth at 440 nm (AOD440 nm) increased from remote and rural sites (0.12) to urban sites (0.79), and the extinction Ångström exponent (EAE440–870 nm) increased from 0.71 at the arid and semi-arid sites to 1.15 at the urban sites, presumably due to anthropogenic emissions. Single-scattering albedo (SSA440 nm) ranged from 0.88 to 0.92, indicating slightly to strongly absorbing aerosols. Absorption AOD440 nm values were 0.01 at the remote sites versus 0.07 at the urban sites. The average direct aerosol radiative effect (DARE) at the bottom of atmosphere increased from the sites in the remote areas (−24.40 W m−2) to the urban areas (−103.28 W m−2), indicating increased cooling at the latter. The DARE for the top of the atmosphere increased from −4.79 W m−2 at the remote sites to −30.05 W m−2 at the urban sites, indicating overall cooling effects for the Earth–atmosphere system. A classification method based on SSA440 nm, fine-mode fraction (FMF), and EAE440–870 nm showed that coarse-mode particles (mainly dust) were dominant at the rural sites near the northwestern deserts, while light-absorbing, fine-mode particles were important at most urban sites. This study will be important for understanding aerosol climate effects and regional environmental pollution, and the results will provide useful information for satellite validation and the improvement of climate modelling.


Land ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 460
Author(s):  
Pablo Martí ◽  
Clara García-Mayor

The Huerta is recognised as one of the 13 specific agricultural landscapes in Europe, present in only three Mediterranean countries, namely Spain, Italy, and Greece. In the case of Spain, three areas fall within the established Huerta agricultural classification: the Huertas de Valencia, Murcia, and Vega Baja. While all of them share common landscape features, each Huerta has distinguishing singularities which are approached through two perspectives: firstly, the structural tangible elements, related to functional networks—water distribution, pathways networks, settlement patterns, and the agricultural production system; and secondly, the role of the intangible components—connotations of the word Huerta, water management, canal and path upkeep rules, and the administration of these territories. The analysis of the tangible elements and intangible components in the three Spanish Huertas shows these territories as complex and balanced systems that have historically counterbalanced the environmental drawbacks in one of the most arid European regions. Despite being a highly appreciated environmental and productive asset, these Huertas are under intense pressure from urban development in highly urbanized metropolitan areas. This study shows Huertas’ uniqueness through their historical role in the territorial planning and management strategies at the local level, finally depicting Huertas as a present strategical opportunity for reaching environmental goals in peri-urban areas.


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