Optimising UK urban road verge contributions to biodiversity and ecosystem services with cost-effective management

Urban road verges can contain significant biodiversity, contribute to structural connectivity between other urban greenspaces, and due to their proximity to road traffic are well placed to provide ecosystem services. Using the UK as a case study we review and critically evaluate a broad range of evidence to assess how this considerable potential can be enhanced despite financial, contractual and public opinion constraints. Reduced mowing frequency and other alterations would enhance biodiversity, aesthetics and pollination services, whilst delivering costs savings and potentially being publically acceptable. Retaining mature trees and planting additional ones is favourable to residents and would enhance biodiversity, pollution and climate regulation, carbon storage, and stormwater management. Optimising these services requires improved selection of tree species, and creating a more diverse tree stock. Due to establishment costs additional tree planting and maintenance could benefit from payment for ecosystem service schemes. Verges could also provide areas for cultivation of biofuels and possibly food production. Maximising the contribution of verges to urban biodiversity and ecosystem services is economical and becoming an increasingly urgent priority as the road network expands and other urban greenspace is lost, requiring enhancement of existing greenspace to facilitate sustainable urban development

Evaluation of human thermal comfort ranges in urban climate of winter cities on the example of Erzurum city

Human thermal comfort conditions can be evaluated using various indices based on simple empirical approaches or more complex and reliable human-biometeorological approaches. The latter is based on the energy balance model of the human body, and their calculation is supplemented with computer software. Facilitating the interpretation of results, the generally applied indices express the effects of thermal environment in the well-known temperature unit, just like in the case of the widely used index, the physiologically equivalent temperature (PET). Several studies adopting PET index for characterizing thermal components of climate preferred to organize the resulted PET values into thermal sensation categories in order to demonstrate the spatial and/or temporal characteristics of human thermal comfort conditions. The most general applied PET ranges were derived by Central European researchers, and they are valid for assumed values of internal heat production of light activity and thermal resistance of clothing representing a light business suit. Based on the example of Erzurum city, the present work demonstrates that in a city with harsh winter, the original PET ranges show almost purely discomfort and they seem to be less applicable regarding cold climate conditions. Taking into account 34-year climate data of Erzurum, the annual distribution of PET is presented together with the impact of application of different PET categorization systems, including 8A degrees- and 7A degrees-wide PET intervals. The demonstrated prior analyses lack any questionnaire filed surveys in Erzurum. Thus, as a next step, detailed field investigations would be required with the aim of definition of new PET categorization systems which are relevant for local residents who are adapted to this climatic background, and for tourists who may perform various kinds of winter activities in Erzurum and therefore may perceive the thermal environment more comfortable

Evaluation of thermal perception in schoolyards under Mediterranean climate conditions

The aim of this paper was to study qualitatively and quantitatively the thermal perception and corresponding heat stress conditions that prevail in two schoolyards in a coastal city in central Greece. For this purpose, meteorological parameters (i.e., wind speed, temperature, relative humidity, solar radiation) were recorded at 70 and 55 measuring points in the schoolyards, from 14:00 to 15:30 local time, during May and June of 2011. The measuring points were distributed so as to get measurements at points (a) directly exposed to the sun, (b) under the shadow of trees and building structures, and (c) near building structures. Cluster analysis was applied to group observations and revealed places that are microclimatically homogeneous. Thermal perception and heat stress conditions were assessed by means of the physiologically equivalent temperature (PET, °C), and the results are presented in relevant charts. The impact of material’s albedo, radiation’s reflection by structures and obstacles, and different tree species on thermal perception and heat stress conditions was also assessed. The analysis showed that trees triggered a reduction of incident solar radiation that ranged between 79 and 94 % depending on tree’s species, crown dimension, tree height, and leaf area. PET values were mainly affected by solar radiation and wind speed. Trees caused a reduction of up to 37 % in PET values, while a 1-m s−1 increase in wind speed triggered a reduction of 3.7–5.0 °C in PET value. The effective shading area in the two schoolyards was small, being 27.5 and 11 %. The results of this study could be exploited by urban planning managers when designing or improving the outdoor environment of a school complex. © 2015 IS