| 1. |
- Andersson-Sköld, Yvonne, et al.
(författare)
-
A framework for assessing urban greenery's effects and valuing its ecosystem services
- 2018
-
Ingår i: Journal of Environmental Management. - : Academic Press. - 0301-4797 .- 1095-8630. ; 205, s. 274-285
-
Tidskriftsartikel (refereegranskat)abstract
- Ongoing urban exploitation is increasing pressure to transform urban green spaces, while there is increasing awareness that greenery provides a range of important benefits to city residents. In efforts to help resolve associated problems we have developed a framework for integrated assessments of ecosystem service (ES) benefits and values provided by urban greenery, based on the ecosystem service cascade model. The aim is to provide a method for assessing the contribution to, and valuing, multiple ES provided by urban greenery that can be readily applied in routine planning processes. The framework is unique as it recognizes that an urban greenery comprises several components and functions that can contribute to multiple ecosystem services in one or more ways via different functional traits (e.g. foliage characteristics) for which readily measured indicators have been identified. The framework consists of five steps including compilation of an inventory of indicator; application of effectivity factors to rate indicators' effectiveness; estimation of effects; estimation of benefits for each ES; estimation of the total ES value of the ecosystem. The framework was applied to assess ecosystem services provided by trees, shrubs, herbs, birds, and bees, in green areas spanning an urban gradient in Gothenburg, Sweden. Estimates of perceived values of ecosystem services were obtained from interviews with the public and workshop activities with civil servants. The framework is systematic and transparent at all stages and appears to have potential utility in the existing spatial planning processes.
|
|
| 2. |
|
|
| 3. |
- Konarska, Janina, 1986, et al.
(författare)
-
Transpiration of urban trees and its cooling effect in a high latitude city
- 2016
-
Ingår i: International journal of biometeorology. - : Springer Science and Business Media LLC. - 0020-7128 .- 1432-1254. ; 60:1, s. 159-172
-
Tidskriftsartikel (refereegranskat)abstract
- An important ecosystem service provided by urban trees is the cooling effect caused by their transpiration. The aim of this study was to quantify the magnitude of daytime and night-time transpiration of common urban tree species in a high latitude city (Gothenburg, Sweden), to analyse the influence of weather conditions and surface permeability on the tree transpiration, and to find out whether tree transpiration contributed to daytime or nocturnal cooling. Stomatal conductance and leaf transpiration at day and night were measured on mature street and park trees of seven common tree species in Gothenburg: Tilia europaea, Quercus robur, Betula pendula, Acer platanoides, Aesculus hippocastanum, Fagus sylvatica and Prunus serrulata. Transpiration increased with vapour pressure deficit and photosynthetically active radiation. Midday rates of sunlit leaves ranged from less than 1 mmol m−2 s−1 (B. pendula) to over 3 mmol m−2 s−1 (Q. robur). Daytime stomatal conductance was positively related to the fraction of permeable surfaces within the vertically projected crown area. A simple estimate of available rainwater, comprising of precipitation sum and fractional surface permeability within the crown area, was found to explain 68 % of variation in midday stomatal conductance. Night-time transpiration was observed in all studied species and amounted to 7 and 20 % of midday transpiration of sunlit and shaded leaves, respectively. With an estimated night-time latent heat flux of 24 W m−2, tree transpiration significantly increased the cooling rate around and shortly after sunset, but not later in the night. Despite a strong midday latent heat flux of 206 W m−2, a cooling effect of tree transpiration was not observed during the day.
|
|
| 4. |
- Konarska, Janina, 1986, et al.
(författare)
-
Transpiration of urban trees and its impact on nocturnal cooling in Gothenburg, Sweden
- 2015
-
Ingår i: ICUC9 – 9 th International Conference on Urban Climate jointly with 12th Symposium on the Urban Environment. 20-24 July 2015, Toulouse, France.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- One of the ecosystem services provided by urban trees is the cooling effect caused by their transpiration. However, while the transpiration of forest trees has been widely studied, little research has been conducted on the daytime and night-time transpirational cooling effect of mature urban trees. Knowledge about the transpiration of street and park trees and its response to different environmental factors can prove useful in estimating the thermal influence of urban greenery as well as in urban planning and management. The aim of this study is to i) quantify the magnitude and diurnal variation of transpiration of common urban tree species in a high latitude city (Gothenburg, Sweden), ii) analyse the influence of weather conditions and fraction of permeable surfaces within the vertically projected crown area on tree transpiration, and iii) find out whether transpiration of urban trees remains active during the night and therefore contributes to nocturnal cooling. Measurements were conducted on mature street and park trees of seven tree species common in Gothenburg: Tilia europaea (Common lime), Quercus robur (English oak), Betula pendula (Silver birch), Acer platanoides (Norway maple), Aesculus hippocastanum (Horse chestnut), Fagus sylvatica (European beech) and Prunus serrulata (Japanese cherry). Stomatal conductance and leaf transpiration were measured using a LI-6400XT Portable Photosynthesis System (LI-COR Biosciences) at daytime and night-time on warm summer days of 2012-2013 in Gothenburg. Leaf area index (LAI) of the studied trees was measured with a LAI-2200 Plant Canopy Analyser (LI-COR Biosciences) in order to estimate the latent heat flux due to tree transpiration. Leaf transpiration was found to increase with vapour pressure deficit and photosynthetically active radiation, with on average 22% of the midday incoming solar radiation being converted into latent heat flux. Midday rates of sunlit leaves varied between species, ranging from less than 1 mmol m-2 s-1 (B. pendula) to over 3 mmol m-2 s-1 (Q. robur). Daytime stomatal conductance was positively related to the fraction of permeable surfaces within the vertically projected tree crown area. A simple estimate of available rainwater, comprising of precipitation sum and a fractional surface permeability within the tree crown area, was found to explain 68% of variation in midday stomatal conductance. The results indicate that a high fractional surface permeability can minimize the frequency of water stress experienced by urban trees and enhance their transpirational cooling. Night-time transpiration was observed in all studied species and was positively related to daytime tree water use. Nocturnal transpiration amounted to 7% and 20% of midday transpiration of sunlit and shaded leaves, respectively. With an estimated latent heat flux of 27 W m-2, evening tree transpiration enhanced the cooling rates around and 1-2 hours after sunset, but not later in the night. The results of transpiration measurements will be combined with vegetation data derived from LIDAR and LAI measurements to estimate neighbourhood- to city-scale cooling effect provided by urban trees.
|
|
| 5. |
- Aminipouri, M., et al.
(författare)
-
Urban tree planting to maintain outdoor thermal comfort under climate change: The case of Vancouver's local climate zones
- 2019
-
Ingår i: Building and Environment. - : Elsevier BV. - 0360-1323. ; 158, s. 226-236
-
Tidskriftsartikel (refereegranskat)abstract
- Spatiotemporal variation of mean radiant temperature (Tmrt), a major driver of outdoor human thermal comfort, is driven by exposure to solar and longwave radiation, which in turn respond to local patterns of shading, wind speed, air humidity and air temperature. In this study, the SOlar and LongWave Environmental Irradiance Geometry (SOLWEIG) model was used to simulate how changes in minimum and maximum air temperature and solar radiation under Representative Concentration Pathways (RCP) 4.5 and 8.5 climate projections would change Tmrt in Vancouver over the 2070-2100 period. With micrometeorological variables representative of a changed climate, days with Tmrt above 65 degrees C were predicted to increase three-to five-fold under RCP 4.5 and 8.5, respectively. SOLWEIG was also used to quantify the potential of maximum feasible street tree cover to reduce Tmrt for the hottest day on record for Vancouver (July 29, 2009), and an end-of-century hot day under the two future climate scenarios. SOLWEIG simulations with maximum feasible street tree cover under RCP 4.5 demonstrated an average reduction of 1.3 degrees C in Tmrt, compared to the contemporary extreme heat day with current street trees. However, average Tmrt increased by 1.9 degrees C under the RCP 8.5 scenario even with maximum feasible street tree cover, relative to the contemporary extreme heat day. We conclude that adding street trees has the potential to offset Tmrt increases under the RCP 4.5 scenario, however this measure is insufficient to maintain contemporary Tmrt under the RCP 8.5 scenario.
|
|
| 6. |
- Andersson-Sköld, Yvonne, et al.
(författare)
-
An integrated method for assessing climate-related risks and adaptation alternatives in urban areas
- 2015
-
Ingår i: Climate Risk Management. - : Elsevier BV. - 2212-0963. ; 7, s. 31-50
-
Tidskriftsartikel (refereegranskat)abstract
- © 2015 The Authors. The urban environment is a complex structure with interlinked social, ecological and technical structures. Global warming is expected to have a broad variety of impacts, which will add to the complexity. Climate changes will force adaptation, to reduce climate-related risks. Adaptation measures can address one aspect at the time, or aim for a holistic approach to avoid maladaptation. This paper presents a systematic, integrated approach for assessing alternatives for reducing the risks of heat waves, flooding and air pollution in urban settings, with the aim of reducing the risk of maladaptation. The study includes strategies covering different spatial scales, and both the current climate situation and the climate predicted under climate change scenarios. The adaptation strategies investigated included increasing vegetation; selecting density, height and colour of buildings; and retreat or resist (defend) against sea-level rise. Their effectiveness was assessed with regard to not only flooding, heat stress and air quality but also with regard to resource use, emissions to air (incl. GHG), soil and water, and people's perceptions and vulnerability. The effectiveness of the strategies were ranked on a common scale (from -3 to 3) in an integrated assessment. Integrated assessments are recommended, as they help identify the most sustainable solutions, but to reduce the risk of maladaptation they require experts from a variety of disciplines. The most generally applicable recommendation, derived from the integrated assessment here, taking into account both expertise from different municipal departments, literature surveys, life cycle assessments and publics perceptions, is to increase the urban greenery, as it contributes to several positive aspects such as heat stress mitigation, air quality improvement, effective storm-water and flood-risk management, and it has several positive social impacts. The most favourable alternative was compact, mid-rise, light coloured building design with large parks/green areas and trees near buildings.
|
|
| 7. |
- Andersson-Sköld, Yvonne, 1957-, et al.
(författare)
-
Metod för bedömning och värdering av ekosystemtjänster i staden (VEKST) : Handbok version 1.0
- 2018
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Under åren 2013–2016 genomfördes forskningsprojektet Värdering av ekosystemtjänster av urban grönska med syftet att kartlägga, synliggöra och värdera den urbana grönskan. Inom forskningsprojektet studerades bland annat hur ekosystemtjänsterna klimatreglering, förbättrad luftkvalitet, dagvattenhantering, bullerdämpning, rekreation och välbefinnande kan bedömas och värderas. Dessutom kartlades delar av den biologiska mångfalden (träd, buskar, örter, bin och fåglar). För att kunna bedöma och värdera de ekosystemtjänster som ingick i projektet utvecklades en stegvis metod. Metoden baseras på mätningar och inventeringar i sju fallstudieområden i Göteborg, intervjuer och enkätstudier samt relevant litteratur. I denna handbok presenteras metoden samt mallar som guidar användaren genom metodens fem steg. Handboken innehåller också exempel på hur metoden har använts. Viktigt att poängtera är att metoden som beskrivs i denna handbok inte är en slutprodukt utan en första version. I takt med ökad kunskap kan, och bör, metoden utvecklas, kompletteras och förbättras. Till exempel kan fler ekosystemtjänster bedömas och värderas. Metoden är utvecklad med tanken att den ska vara enkel att använda, systematisk och transparent i alla steg. Denna handbok vänder sig bland annat till stadsplanerare och konsulter som på uppdrag av planerare arbetar med beslutsstöd i planprocessen. Metoden kan användas för att bedöma inverkan av förändringar i stadsbilden, t ex vid förtätning, eller för att följa förändringar över tid.
|
|
| 8. |
|
|
| 9. |
- Carlström, Eric, 1957, et al.
(författare)
-
Medical Emergencies During a Half Marathon Race - The Influence of Weather
- 2019
-
Ingår i: International Journal of Sports Medicine. - Stuttgart : Georg Thieme Verlag KG. - 0172-4622 .- 1439-3964. ; 40:5, s. 312-316
-
Tidskriftsartikel (refereegranskat)abstract
- The aim was to analyze the influence of weather conditions on medical emergencies in a half-marathon, specifically by evaluating its relation to the number of non-finishers, ambulance-required assistances, and collapses in need of ambulance as well as looking at the location of such emergencies on the race course. Seven years of data from the world's largest half marathon were used. Meteorological data were obtained from a nearby weather station, and the Physiological Equivalent Temperature (PET) index was used as a measure of general weather conditions. Of the 315,919 race starters, 104 runners out of the 140 ambulance-required assistances needed ambulance services due to collapses. Maximum air temperature and PET significantly co-variated with ambulance-required assistances, collapses, and non-finishers (R (2) =0.65-0.92; p=0.001-0.03). When air temperatures vary between 15-29 degrees C, an increase of 1 degrees C results in an increase of 2.5 (0.008/1000) ambulance-required assistances, 2.5 (0.008/1000) collapses (needing ambulance services), and 107 (0.34/1000) non-finishers. The results also indicate that when the daily maximum PET varies between 18-35 degrees C, an increase of 1 degrees C PET results in an increase of 1.8 collapses (0.006/1000) needing ambulance services and 66 non-finishers (0.21/1000).
|
|
| 10. |
|
|
