Greenbelts do not reduce NO2 concentrations in near-road environments

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Trees are believed to improve air quality, thus providing an important ecosystem service for urban inhabitants. However, empirical evidence on the beneficial effects of urban vegetation on air quality at the local level and in boreal climatic regions is scarce. We studied the influence of greenbelt-type forest patches on NO2 levels (i) in front of, (ii) inside and (iii) behind greenbelts next to major roads in the Helsinki Metropolitan Area, Finland, during summer and winter using passive collectors. Concentrations of NO2 were significantly higher in front of greenbelts compared to road sides without greenbelts. The more trees there were inside greenbelts the higher the NO2 level in front of greenbelts, likely due to the formation of a recirculation zone of air flow in front of greenbelts. Similarly, NO2 levels were higher inside greenbelts than in open areas without them, likely due to reduced air flow inside greenbelts. NO2 levels behind greenbelts were similar to those detected at the same distance from the road but without greenbelts. Our results suggest that, regardless of season, roadside greenbelts of mostly broadleaf trees do not reduce NO2 levels in near-road environments, but can result in higher NO2 levels in front of and inside greenbelts.
Original languageEnglish
JournalUrban Climate
Volume21
Pages (from-to)306-317
Number of pages12
ISSN2212-0955
DOIs
Publication statusPublished - 10 Aug 2017
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 1172 Environmental sciences
  • Air pollution
  • Air Pollutants
  • Urban vegetation
  • URBAN TREES
  • Greenbelts
  • Vegetation barrier
  • PASSIVE SAMPLERS
  • HELSINKI
  • FOREST PATCHES
  • NO2
  • Nitrogen dioxide
  • ECOSYSTEM SERVICES
  • near-road environment
  • Road traffic
  • Urban ecosystems

Cite this

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title = "Greenbelts do not reduce NO2 concentrations in near-road environments",
abstract = "Trees are believed to improve air quality, thus providing an important ecosystem service for urban inhabitants. However, empirical evidence on the beneficial effects of urban vegetation on air quality at the local level and in boreal climatic regions is scarce. We studied the influence of greenbelt-type forest patches on NO2 levels (i) in front of, (ii) inside and (iii) behind greenbelts next to major roads in the Helsinki Metropolitan Area, Finland, during summer and winter using passive collectors. Concentrations of NO2 were significantly higher in front of greenbelts compared to road sides without greenbelts. The more trees there were inside greenbelts the higher the NO2 level in front of greenbelts, likely due to the formation of a recirculation zone of air flow in front of greenbelts. Similarly, NO2 levels were higher inside greenbelts than in open areas without them, likely due to reduced air flow inside greenbelts. NO2 levels behind greenbelts were similar to those detected at the same distance from the road but without greenbelts. Our results suggest that, regardless of season, roadside greenbelts of mostly broadleaf trees do not reduce NO2 levels in near-road environments, but can result in higher NO2 levels in front of and inside greenbelts.",
keywords = "1172 Environmental sciences, Air pollution, Air Pollutants, Urban vegetation, URBAN TREES, Greenbelts, Vegetation barrier, PASSIVE SAMPLERS, HELSINKI, FOREST PATCHES, NO2, Nitrogen dioxide, ECOSYSTEM SERVICES, near-road environment, Road traffic, Urban ecosystems",
author = "Yli-Pelkonen, {Vesa Johannes} and Viippola, {Juho Viljami} and Kotze, {David Johannes} and Set{\"a}l{\"a}, {Heikki Martti}",
year = "2017",
month = "8",
day = "10",
doi = "10.1016/j.uclim.2017.08.005",
language = "English",
volume = "21",
pages = "306--317",
journal = "Urban Climate",
issn = "2212-0955",
publisher = "Elsevier Scientific Publ. Co",

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Greenbelts do not reduce NO2 concentrations in near-road environments. / Yli-Pelkonen, Vesa Johannes; Viippola, Juho Viljami; Kotze, David Johannes; Setälä, Heikki Martti.

In: Urban Climate , Vol. 21, 10.08.2017, p. 306-317.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Greenbelts do not reduce NO2 concentrations in near-road environments

AU - Yli-Pelkonen, Vesa Johannes

AU - Viippola, Juho Viljami

AU - Kotze, David Johannes

AU - Setälä, Heikki Martti

PY - 2017/8/10

Y1 - 2017/8/10

N2 - Trees are believed to improve air quality, thus providing an important ecosystem service for urban inhabitants. However, empirical evidence on the beneficial effects of urban vegetation on air quality at the local level and in boreal climatic regions is scarce. We studied the influence of greenbelt-type forest patches on NO2 levels (i) in front of, (ii) inside and (iii) behind greenbelts next to major roads in the Helsinki Metropolitan Area, Finland, during summer and winter using passive collectors. Concentrations of NO2 were significantly higher in front of greenbelts compared to road sides without greenbelts. The more trees there were inside greenbelts the higher the NO2 level in front of greenbelts, likely due to the formation of a recirculation zone of air flow in front of greenbelts. Similarly, NO2 levels were higher inside greenbelts than in open areas without them, likely due to reduced air flow inside greenbelts. NO2 levels behind greenbelts were similar to those detected at the same distance from the road but without greenbelts. Our results suggest that, regardless of season, roadside greenbelts of mostly broadleaf trees do not reduce NO2 levels in near-road environments, but can result in higher NO2 levels in front of and inside greenbelts.

AB - Trees are believed to improve air quality, thus providing an important ecosystem service for urban inhabitants. However, empirical evidence on the beneficial effects of urban vegetation on air quality at the local level and in boreal climatic regions is scarce. We studied the influence of greenbelt-type forest patches on NO2 levels (i) in front of, (ii) inside and (iii) behind greenbelts next to major roads in the Helsinki Metropolitan Area, Finland, during summer and winter using passive collectors. Concentrations of NO2 were significantly higher in front of greenbelts compared to road sides without greenbelts. The more trees there were inside greenbelts the higher the NO2 level in front of greenbelts, likely due to the formation of a recirculation zone of air flow in front of greenbelts. Similarly, NO2 levels were higher inside greenbelts than in open areas without them, likely due to reduced air flow inside greenbelts. NO2 levels behind greenbelts were similar to those detected at the same distance from the road but without greenbelts. Our results suggest that, regardless of season, roadside greenbelts of mostly broadleaf trees do not reduce NO2 levels in near-road environments, but can result in higher NO2 levels in front of and inside greenbelts.

KW - 1172 Environmental sciences

KW - Air pollution

KW - Air Pollutants

KW - Urban vegetation

KW - URBAN TREES

KW - Greenbelts

KW - Vegetation barrier

KW - PASSIVE SAMPLERS

KW - HELSINKI

KW - FOREST PATCHES

KW - NO2

KW - Nitrogen dioxide

KW - ECOSYSTEM SERVICES

KW - near-road environment

KW - Road traffic

KW - Urban ecosystems

U2 - 10.1016/j.uclim.2017.08.005

DO - 10.1016/j.uclim.2017.08.005

M3 - Article

VL - 21

SP - 306

EP - 317

JO - Urban Climate

JF - Urban Climate

SN - 2212-0955

ER -