Long-term climate for selected "ICP Forests Level II" plots in Sweden

Abstract

Forest conditions in Europe are monitored for the UN ECE region in an international cooperative programme on Assessment and Monitoring of Air Pollution Effects on Forests – ”ICP Forests” of the ”Convention on Long-Range Transboundary Air Pollution” (CLRTAP). Primarily, it was in the start directed on air pollution effects on the forests. Other pressures developing, such as climate change, furnish extended use of the observations. Air pollution deposition is one part of the conditions giving impacts on forests. Other conditions are related to abiotic conditions like climate being characterised by temperature, precipitation, solar radiation, air humidity and wind. Measurements of these meteorological variables are needed to get information on relevant conditions for monitoring sites. On some sites, such determinations were made in the Swedish forest monitoring network included in the ICP Forests network. These sites are related to the Level II plots but most of these do not measure climatic variables on site. Instead representative national stations in the Swedish Meteorological and Hydrological Institute (SMHI) station network were used to give meteorological information. Such measurements over long-time periods (30 years) furnish climatic information. In this report long-time values are presented mainly for the period 19611990. In Sweden, ten sites were selected as core sites for which climatic information is provided. These sites are located from the very north part of Sweden with Myrberg and Högbränna in Lappland to south Sweden with Fagerhult, Timrilt and Västra Torup. Current reporting of annual data relates to selected SMHI stations but not all of these have been running for 30 years and therefore new stations on a somewhat longer distances had to be selected for the climate characterisation. However, these stations could be considered to be reasonable representative. Different stations had to be used to give values on all variables for one Level II site due to not complete measurements at all SMHI stations. Distances between station and Level II site should be short. Mainly 28 SMHI stations were used for the 10 Level II sites. Data provided have been quality controlled by the SMHI. However, calculations to complete total 30 year records were made but results in reasonable good characterisation of the sites. In a larger geographical comparison the conditions for Sweden were fairly similar over the country but with a latitudinal distribution and for precipitation also higher values in the West and on higher altitudes. Regionally, there were differences. Solar radiation was besides latitude also dependent on cloudiness and highest values were found for south-west central Sweden. The geographical distribution showed higher humidity in south-west Sweden and lower in the central North. Wind speed at the Level II sites showed on average higher values in south Sweden and lower in the northern parts. The prevailing wind direction was from south-west but also easterly and northerly directions occurred fairly frequently.

Published in

Rapport / Sveriges lantbruksuniversitet, Miljöanalys
2007, number: 2007:24
Publisher: Department of Environmental Assessment, Swedish University of Agricultural sciences

SLU Authors

• Lundin, Lars

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Lode, Elve

  • Department of Forest Soils, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Environmental Sciences and Nature Conservation

Permanent link to this page (URI)

https://res.slu.se/id/publ/16545