title: Long-term exposure to enhanced UV-B radiation has no significant effects on growth or secondary compounds of outdoor-grown Scots pine and Norway spruce seedlings.
abstract: The effects of long-term enhanced UV-B radiation on growth and secondary compounds of two conifer species were studied in an outdoor experiment. Scots pine (Pinus sylvestris) seedlings were exposed for two growing seasons and Norway spruce (Picea abies) seedlings for three growing seasons to supplemental UV-B radiation, corresponding to a 30% increase in ambient UV-B radiation. The experiment also included appropriate controls for ambient and increased UV-A radiation. Enhanced UV-B did not affect the growth of the conifer seedlings. In addition, neither the concentrations of terpenes and phenolics in the needles nor the concentrations of terpenes in the wood were affected. However, in the UV-A control treatment the concentrations of diterpenes in the wood of Scots pine decreased significantly compared to the ambient control. Apparently, a small increase in UV-B radiation has no significant effects on the secondary compounds and growth of Scots pine and Norway spruce seedlings.
authors.affiliation: Department of Ecology and Environmental Science, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland. satu.turtola@joensuu.fi <satu.turtola@joensuu.fi>
authors.forename: Satu
authors.initials: S
authors.lastname: Turtola
authors.forename: Leena
authors.initials: L
authors.lastname: Sallas
authors.forename: Jarmo K
authors.initials: JK
authors.lastname: Holopainen
authors.forename: Riitta
authors.initials: R
authors.lastname: Julkunen-Tiitto
authors.forename: Pirjo
authors.initials: P
authors.lastname: Kainulainen
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D010636:Phenols / Q000032:analysis; D028222:Picea / Q000254:growth & development / Q000528:radiation effects; D028223:Pinus / Q000254:growth & development / Q000528:radiation effects; D018515:Plant Leaves / Q000737:chemistry / Q000528:radiation effects; D036226:Seedlings / Q000254:growth & development / Q000528:radiation effects; D013729:Terpenes / Q000032:analysis; D013995:Time; D014197:Trees / Q000254:growth & development / Q000528:radiation effects*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D010636:Phenols; D013729:Terpenes