title: UV-B radiation and acclimation in timberline plants.
abstract: Research has shown that some plants respond to enhanced UV-B radiation by producing smaller and thicker leaves, by increasing the thickness of epidermis and concentration of UV-B absorbing compounds of their surface layers and activation of the antioxidant defence system. The response of high-altitude plants to UV-B radiation in controlled conditions is often less pronounced compared to low-altitude plants, which shows that the alpine timberline plants are adapted to UV-B. These plants may have a simultaneous co-tolerance for several stress factors: acclimation or adaptation to the harsh climate can also increase tolerance to UV-B radiation, and vice versa. On the other hand, alpine timberline plants of northern latitudes may be less protected against increasing UV-B radiation than plants from more southern latitudes and higher elevations due to harsh conditions and weaker preadaptation resulting from lower UV-B radiation exposure. It is evident that more long-term experimental field research is needed in order to study the interaction of climate, soil and UV-B irradiance on the timberline plants.
authors: Arctic Centre, University of Lapland, PO Box 122, FI-96101 Rovaniemi, Finland. minna.turunen@ulapland.fi
authors: Minna
authors: M
authors: Turunen
authors: Kirsi
authors: K
authors: Latola
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D000531:Altitude; D002980:Climate; D004463:Ecology / Q000379:methods*; D005387:Finland; D018384:Oxidative Stress; D018521:Plant Physiological Phenomena / Q000528:radiation effects*; D014197:Trees / Q000528:radiation effects; D014466:Ultraviolet Rays / Q000009:adverse effects*