title: The dynamics of leaf extension in plants with diverse altitudinal ranges : II. Field studies in Poa species between 600 and 3200 m altitude.
abstract: The dynamics of leaf extension in five species of Poa were studied with electronic auxanometers (LVDTs) along an elevational gradient from 600 to 3200 m in the Austrian Alps. Extension rates peak at midday at all elevations and rates at 20°C are almost twice as high at low elevation as compared with those from the highest sites. The low temperature threshold for leaf extension drops by 7 K over this range of elevation, with plants from the highest sites showing some extension around freezing point. Thus, there is a substantial adaptive adjustment in response of leaf extension to declining mean temperatures with increasing altitude, which is not paralleled by known altitudinal trends of photosynthetic responses in herbaceous plants.
authors.affiliation: Institut für Botanik, Universität Innsbruck, Sternwartestrasse 15, A-6020, Innsbruck, Austria.
authors.forename: Ch
authors.initials: C
authors.lastname: Körner
authors.affiliation: Department of Botany, University of Cambridge, Downing Street, CB2 3EA, Cambridge, UK.
authors.forename: F I
authors.initials: FI
authors.lastname: Woodward
keywords: Altitude; Leaf extension; Poa; Temperature