© 2007 Heron Publishing—Victoria, Canada
Impact of elevated carbon dioxide concentration and temperature on bud burst and shoot growth of boreal Norway spruce
Michelle Slaney (1, 2), Göran Wallin (3), Jane Medhurst (4) and Sune Linder (1)
1. Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, PO Box 49, SE-230 53 Alnarp, Sweden / 2. Corresponding author (Michelle.Slaney@ess.slu.se) / 3. Department of Plant and Environmental Sciences, Göteborg University, PO Box 461, SE-405 30 Göteborg, Sweden / 4. University of Tasmania, CRC Forestry, Private Bag 12, Hobart, Tasmania 7001, Australia / Received February 24, 2006; accepted May 18, 2006; published online November 1, 2006
Summary
Effects of elevated temperature and atmospheric CO2 concentration ([CO2]) on spring phenology of mature field-grown Norway spruce (Picea abies (L.) Karst.) trees were followed for three years. Twelve whole-tree chambers (WTC) were installed around individual trees
and used to expose the trees to a predicted future climate. The predicted climate scenario for the site, in the year 2100,
was 700 µmol mol–1 [CO2], and an air temperature 3 °C higher in summer and 5 °C higher in winter, compared with current conditions. Four WTC treatments
were imposed using combinations of ambient and elevated [CO2] and temperature. Control trees outside the WTCs were also studied. Bud development and shoot extension were monitored from
early spring until the termination of elongation growth. Elevated air temperature hastened both bud development and the initiation
and termination of shoot growth by two to three weeks in each study year. Elevated [CO2] had no significant effect on bud development patterns or the length of the shoot growth period. There was a good correlation
between temperature sum (day degrees ≥ 0 °C) and shoot elongation, but a precise timing of bud burst could not be derived
by using an accumulation of temperature sums.
Keywords:
climate change, Picea abies, shoot development, whole-tree chambers.
