Effects of elevated CO2 concentration on growth, annual ring structure and photosynthesis in Larix kaempferi seedlings

Abstract

We evaluated the effects of elevated carbon dioxide concentration ([CO2]) and two nutrient regimes on stem growth rate, annual ring structure and temporal variations in photosynthetic characteristics of seedlings of Japanese larch (Larix kaempferi (Lamb.) Carr.). Seedlings were grown in phytotron chambers in an ambient (360 ppm) or an elevated (720 ppm) [CO2] in two nutrient regimes for one growing season. Elevated [CO2] reduced stem height and increased stem basal diameter compared with ambient [CO2]. The effect of elevated [CO2] on growth tended to be greater at high-nutrient supply than at low-nutrient supply. Elevated [CO2] had no significant effect on ring width or the number of tracheids per radial file. There was no obvious difference in cell wall thickness or the relative area of the cell wall between seedlings grown in ambient or elevated [CO2]. Although growth in elevated [CO2] resulted in a slight increase in cell diameter, the increase had a relatively minor effect on the relative area of the cell wall. Net assimilation rate increased in response to elevated [CO2]; however, the increase in whole-crown photosynthetic rate (Total Agrowth) in seedlings in the elevated [CO2] treatment was minimal because of the smaller specific needle area and acclimation of the photosynthetic characteristics of the needles to the growth [CO2]. In conclusion, we observed no obvious enhancement in the capacity for carbon fixation in Japanese larch seedlings grown in the presence of elevated [CO2] that might be attributable to changes in stem growth. However, elevated [CO2] caused changes in the temporal pattern of stem growth and in some anatomical features of the tracheids.

Photoperiod and Nitrogen Supply Limit the Scope of Northward Migration and Seed Transfer of Black Spruce in a Future Climate Associated with Doubled Atmospheric CO2 Concentration

“…The results are consistent with the findings of others that elevated CO 2 alone [22] [32]- [35] or in combination with high nutrient supply [36] [37] enhances photosynthesis and promotes growth. The increased growth under the PNM was probably due to the longer photoperiod (17 h vs. 15 h) during the longer growing season (95 days vs. 75 days, Figure 1).…”

Effects of elevated CO2 and nitrogen on wood structure related to water transport in seedlings of two deciduous broad-leaved tree species

“…Elevated [CO 2 ] and N-fertilization altered the dimensions of xylem vessels and wood fibers in a genotypespecific manner in three species of Populus (Luo et al 2005). However, little information is available regarding the effects of the changing environment on wood formation (Kirschbaum 2004;Yazaki et al 2004Yazaki et al , 2005. Therefore, we studied combined effects of [CO 2 ] and nitrogen on wood formation and water relations in tree species in northern Japan.…”

The photosynthetic response of four seral deciduous broad-leaved tree seedlings grown under elevated CO₂ concentrations

“…and 720 μmol mol -1 (elevated CO 2 ) with a CO 2 analyzer (FU-DDF23, Fuji, Tokyo, Japan) as described previously (Yazaki et al, 2004;Kitao et al, 2007). There were three chamber replications for each CO 2 level; a total of six chambers were used for this experiment.…”