Figure 3.

Contents (g dry weight, DW) of total nonstructural carbohydrates (TNCs) in fine roots of silver birch seedlings. These are divided into insoluble starch and soluble carbohydrates, sucrose, fructose, and glucose. Estimated marginal means with ±SE are presented as histograms in different treatment combinations (A: CO₂ × fertilization; B: temperature × fertilization; and C: fertilization × defoliation). In A and B, the letter “C” indicates a statistically significant (P < 0.05, based on the Tukey's test) difference between ambient and elevated climate treatment, and the letter “d”, unfertilized and fertilized seedlings. In 3C, the letter “C” indicates a statistically significant difference between unfertilized and fertilized seedlings, and the letter “d”, defoliated and intact seedlings. Fine root samples for the analysis were collected in late March 2003.