Figure Captions
Figure 1. Mean (±SE) (µg mg-1 of dried weight) monthly variation of starch, total sugars, total non-structural carbohydrates (NSC), and diterpenes of Pinus ponderosa trees in six treatments from July to November 2014 and May to September 2015.
Figure 2. Means (±SE) (µg mg-1 of dried weight) of starch, total sugars, and total non-structural carbohydrates (NSCs) of Pinus ponderosa trees in six treatments. Trees included in each comparison were reported in Table 1.
Figure 3. Monthly means (±SE) (µg mg-1 of dried weight) of starch, total sugars, and total non-structural carbohydrates (NSCs) of Pinus ponderosa trees in different comparisons. * denotes that concentrations vary in a given month (95% confidence level adjusted with Sidak method for two estimates). Suppl. Table S4 shows statistical results.
Figure 4. Relationship between concentrations of total diterpenes and non-structural carbohydrates (NSCs) of Pinus ponderosa trees by treatments. Regression lines for: (a) NSC, (b) total sugars, and (c) starch are from repeated measures ANCOVAs on the log of total diterpenes. Top figures: Significance of interaction between NSCs and total diterpenes were as follows: (a) Total NSCs: F(5,256)=1.96, P=0.085, (b) Total sugars: F(5,258)=2.18, P=0.057, and (c) Starch: F(5,254)=1.34, P=0.247. Bottom figures. Significance of interaction between NSCs and total monoterpenes were as follows: (d) Total NSCs: F(5,255)=2.07, P=0.069, (e) Total sugars: F(5,254)=1.58, P=0.166, (f) Starch: F(5,286)=4.98, P=0.0002. Degrees of freedom were calculated with Satterthwaite’s method.
Figure 5. Monthly means (±SE) (µg mg-1 of dried weight) of carbohydrates, total diterpenes, and total monoterpenes of dying and live Pinus ponderosa trees in the trenched-attacked treatment. Data are from 2014. * shows months where differences among treatments are significant (95% confidence level adjusted with Sidak method for two estimates).
Figure 6. Monthly means (±SE) (µg mg-1 of dried weight) of carbohydrates, total diterpenes, and total monoterpenes of dying Pinus ponderosa trees in the trenched-attacked treatment and live trees in the untrenched-control treatment. Data are from 2014. * shows months where differences among treatments are significant (95% confidence level adjusted with Sidak method for two estimates).
Figure 7. Relationship between carbohydrate and terpene concentrations from 2014 for dying Pinus ponderosa trees in the trenched-attacked category and all treatment categories of live trees averaged over months. Solid (dying trees) and dashed (live trees) trend lines indicate significant Pearson correlations. Dying trees n=8 and live trees n=42 (except diterpene comparisons n=40). Total non-structural carbohydrates (NSC) are the sums of starch and total sugar concentrations.
Figure 8. Schematic representation of how mild drought alone or in combination with pathogenic microbial infection and bark beetle attacks affect carbohydrates and carbon-dependent defense metabolites (terpenes) in pines.