Ethanol synthesis, nitrogen, carbohydrates, and growth in tissues from nitrogen fertilized Pseudotsuga menziesii (Mirb.) Franco and Pinus ponderosa Dougl. ex Laws. seedlings

Supply and demand processes as controls over needle monoterpene synthesis and concentration in Douglas fir [Pseudotsuga menziesii (Mirb.) Franco]

“…All three growth treatments significantly altered needle starch/nitrogen ratios, an indication that these treatments were effective in altering carbon assimilation rates relative to that required for growth. As predicted and observed in other studies, starch and starch/N ratios increased at elevated CO 2 (Griffin et al 1996), but decreased at elevated temperature (Saxe et al 2001) and with higher levels of nitrogen fertilization (Kelsey et al 1998). If monoterpene pool size was limited solely by available carbon substrate, pool sizes should be positively correlated with starch, C/N, or starch/N ratios.…”

“…Growth at elevated CO 2 , and/or low nutrient availability, typically increases the amount of carbon in woody plant tissues that is in excess of that required for immediate growth (Griffin et al 1996;Kelsey et al 1998). Yet, monoterpene pool sizes in conifer tissues either increase (Heyworth et al 1998), decrease (Williams et al 1994) or do not change (Roth and Lindroth 1994;Kainulainen et al 1998;Constable et al 1999) in response to growth at elevated CO 2 .…”

Dry matter and nitrogen allocation in western redcedar, western hemlock, and Douglas fir seedlings grown in low- and high-N soils

“…The current study may not have been of sufficient duration to realize any growth effects of N addition. Kelsey et al [20] reported that differences in height and stem diameter growth were not apparent among unamended and N-amended seedlings during the first 8-10 weeks after bud-break. In addition, the amount of N applied may not Similarly, Hawkins and Henry [16] On the basis of this study, we suggest that western hemlock may be the best option among the three species when planting seedlings to N-limited forest sites in the Western Hemlock Zone.…”

Effect of Swiss needle cast on Douglas-fir stem ethanol and monoterpene concentrations, oleoresin flow, and host selection by the Douglas-fir beetle

“…First, by limiting aerobic respiration rates. Ethanol biosynthesis may be induced during brief intervals of hypoxia when cambial respiration rates associated with growth are fast enough to deplete tissue O 2 supplies (Harry and Kimmerer, 1991;Kelsey et al, 1998a;authors' unpublished data). But, if growth is substrate limited then hypoxia from rapid respiration should occur less frequently and produce less ethanol.…”

“…But, if growth is substrate limited then hypoxia from rapid respiration should occur less frequently and produce less ethanol. Secondly, since ethanol biosynthesis also requires carbohydrates (Harry and Kimmerer, 1991;Kelsey et al, 1998a), when hypoxia does occur the amount of ethanol synthesized would be limited by the low carbohydrate supply in trees with SNC. Douglas-fir beetles respond more strongly to traps releasing ethanol and pheromones simultaneously compared to traps with just the pheromones alone (Pitman et al, 1975;Ross and Daterman, 1995).…”