The variation in nitrogen, insoluble and soluble proteins, and chlorophyll concentrations (mg·g-1) and contents per unit leaf area (mg·cm-2) as a function of specific leaf area (SLA) was examined in leaves sampled at the bottom, middle, and upper sections of the crowns of balsam fir (Abies balsamea) and black spruce (Picea mariana) trees located along a temperature gradient in Quebec, Canada. Differences in needle dimensions, mass, surface, and SLA among crown sections and needle age were more pronounced for balsam fir than for black spruce. Relationships of foliage nitrogen, insoluble and soluble proteins, and chlorophyll content per unit leaf area as a function of SLA were generally more significant than those based on concentration. However, the different variables varied little along a temperature gradient. The higher significance of area-based relationships in comparison with mass-based relationships was attributed to the change in leaf morphology in response to light availability within the crown. Yet, nitrogen availability most likely restricted light acclimation to changes in morphology, since there was very limited modulation of nitrogen partitioning among the different protein fractions as a function of light environment.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 21 • No. 3–4