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Summary

Published in Communications in Soil Science and Plant Analysis 42: 2738-2750

Black spruce (Picea mariana) trees have needles that persist for a number of years, and it is not clear which age class should be evaluated for photosynthesis to best understand physiological responses. Moreover, the impact of sampling current versus older foliage is rarely acknowledged in published literature, even though it may influence the interpretation of results. We compared the photosynthesis rate of current and 1-year-old foliage of black spruce natural regeneration during three growing seasons. The photosynthesis rate was consistently greater for 1-year-old needles compared to current-year needles at the beginning of each growing season; however, after about 1 month, rates were similar between the two age classes. This same pattern was repeated every season and was independent of light availability induced by different harvesting treatments. We suggest that photosynthesis measurements of black spruce should be performed on 1-year-old needles instead of current-year foliage to ensure more uniform photosynthesis values throughout the season.

Sector(s): 

Forests

Categorie(s): 

Scientific Article

Theme(s): 

Forestry Research, Forests, Silviculture

Departmental author(s): 

Author(s)

HÉBERT, François, Nelson THIFFAULT and Alison D. MUNSON

Year of publication :

2011

Format :

Paper

ISSN

0010-3624

Keywords :

épinette noire, photosynthèse, classe d'âge feuillage, croissance, sylviculture des forêts naturelles résineuses, Picea mariana, article scientifique de recherche forestière, sylviculture et rendement des forêts naturelles - peuplements résineux, silviculture and yield of natural forests - softwood stands, black spruce, photosynthesis, needle age class, growth

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