Nitrogen uptake characteristics for roots of conifer seedlings and common boreal forest competitor species
Little is known about the N uptake abilities of competitor species and planted seedlings in the boreal forest. The objective of this study was to determine the MichaelisMenten kinetic parameters of NH 4 + and NO 3 for white spruce (Picea glauca (Moench) Voss) and jack pine (Pinus banksiana Lamb.)...
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Published in | Canadian journal of forest research Vol. 33; no. 1; pp. 156 - 163 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Ottawa, Canada
NRC Research Press
01.01.2003
National Research Council of Canada Canadian Science Publishing NRC Research Press |
Subjects | |
Online Access | Get full text |
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Summary: | Little is known about the N uptake abilities of competitor species and planted seedlings in the boreal forest. The objective of this study was to determine the MichaelisMenten kinetic parameters of NH
4
+
and NO
3
for white spruce (Picea glauca (Moench) Voss) and jack pine (Pinus banksiana Lamb.) seedlings, and three competitive common boreal forest early successional species: aspen (Populus tremuloides Michx.), fireweed (Epilobium angustifolium L.), and cala magrostis (Calamagrostis canadensis (Michx.) Beauv.). Uptake kinetics were measured in hydroponic cultures and expressed as maximum uptake (I
max
) and ion affinity (K
m
). The ranking of I
max
values (pmol·cm
-2
·s
1
) for NH
4
+
uptake was calamagrostis (84.6), fireweed (58.1), white spruce (20.7), aspen (12.5), and jack pine (10.9), and for NO
3
uptake was calamagrostis (17.7), fireweed (12.5), aspen (5.8), white spruce (4.5), and jack pine (2.1). The ranking of K
m
values (µM) for NH
4
+
uptake was calamagrostis (125.9), fireweed (163.8), aspen (205.7), white spruce (217.1), and jack pine (270.5), and for NO
3
uptake was calamagrostis (229.9), fireweed (274.6), aspen (336.5), white spruce (344.5), and jack pine (350.5). Calamagrostis exhibited the greatest uptake rates and affinity for NH
4
+
and NO
3
, suggesting that silviculture practices that specifically reduce establishment of this grass should benefit the growth of planted seedlings. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0045-5067 1208-6037 |
DOI: | 10.1139/x02-169 |