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Role of soil nitrogen for the conifers of the boreal forest : a critical review

Lupi Carlo, Morin Hubert, Deslauriers Annie, Rossi Sergio et Houle Daniel. (2013). Role of soil nitrogen for the conifers of the boreal forest : a critical review. International Journal of Plant & Soil Science, 2, (2), p. 155-189.

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URL officielle: http://dx.doi.org/doi:10.9734/IJPSS/2013/4233

Résumé

Nitrogen is considered the most important element in plant nutrition and growth. However its role and availability for boreal forest conifers is still debated. Boreal conifers have adapted strategies to cope with the reduced availability of N. ECM fungi, associated with boreal conifer roots, increase soil exploration and N nutrition, especially where organic N predominates. Conifers usually take up ammonium at levels comparable to simple organic N, which probably grows in importance as organic matter accumulates with stand age, while estimates of nitrate uptake are generally lower. Conifers, especially slow growing species, may rely on internal N cycling to sustain the development of new tissues in spring. N increases photosynthesis and leaf area and thus increases growth and wood formation, leading to wider radial rings mostly because of increased earlywood production. N-depositions and disturbances (e.g. fire and harvest) may alter the soil N-cycle and affect boreal forest growth. N depositions are considered responsible for the increase in boreal forest growth during the last century. Intensive harvest and high N-depositions may shift limitation from N to another element (e.g. P, K, and B). Climate change should affect the N cycle through complex mechanisms, including changes in the fire return interval, direct effects of warmer soils on N mineralization and stimulating plant growth modifying the balance between N stored in soils and in the living and dead (e.g. wood) biomass. Future research should try to improve our understanding of the possible outcomes of changes in disturbance regimes, N-depositions and climate, including the role of N fixation by mosses, canopy N uptake and the responses of conifers in relation to changes in microbial (symbiotic and not) communities.

Type de document:Article publié dans une revue avec comité d'évaluation
Volume:2
Numéro:2
Pages:p. 155-189
Version évaluée par les pairs:Oui
Date:2013
Sujets:Sciences naturelles et génie > Sciences appliquées > Foresterie et sciences du bois
Sciences naturelles et génie > Sciences naturelles > Biologie et autres sciences connexes
Département, module, service et unité de recherche:Départements et modules > Département des sciences fondamentales
Mots-clés:Ammonium, boreal conifers, growth, N limitation, nitrate, N uptake
Déposé le:06 juin 2016 15:32
Dernière modification:05 déc. 2016 20:46
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