Nitrogen sources for current-year shoot growth in 50-year-old sessile oak trees: an in situ (15)N labeling approach.

@article{Zein2011NitrogenSF,
  title={Nitrogen sources for current-year shoot growth in 50-year-old sessile oak trees: an in situ (15)N labeling approach.},
  author={Rana El Zein and Nathalie Breda and Dominique G{\'e}rant and B. Zeller and Pascale Maillard},
  journal={Tree physiology},
  year={2011},
  volume={31 12},
  pages={1390-400}
}
We used long-term in situ (15)N labeling of the soil to investigate the contribution of the two main nitrogen (N) sources (N uptake versus N reserves) to sun shoot growth from bud burst to full leaf expansion in 50-year-old sessile oaks. Recovery of (15)N by growing compartments (leaves, twigs and buds) and presence of (15)N in phloem sap were checked weekly. During the first 2 weeks following bud burst, remobilized N contributed ~90% of total N in growing leaves and twigs. Nitrogen uptake from… CONTINUE READING