Journal Article

Intact amino acid uptake by northern hardwood and conifer trees

Gallet-Budynek, Anne, Rodgers, Vikki L., Finzi, Adrien C., Talbot, Jennifer M., Hyzy, Sharon, Brzostek, Edward

2009

Overview

Empirical and modeling studies of the N cycle in temperate forests of eastern North America have focused on the mechanisms regulating the production of inorganic N, and assumed that only inorganic forms of N are available for plant growth. Recent isotope studies in field conditions suggest that amino acid capture is a widespread ecological phenomenon, although northern temperate forests have yet to be studied. We quantified fine root biomass and applied tracer-level quantities of U-¹³C₂-¹⁵N-glycine, ¹⁵NH₄ ⁺ and ¹⁵NO₃ ⁻ in two stands, one dominated by sugar maple and white ash, the other dominated by red oak, beech, and hemlock, to assess the importance of amino acids to the N nutrition of northeastern US forests. Significant enrichment of ¹³C in fine roots 2 and 5 h following tracer application indicated intact glycine uptake in both stands. Glycine accounted for up to 77% of total N uptake in the oak-beech-hemlock stand, a stand that produces recalcitrant litter, cycles N slowly and has a thick, amino acid-rich organic horizon. By contrast, glycine accounted for only 20% of total N uptake in the sugar maple and white ash stand, a stand characterized by labile litter and rapid rates of amino acid production and turnover resulting in high rates of mineralization and nitrification. This study shows that amino acid uptake is an important process occurring in two widespread, northeastern US temperate forest types with widely differing rates of N cycling.

• Publisher: Springer Verlag,CCSD,Berlin/Heidelberg : Springer-Verlag,Springer,Springer-Verlag,Springer Nature B.V
• Subject: Acer saccharum / Acid production / Acid soils / Amino acids / Amino Acids - metabolism / Amino Acids - pharmacokinetics / analysis / Animal and plant ecology / Animal, plant and microbial ecology / Biological and medical sciences / biomass / Biomedical and Life Sciences / Carbon Isotopes / Carbon Isotopes - analysis / Carbon Isotopes - pharmacokinetics / Coniferous trees / conifers / Ecology / Ecology, environment / Ecosystem Ecology - Original Paper / Ecosystem Ecology - Original Papers / Forest soils / forest types / Forests / Fraxinus americana / Fundamental and applied biological sciences. Psychology / General aspects / hardwood / Hydrology/Water Resources / Isotope studies / isotopes / labeling techniques / Life Sciences / Litter / Maple sugar / metabolism / Mineral soils / Mineralization / Models, Biological / Nitrification / Nitrogen / nitrogen content / Nitrogen Isotopes / Nitrogen Isotopes - analysis / Nitrogen Isotopes - pharmacokinetics / nutrition / Organic horizons / Organic soils / pharmacokinetics / Plant growth / Plant Roots / Plant Roots - metabolism / Plant Sciences / Quercus / roots / Soil / Soil - analysis / Soil ecology / Soil horizons / Species Specificity / Sugar / Temperate forests / trees / Trees - metabolism / United States / white sugar
• ISBN: 0002651005000