Whole-tree carbon and nitrogen partitioning in young hybrid poplars.

The effects of water, nitrogen (N), and genotype on whole-tree carbon and nitrogen partitioning were examined in two Populus genotypes grown from cuttings in large pots set in the ground. Four replicate trees from each genotype/water/N treatment combination were harvested in either August, September, or November of their first year of growth. Aboveground biomass was linearly related to total leaf area. Clones allocated photosynthate differently. Populus tristis x P. balsamifera cv. Tristis #1 produced 14.5 cm of fine roots (< 0.5 cm diameter) per cm(2) of foliage, whereas P. x euramericana cv. Eugenei only produced 4.0 cm of fine roots per cm(2) of foliage. The large diameter structural roots of Eugenei grew rapidly late in the growing season so that large-root biomass was 3.8 to 7.5 times greater in November than in mid-August. In both clones, the root system grew twice as fast as the stem and branches late in the year. During August, about 75% of total tree N was in the canopy, but at least 80% of the September N content was still present in November following leaf fall. The major site of N storage was the large diameter structural roots. Nitrogen concentrations in these roots doubled following bud set.

[1]  Kurt S. Pregitzer,et al.  Late-season changes in allocation of starch and sugar to shoots, coarse roots, and fine roots in two hybrid poplar clones. , 1990, Tree physiology.

[2]  M. P. Coutts,et al.  Developmental processes in tree root systems , 1987 .

[3]  Richard H. Waring,et al.  Forest Ecosystems: Concepts and Management , 1985 .

[4]  N. Nelson,et al.  Growth and development during the establishment year of two Populus clones with contrasting morphology and phenology. , 1988, Tree physiology.

[5]  D. Dickmann,et al.  Incorporation of C-Photosynthate into Protein during Leaf Development in Young Populus Plants. , 1975, Plant physiology.

[6]  A. Srivastava,et al.  Quantitative Separation of Roots from Compacted Soil Profiles by the Hydropneumatic Elutriation System1 , 1982 .

[7]  J. G. Isebrands,et al.  Yield physiology of short rotation intensively cultured poplars , 1983 .

[8]  D. Dickmann,et al.  Differential physiological and morphological responses of two hybrid Populus clones to water stress. , 1988, Tree physiology.

[9]  G. Ågren,et al.  Nutrient uptake and allocation at steady-state nutrition , 1988 .

[10]  E. KostShelton,et al.  Growth and development. , 1951, Ciba clinical symposia.

[11]  J. Sauter,et al.  Ultrastructural and Biochemical Results on the Localization and Distribution of Storage Proteins in a Poplar Tree and in Twigs of Other Tree Species , 1989 .

[12]  Christopher B. Field,et al.  photosynthesis--nitrogen relationship in wild plants , 1986 .

[13]  T. Ingestad,et al.  Nitrogen stress in birch seedlings. II. N, K, P, Ca, and Mg nutrition , 1979 .

[14]  Henry L. Gholz,et al.  Environmental Limits on Aboveground Net Primary Production, Leaf Area, and Biomass in Vegetation Zones of the Pacific Northwest , 1982 .

[15]  J. C. Gordon.  Changes in total nitrogen, soluble protein, and peroxidases in the expanding leaf zone of eastern cottonwood. , 1971, Plant physiology.

[16]  B. Taylor,et al.  The nitrogen nutrition of the peach tree. VI. Influence of autumn nitrogen applications on the accumulation of nitrogen, carbohydrate and macroelements in 1-year-old peach trees. , 1970 .

[17]  Richard H. Waring,et al.  Estimating Forest Growth and Efficiency in Relation to Canopy Leaf Area , 1983 .

[18]  J. Isebrands,et al.  The Relation Between Leaf Production and Wood Weight in First-Year Root Sprouts of Two Populus Clones , 1972 .

[19]  N. Nelson,et al.  Distribution of [14C]‐labeled photosynthates within intensively cultured Populus clones during the establishment year , 1983 .

[20]  S. Running,et al.  Leaf Area of Mature Northwestern Coniferous Forests: Relation to Site Water Balance , 1977 .

[21]  Dr. Wolfgang Böhm.  Methods of Studying Root Systems , 1979, Ecological Studies.