Foliar nutrition and growth in red pine: distribution of photoassimilated carbon in seedlings during bud expansion

1972 ◽  
Vol 50 (10) ◽  
pp. 2053-2061 ◽  
Author(s):  
P. V. Rangnekar ◽  
D. F. Forward
Keyword(s):  
Spatial Distribution ◽  
Red Pine ◽  
Foliar Nutrition ◽  
Young Leaves ◽  
Major Increase ◽  
Insoluble Compounds

14CO2 was supplied to shoots of 4-year-old seedlings of red pine, and segments analyzed after 8 h, 3 days, and 7 days. The distribution of 14C after 7 days was similar to that observed earlier in a seedling 6 days after feeding. This pattern of spatial distribution developed within 3 days, after which it was stable.Most of the 14C was found initially in sugars, but redistribution among metabolites continued for 7 days. Transfer to insoluble compounds reached 55–60% in the seedlings, more in the expanding bud and the leaves. Glucose and fructose were initially equally labeled, but the ratio of 14C fructose to 14C glucose increased with time as labeled glucose disappeared more rapidly.Transfer of 14C to quinic and shikimic acids began immediately in the expanding bud and after 3 days these acids contained more of the activity in the bud than sugars. Young leaves also acquired substantial label in quinic and shikimic acids, but the major increase occurred later.

Foliar nutrition and wood growth in red pine: the distribution of radiocarbon photoassimilated by individual branches of young trees

1969 ◽  
Vol 47 (11) ◽  
pp. 1701-1711 ◽  
Author(s):  
P. V. Rangnekar ◽  
D. F. Forward ◽  
N. J. Nolan
Keyword(s):  
Cell Wall ◽  
Secondary Xylem ◽  
Growth Period ◽  
Red Pine ◽  
Unit Weight ◽  
Foliar Nutrition ◽  
Cambial Growth ◽  
Carbon 14 ◽  
Insoluble Compounds ◽  
Single Branch

The distribution of photoassimilated carbon-14 in young plantation trees was studied 6 or 10 days after supplying 14CO2 for a day to a single branch in the second, third, or fourth whorl. Both apical and cambial growth occurred during the interval, and apical growth throughout the trees was measured. Elongating terminals and products of cambial growth in the fed branch were highly labeled. In all trees some 14C was exported to the adjacent side of the tree. Movement in the trunk was bidirectional, but the position of the donor branch determined the direction of major transport. Only from whorl 2 was it upward; from whorl 3 or 4 it was downward. In both directions activity decreased with distance from the base of the donor branch, and the leader did not accumulate more, per unit weight, than the intervening internodes. Some 14C entered branches arising in the path of transport.Radioactivity was concentrated only in regions of growth, whether apical or cambial. Most of the 14C was in ethanol-insoluble compounds, largely in cell wall constituents. Autoradiographs of stem sections confirmed that 14C was deposited in currently developing tracheids of secondary xylem during most of the 10-day growth period. The ratio of activity in lignin to that in cellulose was inversely related to the total 14C in the cell wall constituents.

Foliar nutrition and growth in red pine: the fate of photoassimilated carbon in a seedling tree

1969 ◽  
Vol 47 (6) ◽  
pp. 897-906 ◽  
Author(s):  
Pratap V. Rangnekar ◽  
Dorothy F. Forward
Keyword(s):  
Organic Acids ◽  
Ethanol Extract ◽  
Water Soluble ◽  
Red Pine ◽  
Unit Weight ◽  
Chemical Methods ◽  
Foliar Nutrition ◽  
Terminal Bud ◽  
Ethanol Extracts ◽  
Insoluble Compounds

A 2- to 3-year-old red pine seedling was allowed to assimilate 14CO2 for 3 hours at 2000 ft-c and left under the same illumination for 6 days, then divided into segments and analyzed. Ethanol extracts were resolved by chromatography, insoluble residues by chemical methods. The radioactivity in various components was determined for all segments. Autoradiographs were made from stem sections at four levels.Radioactivity was found in all parts of the plant. Per unit mass of tissue, it was more or less uniformly apportioned among root, stem, and leaves, but the expanding terminal bud contained 5 times as much activity per gram of tissue. Overall, about one-third of the radioactivity was in insoluble compounds, mainly in cell wall constituents. In localities where conspicuous growth had occurred the proportion was higher. Autoradiographs of stem sections showed that 14C was concentrated in newly differentiated tracheids, and was still being incorporated after 6 days. About one-third of the activity in the ethanol extract was chloroform soluble, two-thirds water soluble. In the latter fraction, activity was largely in sugars and organic acids, little in amino acids. Activity in sugars, per unit weight of tissue, was more or less uniform throughout the plant, but activity in organic acids varied greatly. It was lowest in the stem, highest in the bud, where organic acids, almost exclusively quinic and shikimic, carried 75% of the label in the ethanol and water-soluble fraction, and 23% of all the activity in the bud.

Changes of Spatial Distribution of Korean Red Pine Forest in Hallasan National Park1

2019 ◽  
Vol 33 (5) ◽  
pp. 578-586
Author(s):  
Jong-Kab Kim ◽  
◽  
Jung-Goon Koh ◽  
Hyeong-Taek Yim ◽  
Dong-Soon Kim
Keyword(s):  
Spatial Distribution ◽  
Pine Forest ◽  
Red Pine ◽  
Korean Red Pine

Spatially random mortality in old-growth red pine forests of northern Minnesota

2012 ◽  
Vol 42 (5) ◽  
pp. 899-907 ◽  
Author(s):  
Tuomas Aakala ◽  
Shawn Fraver ◽  
Brian J. Palik ◽  
Anthony W. D’Amato
Keyword(s):  
Spatial Distribution ◽  
Tree Mortality ◽  
Empirical Studies ◽  
Pair Correlation ◽  
Growth Conditions ◽  
Initial Distribution ◽  
Red Pine ◽  
Old Growth ◽  
Dead Trees ◽  
Old Growth Forests

Characterizing the spatial distribution of tree mortality is critical to understanding forest dynamics, but empirical studies on these patterns under old-growth conditions are rare. This rarity is due in part to low mortality rates in old-growth forests, the study of which necessitates long observation periods, and the confounding influence of tree in-growth during such time spans. Here, we studied mortality of red pine ( Pinus resinosa Ait.) in five old-growth stands in Minnesota, USA, demonstrating the use of preexisting information of cohort age structures to account for in-growth after the most recent cohort establishment. Analyses of spatial point patterns, using both Ripley’s K-function and the pair correlation function, showed that tree mortality was essentially a random process, without evidence of contagious mortality patterns that are often expected for old-growth forests. Our analyses further demonstrated in practice that the distribution of dead trees may differ from that of the tree mortality events, which are constrained to occur within the initial distribution, and how mortality patterns can shape the spatial distribution of mature living trees, often attributed to aggregated regeneration patterns. These findings emphasize the need to disentangle the influence of the initial distribution of trees from that of actual tree mortality events.

Foliar nutrition and wood growth in red pine: effects of darkening and defoliation on the distribution of 14C-photosynthate in young trees

1973 ◽  
Vol 51 (1) ◽  
pp. 103-108 ◽  
Author(s):  
P. V. Rangnekar ◽  
D. F. Forward
Keyword(s):  
Red Pine ◽  
Foliar Nutrition ◽  
The Third ◽  
Pine Trees ◽  
Terminal Shoot

Young red pine trees were supplied with 14CO2 through a branch in the third whorl. Darkening or removal of all other needles caused a major diversion of 14C to the expanding terminal shoot. Defoliation had a much greater effect than darkening. The diversion can be only partially explained on the basis of removal of competing sources of carbohydrate. Use as well as distribution of labeled photosynthate was affected by the treatments.

Lithography below 100 nm

1983 ◽  
Vol 41 ◽  
pp. 96-99
Author(s):  
L. D. Jackel
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Electron Scattering ◽  
Electron Beam Lithography ◽  
Substrate Material ◽  
Local Electron ◽  
Electron Dose ◽  
Positive Resist ◽  
Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

SEM evaluation of the TEM cold-stage double-film specimen

1984 ◽  
Vol 42 ◽  
pp. 272-273
Author(s):  
Jayesh Bellare
Keyword(s):  
Spatial Distribution ◽  
Sample Preparation ◽  
Sample Thickness ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Liquid Sample ◽  
Thin Specimen ◽  
Sample Preparation Technique ◽  
Cold Stage ◽  
Film Specimen

Seeing is believing, but only after the sample preparation technique has received a systematic study and a full record is made of the treatment the sample gets.For microstructured liquids and suspensions, fast-freeze thermal fixation and cold-stage microscopy is perhaps the least artifact-laden technique. In the double-film specimen preparation technique, a layer of liquid sample is trapped between 100- and 400-mesh polymer (polyimide, PI) coated grids. Blotting against filter paper drains excess liquid and provides a thin specimen, which is fast-frozen by plunging into liquid nitrogen. This frozen sandwich (Fig. 1) is mounted in a cooling holder and viewed in TEM.Though extremely promising for visualization of liquid microstructures, this double-film technique suffers from a) ireproducibility and nonuniformity of sample thickness, b) low yield of imageable grid squares and c) nonuniform spatial distribution of particulates, which results in fewer being imaged.

Macroprobe Mode for the Study of Segregation in Steels

1990 ◽  
Vol 48 (2) ◽  
pp. 260-261
Author(s):  
Auclair Gilles ◽  
Benoit Danièle
Keyword(s):  
Mechanical Properties ◽  
Spatial Distribution ◽  
High Performance ◽  
Volume Fraction ◽  
Sheet Steel ◽  
Acquisition Time ◽  
Chemical Information ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Optical Micrographs

During these last 10 years, high performance correction procedures have been developed for classical EPMA, and it is nowadays possible to obtain accurate quantitative analysis even for soft X-ray radiations. It is also possible to perform EPMA by adapting this accurate quantitative procedures to unusual applications such as the measurement of the segregation on wide areas in as-cast and sheet steel products.The main objection for analysis of segregation in steel by means of a line-scan mode is that it requires a very heavy sampling plan to make sure that the most significant points are analyzed. Moreover only local chemical information is obtained whereas mechanical properties are also dependant on the volume fraction and the spatial distribution of highly segregated zones. For these reasons we have chosen to systematically acquire X-ray calibrated mappings which give pictures similar to optical micrographs. Although mapping requires lengthy acquisition time there is a corresponding increase in the information given by image anlysis.

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