Species patterns in foliar nitrogen concentration, nitrogen content and 13C abundance for understory saplings across light gradients

2009 ◽  
Vol 327 (1-2) ◽  
pp. 389-401 ◽  
Author(s):  
J. M. Kranabetter ◽  
S. W. Simard ◽  
R. D. Guy ◽  
K. D. Coates
Keyword(s):  
Nitrogen Content ◽  
Nitrogen Concentration ◽  
Foliar Nitrogen ◽  
13C Abundance

Canopy-scale relationships between foliar nitrogen and albedo are not observed in leaf reflectance and transmittance within temperate deciduous tree species

Botany ◽  
2011 ◽  
Vol 89 (7) ◽  
pp. 491-497 ◽  
Author(s):  
Megan K. Bartlett ◽  
Scott V. Ollinger ◽  
David Y. Hollinger ◽  
Haley F. Wicklein ◽  
Andrew D. Richardson
Keyword(s):  
Nitrogen Content ◽  
Near Infrared ◽  
Structural Characteristics ◽  
Nitrogen Concentration ◽  
Deciduous Tree ◽  
Integrating Sphere ◽  
Area Index ◽  
Foliar Nitrogen ◽  
Crown Shape ◽  
Leaf Level

Strong positive correlations between the maximum rate of canopy photosynthesis, canopy-averaged foliar nitrogen concentration, and canopy albedo have been shown in previous studies. While leaf-level relationships between photosynthetic capacity and foliar nitrogen are well documented, it is not clear whether leaf-level relationships between solar-weighted reflectance and nitrogen underlie the canopy-scale patterns. Using an integrating sphere, we measured the reflectance and transmittance (350–2500 nm) of both individual leaves and multileaf stacks. Samples were collected from 12 broadleaf species at the Harvard Forest in central Massachusetts, USA. Across all species, foliar nitrogen (both mass-based nitrogen concentration and area-based nitrogen content) and leaf mass / area ratio were negatively, rather than positively, correlated with solar-weighted reflectance and transmittance in ultraviolet–visible and near-infrared wavelength bands (350–700 nm and 700–2500 nm, respectively). Leaf-level anatomy and biochemistry, therefore, do not appear to drive the canopy-level association between increasing foliar nitrogen content and increasing canopy albedo. This suggests that interactions between leaf optical properties and structural canopy-scale traits that correlate with nitrogen content (perhaps some combination of crown shape, leaf area index, leaf angular distribution, or other structural characteristics of the canopy), may instead underlie the previously observed relationship between nitrogen and canopy-level shortwave albedo.

Early growth of lodgepole pine after establishment of alsike clover–Rhizobium nitrogen-fixing symbiosis

1992 ◽  
Vol 22 (8) ◽  
pp. 1089-1093 ◽  
Author(s):  
R. Trowbridge ◽  
F.B. Holl
Keyword(s):  
Forest Floor ◽  
Lodgepole Pine ◽  
Nitrogen Concentration ◽  
Growing Season ◽  
Early Growth ◽  
Percent Cover ◽  
Foliar Nitrogen ◽  
Growing Seasons ◽  
Pine Seedlings ◽  
Needle Mass

An overdense lodgepole pine (Pinuscontorta Dougl. ex Loud.) stand was knocked down and the site was prepared by broadcast burn, windrow burn, or mechanical forest floor removal. Inoculated alsike clover (Trifoliumhybridum L.) was seeded at 0, 10, 20, and 30 kg/ha for the three different site preparation treatments to determine the effects of (i) site preparation on infection and effectiveness of the clover–Rhizobium symbiosis and clover percent cover and (ii) the clover–Rhizobium N2-fixing symbiosis on survival, early growth, and foliar nitrogen concentration of lodgepole pine seedlings. The N2-fixing symbiosis established well in all treatments. Clover percent cover increased with increasing rate of seeding, although by relatively few percent in the clover seeded plots. Broadcast burning, windrow burning, and mechanical forest floor removal did not affect the establishment of the N2-fixing symbiosis or clover percent cover. Lodgepole pine survival was not affected by the seeding treatments in any year, nor were height measurements during the first three growing seasons. Seedling height was slightly less in clover-seeded plots compared with controls in the fourth growing season. Lodgepole pine seedlings on clover-seeded plots had decreased diameter growth compared with controls during the first three growing seasons, but incremental diameter growth no longer showed this effect by the fourth growing season. Needle mass (g/100 needles) was less in clover-seeded plots at the end of the second growing season, but this effect was reversed by the fourth growing season, when both needle mass and foliar nitrogen concentration in lodgepole pine foliage were greater in clover-seeded plots.

scholarly journals Aplicações de glyphosate: Desempenho de soja transgênica, comunidade bacteriana e teor de nitrogênio foliar / Glyphosate applications: Performance of transgenic soy, bacterial community and foliar nitrogen content

2021 ◽  
Vol 7 (10) ◽  
pp. 99306-99322
Author(s):  
Evelin Regina Albano Balastrelli ◽  
Miriam Hiroko Inoue ◽  
Júlia Rodrigues Novais ◽  
Kassio Ferreira Mendes ◽  
Ana Carolina Dias Guimarães ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Nitrogen Content ◽  
Foliar Nitrogen

Solvothermal synthesis of carbon nitrogen nanotubes and nanofibers

2006 ◽  
Vol 21 (7) ◽  
pp. 1658-1663 ◽  
Author(s):  
Tiancheng Mu ◽  
Jun Huang ◽  
Zhimin Liu ◽  
Zhonghao Li ◽  
Buxing Han
Keyword(s):  
Electron Microscopy ◽  
Nitrogen Content ◽  
Solvothermal Synthesis ◽  
Spectroscopic Analysis ◽  
Nitrogen Concentration ◽  
Cyanuric Chloride ◽  
Sodium Metal

Carbon nitrogen nanotubes and nanofibers with controlled nitrogen concentration have been prepared by reaction of cyanuric chloride and hexachlorobenzene (HCB) with sodium metal at 250 °C in cyclohexane. Electron microscopy and spectroscopic analysis were used to characterize the products. The total yields of the tubes and fibers decrease as the ratio of cyanuric chloride to HCB increases, and nitrogen content in the products could be controlled by the ratio. The nanostructures depended strongly on the nitrogen content. Lower nitrogen content was favorable for producing linear products.

Endophytic fungus diversity in soybean plants submitted to conditions of elevated atmospheric CO2 and temperature

2020 ◽  
Author(s):  
Huberman Valadares Gonçalves ◽  
Yumi Oki ◽  
Leandra Bordignon ◽  
Mariana Costa Ferreira ◽  
José Eustáquio dos Santos Jr ◽  
...  
Keyword(s):  
Endophytic Fungi ◽  
Nitrogen Concentration ◽  
C:N Ratio ◽  
Climatic Changes ◽  
Foliar Nitrogen ◽  
Increased Temperature ◽  
The World ◽  
Species Substitution ◽  
Soybean Plants ◽  
Species Productivity

Global climatic changes can have drastic impacts on plant species including severe consequences for the agricultural species productivity. Many of these species present important mutualisms with endophytic fungi that positively influence their performance. The present study evaluated whether the increases in CO<sub>2</sub> and temperature predicted for the year 2100 may cause changes in foliar carbon (C) and nitrogen (N) concentrations in soybean (<i>Glycine max</i>) and, consequently, the interactions with its endophytic fungi. The effects of elevated CO<sub>2</sub> and temperature were evaluated in four treatments in open-top chambers: (1) Control; (2) Increased Temperature; (3) Increased CO<sub>2</sub>; (4) Increased CO<sub>2</sub> and Temperature. Increased atmospheric CO<sub>2</sub> resulted in decreased foliar nitrogen concentration, while increased temperature increased it. A total of 16 taxa of endophytic fungi were identified based on sequencing <i><i>ITS</i></i> (Internal Transcribed Spacer) regions of rRNA subunits. Increased atmospheric CO<sub>2</sub> and temperature were observed to potentially modify the endophytic mycobiota of soybean plants. Results suggest the fungi species substitution as a consequence of changes in foliar nitrogen concentration and C:N ratio. Predicted climatic changes shall affect the plant and endophytes relationships, which will in turn affect the performance and resistance of soybean, one of the most important crops in the world.

Five-year growth responses of Douglas-fir, western hemlock, and western redcedar seedlings to manipulated levels of overstory and understory competition

2006 ◽  
Vol 36 (10) ◽  
pp. 2439-2453 ◽  
Author(s):  
Timothy B Harrington
Keyword(s):  
Growth Rate ◽  
Nitrogen Content ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Volume Index ◽  
Stem Volume ◽  
Western Redcedar ◽  
Foliar Nitrogen ◽  
Relative Growth ◽  
Vegetation Control

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western redcedar (Thuja plicata Donn ex D. Don) seedlings were planted in March 2001 within three clearcut-harvested, shelterwood, or thinned stands of mature Douglas-fir near Olympia, Washington. From 2002 to 2005, areas of vegetation control of 0, 4.5, or 9 m2 were maintained with herbicides around a total 162 seedlings per species. Photosynthetically active radiation (PAR) was 34%, 62%, and 100% of full sunlight in thinned stands, shelterwoods, and clearcuts, respectively. Effects of overstory level and vegetation control on seedling growth and resource availability generally were additive. Seedling stem volume index in clearcuts averaged four to eight times that observed in thinned stands, and with vegetation control, it averaged two to four times that observed without it. In thinned stands, relative growth rate of seedling stem volume index had a positive linear relationship with PAR (R2 = 0.38). Foliar nitrogen content of Douglas-fir explained 71% of the variation in relative growth rate. Factors explaining the most variation in foliar nitrogen content differed between thinned stands (PAR, R2 = 0.34) and clearcuts or shelterwoods (midday water potential, R2 = 0.63), suggesting that light and root competition, respectively, were the primary growth-limiting factors for these overstory levels.

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