| ENVIRONMENTAL INFLUENCES ON GAS EXCHANGE IN FERTILIZED AND NON-FERTILIZED STANDS OF LOBLOLLY PINE | |
Abstract/OtherAbstract
:
|
Spatial and temporal variation in foliar gas exchange on both a diurnal and seasonal scale was examined in 15-year-old fertilized and non-fertilized loblolly pine in the upper and lower thirds of crowns in stands located in the North Carolina sandhills. Photosynthesis rates between control and fertilized stands for both seasonal and diurnal measurement periods were different during only three months. Photosynthesis rates were consistently greater in the upper third of the crown compared to the lower third. Seasonal trends in both conductance and transpiration closely resembled trends found in seasonal photosynthesis. Foliar nitrogen concentrations were greater in fertilized stands for all months sampled. However, nitrogen content generally did not correlate with photosynthesis rates. Mean monthly water use efficiencies were significantly higher in fertilized stands during two months and were usually greater in upper crown foliage. Common empirical gas exchange models reveal that light and vapor pressure deficit (VPD) explain a majority of the variation observed in photosynthesis and transpiration, respectively. Conductance was not modeled since environmental variation did not adequately explain conductance patterns. Predicted light response curves reveal that upper crown foliage has higher maximum photosynthesis rates, respiration rates, light compensation points, and lower initial quantum yield compared to lower crown foliage. Models predict that foliage from fertilized stands is more sensitive to VPD and light during the growing season. Transpiration models predict highly variable responses to VPD depending on the treatment combination and season. Model R-square and predicted gas exchange values suggest that seasonal acclimation occurred. |
Authors
:
|
Gough, Christopher Michael |
Related Documents
:
|
0010329099 - Control of photosynthesis and stomatal conductance in ricinus communis l. (castor bean)... 0008529419 - Crown development and architecture of fraxinus pennsylvanica var. subintegerrima (vahl)... 0032763009 - Can haematococcus lacustris (chlorophyta) recovered from photoinhibition of photosynthe... 0010324489 - Photosynthetic and respiratory activity of fruiting forms within the cotton canopy 1 0033533389 - Interaction between external and internal conditions in the development of photosynthet... 0033394399 - Photoreactions in phycomyces : growth and tropic responses to the stimulation of narrow... 0001325729 - Where to stay by night and day: size-specific and seasonal differences in horizontal an... 0004772089 - Effects of noise on hearing international symposium (5th) held in gothenburg, sweden on... 0010318229 - Far-red light-induced changes in intracellular potentials of spinach mesophyll cells: i... |
Contributors
:
|
John R. Seiler, Boris I. Chevone, Paul Mou |
Publication Detail
:
|
Publisher : VT Type : text Format : application/pdf |
Date Detail
:
|
2000-08-14 |
Subject
:
|
Forestry |
Coverage
:
|
- |
Relation
:
|
- |
Source
:
|
http://scholar.lib.vt.edu/theses/available/etd-08022000-11480057/ |
Copyright Information
:
|
unrestricted, I hereby grant to Virginia Tech or its agents the right to archive and to make available my thesis or dissertation in whole or in part in the University Libraries in all forms of media, now or hereafter known. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation. |
Other Details
:
|
Languages : en |
Export Citation
:
|
APA/MLA Format Download EndNote Download BibTex |
Previous Document: Induction of Protection, Antibodies and Cell Mediated Immune Responses by Brucella Abortus Strain RB...
Next Document: Effects of Feeding Phytase Enzyme and HAP Corn on Solubility of Phosphorus, Copper, and Zinc in Turk...