Allocation of current photosynthate and changes in tissue dry weight within northern red oak seedlings: individual leaf and flush carbon contribution during episodic growth

2000 ◽  
Vol 30 (8) ◽  
pp. 1296-1307 ◽  
Author(s):  
Richard E Dickson ◽  
Patricia T Tomlinson ◽  
J G Isebrands

Relatively little is known about the changing carbon allocation patterns in species with episodic growth cycles such as northern red oak (Quercus rubra L.). To examine such changing allocation and growth patterns, northern red oak plants were grown from seed in controlled environment chambers through four cycles of growth. 14CO2 was supplied to leaves of the first, second, or third flushes at different Quercus morphological index growth stages within each flush, and the distribution of 14C within the plant was analyzed. Carbon allocation from source leaves of the first and second flush was primarily upward during the subsequent cycle of shoot growth and downward during lag and bud growth stages. All leaves within a flush did not respond the same. Upper leaves allocated most 14C-photosynthate upward during leaf and shoot growth while lower leaves supplied more 14C to lower stem and roots. During the third and fourth flushes, differential allocation from leaves within a flush resulted in essentially equal upward and downward carbon allocation. Growth and allometric relationships reflected these changes in carbon allocation.

2011 ◽  
Vol 41 (4) ◽  
pp. 773-781 ◽  
Author(s):  
L.J. Haavik ◽  
D.W. Stahle ◽  
F.M. Stephen

Extreme climate events are frequently important factors associated with episodes of forest decline. A recent oak decline event and concurrent outbreak of a native wood-boring beetle, the red oak borer ( Enaphalodes rufulus (Haldeman)), occurred throughout Arkansas Ozark and Ouachita Mountains. To investigate the role of drought and stand maturity on northern red oak ( Quercus rubra L.) decline, we analyzed tree-ring growth patterns and their relationships to climate from 815 live and 161 recently dead Q. rubra. While younger Q. rubra exhibited faster growth rates and stronger climate relationships than older Q. rubra, some individuals within all stands that originated >60 years ago were susceptible to growth decline or mortality. A significant growth interaction occurred among the three age classes identified where currently healthy Q. rubra were initially growing at slower decadal rates than currently declining or recently dead Q. rubra and later transitioned to higher growth rates than the others. These differences appear to be related to carbon allocation patterns towards rapid aboveground and (or) belowground growth early in development that led to later decline and (or) mortality. Decline in growth and weakening tree growth – climate relationships appeared to be initiated by an unusually severe and sustained drought in the early 1950s.


2000 ◽  
Vol 30 (8) ◽  
pp. 1308-1317 ◽  
Author(s):  
Richard E Dickson ◽  
Patricia T Tomlinson ◽  
J G Isebrands

The episodic or flushing growth habit of northern red oak (Quercus rubra L.) has a significant influence on carbon fixation, carbon transport from source leaves, and carbon allocation within the plant; however, the impact of episodic growth on carbon partitioning among chemical fractions is unknown. Median-flush leaves of the first and second flush were photosynthetically labeled with 14CO2, and partitioning of 14C into lipids and pigments, sugars, amino acids, organic acids, protein, starch, and structural carbohydrates of source leaves, stem, and roots was determined. In addition, four chemical fractions (sugars, starch, amino acids, and total structural carbohydrates) were quantitatively analyzed in leaves, stems, and roots. Chemical changes in source leaves reflected leaf maturation, changing sink demand during a growth cycle, and leaf senescence. Starch and sugar storage in leaves, stems, and roots during lag and bud growth stages indicate a feedback response of these tissues to decreasing sink strength and temporary storage of both starch and sugar in these plant tissues. Northern red oak, with episodic shoot growth patterns, provides an experimental system in which large changes in sink strength occur naturally and require no plant manipulation. Metabolic changes in leaf, stem, and root tissue of red oak have broad application for other oak species and for both temperate and tropical tree species with cyclic growth habits.


2018 ◽  
Vol 48 (9) ◽  
pp. 1067-1072 ◽  
Author(s):  
Joshua L. Sloan ◽  
George S. Jackson ◽  
Douglass F. Jacobs

Variability between individuals can cause error in plant physiology studies when measurements or treatments occur on a chronological basis. Thus, plant growth indices such as the Quercus morphological index (QMI) were developed, enabling distinctions between exogenous treatment effects and endogenous ontological effects. Few studies have examined post-transplant northern red oak (Quercus rubra L.) seedling physiology in relation to the QMI. We used 14CO2 to label current photosynthate of post-transplant northern red oak seedlings during the first flush to assess endogenous patterns of current photosynthate translocation. Carbon translocation patterns relative to QMI growth stages of post-transplant seedlings resembled those described in pre-transplant seedlings, with expanding leaves and shoots retaining the majority of current photosynthate early in the flush, followed by increases in downward translocation to both new and old roots during the lag stage, when active aboveground growth ceased for the flush. Early post-transplant growth of new shoots relied heavily on stored carbohydrates, and old shoots demonstrated negligible sink strength for current photosynthate throughout the experiment. Our findings emphasize the importance of stored carbohydrates for early post-transplant growth and suggest that QMI-based observations regarding carbohydrate translocation patterns of pre-transplant seedlings in this species remain largely valid for post-transplant seedlings.


1980 ◽  
Vol 10 (4) ◽  
pp. 549-554 ◽  
Author(s):  
M. M. Larson

Northern red oak (Quercusrubra L.) 1-0 seedlings were planted in plastic tubes with a rubber moisture barrier placed around taproots at midpoint so that upper and lower sections of the root system could be independently watered with polyethylene glycol solutions to induce various soil moisture stress conditions. Trees were also grown at two relative humidity (RH) levels.In the first of two studies, soil moisture stress levels were −1/3, −3, −6 bars (1 bar = 105 Pa), and RH's were 75 and 45%. Root regeneration (largely confined to cut end of lower taproot) and top growth decreased, and dieback of planted stems increased, as soil moisture stress of either upper or lower root sections increased. When both sections were −6 bars, root regeneration was nil.In the second study, upper root soil moisture stress levels included a −12-bar treatment which reduced dry weight of leaves and roots to about one-half that of unstressed plants. However, a unit increase in stress to lower root sections was 1.5 to 4 times more inhibitory to growth than a similar stress to upper root sections. Low RH decreased several measures of seedling growth, increased stem dieback, and prolonged time to budbreak from 6 to 12 days for most soil moisture treatments.These studies demonstrate that root regeneration is very sensitive to soil moisture stress on lower roots, where most of the new roots originate, and moderately sensitive to stress on upper roots and to atmospheric stress on shoots.


1975 ◽  
Vol 5 (3) ◽  
pp. 381-386 ◽  
Author(s):  
M. M. Larson

Northern red oak seedlings were top-pruned in the seedbed each month from August until the next March. In late March, all trees were lifted, planted in the greenhouse, and harvested 30 days later. Any top-pruning treatment that directly or indirectly removed the leaves in late summer or early fall markedly reduced root regeneration and initial shoot growth after planting in March. Removal of all the visible buds at any date resulted in increased numbers of new shoots after planting, while pruning stems at the groundline reduced new shoot growth.In additional studies, shoots and roots of trees lifted in March were pruned to various levels before planting. Results indicated that root pruning influenced seedling growth much more than shoot pruning. The amount of new shoot growth was significantly correlated with root weight of seedlings when planted, whether differences in root weight were natural or obtained by pruning. The effects of shoot pruning and root pruning on seedling growth were largely independent of each other.


1995 ◽  
Vol 25 (4) ◽  
pp. 603-613 ◽  
Author(s):  
Andrew M. Gordon ◽  
James A. Simpson ◽  
Peter A. Williams

This study investigated the potential for underplanting 1 + 0 and 1 + 1 northern red oak (Quercusrubra L.) in conjunction with a two-cut shelterwood harvest of a low-quality, ridgetop, tolerant hardwood stand in central Ontario. Growth patterns were followed for 6 years; herbicide (glyphosate) application and prescribed fire (two burns, 3 years apart) were used as competition control measures in an experimental design that tested all possible combinations of stock type, competition control, and clipping 2 years after planting. Six years after outplanting the mean height attained across all treatments for 1 + 0 stock was 76 cm and for 1 + 1 stock, almost 90 cm. Depending upon treatment, some individuals were almost 3 m tall. In the presence of heavy deer (Odocoileusvirginianus Zimmerman) browsing, competition control of any type does not appear to be warranted. Clipping also does not appear to be advantageous. We can speculate that competition control made seedlings more susceptible to browsing by deer or damage by heavy snow and ice accumulation. The competitive ability of red oak on these sites is such that it will respond well to even late release from normal competition resulting from overstory disturbance (i.e., control treatment). The general technique for establishment of oak in this manner appears to be logical for these site conditions, but further investigation is necessary to address the direct impact of browsing pressure on seedling growth and the potential for similar silvicultural prescriptions on more marginal oak sites.


1984 ◽  
Vol 14 (4) ◽  
pp. 536-542 ◽  
Author(s):  
Paul S. Johnson

Northern red oak (Quercusrubra L.) were planted in upland oak forests of the Missouri Ozarks. Plantings were made in 8 clearcut plots and in 16 plots thinned to 60% stocking. After three field growing seasons, the overstory was removed on one-half of the underplanted plots. The 2304 planted trees consisted of four classes of planting stock: small 1 + 0, large 1 + 0, 1 + 1, and container-grown. Shoots were clipped on one-half of the trees in each class. After five field growing seasons, average survival was 84%. Average heights of survivors were as follows: 118 cm for trees planted directly into clearcuts, 97 cm for underplanted–released trees, and 59 cm for underplanted–unreleased trees. Based on net shoot growth of trees after overstory removal, success probabilities were estimated using logistic regression analysis. The most successful trees were clipped 1 + 1 stock with initial shoot diameters (2 cm above the root collar) of 10 mm or more that were underplanted and subsequently released. For clipped 1 + 1 stock, success probabilities for a success criterion of 30 cm net height growth per year after overstory removal ranged from 0.61 to 0.77 for 10 to 16 mm diameter trees; for a success criterion of 40 cm, success probabilities were 0.42 to 0.63, respectively.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 607f-607
Author(s):  
Daniel G. Krueger ◽  
Bert T. Swanson

To increase root fibrosity, acorns of northern red oak (Quercus rubra L.) were germinated and subjected to several radicle clipping (+/-) and K-IBA concentration treatments combintations prior to planting. Taproots and laterals ≥ 1 mm in diameter at the point of origin were counted. Low concentrations of K-IBA (0-4000 ppm) resulted in four root morphologies: 1) a single taproot and 3-6 laterals (no clipping/no K-IBA), 2) 4-5 taproots and 1-3 laterals (clipped only), 3) a single taproot and 5-12 laterals (not clipped/K-IBA) and 4) 6-12 taproots and 1-2 laterals. High concentrations of K-IBA (4000-10,000 ppm) `clipped' unclipped radicles resulting in root systems similiar to those clipped by hand. Stem height was unaffected by treatment. Radicle-clipping may increase stem caliper. K-IBA treatments may decrease root dry weight.


HortScience ◽  
2008 ◽  
Vol 43 (7) ◽  
pp. 2179-2185 ◽  
Author(s):  
Mindy L. Bumgarner ◽  
K. Francis Salifu ◽  
Douglass F. Jacobs

Container seedling production systems for forest tree nurseries are challenged by the need for judicious water consumption. Subirrigation systems may provide an alternative to overhead systems by mitigating water use, yet remain relatively untested for propagation of forest tree seedlings. We evaluated effects of overhead versus subirrigation under varying media (40:60, 60:40, and 80:20 peat:perlite) and fertilization (0 or 1.2 g nitrogen/plant) regimes on nursery development and first-year field performance of northern red oak (Quercus rubra L.) seedlings. Fertilization increased aboveground biomass production and nutrient content, but decreased root dry weight. Relative to overhead-irrigated seedlings, subirrigation increased red oak seedling aboveground biomass production as well as above- and belowground nitrogen content under fertilized conditions. Media had no effect on plant response. Subirrigation increased electrical conductivity (5 dS·m−1 greater) and decreased pH in the upper media zone (0 to 5 cm from top), whereas the opposite effect was found in the lower zone. Nursery fertilization was associated with reduced field survival and growth, which may have been the result of transplant stress resulting from higher shoot:root. Subirrigated seedlings had greater field diameter growth. Our results suggest that subirrigation could serve as a viable alternative to overhead systems in container propagation of hardwood seedlings.


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