Responses of northern red oak seedlings to lime and deer exclosure fencing in Pennsylvania

2012 ◽  
Vol 42 (4) ◽  
pp. 698-709 ◽  
Author(s):  
Robert P. Long ◽  
Patrick H. Brose ◽  
Stephen B. Horsley

In Pennsylvania, two hypotheses compete to explain the chronic oak ( Quercus spp.) regeneration problem: excessive deer browsing and soil cation depletion. We tested these hypotheses by evaluating the effect of forest liming and deer exclosure fencing on northern red oak ( Quercus rubra L.) seedling growth and nutrition in five oak shelterwood stands in Pennsylvania over 6 years. In each stand, four planting plots were located inside a 2.4 m high woven wire fence and another four were established outside the fence. About 225 northern red oak acorns were planted in each plot in spring 2004. Dolomitic limestone was applied to randomly selected plots at rates of 0, 4.5, 9.0, and 13.5 Mg·ha–1 during May 2004. There were no statistically significant (P ≤ 0.05) growth responses to lime applications. The only significant growth responses resulted from the fence versus no-fence treatment. A significant (P < 0.003) fence × year interaction for seedling height and root collar diameter indicates differential impacts of deer browsing. By 2009, seedlings inside fences averaged 32 cm tall, while seedlings outside the fences averaged 17 cm. Similarly, root collar diameter averaged 6.6 mm outside the fences and 9.1 mm inside fences.

2001 ◽  
Vol 19 (2) ◽  
pp. 69-72
Author(s):  
M. Pardos ◽  
J.A. Pardos ◽  
G. Montero

Abstract Cork oak (Quercus suber L.) seedlings of two Iberian provenances (PA-SR and SM-Lp) were grown for one growing season in non-treated containers or in containers treated on their interior surfaces with white exterior latex paint containing 80 g CuCO3/liter. Copper carbonate-treated containers effectively prevented root deformation and decreased the amount of circled, kinked and matted roots formed at the container wall-medium interface. Root morphology was altered by the copper coating, so elongation of lateral roots contacting CuCO3-treated surfaces was more reduced than that of the tap root (82.7% vs 1.5%). These lateral roots showed higher branching frequency than roots contacting untreated container walls. CuCO3 treatment decreased root collar diameter, but did not influence seedling height, leaf area and tap root length. No sign of copper toxicity was observed in any seedling treated with CuCO3. Provenance had a significant effect on height, root collar diameter, tap root length and root weight per unit length; these results may reflect differences in growth habit of the two provenances. Other growth parameters measured were affected by a copper × provenance interaction. Seedlings of the PA-SR provenance produced less root and plant dry wt when grown in CuCO3-treated than in control containers, but shoot:root ratio was not influenced.


1989 ◽  
Vol 19 (7) ◽  
pp. 821-831 ◽  
Author(s):  
S. R. Shafer ◽  
A. S. Heagle

Dose–response relationships were developed for ozone and four full-sib families of Pinustaeda L. Seedlings were planted in field plots in open-top chambers near Raleigh, North Carolina, and exposed daily during three growing seasons (1985, 1986, and 1987) to ozone at concentrations from 0.022 to 0.092 μL/L of air (seasonal mean concentrations for the daily exposure period 08:00 to 20:00 eastern standard time). Plants were harvested on five dates during the study to quantify effects of ozone on growth. Ozone suppressed stem height, root collar diameter, total branch length, and (or) dry weights of above-ground parts of plants in three families, but response to ozone depended upon dose, family, and the plant part measured. One family exposed during 1985 and 1986 did not exhibit significant growth responses to ozone. The family that exhibited the greatest growth suppression in 1985 and 1986 was exposed during the 3rd year, and ozone continued to reduce growth. Suppression of root dry weight was observed after three seasons of exposure. Root collar diameter and dry weight of stem + branches (without needles) may be the most useful measurements of growth response in multiple-year experiments. Dose–response models predicted that ambient levels of ozone could reduce growth relative to the growth predicted for chronic exposure to half-ambient levels (charcoal-filtered air). For aboveground woody tissue, this suppression ranged from 0 to 19% among the four families after two seasons of exposure and was 13% for the most sensitive family after three seasons.


1991 ◽  
Vol 21 (7) ◽  
pp. 966-973 ◽  
Author(s):  
J. Gagnon ◽  
C. G. Langlois ◽  
J. Garbaye

Containerized red oak (Quercusrubra L.) seedlings were inoculated at the time of sowing with Laccariabicolor (Maire) Orton using two methods to compare the efficiency of two inoculum types: a mycelial suspension (Ecot-Sol®101) produced by Rhizotec Laboratories Inc. and calcium alginate beads containing this mycelial suspension. Red oak seedlings were also grown for 19 weeks in a peat moss – vermiculite substrate under three levels of N fertilization (100, 120, and 140 mg/seedling per season) to determine the N level that maximizes the ectomycorrhizae formation and growth of seedlings. After 19 weeks in the greenhouse, seedlings inoculated with liquid inoculum had significantly more mycorrhizae than both those inoculated with beads and controls, regardless of the N level. For any of the N levels, liquid-inoculated seedlings had significantly lower shoot height, root-collar diameter, and dry weights (shoot, root, and total) than both those inoculated with beads and the controls, whereas there were no significant differences for any growth parameters between the bead and control treatments. For the three inoculum treatments, root and total dry weights of seedlings fertilized with 100 mg N were significantly lower than those of seedlings that received both 120 and 140 mg N, whereas shoot height, root-collar diameter, and shoot:root ratio of seedlings did not differ significantly between any of the three N levels. After 19 weeks, seedlings inoculated with liquid inoculum had significantly greater N and P concentrations (%) and contents (mg/seedling) than those inoculated with beads only at the 140 mg N level. Analyses show that seedling concentrations of 1.2% N and 0.1% P and substrate fertility of 25 ppm N and 30 ppm P would be appropriate to maintain the ectomycorrhizal association Q. rubra – L. bicolor.


2015 ◽  
Vol 67 (4) ◽  
pp. 1357-1360
Author(s):  
Vladan Popovic ◽  
Aleksandar Lucic ◽  
Ljubinko Rakonjac ◽  
Tatjana Cirkovic-Mitrovic ◽  
Ljiljana Brasanac-Bosanac

The aim of this research was to examine the influence of acorn size on morphological characteristics of one-year-old Northern red oak (Quercus rubra L.) seedlings. The quality of seedlings correlates with the quality of the seed they are derived from. In species with large seeds, as in the case of Northern red oak, the seedling growth in the first growing season is closely related to seed size or the amount of reserve nutrients that are stored in the seed. The height and root collar diameter of one-year-old Northern red oak seedlings increases with increase in acorn size. The results obtained in this research can be used as a guideline for acorn grading, because they show that improved Northern red oak seedlings quality can be achieved using seeds of appropriate size.


2002 ◽  
pp. 147-160
Author(s):  
Milun Krstic ◽  
Nevena Vojinovic

Five morphological and quantitative characteristics of one-year old seedlings of Red oak (Quercus rubra L), Black walnut (Juglans nigra L), Wild pear (Pyrus pygrowser Borkh) and Birch (Betula verrucosa Ehrh) were studied. The seedlings were produced and cultivated in the controlled conditions of the nursery in the region of Jastrebac, by the classical method. Aboveground seedling height, root collar diameter, root length, number of secondary roots and the leaf assimilation area were analysed. Intraspecific and interspecific variability of morphological features of the above species were assessed by the comparative analysis and statistical methods The comparative analysis shows the great individual variability of seedlings, which can indicate their genetic potential, adaptation to environment conditions, further spontaneous selection and the development in natural conditions. This justifies the need of the quality assessment and the first selection already in the nursery, in order to ensure the quality planting material and to reduce the risk of afforestation failure One-year old birch seedlings have the lowest average height (18.8 cm). Black walnut and Wild pear seedlings are approximately twice as high, and Red oak about 2.5 times higher. At the same time Red oak seedlings have for about one-fourth greater height than Black walnut, and for one-third greater height than Wild pear. Wild pear seedlings attain the averagely twice larger root collar diameter than Birch (2.8 cm), Red oak seedlings about 2.5 times larger diameter, and Black walnut 3.5 times larger diameter. Black walnut has a larger root collar diameter than Red oak for about one third, and almost twice larger than Wild pear. Birch, Red oak and Wild pear have almost twice longer root (1.8-1.9 times), Black walnut about 2.25 times longer. The total assimilation area of a Birch seedling is averagely 89.0 cm2. Compared to birch, wild pear has approximately double assimilation area per tree, Red oak 10 times larger, Black walnut even 14 times larger assimilation area The analysis of variance shows that the experiment is homogeneous in general, i.e. that variance within the group of the same species per all characteristics is not statistically significant at the level p>0.01. The statistically significant difference was found in the attained heights of one-year old seedlings of Red oak and Birch, as well as between them and other species, while there is no difference between Black walnut and Wild pear. All analysed species differ significantly in root collar diameter of one-year old seedlings. Black walnut and Birch differ significantly in root length, and also compared to other species. There are no statistically significant differences in root length between Red oak and Wild pear. All the analysed species differ statistically significantly per total assimilation area of one seedling .


2007 ◽  
Vol 64 (1) ◽  
pp. 23-29
Author(s):  
José Geraldo de Araújo Carneiro ◽  
Deborah Guerra Barroso ◽  
Luis Maurício da Silva Soares

Seedlings compete for nutrients, water and light. The available area for each seedling affects their behavior related to requirements for these resources. This experiment evaluated the influence of five plant densities on the growth of bare root Pinus taeda, L. seedlings in a nursery after outplanting. The analyzed characteristics were: height (H), root collar diameter (D), H/D ratio, and dry matter weight. Higher densities stimulated H growth and the lowest densities increased D average and dry matter weight and lowered the H/D ratio. Seedlings were distributed by H, D and H/D classes. Higher densities had a larger number of seedlings in larger H classes. Larger numbers of seedlings with larger D and lower H/D ratios were found in lower densities. Ten months after outplanting the seedlings grown in lower densities had higher survival percentages and growth. Some saplings of standardized heights were uprooted with the objective of studying their root systems. The lowest densities stimulated higher numbers of first and second order roots as well as fresh and dry matter weights of thin roots with mycorrhizae presence. In both parts of the experiment, the density of 278 seedlings m-2 yielded equivalent averages as compared to the lowest densities.


2019 ◽  
Vol 11 (10) ◽  
pp. 277 ◽  
Author(s):  
Meire Pereira de Souza Ferrari ◽  
Mayara dos Santos Queiroz ◽  
Matheus Marquezini de Andrade ◽  
Jessica Rezende Trettel ◽  
Hélida Mara Magalhães

This study aimed to evaluate the in vitro growth and biochemical activity of Curcuma longa explants using different MS medium formulations and growth regulators. In all the experiments, plants were grown in MS medium supplemented with agar (6.5 g L-1) and pH adjusted to 5.8. In the first assay, the MS culture medium at 70% strength, supplemented with 30 g L-1 of sucrose, and without the addition of activated carbon, resulted in the highest number of shoots. The sucrose concentration of 60 g L-1, combined with the addition of actived charcoalin half-strength MS medium, resulted in the increased root dry mass, root collar diameter, and relative chlorophyll index. In the second assay, the highest root collar diameter and dry matter of shoots and roots were found in the MS medium supplemented with 4.44 BAP, 0.46 KIN, and 1.08 NAA. The MS medium with 8.88 BAP, 0.92 KIN, and 2.16 &mu;M NAA resulted in the highest number of shoots (7.75), number of leaves (35), and shoot length (88.57 mm). The antioxidant activity was significantly higher in the treatments that resulted in better plantlets growth performance, demonstrating that the antioxidant activity is related to other factors such as a possible role of growth regulators on the elicitation of compounds in plants. Superoxide dismutase had a high enzymatic activity in both assays, whereas the enzymatic activity of catalase and ascorbate peroxidase was dependent on the culture media used.


Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 682 ◽  
Author(s):  
Fenglu Liu ◽  
Pengfei Xu ◽  
Houjiang Zhang ◽  
Cheng Guan ◽  
Dan Feng ◽  
...  

In this study, 145 poplar (Populus × euramericana cv.’74/76’) seedlings, a common plantation tree species in China, were selected and their ultrasonic velocities were measured at four timepoints during the first growth year. After that, 60 poplar seedlings were randomly selected and cut down to determine their acoustic velocity, using the acoustic resonance method. The effects of influencing factors such as wood green density, microfibril angle, growth days, and root-collar diameter on acoustic speed in seedlings and the relationship between ultrasonic speed and acoustic resonance speed were investigated and analyzed in this work. The number of specimens used for investigating growth days and root-collar diameter was 145 in both cases, while 60 and two specimens were used for investigating wood density and the microfibril angle, respectively. The results of this study showed that the ultrasonic speed of poplar seedlings significantly and linearly increased with growth days, within 209 growing days. The ultrasonic velocity of poplar seedlings has a high and positive correlation with growth days, and the correlation was 0.99. However, no significant relationship was found between the ultrasonic velocity and root-collar diameter of poplar seedlings. Furthermore, a low and negative relationship was found between wood density and ultrasonic speed (R2 = 0.26). However, ultrasonic velocity significantly decreased with increasing microfibril angle (MFA) in two seedlings, and thus MFA may have an impact on ultrasonic speed in poplar seedlings. In addition, ultrasonic velocity was found to have a strong correlation with acoustic resonance velocity (R2 = 0.81) and a good correlation, R2 = 0.75, was also found between the dynamic moduli of elasticity from ultrasonic and acoustic resonance tests. The results of this study indicate that the ultrasonic technique can possibly be used to measure the ultrasound speed of young seedlings, and thus early screen seedlings for their stiffness properties in the future.


2018 ◽  
Vol 10 (6) ◽  
pp. 184
Author(s):  
Camila Oliveira Muniz ◽  
Eliana Paula Fernandes Brasil ◽  
Lucas Morais Lobo ◽  
Evaldo De Melo Ferreira ◽  
João Augusto da Silva ◽  
...  

Khaya ivorensis A. Chev. (African mahogany) is one of the most economically important forest species, since it is used in the international furniture market. However, little is known about its culture and nutritional requirements. This study aimed to assess the development of K. ivorensis plants subjected to different base saturations, as well as to different N, P and K levels. An 8-ha area was used, wherein 4 ha had base saturation increased to 55% and the remaining 4 ha to 75%. The experimental design adopted was randomized blocks with eight repetitions in a factorial scheme (4 × 4 × 4), being four N doses, four P doses and four K doses. The base saturation was assessed through the block effect. The root collar diameter and the plant height were measured 12 months after planting. Each experimental plot comprised six plants. The root collar diameter showed statistical differences between blocks and N doses. Only the NPK association showed statistical variation in plant height. However, a growth decreasing trend resulting from increased N doses was observed, as well as a growth increasing trend resulting from increased P and K doses. All treatments favored African mahogany growth. The most indicated base saturation was 55%, since there was no plant growth improvement when V% was increased to 75%. The excess of N impaired the growth of the species. The best treatment comprised 60 g urea, 240 g triple superphosphate, and 168 g potassium chloride.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Kupatsa Mtambalika ◽  
Chimuleke Munthali ◽  
Dominic Gondwe ◽  
Edward Missanjo

Afzelia quanzensisWelw is a valuable timber producing tree species in Africa. A study was conducted to evaluate the influence of seed size on seed germination and seedlings quality ofAfzelia quanzensis. Seed was categorized into three groups in regard to their length, small (<1.5 cm), medium (≥ 1.5 ≤ 2.5 cm), and large (>2.5 cm). The treatments were completely randomized into four replications. Germination percentage was not significantly(P>0.05)different between the treatments, although large seeds had the highest germination percentage of 94.9%. There were significant(P<0.05)differences in seedling height and root collar diameter among the different seed sizes, with large seeds having the highest seedlings height and largest root collar diameter. This was attributed to differences in the food reserves. Survival of transplants from shoot dieback was significantly(P<0.05)different such that seedlings from large seed attained the highest survival of 92%. It is therefore recommended that, for production of high quality transplants in the nursery, large seeds should be used.


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