Effets à moyen terme de la fertilisation par urée ou par potassium sur Pinusbanksiana L. et le comportement de ses insectes dévastateurs: tel que Neodiprionswainei (Hymenoptera, Tenthredinidae) et Toumeyellanumismaticum (Homoptera, Coccidae)

1975 ◽  
Vol 5 (2) ◽  
pp. 236-244 ◽  
Author(s):  
W. A. Smirnoff ◽  
J. Valéro
Keyword(s):  
Osmotic Pressure ◽  
Jack Pine ◽  
Glutamic Oxaloacetic Transaminase ◽  
Urea Nitrogen ◽  
Natural Stand ◽  
Glutamic Dehydrogenase ◽  
Unfertilized Plot ◽  
Urea Fertilization ◽  
Low Dosage

The effect of fertilization on the physiology of jack pine (Pinusbanksiana Lamb.) in a natural stand and on two important foliage pests, Neodiprionswainei Middleton and Toumeyellanumismaticum Pettit and McDaniel, was studied.It was established in 1973 that fertilization with 400 kg of urea per hectare (1 ha = 1 × 104 m2) in 1969 and in 1970 was still influencing the level of chloride, the osmotic pressure and the activity of two enzymes, glutamic–oxaloacetic transaminase (GOT) and glutamic dehydrogenase (GLDH) contained in the foliage. In June 1974 in current and previous years' growth, the amount of chloride had decreased, respectively, to 81 and 50 p.p.m. (mg/kg) in fertilized trees, and the osmotic pressure increased by 37 and 49 m[Formula: see text]smol/kg. The activity of GOT and GLDH in the foliage of fertilized trees was 41 and 14 mU/g, respectively, compared with 163 and 21 mU/g, respectively, in the foliage of unfertilized trees.It was found 3 years after fertilization that the mortality of N. swainei larvae was 50% higher and the damage they caused was 42% less in fertilized trees. Also, it was observed that urea fertilization, even at low dosage, favoured T. numismaticum, this infestation increasing 2,7 and 9 times in plots fertilized with 100, 200 and 400 kg of urea nitrogen per hectare.The studies revealed, however, that fertilization with potassium may reduce T. numismaticum. The infestation in the fertilized plot showed a reduction from 42 to 21%, and in the unfertilized plot there was an increase from 38 to 80%.

Ammonia Volatilization from some Forest Floor Materials Following Urea Fertilization

1975 ◽  
Vol 5 (2) ◽  
pp. 210-216 ◽  
Author(s):  
M. K. Mahendrappa
Keyword(s):  
Concentration Gradient ◽  
Forest Floor ◽  
Ammonia Volatilization ◽  
Experimental Period ◽  
Hardwood Forest ◽  
Forest Stands ◽  
Urea Nitrogen ◽  
Organic Layers ◽  
Ph Values ◽  
Urea Fertilization

Ammonia volatilization from urea-treated organic layers of four softwood and three hardwood forest stands was investigated under laboratory conditions. All samples were treated with urea at rates equivalent to 168, 336, and 500 kg N per hectare. In addition, samples from a jack pine (Pinusbanksiana) stand were treated with urea at rates equivalent to 1100 and 1680 kg N per hectare (1 ha = 104 m2). At the end of a 7-day volatilization period the pH values of L and F + H layers were determined.In both softwood and hardwood samples, the proportions of added N volatilized as ammonia were larger when higher dosages of urea were applied. It is suggested that the rate of ammonia volatilization is determined by the concentration gradient of urea in solution around the sites where the enzyme urease hydrolyses urea. Less ammonia was evolved from hardwood than from softwood organic layers. Ammonia volatilization from softwood and hardwood organic layers treated with 336 kg N per hectare in urea was 0.41 to 3.75 and 0.16 to 1.76% of the added N, respectively. At the end of the experimental period the pH values of the L layers were generally higher than those of the F + H layers. The organic layers from the hardwood stands showed a smaller shift in pH than those from the softwood stands treated with the same levels of urea nitrogen.

A 10-year tree and stand response of jack pine to urea fertilization and low thinning

1984 ◽  
Vol 14 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Arthur Groot ◽  
Kenneth M. Brown ◽  
Ian K. Morrison ◽  
J. E. Barker
Keyword(s):  
Form Factor ◽  
Growth Response ◽  
Volume Growth ◽  
Basal Area ◽  
Growing Season ◽  
Jack Pine ◽  
Positive Effects ◽  
Stand Thinning ◽  
Urea Fertilization

This study examined the 10-year effects of a light (20% basal area removed) low thinning and urea fertilization (336 kg N/ha) on a 45-year-old Pinusbanksiana Lamb. stand. Thinning had no effect other than salvaging potential mortality, while fertilization resulted in an average annual gross volume growth response of about 2 m3 ha−1 year−1. Volume growth response to fertilization was greatest in the largest diameter trees, and continued until 10 years after treatment. Growth response did not begin until the second growing season after treatment. There were indications that fertilization had positive effects on form factor.

scholarly journals Effect of Salinity and Alkalinity on Luciobarbus capito Gill Na+/K+-ATPase Enzyme Activity, Plasma Ion Concentration, and Osmotic Pressure

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Longwu Geng ◽  
Guangxiang Tong ◽  
Haifeng Jiang ◽  
Wei Xu
Keyword(s):  
Enzyme Activity ◽  
Atpase Activity ◽  
Osmotic Pressure ◽  
Orthogonal Experiment ◽  
Gill Filament ◽  
Ion Concentration ◽  
Initial Increase ◽  
Urea Nitrogen ◽  
Nitrogen Concentrations ◽  
The Individual

We evaluated the individual and combined effects of salinity and alkalinity on gill Na+/K+-ATPase enzyme activity, plasma ion concentration, and osmotic pressure in Luciobarbus capito. Increasing salinity concentrations (5, 8, 11, and 14 g/L) were associated with an initial increase and then decrease in L. capito gill Na+/K+-ATPase activity. Activity was affected by the difference between internal and external Na+ ion concentrations and osmotic pressure (P<0.05). Both plasma ion (Na+, K+, and Cl−) concentration and osmotic pressure increased significantly (P<0.05). An increase in alkalinity (15, 30, 45, and 60 mM) caused a significant increase in plasma K+ and urea nitrogen concentrations (P<0.05) but had no effect on either plasma osmotic pressure or gill filament ATPase activity. In the two-factor experiment, the saline-alkaline interaction caused a significant increase in plasma ion (Na+, Cl−, and urea nitrogen) and osmotic pressure (P<0.05). Variance analysis revealed that salinity, alkalinity, and their interaction significantly affected osmotic pressure, with salinity being most affected, followed by alkalinity, and their interaction. Gill filament ATPase activity increased at first and then decreased; peak values were observed in the orthogonal experiment group at a salinity of 8 g/L and alkalinity of 30 mM.

Temporal analysis of breeding structure in jack pine (Pinusbanksiana Lamb.)

1985 ◽  
Vol 15 (6) ◽  
pp. 1159-1166 ◽  
Author(s):  
Thomas P. Snyder ◽  
Dale A. Stewart ◽  
Ann F. Strickler
Keyword(s):  
Seed Germination ◽  
Temporal Analysis ◽  
Jack Pine ◽  
Outcrossing Rate ◽  
Fixation Index ◽  
General Increase ◽  
Mendelian Segregation ◽  
Selection Hypothesis ◽  
Natural Stand ◽  
Breeding Structure

Outcrossing rates for 10 pollination years were estimated for a natural stand of jack pine using allozymic markers at the Mdh-2 and 6-pgd-1 loci. Outcrossing rate estimates showed a general increase with time since pollination. Population fixation index values for the progeny decrease with time since pollination, showing an increasing proportion of heterozygous progeny. These increases parallel those observed for jack pine, lodgepole pine, and alpine ash by other investigators, suggesting selection against inbred progeny may be occurring during the retention of the seed in the serotinous cones. Evaluation of the selection hypothesis by regression of the proportion of heterozygous progeny and of seed germination on year of pollination showed significant linear decreases in germination over a 10-year period for only one of eight trees. This was not accompanied by an increase in the proportion of heterozygous progeny. Apparent deviations from normal Mendelian segregation were noted at the Mdh-2 locus in two trees.

Comparative Growth and Development of Planted and Natural Stands of Jack Pine

1988 ◽  
Vol 64 (4) ◽  
pp. 320-328 ◽  
Author(s):  
P. S. Janas ◽  
D. G. Brand
Keyword(s):  
Pinus Banksiana ◽  
Initial Density ◽  
Jack Pine ◽  
Growth And Yield ◽  
Large Individual ◽  
Individual Tree ◽  
Natural Stand ◽  
Tree Form ◽  
Stem Quality ◽  
Natural Stands

This study compares growth yield, and stem quality differences at age 21 between plantations spaced at 2.13 × 2.13 m (2204 stems/ha) and 4.27 × 4.27 m (548 stems/ha), and a nearby natural jack pine stand of identical age (initial density of 29 800 stems/ha). Merchantable volume/ha was greatest at the 2.13 m spacing, followed by the less dense plantation and natural stand. Total volume/ha (trees > 1.3 m height) was also greatest in the 2.13 m plantation, followed by the natural stand and the 4.27 m plantation. Individual tree mean merchantable volumes decreased with increasing density. Height growth decreased with increasing density. Height 4.27 m plantation relative to the 2.13 m plantation. Stem quality of the natural stand was markedly better than in both plantations. A comparison of an older natural stand and a plantation in the same area suggests that superiority of tree form of denser natural stands will continue through to rotation. High mortality in the natural stand was largely the result of snow and ice damage which caused patchy and irregular stocking. These results imply that widely spaced plantations of unimproved jack pine will produce large individual tree sizes, but at the expense of quality. Key words: Pinus banksiana, plantations, natural stands, stem quality growth and yield, stand density, mortality, spacing, silviculture.

Increased Mortality of the Swaine Jack-pine Sawfly, and Foliar Nitrogen Concentrations After Urea Fertilization

1973 ◽  
Vol 3 (1) ◽  
pp. 112-121 ◽  
Author(s):  
W. A. Smirnoff ◽  
B. Bernier
Keyword(s):  
Larval Mortality ◽  
Nitrogen Concentration ◽  
Jack Pine ◽  
Application Rate ◽  
Foliar Nitrogen ◽  
Sawfly Larvae ◽  
Pine Sawfly ◽  
Direct Measurements ◽  
Nitrogen Concentrations ◽  
Urea Fertilization

Mortality of the Swaine jack-pine sawfly larvae (Neodiprionswainei Midd.) introduced as colonies on jack-pine (Pinusbanksiana Lamb.) foliage was measured in untreated and urea-treated plots of natural forest. Following applications of urea (400 kg N/ha) repeated in two successive years, natural mortality increased from 40 to 70% after 4 weeks, from 33 to 51% after 6 weeks, and from 18 to 36% after 4 weeks for larvae introduced as 1st instar, 2nd instar, and 3rd instar, respectively. This was accompanied by a marked reduction in foliage consumption as revealed by direct measurements or by the weight of frass collected. With 3rd-instar larvae sprayed with a suspension of the virus Borrelinavirusswainei (Smirnoff), viral infection developed much more rapidly in larvae placed on fertilized trees, mortality reaching 100%, double that measured on unfertilized trees. Single applications of urea at lower rates (100 and 200 kg N/ha) revealed a trend of increasing mortality for both unsprayed and virus-sprayed larvae with increasing urea application rate and increasing nitrogen concentration in the needles. Changes in the nitrogenous composition of needle tissue are considered an important factor in the increased larval mortality.

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