Effects of organic horizon removal, ash, watering regime, and shading on red pine seedling emergence

1996 ◽  
Vol 26 (3) ◽  
pp. 422-427 ◽  
Author(s):  
David G. Herr ◽  
Luc C. Duchesne
Keyword(s):  
Water Regime ◽  
Prescribed Burning ◽  
Seedling Emergence ◽  
High Water ◽  
Jack Pine ◽  
Red Pine ◽  
The Other ◽  
Organic Horizon ◽  
Water Regimes

Soil monoliths were used to determine the effects of organic horizon removal, ash, water regime, and shading on red pine (Pinusresinosa Ait.) seedling emergence. Soil monoliths were collected from a jack pine (Pinusbanksiana Lamb.) stand and taken to the laboratory for prescribed burning, leading to 25%, 50%, 75%, and 100% organic horizon removal. One half of each monolith contained ash generated from burning, while the other half was kept ash-free. Each half of every monolith was sown with red pine seeds. The monoliths were then placed in a greenhouse and, in separate experiments, were exposed to different water regimes and shade regimes. Red pine seedling emergence was highest under high water regimes, increased shade regimes, and increased organic horizon removal. Seedling emergence was reduced by the presence of ash.

scholarly journals Effect of Water Regime on the Sucrose-Enzyme Relationships of Sugarcane Desiccated with Paraquat

1969 ◽  
Vol 56 (2) ◽  
pp. 134-153
Author(s):  
Rafael Montalvo-Zapata ◽  
Alex G. Alexander
Keyword(s):  
Water Supply ◽  
Water Regime ◽  
High Water ◽  
Sand Culture ◽  
Mitochondrial Enzymes ◽  
Intermediate Water ◽  
Chemical Application ◽  
Storage Tissue ◽  
Water Regimes ◽  
Variable Water

Immature sugarcane was given variable-water regimes in sand culture and subsequently treated with a powerful desiccant, the bipyridylium herbicide Paraquat, applied as a 0.05-percent aqueous foliar spray. There were two objectives: (a) To evaluate the effects of water regime on sucroseenzyme relationships in desiccating sugarcane; and (b) to determine whether controlled water regimes could effectively modify Paraquat activity in sugarcane. Tissue samples were harvested for moisture, sugar and enzyme analyses at 1,3 and 9 days after Paraquat application. Low water supply (1 liter per day) reduced total fresh weights and stalk weights, and increased sucrose content of immature storage tissue. Paraquat significantly lowered total fresh weights, stalk weights, sheath moisture and leaf sucrose by the 9-day harvest. Desiccant action was generally more rapid within the low-water regime. High- and intermediate-water regimes tended to modify Paraquat activity at 1 or 3 days, but its ultimate effects were comparable regardless of water regime. No evidence was found to support the theory that desiccating cane accumulates water as a function of continued water absorption when transpiration has ceased. Acid invertase was suppressed by Paraquat, an effect consistent with earlier findings. The suppression was most severe in the low-water regime. Low-water supply significantly lowered invertase level but the response was not consistent at all harvests. Acid phosphatase and ATP-ase were severely repressed by Paraquat in leaves but not in immature storage tissue. An explanation was offered in terms of distinct chloroplast and mitochondrial enzymes rather than localized Paraquat action. For both enzymes the desiccant repression was significantly more severe in the high-water regime at 1 or 3 days, but water regime showed no effect at 9 days. Paraquat significantly increased ß-amylase in leaves (consistent with earlier studies), particularly within the high-water regime. In immature stem tissue ß-amylase was repressed by high water in Paraquat-free plants. Paraquat eliminated the water effect. Peroxidase was increased in storage tissue by Paraquat. This response was statistically significant only under conditions of low-water supply. It is concluded that variable water regimes can modify the rate of initial Paraquat activity in sugarcane; however, the ultimate effects of Paraquat will not be changed under conditions of thorough chemical application. Under field conditions of marginal chemical penetration, the plant's moisture status might play a more decisive role in determining the desiccant's effectiveness.

Effects of Sand Burial and Water Regimes on Seed Germination and Seedling Emergence of Two Desert Species

2011 ◽  
Vol 356-360 ◽  
pp. 2465-2472
Author(s):  
Fei Peng ◽  
Wataru Tsuji ◽  
Tao Wang ◽  
Atsushi Tsunekawa
Keyword(s):  
Seed Germination ◽  
Water Supply ◽  
Water Regime ◽  
Field Experiments ◽  
Seedling Emergence ◽  
Burial Depth ◽  
Dune System ◽  
Sand Burial ◽  
Water Regimes ◽  
Simulated Precipitation

Reaumuria songarica (Pall.) Maxim and Nitraria tangutorum Bobr. are two species growing on nebkhas in dune system. But N. tangutorum distributes more widely than R. songarica does. Sand burial and drought are two major disturbing factors in the field. Experiments were conducted under controlled conditions to investigate sand burial depth and simulated precipitation amount on seed germination, seedling emergence and seedling mass of the two shrubs to explain the dominance of N. tangutorum over R. songarica. Seeds were buried at 6 depths (0, 0.5, 1.5, 3, 5, 8 cm) and irrigated with 3 water regimes (5, 7, 10 mm) in plastic pots (8 cm in diameter and 11 cm in height) under the same light intensity and alternating temperature in an environment controlled growth chamber. R. songarica has a greater germination percentage than N. tangutorum under each burial depth with any water regime. R songarica seed germination increased with burial depth at each water regime and when depth is deeper than 1.5 cm all the seeds germinated under 7 and 10 mm water treatment. N. tangutorum seed germination increased until an optimal burial depth and then decreased. The optimal burial depth shifts with water regime. Seedling emergence of R songarica did not occur at depth deeper than 1.5 cm under any water regime. N. tangutorum seedling emergence maximized at 3, 1.5 and 0.5 cm with 5, 7 and 10 mm water supply regime respectively. Under all the treatments, N. tangutorum seedlings had larger dry mass than R. songarica seedlings. Higher N. tangutorum seedling emergence percentage and seedling mass with given water supply enhance its possibility to appear on nebkhas in the study area.

The effect of sonication on the growth of some tree seeds

1981 ◽  
Vol 11 (4) ◽  
pp. 840-844 ◽  
Author(s):  
Pearl Weinberger ◽  
C. Burton
Keyword(s):  
Tree Species ◽  
Peak Velocity ◽  
Jack Pine ◽  
Red Pine ◽  
The Other ◽  
Pine Seedlings ◽  
Length Range ◽  
Percent Germination ◽  
Tree Seeds ◽  
All Treatment

Air-dry seeds of jack pine (Pinusbanksiana Lamb.), red pine (P. resinosa Ait.), tamarack (Larixeuropaea L.), and white spruce (Piceaglauca (Moench) Voss) were subjected for 30 min to 1 MHz ultrasound at one of three intensities of ultrasound ranging from 0.5 to 6.0 W/cm2. Subsequent germination was assessed in terms of percent germination, mean daily germination (MDG), and peak velocity of germination (PV). From these, germination values (GV) were obtained. Only jack pine responded to the ultrasonic treatments by giving rise to higher MDG and GV values. The seeds were equally stimulated by all the intensities used. The rates and percent germination of the other tree species were unaffected by any of the sonication treatments. Seeds of jack pine were also sonicated at 25, 50, 100, 250, and 750 kHz at an intensity in the range of 0.5–1.0 W/cm2. None of these treatments affected the course of germination.Subsequent seedling growth of all the seeds in all treatment sets was also monitored by summing the total length of all the seedlings following 8 and 14 days of growth. The seedlings were divided into five length-range categories. The jack pine seedlings alone, sonicated at 1 MHz, had significantly more seedlings in the larger size group than the untreated seedlings.

The Influence of Water Regime on the Performance of Aquatic Plants

1994 ◽  
Vol 29 (4) ◽  
pp. 127-132 ◽  
Author(s):  
Naomi Rea ◽  
George G. Ganf
Keyword(s):  
Deep Water ◽  
Aquatic Plants ◽  
Water Regime ◽  
Optimal Performance ◽  
Experimental Results ◽  
The Other ◽  
Full Potential ◽  
Influence Of Water ◽  
Emergent Species

Experimental results demonstrate bow small differences in depth and water regime have a significant affect on the accumulation and allocation of nutrients and biomass. Because the performance of aquatic plants depends on these factors, an understanding of their influence is essential to ensure that systems function at their full potential. The responses differed for two emergent species, indicating that within this morphological category, optimal performance will fall at different locations across a depth or water regime gradient. The performance of one species was unaffected by growth in mixture, whereas the other performed better in deep water and worse in shallow.

Establishment of Three Emergent Macrophytes Under Different Water Regimes

1999 ◽  
Vol 40 (3) ◽  
pp. 233-240 ◽  
Author(s):  
S. G. T. Giovannini ◽  
D. M. L. da Motta Marques
Keyword(s):  
Water Level ◽  
Aquatic Macrophytes ◽  
Water Regime ◽  
Emergent Macrophytes ◽  
Morphological Response ◽  
Water Regimes ◽  
Wetland Construction ◽  
Scirpus Californicus ◽  
Level 3 ◽  
Plot Design

The behavior of three emergent aquatic macrophytes under different water regimes was studied with the aim of achieving reconvertion of degraded wetlands and wetland construction for water quality improvement. Scirpus californicus, Typha subulata and Zizaniopsis bonariensis establishment was evaluated under a split plot design, in a factorial experiment with three levels of a water regime factor over a subsoil substratum. The stagnant 10±2 cm water level was best suited to T. subulata and Z. bonariensis development and S. californicus developed better at oscillating water level (3±2 cm) with flooding at 48 hour intervals. The morphological response variables (thickness and width at half length of the tallest leaf or stem per plant, height of tallest leaf or stem per plant, number of green leaves or stems and number of shoots per plant, and survival of propagules' original leaves or stems) were satisfactory descriptors to differentiate (p<0.1%) growth of above ground parts as related to water regimes and species. The three species did survive satisfactory in subsoil-like substratum under the tested water regimes. Mortality was in the worse case, 17.2%, 36.7%, and 9.4% for S. californicus, T. subulata, and Z. bonariensis, respectively. Although Z. bonariensis growth was very poor, only S. californicus and T. subulata could be indicated for planting under similar limiting conditions.

scholarly journals Modeling of solid sediment transport in mountain rivers

2020 ◽  
Vol 175 ◽  
pp. 12002 ◽  
Author(s):  
Issam Boukhanef ◽  
Anna Khadzhidi ◽  
Lyudmila Kravchenko ◽  
Zeroual Ayoub ◽  
Kastali Abdennour
Keyword(s):  
Sediment Transport ◽  
Fine Particles ◽  
Agricultural Soils ◽  
Suspended Sediments ◽  
High Water ◽  
The Other ◽  
Concentration Data ◽  
Solid Transport ◽  
One Year ◽  
The One

In Algeria, the problems of erosion and sediment transport are critical, since they have the most dramatic consequences of the degradation of agricultural soils on the one hand and the siltation of the dam on the other .The sediment transport in the Algerian basins is very important especially during the periods of floods, It is in this sense that this study, which consists of estimating the sediment transport in suspension and determining the models of relation linking the liquid discharge and the sediment discharge in order to estimate the solid transport in the absence of suspended sediments concentration data at the Sidi Akkacha station at the outlet of the basin of Oued Allala which is subject to a high water erosion, it degrades from one year to the other under the effect of this phenomenon especially during the floods which drain high amounts of fine particles exceeding in general, the concentration of 150 g/l, the results obtained from the application of the models are very encouraging since the correlation between liquid and solid discharge exceeds 80 %.

Estimation de la production de jeunes plantations de pin rouge et de pin gris du sud du Québec

1976 ◽  
Vol 6 (4) ◽  
pp. 478-486 ◽  
Author(s):  
H. A. Bolghari
Keyword(s):  
Multiple Regression ◽  
Jack Pine ◽  
Red Pine ◽  
Pine Plantations ◽  
Regression Equations ◽  
Pine Plantation ◽  
South Shore ◽  
Pine Stands ◽  
Natural Stands ◽  
St Lawrence River

Multiple regression equations have been developed to predict yield from young red pine and jack pine plantations. Data from 446 sample plots representing young red pine and jack pine stands located on the south shore of the St. Lawrence River between Quebec and Montreal were analysed. The red pine plantation yielded more than the jack pine. However, in plantation both species yield more than in natural stands. Taking into account the age and spacing of the sampled plantations, the equation obtained can provide information on yield of red pine and jack pine stands the maximum spacing of which is 3 × 3 m, up to the age of 45 and 35 years respectively. The equations will allow the construction of preliminary yield tables for both species.

Pathogenicity of Bursaphelenchusxylophilus on three species of pine

1987 ◽  
Vol 17 (1) ◽  
pp. 51-57 ◽  
Author(s):  
P. J. Bedker ◽  
M. J. Wingfield ◽  
R. A. Blanchette
Keyword(s):  
Jack Pine ◽  
Red Pine ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Water Extracts ◽  
Pine Trees ◽  
Branch Death

Three species of 11-year-old pine trees were inoculated with Bursaphelenchusxylophilus in the field. Four branches in single whorls on red, Scots, and jack pine trees were wounded and inoculated with 10 000 nematodes each or with water extracts from Botrytiscinerea cultures. Prior to field inoculations, the pathogenicity of the nematode isolate was confirmed on seedlings in the greenhouse. Fourteen weeks after inoculation, 27 of 80 and 13 of 52 branches were dead or dying on Scots and jack pine trees, respectively. No symptoms were observed on red pine trees inoculated with B. xylophilus or on any controls. Branch death was attributed to the formation of girdling cankers resulting from inoculation. An average of 9.14, 10.39, and 0.02 nematodes were extracted per gram of wood from branch samples collected from Scots, jack, and red pine trees at 14 weeks, respectively, and at 58 weeks an average of 13.82, 1.01, and 0.05 nematodes per gram of wood sampled were recovered. Proportions of branch samples with nematodes declined from 14 to 58 weeks after inoculation. Although limited mortality of branches occurred, the pine wood nematode was not found to cause tree death following inoculation.

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