Effects of depth of water table and substrate temperature on root and top growth of Picea mariana and Larix lancina seedlings

1986 ◽  
Vol 16 (6) ◽  
pp. 1201-1206 ◽  
Author(s):  
V. J. Lieffers ◽  
R. L. Rothwell

Three thermally insulated tanks were divided in half and one side of each was cooled using a network of copper tubing, through which chilled ethylene glycol was pumped. Tanks were filled with peat and seedlings of black spruce (Piceamariana (Mill.) B.S.P.) and tamarack (Larixlaricina (Du Roi) K. Koch.) were transplanted to both ambient and cooled sides. Water table levels of the tanks were maintained at either 4, 10, or 25 cm below the substrate surface. Root biomass, length, and maximum depth, and shoot height, biomass, and branching for both species were lowest in the tank with water table at 4 cm below the surface. Oxygen diffusion rates were lowest and lenticel intumescences of black spruce roots most abundant in this treatment. With water table depth at 25 cm, the cooling treatment (9 °C at the 10 cm level) had a negative effect on root growth compared with the ambient treatment (18 °C at the 10 cm level). The reverse was true for the tank with water levels at 4 cm; the cooled side had greater root growth than the ambient side.

1993 ◽  
Vol 71 (2) ◽  
pp. 359-360 ◽  
Author(s):  
Timothy S. S. Conlin ◽  
Victor J. Lieffers

Seasonal growth of black spruce (Picea mariana Mill. BSP) and tamarack (Larix laricina (Du Roi) K. Koch) roots in an Alberta peatland were assessed by measuring growth into emplaced soil cores that did not contain plant roots. Five cores were positioned 1 m from the base of each tree and 10 replicates of this treatment were used for each species. Sequential lifting of these cores during the growing season showed that root growth by these species did not begin until midsummer. Tamarack root growth was restricted to August and September, while black spruce root growth continued into October. Key words: flooding, Larix laricina, peatland, phenology, Picea mariana, temperature, root growth.


1975 ◽  
Vol 5 (3) ◽  
pp. 359-366 ◽  
Author(s):  
H. van Groenewoud

Soil water levels, rainfall, and tree diameter increments were measured during four successive growing seasons. Microrelief data and depth of the fluctuating water tables were incorporated into a measure of mean soil depth.Water table fluctuations were closely linked to rainfall. Deviations from the mean tree diameter growth were related to deviations from the mean depth of the water table. Maximum growth took place at the mean depth of the water table, with decreases in growth at higher or lower than average water levels.


1999 ◽  
Vol 29 (5) ◽  
pp. 563-574 ◽  
Author(s):  
Vincent Roy ◽  
Pierre-Y. Bernier ◽  
André P Plamondon ◽  
Jean-Claude Ruel

Black spruce (Picea mariana (Mill.) BSP) seedlings were planted on eight drained forested wetland cutblocks to study the effects of soil type, distance from drainage ditch, and microtopography on the physical conditions of the rooting zone and on seedling growth, survival, and physiology. After two growing seasons, providing a raised planting spot had a greater impact on seedling growth than locally intensive drainage. Less saturated, better aerated, and warmer rooting zone on hummocks increased foliar N and Ca concentrations, which led to significantly greater relative growth rate, terminal shoot height growth, diameter, and survival compared with the seedlings in hollows. The effect of drainage on seedling growth is not conclusive. Depth of the aerobic layer and soil water content at 10 cm depth were similar at all distances to the ditch despite a significantly lower water table level in the 5-m plot. Thus, no significant differences were observed as a function of distance to drainage ditch for water relation and growth parameters except for better height growth in the 5-m plot the second year after planting. Water table levels were identical for both soil types and consequently growth was similar on wet mineral and organic soil types.


Author(s):  
Sandeep Samantaray ◽  
Abinash Sahoo

Accurate prediction of water table depth over long-term in arid agricultural areas are very much important for maintaining environmental sustainability. Because of intricate and diverse hydrogeological features, boundary conditions, and human activities researchers face enormous difficulties for predicting water table depth. A virtual study on forecast of water table depth using various neural networks is employed in this paper. Hybrid neural network approach like Adaptive Neuro Fuzzy Inference System (ANFIS), Recurrent Neural Network (RNN), Radial Basis Function Neural Network (RBFN) is employed here to appraisal water levels as a function of average temperature, precipitation, humidity, evapotranspiration and infiltration loss data. Coefficient of determination (R2), Root mean square error (RMSE), and Mean square error (MSE) are used to evaluate performance of model development. While ANFIS algorithm is used, Gbell function gives best value of performance for model development. Whole outcomes establish that, ANFIS accomplishes finest as related to RNN and RBFN for predicting water table depth in watershed.


Botany ◽  
2011 ◽  
Vol 89 (2) ◽  
pp. 133-140 ◽  
Author(s):  
Marios Viktora ◽  
Rodney A. Savidge ◽  
Om P. Rajora

Black spruce (Picea mariana) reproduces sexually from seeds and asexually by layering. There is a prevalent concept that clonal reproduction maintains populations of this species in the subarctic and arctic regions. We used microsatellite DNA markers of the nuclear genome to investigate the genetic structure of montane and subalpine black spruce populations from the Western Yukon Plateau in relation to this concept. Sixty individual trees at a minimum distance of 4 m from each other were sampled from each of four populations and individual trees were genotyped for eight microsatellite loci. Each of the 60 individuals from three montane pure black spruce populations growing on flat terrain at relatively low elevations had unique multilocus genotypes, indicating an absence of clonal structure in those populations. However, in an anthropologically undisturbed climax white spruce-dominated subalpine black spruce population on a northwest slope near Mount Nansen, the majority of the sampled individuals belonged to eight genetically distinct clones (genets). Clone size differed by altitude, the dominant genet being nearest the timberline–tundra ecotone. The results indicate that black spruce reproduction is variable and adaptive, being primarily sexual in flat-terrain montane populations previously subjected to fire disturbance, but mixed vegetative–sexual in the anthropogenically undisturbed subalpine population. This study is the first to employ molecular markers a priori to examine the mode of reproduction in natural black spruce populations.


1978 ◽  
Vol 54 (6) ◽  
pp. 296-297 ◽  
Author(s):  
Douglas A. Mead

Height growth of eastern larch (Larix laricina (Du Roi) K. Koch) and black spruce (Picea mariana (Mill.) B.S.P.) was determined using standard stem analysis methods on trees from two sites in northwestern Ontario. The data were obtained from mixed larch-spruce stands which were relatively undisturbed. The larch exhibited substantially better height growth than the spruce through age 65.


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