Growth Of White Spruce Seedlings Research Articles

Granular Calcite Stimulates Natural Mycorrhization and Growth of White Spruce Seedlings in Peat-Based Substrates in Forest Nursery.

The acidity of peat-based substrates used in forest nurseries limits seedling mineral nutrition and growth as well as the activity of microorganisms. To our knowledge, no study has yet evaluated the use of granular calcite as a covering material to increase pH, calcium and CO2 concentrations in the rhizosphere and ectomycorrhizal development. The objective is to compare different covering treatments on early colonization of the roots by ectomycorrhizal fungi, as well as the growth and calcium nutrition of white spruce seedlings in the forest nursery. Three treatments were used to cover the plant cavities (Silica (29 g/cavity; control treatment), Calcite (24 g/cavity) and calcite+ (31 g/cavity)) and were distributed randomly inside each of the five complete blocks of the experimental design. The results show that calcite stimulates natural mycorrhization. Seedlings grown with calcite have significant gains for several growth and physiological variables, and that the periphery of their root plugs are more colonized by the extramatrical phase of ectomycorrhizal fungi, thus improving root-plug cohesion. The authors discuss the operational scope of the results in relation to the tolerance of seedlings to environmental stress and the improvement of their quality, both in the nursery and in reforestation sites.

Mycorrhizae and Rhizobacteria on Precambrian Rocky Gold Mine Tailings: I. Mine-Adapted Symbionts Promote White Spruce Health and Growth.

White spruce [Picea glauca (Moench) Voss] is a commercially valuable boreal tree that has been known for its ability to colonize deglaciated rock tailings. Over the last decade, there has been an increasing interest in using this species for the revegetation and successful restoration of abandoned mine spoils. Herein, we conducted a glasshouse experiment to screen mycorrhizal fungi and rhizobacteria capable of improving the health and growth of white spruce seedlings growing directly on waste rocks (WRs) or fine tailings (FTs) from the Sigma-Lamaque gold mine located in the Canadian Abitibi region. After 32 weeks, measurements of health, growth, and mycorrhizal colonization variables of seedlings were performed. Overall, symbionts isolated from roots of healthy white spruce seedlings growing on the mining site, especially Cadophora finlandia Cad. fin. MBN0213 GenBank No. KC840625 and Pseudomonas putida MBN0213 GenBank No. AY391278, were more efficient in enhancing seedling health and growth than allochthonous species and constitute promising microbial symbionts. In general, mycorrhizae promoted plant health and belowground development, while rhizobacteria enhanced aboveground plant biomass. The observed beneficial effects were substrate-, strain-, and/or strains combination-specific. Therefore, preliminary experiments in control conditions such as the one described here can be part of an efficient and integrated strategy to select ecologically well-adapted symbiotic microorganisms, critical for the success of a long-term revegetation program.

Ecophysiology and Growth of White Spruce Seedlings from Various Seed Sources along a Climatic Gradient Support the Need for Assisted Migration.

With climate change, favorable growing conditions for tree species are shifting northwards and to higher altitudes. Therefore, local populations are becoming less adapted to their environment. Assisted migration is one of the proposed adaptive measures to reduce the vulnerability of natural populations and maintain forest productivity. It consists of moving genetic material to a territory where future climate conditions correspond to those of its current location. Eight white spruce (Picea glauca [Moench] Voss) seed sources representing as many seed orchards were planted in 2013 at three forest sites simulating a south-north climatic gradient of 1.7°C in Québec, Canada. The objectives were to (1) evaluate the morpho-physiological responses of the different seed sources and (2) determine the role of genetic adaptation and physiological plasticity on the observed variation in morpho-physiological traits. Various seedling characteristics were measured, notably height growth from nursery to the fourth year on plantation. Other traits such as biomass and carbon allocation, nutritional status, and various photosynthetic traits before bud break, were evaluated during the fourth growing season. No interaction between sites and seed sources was observed for any traits, suggesting similar plasticity between seed sources. There was no change in the rank of seed sources and sites between years for height growth. Moreover, a significant positive correlation was observed between the height from the nursery and that after 4 years in the plantation. Southern seed sources showed the best height growth, while optimum growth was observed at the central site. Juvenile height growth seems to be a good indicator of the juvenile carbon sequestration and could serve as a selection criterion for the best genetics sources for carbon sequestration. Vector analysis showed no nitrogen deficiency 4 years after planting. Neither seed sources nor planting sites had a significant effect on photosynthesis before bud break. The observed results during the establishment phase under different site conditions indicate that southern seed sources may already benefit from assisted migration to cooler climatic conditions further north. While northern seed sources are likely to benefit from anticipated local global warming, they would not match the growth performance of seedlings from southern sources.

Weed control increases nitrogen retranslocation and growth of white spruce seedlings on a reclaimed oil sands soil

Early establishment of seedlings in reclaimed oil sand areas is often limited by low nutrient and water availability due to factors such as strong understory vegetation competition. Management practices such as nursery fertilization and field weed control could help early establishment of planted seedlings and reclamation success. We investigated the effect of nursery nutrient loading and field weed control on the growth, nitrogen (N) retranslocation within seedling components, and plant N uptake from the soil for white spruce (Picea glauca [Moench] Voss) seedlings planted on a highly competitive reclaimed oil sands site for two years. Exponential fertilization during nursery production increased the root biomass but not the nutrient reserve in the seedling. In the field experiment, on average across the treatments, 78 and 49% of the total N demand of new tissue growth in the first and second year were met by N retranslocation, respectively. Though exponential fertilization did not affect N retranslocation, it increased the percent height and root collar diameter growth. Weed control increased not only the growth of seedlings by increasing soil N availability, but also N retranslocation within the seedlings in the second year after outplanting. We conclude that vegetation management by weed control is feasible in improving the early growth of white spruce seedlings planted on reclaimed soils and facilitate tree establishment in the oil sands region. Optimization of the nursery exponential N fertilization regime for white spruce may further help with early revegetation of reclaimed oil sands sites.

Relationships between frost hardiness, root growth potential, and photosynthesis of nursery-grown white spruce seedlings

Root growth is a characteristic to which nursery personnel is particularly attentive. The increase in root growth of white spruce seedlings in the autumn relies on the current season’s photosynthates. Needle hardening or a decrease in the mass of photosynthetically active foliage as a result of early frost may negatively affect the seedling’s photosynthetic capacity and its ability to fuel root growth. This study evaluated the relationship between cold hardiness, root growth potential, and photosynthesis of 2-year-old white spruce seedlings. At the end of their second growing season under standard cultural practices in a forest nursery, seedlings were hardened under natural conditions of photoperiod and temperature. After being subjected to artificial freezing tests on four sampling dates during the fall, the seedlings were compared for cold tolerance and recovery of gas exchange. The effect of artificial freezing treatments on seedling photosynthesis varied with frost intensity and degree of needle hardening. The mass of new roots formed over a 21-day cultivation test period following the freeze tests was positively related to the photosynthetic capacity of the seedlings and negatively related to the proportion of damaged needles. These results imply that autumnal cold damage to needles directly affects seedling root growth and emphasize the importance of maintaining seedlings in an environment favorable for photosynthesis during the fall to promote root growth.

Spatial Variability of Substrate Water Content and Growth of White Spruce Seedlings

Irrigation by jet‐type sprinklers contributes to the spatial variability of substrate water content and growth of containerized white spruce [Picea glauca (Moench) Voss.] seedlings grown outdoors during their second growing season. Geostatistical analyses were used to identify the spatial structure of this variability throughout the growing season and to help develop a sampling strategy to facilitate irrigation management. Boundary line analysis confirmed that the heterogeneity of height growth is related to seasonal variations in substrate water content and that maximum height growth and seedling biomass is attained when average seasonal substrate water content is approximately 40% (v/v). Parameters estimated from semi‐variograms, most notably the range (a) and total variance (C0 + C1) of substrate water content, can be used to define sampling strategies specific to irrigation management and morphophysiological evaluation of seedlings. The relationship between leaching and substrate water content can be used, in conjunction with kriged maps, to estimate potential losses of mineral nutrients and to quantify water use for the production of white spruce seedlings during their second growing season in a forest nursery. More than 15% of the seedlings in the crop used in the present study were rejected at delivery. Knowledge of the spatial variability within a crop enables forest nurserymen to modify sampling techniques and cultural practices, produce more uniform seedlings and reduce the quantity of seedlings that fail to meet morphophysiological criteria.

Effects of Plant Leachates from Four Boreal Understorey Species on Soil N Mineralization, and White Spruce (Picea glauca) Germination and Seedling Growth

Natural regeneration of white spruce (Picea glauca) after disturbance has been reported to be very poor. Here a study was made to determine whether C compounds released from understorey species growing together with white spruce could be involved in this regeneration failure, either by (1) changing soil nutrient dynamics, (2) inhibiting germination, and/or (3) delaying seedling growth. Foliage leachates were obtained from two shrubs (Ledum palustre and Empetrum hermaphroditum) and one bryophyte (Sphagnum sp.) with high phenolic compound concentrations that have been reported to depress growth of conifers in boreal forests, and, as a comparison, one bryophyte (Hylocomium splendens) with negligible phenolic compounds. Mineral soil from a white spruce forest was amended with plant leachates to examine the effect of each species on net N mineralization. Additionally, white spruce seeds and seedlings were watered with plant leachates to determine their effects on germination and growth. Leachates from the shrubs L. palustre and E. hermaphroditum contained high phenolic compound concentrations and dissolved organic carbon (DOC), while no detectable levels of C compounds were released from the bryophytes Sphagnum sp. or H. splendens. A decrease in net N mineralization was determined in soils amended with L. palustre or E. hermaphroditum leachates, and this effect was inversely proportional to the phenolic concentrations, DOC and leachate C/N ratio. The total percentage of white spruce germination and the growth of white spruce seedlings were similar among treatments. These results suggest that the shrubs L. palustre and E. hermaphroditum could negatively affect the performance of white spruce due to a decrease in soil N availability, but not by direct effects on plant physiology.

The Effect of Peatland Drainage and Planting Position on the Growth of White Spruce Seedlings

Abstract The effects of peatland drainage and planting position (peat hummock top, midslope, and bottom) on 2+0 barefoot white spruce seedling survival and growth and foliar nutrients were tested over a 2-yr period. Seedling survival was 44%-56% on hummock tops compared to 80%-96% on hummock midslopes and bottoms. Size of seedling at planting significantly affected survival. Final biomass on drained sites was 34%-53% greater than on undrained peatlands. Foliar nutrient levels were deficient on both drained and undrained peatlands. Foliar nitrogen, however, was significantly higher on the drained site and varied between the different planting positions. Seedling survival and growth was best on midslopes and hummock bottoms on the drained site, and best only on midslopes in the undrained site. Hummock tops were the least favorable planting position on both drained and undrained sites. North. J. Appl. For. 10(4):154-160.

Influence of flooding and soil temperature on the water relations and morphological development of cold-stored black spruce and white spruce seedlings

Fall-lifted, cold-stored black spruce (Piceamariana (Mill.) B.S. P.) and white spruce (Piceaglauca (Moench) Voss) seedlings [Formula: see text] were planted in a controlled environmental chamber with an air temperature of 20 °C, soil temperatures of 10 or 20 °C, and flooded or nonflooded soil treatments. Stomatal conductance (gwv) was lower in flooded seedlings compared with nonflooded seedlings for both black spruce and white spruce seedlings. Black spruce seedlings drained after 14 days of flooding showed gwv similar to nonflooded seedlings, while drained white spruce seedlings had gwv patterns greater than nonflooded seedlings. White spruce seedlings had diurnal xylem pressure potential (ψx) patterns slightly more negative in the flooded treatment compared with the nonflooded treatment. Measured predawn ψx was found to be more negative in flooded seedlings compared with nonflooded seedlings in both black spruce and white spruce. In both species, flooded seedlings 1 day out of cold storage had a greater resistance to water flow through the soil–plant–atmosphere continuum (RSPAC) compared with non-flooded seedlings. After 21 days out of cold storage, rspac decreased in nonflooded seedlings of both species, while flooded seedlings of both species had high RSPAC values. For both black spruce and white spruce seedlings, flooded soils inhibited root growth, while low soil temperatures resulted in a reduction in root growth in nonflooded seedlings. Shoot growth of white spruce seedlings was not influenced by 21 days of flooding or low soil temperature, while the combination of 21 days of flooding and low soil temperature in black spruce seedlings resulted in less shoot development compared with nonflooded seedlings.

The effect of rooting volume and container configuration on the early growth of white spruce seedlings

White spruce (Piceaglauca (Moench) Voss) seedlings were germinated and grown for 20 weeks in containers ranging in volume from 10 cm3 to 524 cm3. Containers for four of the six volumes were constructed in three different ratios of height to diameter (1:1, 3:1, and 6:1), with the remaining two volumes at 3:1. Both container diameter and volume had prounced effects on seedling growth. White spruce produced significantly more roots in the top quarter of the container than did lodgepole pine (Pinnscontorta Dougl. var. latifolia Engelm.), indicating that white spruce and lodgepole pine require containers of different configuration for optimum growth.

The effect of arsenic trioxide on the growth of white spruce seedlings

In the smelting of arsenopyrite ores during the gold extraction process, substantial amounts of As2O3 are released into the environment. The work described in this paper demonstrates the potential effect of this fallout on the growth of white spruce trees. Several small trees were planted in soil containing various amounts of As2O3 and their growth was studied over an ii mo period. Substantial retardation of the growth of the trees with As containing soil was observed.

Growth of white spruce seedlings following cold storage

Growth of white spruce seedlings following cold storage

ESTABLISHMENT AND EARLY DEVELOPMENT OF WHITE SPRUCE IN THE INTERIOR OF BRITISH COLUMBIA

Survival and growth of white spruce seedlings and juvenile trees were compared on two seedbeds, three forest sites, and a range of light conditions in the central interior of British Columbia. For germination, the most favourable seedbed was mineral soil in shade on moist and wet sites; for survival, mineral soil, dry habitats, partial shade; for growth, mineral soil, moist habitats, full light exposure.

The Effect of Phosphorus Placement on the Growth of White Spruce Seedlings

Abstract White spruce seedlings were grown in a sandy soil that received super-phosphate fertilizer at four rates, and placed in three ways in the soil. It was found that placing the fertilizer in a band of soil one inch below the surface produced the greatest seedling growth at all fertilizerlevels. Surface placement resulted in the least growth and mixing the fertilizer throughout the entire rooting volume gave intermediate results.

The Effects of Levels and Times of Fertilizer Application on the Growth of White Spruce Seedlings

AbstractFour levels of nitrogen and phosphorus were added in combination on three different time schedules to white spruce seedlings during their second growing season. The three time schedules were: (1) “Periodic,” in which fertilizer was applied in five dressings from May to September; (2) “Normal,” in which fertilizer was applied in May, June, and July; and (3) “Summer and Fall,” in which fertilizer was applied in May, June, and September.Seedling dry weight increased with increasing level of fertilizer application but was not significantly affected by time of application. Seedling height showed a general increase with increase in amount of fertilizer. Shoot/root ratios increased with increasing level of fertilizer, however, by using a “Periodic” time schedule the increase was minimized. Nitrogen concentrations and contents in the foliage increased with increase in fertilizer level and “Periodic” and “Summer and Fall” applications resulted in larger concentrations than did those under the “Normal” time schedule. Foliage concentrations of phosphorus were not affected by any of the treatments.