Spruce Needles Research Articles

Влияние высокоактивных соединений на механические свойства древесины двухлетних сеянцев сосны обыкновенной в лесных питомниках

Scots pine (Pinus sylvestris L.) has the leading environment-forming function. Also, the pine is an economically valuable tree species in the Ural region. The long-term use of the pesticide complex in forest nurseries has led to the pesticide pollution of the arable soil, which causes disruption in the pine seedlings growth, weakening their ability to overcome the difficult period of transportation into the forest environment. The use of biostimulants created from extracts of fir and spruce needles, as well as organic ameliorant (forest litter from pinebirch plantations), is considered as a way to reduce the negative impact of pesticides on pine seedlings. At the same time, biologically active preparations and substrates can lead to shifts in the metabolic processes of young plants, which affect the formation of physical characteristics of the stems. The research aims at assessing how wood density changes under the influence of highly active substances of different nature in two-year-old Scots pine seedlings grown in forest nurseries of the Middle Urals. The study objects were two-years-old pine seedlings dug out in autumn from sylvicultural fields and experimental sites in different forest nurseries. Morphometric parameters of seedlings were determined in the laboratory conditions. The basic wood density of stems in the 1st and 2nd years of growth was determined by the method of maximum humidity. It was found that the metabolic activity of pesticides and biostimulants leads to changes in the formation of physical properties of stems at the initial stages of pine growth: when growing seedlings in pesticide-polluted soil, the height of seedlings is lower, and the basic density of stem wood is higher, compared to control group. Forest litter from mixed plantations (birch-pine), when introduced to the forest nursery soil, produces seedlings of greater height and has no significant effect on the formation of physical and mechanical properties of wood. The seed treatment by biostimulants leads to a rapid increase in the stems size, but the wood density decreases, relative to the control option. Corrective measures and the development of balanced agronomic machinery for production of pine with the required physical qualities of wood are needed in the future. The study of the qualitative characteristics formation features of trees, when using intensive technologies in nurseries, is necessary for the development of target models for the subsequent use of such seedlings in forest management.

Effects of different nutrient compensation treatments following forest fuel extraction on biomass of young Norway spruce (Picea abies (L.) Karst.)

Whole tree harvesting of forests may require compensation for losses of nutrients and alkalinity. The effects of three different practical ameliorative methods on spruce allometry, total biomass, and nutrient uptake were studied in an experiment in a 3-year-old Norway spruce ( Picea abies (L.) Karst.) stand in south-west Sweden. The treatments were one application of the fine fraction of logging residues, one application of granulated wood ash, two applications of an N-free vitality fertiliser, and untreated control. Analysis of covariance showed that spruce needle and stem allometry depended on treatment. Spruce fine root allometry was very variable, showing no discernible effect of treatment. Fine root distribution was shallower in treatments with higher graminoid biomass (vitality and wood ash). Vitality treatment increased average concentrations of Ca, Mg, and Zn in spruce total biomass. Ash treatment only increased the Zn concentration. The average N concentration was similar between treatments. Spruce total biomass per unit area was inversely correlated with graminoid biomass. Measurements of N uptake in spruce and graminoid biomass indicated that there was competition for N between spruce and graminoids. Thus, the effect of nutrient compensation on competition needs to be considered when predicting the effect on the growth of the target species.

Well-preserved Norway spruce needle phytoliths in sediments can be a new paleoenvironmental indicator

Analysis of phytoliths (plant silica bodies) still may have an unrevealed potential in paleoenvironmental reconstruction studies. This can provide novel findings in research on environmental change as phytoliths play an important role in the silicon biogeochemical cycle. In favorable environmental conditions, Picea abies [L.] H. Karst (Norway spruce) needles develop a phytolith layer consisting of more or less cubical or cuboid (blocky) phytoliths in their transfusion tissue that becomes continuous toward the apex of the needle. This can be studied in situ in fossil (subfossil) needles under a stereomicroscope. This study reports the blocky-type phytolith preservation in fossil spruce needles in sediment sections of the lake Černé jezero (Bohemian Forest, Czech Republic). The oldest needle containing phytoliths was 7.8 cal ka BP. Despite differences in the Energy Dispersive X-ray (EDX) spectra of different age phytoliths, the studied subfossil phytoliths did not lose their globular ultrastructure in the needle tissue, proving the stability of this phytolith morphotype. As the tissue of the needle fossils can preserve phytoliths in situ, further micro-analytical measurements will make these needles promising tools for paleoenvironmental reconstructions. The most favorable period for spruce phytolith formation for the studied region appears to be the period 6.0–4.5 cal ka BP, within the Holocene Climate Optimum period. In order to use these phytoliths as a terrestrial climate proxy, the next step is to refine their sensitivity to environmental changes.

Biogeochemical prospecting for gold at the Yellowknife City Gold Project, Northwest Territories, Canada: Part 2 - Robust statistical analysis

The Yellowknife City Gold Project (YCGP) is a promising Au district located in proximity to the city of Yellowknife, Northwest Territories, Canada. Positive results of a short biogeochemical survey in 2015 over the Crestaurum and Barney shears (Part 1) resulted in a broad survey over the early and advanced Au targets across the YCGP (Part 2). This survey uses a systematic two-phase statistical approach, including process discovery and process validation, to evaluate the multi-element biogeochemical dataset and identify the geochemical process controlling elemental occurrence and distribution in black spruce needles. To achieve these objectives, 2788 black spruce needle samples were collected across the Northbelt and Eastbelt of the YCGP and analyzed by ICP-MS using a multi-element determinations package for unashed vegetation. Following that, a biogeochemical dataset including Au, As, Ag, As, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Ni, P, Pb, S, Sb, Se, Tl, and Zn were prepared and analyzed using univariate and multivariate statistical analyses, including principal component analysis (PCA) and inverse distance weighted (IDW) interpolation method. The univariate statistical analysis showed that the average Au value in the black spruce needle is higher than the background level in all targets. Contiguous anomalous Au values were identified in needle samples collected proximal to the Ptarmigan & Tom mines (∼10 ppb) and Ryan Lake target (3.8 ppb). According to the robust RQ mode-PCA, PC1 and PC2 control the distribution pattern of elements in black spruce needles. PC1 includes two sets of elements indicating geochemical/mineralization factor (Au, As, Sb, Fe, Pb, and Mo) and physiological factor (Cu, Ca, Zn, K, S, P, and Mg). On the other hand, PC2 differentiates these two factors with more emphasis on the influence of the geochemical/mineralization factor. The IDW interpolation method indicates zones of Au enrichments at the YCGP are associated with different sets of pathfinder elements based on the bedrock composition and mineralization style. According to the IDW, elevated Au values associated with shear zones hosted within mafic/ultramafic bodies are accompanied by As, Sb, Pb, and Cu, while those located proximal to late felsic bodies are accompanied by Ag, As, Se, Hg, and Tl. Zones of Au enrichment located along the faulted contacts between the felsic-intermediate metavolcanics and sulphide metasediments are accompanied by Bi, Se, Hg, and Zn. The results of this study attest to the robustness of multivariate statistical analysis in detecting zones of Au enrichment using biogeochemical exploration.

Relations of Phenolic Compounds, Tannins, Lignin, Nitrogen and Carbon in Plants of the Empetro-Piceetum Forests of the Kola Peninsula

The study presents an analysis of aging (falling) organs (leaves/needles) of the following plants: Siberian spruce (Picea abies ssp. obovata (Ledeb.) Domin), downy birch (Betula pubescens Ehrh), common cowberry (Vaccinium vitis-idaea L.), crowberry hermaphroditic (Empetrum hermaphroditum Hager.), blueberry (Vaccinium myrtillus L.), Schreber’s pleurium (Pleurozium schreberi (Brid.) Mitt.), polytrichum (Polytrichum spp.), dwarf cornel (Chamaepericlymenum suecicum (L.) Aschers. Graebn. (Cornus suecica L.)), wavy hair-grass (Deschampsia flexuosa (L.) Trin.). A significant variation in the chemical composition (the content of lignin, phenolic compounds, tannins, nitrogen and carbon, as well as the stoichiometric ratios “C/N”, “lignin/N”, “lignin/cellulose”) was found among plants of the northern taiga forests at the interspecific level. The influx of secondary metabolites with litter depends on the plant communities’ species composition and the contribution of various plant species to the vegetation cover’s composition. At the intraspecific level (for Siberian spruce growing in different landscape positions within empetro-piceetum forests (in automorphic, transit and accumulative landscapes)) an increase in the content of soluble tannins (p 0.05) in spruce needles from the automorphic positions of landscape was determined. Also have been studied some interrelations between secondary metabolites, nitrogen and carbon in the composition of aging photosynthetic organs of dominant plant species in northern taiga empetro-piceetum forests.

Palatability of Norway spruce needles infected with Lophodermium piceae to larvae of two sawfly species

Unequivocal evidence on the antagonistic effects of endophytic fungi associated with woody plants against insect herbivores has been documented in only a few cases so far. Experimental evidence of the significance of needle endophytes to coniferous trees has remained scant because it is difficult to obtain trees with needles free of endophytes that could be used as comparable controls for trees infected with endophytes. Previously we reported a new methodology to get Norway spruce (Picea abies (L.) Karst.) saplings without needle endophytes and to inoculate them with a needle endophyte Lophodermium piceae (Fuckel) Höhn. Here we describe the first trial where spruce saplings with and without needle endophytes were provided as substrate for insect larvae. We transferred larvae of two sawfly species, Neodiprion sertifer Geoffroy and Gilpina pallida Klug, to the seedlings. Even though the main host of these sawfly species is not Norway spruce, but Scots pine (Pinus sylvestris L.), they are also known to occasionally feed on spruce. In this experiment the larvae did not develop to pupae with the provided spruce substrate but consumed measurable amounts of needles. No significant difference was found between the extent of needles consumed by either of the two sawfly species in inoculated and uninoculated saplings.

CHANGES IN THE CONTENT OF WATER-SOLUBLE SUGARS IN NEEDLES OF SCOTS PINE AND SIBERIAN SPRUCE GROWING IN THE SOUTH OF EASTERN SIBERIA

Scots pine (Pinus sylvestris L.) and Siberian spruce (Picea obovata Ledeb.), which are common for the south of Eastern Siberia, differ from each other in their ecophysiological characteristics. Scots pine is more thermophilic and drought-resistant, while Siberian spruce is more hydrophilic and tolerates cooling better. In different seasons, both species accumulate water-soluble sugars (WSS) in their needles, which are one of the factors of cold and drought resistance of needles. The level of WSS accumulation in needles can be influenced by both factors determined by the tree species and territorial ones, associated with the climate of the growing region. For the first time, this study introduces a comparison of changes in WSS content in Scots pine and Siberian spruce growing in the south of Eastern Siberia during two annual cycles. During the observation period, winter 2015-2016 was colder than winter 2016-2017, and the growth period 2015 was warmer and wetter than the same period in 2016. WSS content in Scots pine needles was found to be less subject to fluctuations and, according to the results of most of the observations made, to be higher than in Siberian spruce needles both in more favorable and less favorable conditions for the physiological activity. The exception was the period of November-February 2015-2016 (when WSS content in the needles of both species was the same) and March-April 2016 (when it was higher in Siberian spruce needles). The ability of Scots pine to maintain higher WSS reserve in its needles is possibly one of the mechanisms that allow trees of this species to successfully compete with Siberian spruce and occupy larger territories under the extreme conditions of the south of Eastern Siberia.

Cryogenic transmission electron microscope images of isolated small cellular particles and supernatant from spruce needle homogenate

Cryogenic transmission electron microscope images of isolated small cellular particles and supernatant from spruce needle homogenate

Assessment of Small Cellular Particles from Four Different Natural Sources and Liposomes by Interferometric Light Microscopy

Small particles in natural sources are a subject of interest for their potential role in intercellular, inter-organism, and inter-species interactions, but their harvesting and assessment present a challenge due to their small size and transient identity. We applied a recently developed interferometric light microscopy (ILM) to assess the number density and hydrodynamic radius (Rh) of isolated small cellular particles (SCPs) from blood preparations (plasma and washed erythrocytes) (B), spruce needle homogenate (S), suspension of flagellae of microalgae Tetraselmis chuii (T), conditioned culture media of microalgae Phaeodactylum tricornutum (P), and liposomes (L). The aliquots were also assessed by flow cytometry (FCM), dynamic light scattering (DLS), ultraviolet-visible spectrometry (UV-vis), and imaging by cryogenic transmission electron microscopy (cryo-TEM). In Rh, ILM showed agreement with DLS within the measurement error in 10 out of 13 samples and was the only method used here that yielded particle density. Cryo-TEM revealed that representative SCPs from Tetraselmis chuii flagella (T) did not have a globular shape, so the interpretation by Rh of the batch methods was biased. Cryo-TEM showed the presence of thin filaments in isolates from Phaeodactylum tricornutum conditioned culture media (P), which provides an explanation for the considerably larger Rh obtained by batch methods than the sizes of particles observed by cryo-TEM images. ILM proved convenient for assessment of number density and Rh of SCPs in blood preparations (e.g., plasma); therefore, its use in population and clinical studies is indicated.

N-Alkanes variability in natural populations of Picea omorika (Pančić) Purk. From Bosnia and Herzegovina

Population variability of n-alkanes in the cuticular waxes of Serbian spruce needles from Bosnia and Herzegovina was investigated for the first time. n-Alkanes exhibited composition variability ranging from C18 to C35.The divergence of populations from Bosnia and Herzegovina and previously investigated Serbian populations was statistically confirmed by PCA, DA, and CA (Cluster analysis), which could support the fact that there are two possible spruce chemotypes: one relating to the Bosnian-Herzegovinian and the other to the Serbian populations. Climate parameters (precipitation, temperature, wind, and solar radiation) approved this conclusion.

The evaluation of hazardous element content in the needles of the Norway spruce (Picea abies L.) that originated from anthropogenic activities in the vicinity of the native habitats

The aim of this research was to quantify the content of hazardous elements in the needles of Norway spruce (Picea abies L.) in the natural habitats that were accumulated from thermal power plants, mines, and metal processing industry. Fifteen natural populations of the Norway spruce were sampled from the mountain ranges in Southeastern Europe (Dinaric Alps and Balkan Mountains). Two-year-old spruce needles were evaluated the content of the following hazardous elements: heavy metals cadmium, mercury, nickel, lead and zinc, and metalloid arsenic. The effect of the distance between air pollution emitters and the Norway spruce natural habitats on the hazardous elements content in needles was also evaluated. The results of the analysis of variance confirmed interpopulation differences in the content of all analyzed hazardous elements. The effect of the air pollution source (thermal power plants, mines, and industry) on the content of hazardous elements in the spruce needles was also assessed. Significant correlation was found between the distance of air pollution emitters and the amount of zinc. This study could serve as the startup point of future monitoring programs and provide new prospect of using Norway spruce needles as the bioindicator of air pollution with hazardous elements on Balkan Peninsula since the fact that the Norway spruce natural populations inhabit wide geographic range of the continental Europe, from the Balkan Peninsula, over European Alps to Scandinavia and a large-scale of altitude from 980 to 1860m above sea level.

Mechanical scarification can reduce competitive traits of boreal ericaceous shrubs and improve nutritional site quality

Abstract Ericaceous shrubs often interfere with the growth of black spruce seedlings on regenerating forest sites in Eastern Canada. Mechanical site preparation such as scarification may improve this situation, but it is uncertain whether this is solely due to a reduction in direct competition from the shrubs, or also from a sustained improvement in nutritional site quality. We sampled experimental plots in two boreal climate regions (i.e. warmer-drier Abitibi vs. cooler-wetter Côte-Nord) where scarification, performed 18 years earlier, had increased the growth of black spruce relative to non-scarified plots. Trees of scarified plots had closed the canopy more than trees of non-scarified plots in Côte-Nord, but not in Abitibi. Total ground cover of ericaceous shrubs was lower in scarified plots at both sites, the main species being Kalmia angustifolia (i.e. Kalmia) in Abitibi and Rhododendron groenlandicum (i.e. Labrador tea) in Côte-Nord. Scarified plots at both sites had significantly shorter current-year ericaceous rhizomes than non-scarified plots, but the difference between treatments was significantly greater in Côte-Nord than in Abitibi. In Côte-Nord, ericaceous shrubs on scarified plots had a lower specific rhizome mass, higher specific leaf area, lower tannin and higher N concentrations in leaves and litter, and lower N use efficiency than on non-scarified plots. By comparison, scarification in Abitibi affected only one foliar property, namely a reduction in the C:N ratio of Kalmia leaf litter. Forest floor N mineralization rates and black spruce needle N concentrations were higher in scarified than non-scarified plots across both sites. Taken collectively, results suggest that mechanical scarification on ericaceous shrub-dominated cutovers can reduce competitive traits of boreal ericaceous shrubs and improve nutritional site quality, especially in cooler-wetter climates.Highlights

Potential for significant precipitation cycling by forest‐floor litter and deadwood

AbstractThe forest‐floor litter layer can retain substantial volumes of water, thus affecting evaporation and soil‐moisture dynamics. However, litter layer wetting/drying dynamics are often overlooked when estimating forest water budgets. Here, we present field and laboratory experiments characterizing water cycling in the forest‐floor litter layer and outline its implications for subcanopy microclimatic conditions and for estimates of transpiration and recharge. Storage capacities of spruce needle litter and beech broadleaf litter averaged 3.1 and 1.9 mm, respectively, with drainage/evaporation timescales exceeding 2 days. Litter‐removal experiments showed that litter reduced soil water recharge, reduced soil evaporation rates, and insulated against ground heat fluxes that impacted snowmelt. Deadwood stored ~0.7 mm of water, increasing with more advanced states of decomposition, and retained water for >7 days. Observed daily cycles in deadwood weight revealed decreasing water storage during daytime as evaporation progressed and increasing storage at night from condensation or absorption. Water evaporating from the forest‐floor litter layer modulates the subcanopy microclimate by increasing humidity, decreasing temperature, and reducing VPD. Despite the relatively small litter storage capacity (<3.1 mm in comparison to ~102 mm for typical forest soil rooting zones), the litter layer alone retained and cycled 18% of annual precipitation, or 1/3 of annual evapotranspiration. These results suggest that overlooking litter interception may lead to substantial overestimates of recharge and transpiration in many forest ecosystems.

THE ROLE OF THE NEEDLE AS A BIOLOGICALLY ACTIVE SUBSTANCE OF PLANT ORIGIN IN FOOD PRODUCTION (PATENT REVIEW)

In the article, the authors substantiated the relevance and expediency of using needles as a herbal ingredient in the development of various product categories. The authors also conducted a content analysis of the data on the chemical composition of needles, indicating the uniqueness of the studied plant ingredient. The main forms of application of needles are represented by extracts based on alcohol or water essence, obtained by infusion, as well as CO2-extraction. The author’s generalized information on the type of needles used - the article presents needles of fir, juniper, spruce, pine, and other types of coniferous plants. Categories of homogeneous products using needles are different: flavor products, honey, bakery products, confectionery, biologically active substances, and alcoholic and non-alcoholic drinks. The authors also summarized information on the cities of the Russian Federation, where products are being developed using needles. The list of patent holders was analyzed by the form of ownership of the organization: individuals, scientific organizations, etc., and trends were identified for the publication of patents using the studied raw materials over the years.

Christmas Tree Bio-Waste as a Power Source of Bioactive Materials with Anti-Proliferative Activities for Oral Care.

According to the American Cancer Society, roughly 54,000 new cases of oral cavity or oropharyngeal cancers have been detected in the United States of America in 2021, and they will cause about 10,850 deaths. The main therapies for cancer management, such as surgery and radio- and chemotherapy, have some own benefits, albeit they are often destructive for surrounding tissues; thus, deep investigations into non-surgical treatments for oral cavities are needed. Biologically active compounds (BACs) extracted from European Spruce needles were analyzed to determine the total phenolic and flavonoid content and were used as additional ingredients for oral hygiene products. An anti-proliferation investigation was carried out using extracts containing BACs with the use of several cell lines (cancer and a normal one). ESI-MS studies on BACs showed that luteolin, a natural flavonoid compound with anti-tumorigenic properties against various types of tumors, is the predominant component of the extracts. MTT, BrdU, and LIVE/DEAD studies demonstrated that BAC extracts obtained from Christmas tree needles possess anticancer properties against squamous cell carcinoma (with epithelial origins). We proved that BAC extracts contain high amounts of luteolin, which induces cytotoxicity toward cancer cells; along with their high selectivity, robustness, and nontoxicity, they are very promising materials in oral health applications.

Effect of Silver Nanoparticles Synthesized by ‘Green’ Methods on the Growth of in vitro Culture of Betula pendula L. whole Plants

Background: Metal nanoparticles, such as silver nanoparticles obtained by “green” nanosynthesis, have been increasingly used in research and practice in recent years due to their high biocompatibility and low toxicity. It is important to understand how green nanoparticles have regulatory effects on all groups of living systems, including plants. One of the key questions is how silver nanoparticles obtained by green methods modify plant growth in various cultivation and biotechnological systems, such as in vitro culture. Objective: The aim of this study was to establish how in vitro culture of birch plants (Betula pendula Roth) reacts to different levels of silver nanoparticles synthesized by green methods (based on plant extracts) and chemical approaches. Methods: The paper examined the nodal segments of silver birch Betula pendula Roth grown on Woody Plant Medium (WPM) with the addition of silver nanoparticles (0.3-300 mg L-1). After 30 days of cultivation in an in vitro environment, the growth of shoots and roots was measured. Silver nanoparticles were synthesized using L-ascorbic acid (reducing agent) and polyvinylpyrrolidone (PVP; stabilizer), as well as with needle extract (as a reducing agent and stabilizer). Results: Chemical nanosynthesis based on PVP and L-ascorbate, as well as green nanosynthesis using extract of spruce needles made it possible to obtain spherical nanoparticles with similar physical parameters. Low levels of AgNPs (0.3-10 mg L-1) synthesized by chemical techniques (PVP and L-ascorbate) stimulated the growth of birch shoots. In this case, the maximum stimulating effect on shoot growth was found at 10 mg of L-1 AgNPs (250-300% stimulation compared to the control). Under higher levels of nanoparticles (30-300 mg L-1), the stimulating effect decreased. Concentrations over 300 mg of L-1 inhibited the growth of birch plants. Very similar effects were observed in roots. In experiments with nanoparticles synthesized using spruce needle extract, it was shown that low concentrations of AgNPs (0.3 and 1 mg L-1) did not cause a significant change in the size of birch shoots and roots. At the same time, higher levels of silver nanoparticles (3-300 mg L-1) significantly stimulated growth. Conclusion: The present study demonstrates the production of stable silver nanoparticles based on PVP and L-ascorbic acid, as well as an extract of Betula pendula needles. The resulting nanoparticles have a uniform shape and distribution. The presence of AgNP (1-300 mg L-1) in the nutrient media has a stimulating effect on Betula pendula shoot and root growth.

Classification of Norway spruce drying states on the basis of reflection spectra

The article is devoted to the development of a method for classifying the reflection spectra of spruce needles of different health categories and assessing the quality of the classification. Such health categories of spruces have been chosen that include the initial stages of drying out, which is essential for early detection of disease foci, but makes it difficult to classify according to visual criteria by means of remote sensing of the Earth. An algorithm for untrained classification and visualisation of spectral data based on correlation and cluster analysis is proposed. The reflection spectra of spruce needles obtained under laboratory conditions were studied and the results were interpreted using the developed software. The analysis of various combinations of parameters within the proposed algorithm, as well as combinations of individual components of the algorithm with known classification methods, made it possible to determine the most effective combination of parameters and classification methods (projection of spectra into the space of principal components, elimination of the influence of the first principal component on spectra, the Ward cluster linking metric and the standardised Euclidean metric for calculating the spectral distance) for detection of different stages of spruce disease. Its use to made it possible to increase the F-score classification quality indicator for the 2nd health category (the most important category for the task of detecting drying in the early stages) up to 70.59 %.

Development of a Biochar-Based Substrate Added with Nitrogen from a Mining Effluent for the Production of Picea mariana Seedlings

Ammoniacal nitrogen (N-NH3) is one of the pollutants that has adverse effects on the environment and is present in most effluents generated by mining operations. Therefore, mining companies must manage it to keep it below the regulated discharge criteria to avoid environmental contamination. In this context, the present study aims to valorize N-NH3 in the form of ammonium sulphate ((NH4)2SO4) for the manufacture of biochar pellets used as growth substrates for the production of forest seedlings. The biochar was first produced by fast pyrolysis, at 320 °C, and different recipes of pellets were then prepared to evaluate their hardness, binder type and content, humidity and durability. The optimal granule chosen was composed of biochar, corn starch and canola oil. Six combinations of different compositions were then prepared as substrates for black spruce growth: (1) Peat (P); (2) Peat and bulk biochar (PB); (3) Peat and bulk biochar impregnated with ammonium sulfate (PBAS); (4) Peat and biochar pellets impregnated with water (PBPeW); (5) Peat and biochar pellets impregnated with an ammonium sulfate solution (PBPeAS); (6) Peat, biochar pellets impregnated with ammonium sulfate and perlite (PBPeASPer). The effects of these substrates on the growth of black spruce seedlings, as well as fertilizer leaching, were measured. The results show that seedling biomass is equivalent to the control for the granular treatment, but higher biomass was obtained with bulk biochar (PB). This shows that a quarter of peat could be replaced by biochar to obtain similar or even better results of biomass yield and, consequently, solve part of the supply issue. As to plant nutrition, no tendency was observed for the experiments apart from the higher proportion of Ca in spruce needles. The prepared biochar-based pellet substrate appears to not only be advantageous for spruce production but also for other uses such as golf courses, forestry producers and horticultural nurseries using conventional fertilizers and peat as growing media. In addition, these approaches could help the Abitibi-Témiscamingue region in Québec, Canada to build a local circular economy.

Gasification of pure and mixed feedstock components: Effect on syngas composition and gasification efficiency

The aim of this work was to investigate whether the use of individual tree components (i.e., stem wood, bark, branches, and needles of spruces) as feedstocks during oxygen blow gasification is more efficient than using mixtures of these components. Experiments were performed at three oxygen levels in an 18-kW oxygen blown fixed bed gasifier with both single and mixed component feedstocks. The composition of the resulting syngas and the cold gas efficiency based on CO and H2 (CGEfuel) were used as response variables to evaluate the influence of different feedstocks on gasification performance. Based on the experimental results and data on the composition of ∼26000 trees drawn from a national Swedish spruce database, multivariate models were developed to simulate gasifier performance under different operating conditions and with different feedstock compositions. The experimental results revealed that the optimal CGEfuel with respect to the oxygen supply differed markedly between the different spruce tree components. Additionally, the models showed that co-gasification of mixed components yielded a lower CGEfuel than separate gasification of pure components. Optimizing the oxygen supply for the average tree composition reduced the GCEfuel by 1.3–6.2% when compared to optimal gasification of single component feedstocks. Therefore, if single-component feedstocks are available, it may be preferable to gasify them separately because doing so provides a higher gasification efficiency than co-gasification of mixed components.

Variation in White spruce needle respiration at the species range limits: A potential impediment to Northern expansion.

White spruce (Picea glauca) spans a massive range, yet the variability in respiratory physiology and related implications for tree carbon balance at the extremes of this distribution remain as enigmas. Working at both the most northern and southern extents of the distribution range more than 5000 km apart, we measured the short-term temperature response of dark respiration (R/T) at upper and lower canopy positions. R/T curves were fit to both polynomial and thermodynamic models so that model parameters could be compared among locations, canopy positions, and with previously published data. Respiration measured at 25°C (R25 ) was 68% lower at the southern location than at the northern location, resulting in a significantly lower intercept in R/T response in temperate trees. Only at the southern location did upper canopy leaves have a steeper temperature response than lower canopy leaves, likely reflecting canopy gradients in light. At the northern range limit respiration is nearly twice that of the average R25 reported in a global leaf respiration database. We predict that without significant thermal acclimation, respiration will increase with projected end-of-the-century warming and will likely constrain the future range limits of this important boreal species.