Spruce Research Articles

New aboveground biomass equations by components for small black spruce in peatland ecosystems of Western Canada

Black spruce is the most common tree species in Canada, dominating treed peatlands where they are usually stunted. We used 495 destructively sampled trees from 56 plots to develop allometric models of aboveground biomass by components (stem, branches, and needles) for small (<5 m tall) black spruce from peatlands in the Taiga Plains and Boreal Plains Ecozones of Western Canada, for which there were no specific models available of biomass by components. We used leave-one-plot-out cross-validation to assess transferability and compare our models with existing national and ecozone-specific equations. Our models predicted total tree biomass with better accuracy and less biased estimates than the national model (relative RMSE: 30% versus 35% national; relative bias: +1% versus –12% national). Similar results were obtained in other external datasets. Existing ecozone equations performed worse than either our models or the national ones. When we applied the models at the plot level to predict aboveground biomass density (Mg·ha−1), our models outperformed the national model again (relative RMSE: 15.9% versus 18.6% national, relative bias: +3.5% versus –13.6% national). These results indicate that at least for peatlands of Western Canada, our models provide better aboveground biomass estimates for small black spruce trees than existing models.

No evidence that coring affects tree growth or mortality in three common European temperate forest tree species

Tree cores are a highly valuable scientific resource. Annual growth ring data can, for example, improve our understanding of climate change impacts and effects of environmental pollution, allow for better annual estimations of tree growth patterns and carbon storage, and help quantify dynamics and changes in forest ecosystems. The value of coring trees for research has been weighted against concerns around the potential harm coring might cause to trees. To date, there is indeed limited research accurately quantifying the potential effects of coring on tree growth and only a handful of studies assessing its influence on mortality. Consequently, many European long-term forest inventorying and monitoring programs are concerned that tree coring might bias the repeated tree measurements in permanent plots, which they rely on for assessments of states and changes of forests. In this study, we assessed the effects of tree coring on the growth and mortality of three widespread European tree species approximately 10 years after they were cored. We used repeated tree measurements from permanent research sites in Switzerland and Ukraine. In Switzerland, we assessed 35 cored and 159 uncored Norway spruce (Picea abies) trees as well as 147 cored and 332 uncored silver fir (Abies alba) trees. In Ukraine, we assessed 348 cored and 6′611 uncored European beech (Fagus sylvatica) trees. We found no statistical evidence that coring negatively affected the growth or mortality of the three tree species assessed. Although we cannot rule out subtle effects on tree health and wood quality, our findings do not provide any evidence that coring affects or biases repeated measurements (such as DBH measures and recording of mortality) performed on the investigated tree species. Tree coring could therefore be considered more often for routine incorporation, particularly in long-term forest inventorying and monitoring programs and initiatives.

Ecological adaptations among spruce species along an environmental gradient in urban areas

Knowledge about current state of the trees in urban areas may be important for foresting and green planting of city landscapes and for improving environmental quality in these areas. The object of this study were to screen a range of morphometric, physiological and biochemical parameters among species of the genus spruce (Picea A. Dietr.) in urban areas of Kryvyi Rih City and to assess the ecological adaptations among species of the genus spruce (Picea A. Dietr.) along an environmental gradient in urban areas of Kryvyi Rih City. During 2017-2021, the 7 research plots in Kryvyi Rih City urban areas along an environmental gradient (low, moderate and high levels of the environmental impact) and 1 research plot in the background area (control) were established. The 30–40-year-old trees of indigenous spruce species (Norway spruce (Picea abies (L.) Karst.)) and non-native spruce species (Colorado blue spruce (Picea pungens var. ‘Glauca’)) were investigated. The morphometric characteristics of trees, vitality of trees and chlorophyll a, chlorophyll b content in needles were studied. The results showed that in background area the tree height (14.5-15.1 m and 11.7-12.5 m for Norway spruce and Colorado blue spruce), diameter at breast height (25.3-28.1 cm and 24.6-27.2 for Norway spruce and Colorado blue spruce), chlorophyll a content (0.75-1.04 mg/g of wet weight and 0.96-1.24 mg/g of wet weight for Norway spruce and Colorado blue spruce) and chlorophyll b content (0.33-0.41 mg/g of wet weight and 0.42-0.50 mg/g of wet weight for Norway spruce and Colorado blue spruce) were typical of mature 30-40-year-old spruce trees. In Kryvyi Rih City urban areas the ecological stress along an environmental gradient decreased the values of growth, vitalyty and photosynthetic activity of the trees by 15-50%. Colorado blue spruce trees (non-native species) exhibit greater ecological tolerance and ecological adaptations than Norway spruce trees (indigenous species). Colorado blue spruce is less sensitive to environmental impact and have a better ecological adaptive balance of pigment content than Norway spruce. Our results confirm that from a sustainable development of the urbane areas perspective it is necessary to using the Colorado blue spruce for greene planting.

B chromosomes in Conifers (Study Case of the Genus Picea A. Dietr.)

Data on B chromosomes in the genus Picea (Spruce) species are presented. Species of this genus are good objects for studying many problems on the role and origin of supernumerary chromosomes in conifers. Classical methods for studying chromosomes with staining of preparations with acetohematoxylin and the method of fluorescent in situ hybridization (FISH) were used. We report the B chromosomes occurrence in five Picea species and confirmed the data of different authors for seven species. At present, supernumerary chromosomes are found in 23 Picea species including the interspecies hybrid P. × fennica. B chromosomes of Picea species are smaller than A chromosomes; their size (4-6 µm) is 25-30% of the size of A chromosomes. The B chromosomes of spruce species are either meta- or submetacentric, which have been designated as B1 and B2 types respectively. The number of B chromosomes per cell in spruce species varies from one to six. It is generally agreed that B chromosomes are derived from A chromosomes through chromosome arrangements They differ from A chromosomes in sequence composition. The results allow us to consider that B chromosomes are of importance for organisms and possibly may play a role in their adaptation.

Modeling the response of Norway spruce tree-ring carbon and oxygen isotopes to selection harvest on a drained peatland forest.

Continuous cover forestry (CCF) has gained interest as an alternative to even-aged management particularly on drained peatland forests. However, relatively little is known about the physiological response of suppressed trees when larger trees are removed as a part of CCF practices. Consequently, studies concentrating on process-level modeling of the response of trees to selection harvesting are also rare. Here, we compared, modeled and measured harvest response of previously suppressed Norway spruce (Picea abies) trees to a selection harvest. We quantified the harvest response by collecting Norway spruce tree-ring samples in a drained peatland forest site and measuring the change in stable carbon and oxygen isotopic ratios of wood formed during 2010-20, including five post-harvest years. The measured isotopic ratios were compared with ecosystem-level process model predictions for ${\kern0em }^{13}$C discrimination and ${\kern0em }^{18}$O leaf water enrichment. We found that the model predicted similar but lower harvest response than the measurements. Furthermore, accounting for mesophyll conductance was important for capturing the variation in ${\kern0em }^{13}$C discrimination. In addition, we performed sensitivity analysis on the model, which suggests that the modeled ${\kern0em }^{13}$C discrimination is sensitive to parameters related to CO2 transport through stomata to the mesophyll.

The Growing Problem of the Spruce Bark Beetle

The European spruce bark beetles release aggregation pheromones to trigger attack on Norway spruce trees; attracting beetles through the use of pheromone traps proves less effective than conventional forest management.
 
 
 

Crown defoliation and radial increment among decayed and undecayed Norway spruce trees

Pathogen-caused wood decay is believed to be one of a major cause of decreasing tree vitality and increased susceptibility to external biotic and abiotic damaging agents. Using data collected from twenty decay-affected different maturity Norway spruce (Picea abies (L.) Karst) stands, this study aims to explore the interaction between butt rot and crown defoliation and radial increment as indicators of tree vitality. Study results indicate that vitality decline among butt rot-affected Norway spruce is expressed as a significant reduction in radial increment and considerably greater levels of crown defoliation. Decayed Norway spruce trees were found to have higher crown defoliation than undecayed spruce trees. Additionally, a radial increment reduction in the last five years and the last twenty years of the increment sequence was found when decayed Norway spruce tree growth was compared to undecayed. Severely defoliated trees were observed only among decayed trees, and this made up only 1% of the population, indicating that butt rot acts as a predisposing or inciting factor for the decline of Norway spruce. A stand age-dependent relationship was also found among visually healthy undecayed spruce trees, indicating that spruce trees show signs of increasing defoliation as part of the ageing process. Among decayed Norway spruce, no such relationship was found, indicating changes in the effect-response framework for decayed trees. Naturally, both decayed and undecayed trees showed a negative correlation between the level of crown defoliation experienced and the radial increment for the last five years before increment sequencing.

Spotting ethylene in forest soils—What influences the occurrence of the phytohormone?

AbstractDue to the rapid microbial degradation, ethylene (ethene; C2H4) detection in most soils is difficult. The knowledge about factors favoring the occurrence of C2H4 is mainly based on laboratory experiments which are not necessarily representative for real field conditions in forest soils. We report results from a total of 24 measuring plots in southwest Germany and more than 50,000 gas samples, including long-term forest monitoring sites and other study sites involving liming, artificial soil compaction, and temporary waterlogging. Many of the patterns and influencing factors identified in the laboratory were confirmed. In well-aerated forest soils, C2H4 was detected in 1.3% of the gas samples. C2H4 detection was higher at oxygen (O2) concentrations below 10% in the soil. The effect was positively correlated with bulk density in compacted soils and CO2, CH4, and N2O concentrations—factors that indicate reduced microbial activity and thus also facilitate the detection of C2H4. It could be detected 3.5 times more often in spruce than in beech stands, indicating that plant species plays a role and was not found to follow any distinct spatial or temporal pattern with the exception of seemingly random spatio-temporal clusters of root-born C2H4 near large roots of spruce trees. The long observation period and large dataset of this field study allowed valuable insights into C2H4 occurrence in forest soils under natural conditions supporting the theory that the plant hormone C2H4 is produced as a warning for anaerobic soil areas that are limiting root growth.

Remote Sensing Parameter Extraction of Artificial Young Forests under the Interference of Undergrowth

Due to the lower canopy height at the maximum crown width at the bottom of young Picea crassifolia trees, they are mixed with undergrowth. This makes it challenging to accurately determine crown size using CHM data or point cloud data. UAV imagery, on the other hand, incorporates rich color information and, after processing, can effectively distinguish between spruce trees and ground vegetation. In this study, the experimental site was an artificial young forest of Picea crassifolia in Shangshan Village, Qinghai Province, China. UAV images were used to obtain normalized saturation data for the sample plots. A marker-controlled watershed segmentation algorithm was employed to extract tree parameters, and the results were compared with those obtained via point cloud clustering segmentation and the marker-controlled watershed segmentation algorithm based on Canopy Height Model (CHM) images. The research results showed that the single tree recognition capabilities of the three types of data were similar, with F-measures of 0.96, 0.95, and 0.987 for the CHM image, UAV imagery, and point cloud data, respectively. The mean square errors of crown width information extracted from the UAV imagery using the marker-controlled watershed segmentation algorithm were 0.043, 0.125, and 0.046 for the three sample plots, which were better than the values of 0.103, 0.182, and 0.074 obtained from CHM data, as well as the values of 0.36, 0.461, and 0.4 obtained from the point cloud data. The point cloud data exhibited better fitting results for tree height extraction compared to the CHM images. This result indicates that UAV-acquired optical imagery has applicability in extracting individual tree feature parameters and can compensate for the deficiencies of CHM and point cloud data.

THE INFLUENCE OF THE TYPE OF FOREST AND THE TYPE OF FOREST GROWING CONDITIONS ON THE STABILITY OF SPRUCE STANDS IN THE ZONE OF CONIFEROUS-DECIDUOUS FORESTS OF THE PERM KRAI

There has been a massive drying out of spruce plantations in recent years. Many versions about the cause of this phenomenon have been put forward by scientists. Despite the active study of the problem of drying out of spruce plantations around the world, a forest management system aimed at reducing the damage from drying out has not been developed yet. Important silvicultural indicators of plantations that can affect their stability are the type of forest growing conditions and the type of forest. The purpose of the study was to establish the influence of the type of forest and the type of forest growing conditions on the resistance to drying out of spruce forests growing in the zone of coniferous-deciduous forests of the Perm Krai. The spruce forests of this territory were the objects of study. The sanitary condition of spruce forests growing in common types of forest growing conditions (B2, C2, C3) and forest types (green moss spruce and pine forest, wood sorrel spruce and pine forest, linden spruce and pine forest, grass spruce and pine forest) of the Perm Krai was determined. The weighted average scores values of the sanitary condition of the spruce forest of the surveyed forest plantations were distributed by forest types and types of forest growing conditions. Statistical indicators of the average weighted scores of the sanitary condition of spruce in different types of forests were obtained. A one-factor analysis of variance was carried out to compare the mean values. It was established that the type of forest and the type of forest growing conditions have an impact on the sanitary condition of spruce stands. The better the forest growing conditions, the more resistant the spruce trees are to drying out, on average. At the same time, soil moisture is more important than soil nutrient status.

Long-term risk assessment of uprooting and stem breakage under drought conditions and at high N deposition in beech and Norway spruce

Damage by wind in forests has increased in recent decades, counteracting possible growth increases by nitrogen (N) deposition. This is also shown by the long-term forest monitoring data from this study. The main factors affecting uprooting and stem breakage in Fagus sylvatica (L.) (9′846 individual beech trees in 102 plots) and Picea abies (Karst.) (9′168 Norway spruce trees in 72 plots) have been analysed by binomial mixed regression models. Our long-term forest observations showed that drought increased uprooting of beech and increased both uprooting and stem breakage of Norway spruce. In beech, high N deposition interacted with drought, resulting in increased uprooting under drought. In Norway spruce, N deposition increased stem breakage directly. Foliar potassium (K) deficiency increased uprooting of both beech and Norway spruce. Moreover, we found an indirect effect of soil acidification in increasing uprooting of beech by decreasing foliar calcium (Ca) concentrations. In Norway spruce, the soil acidification effect was confounded by foliar K concentrations. In beech, stem breakage increased with higher temperature which can be explained by a temperature-mediated growth increase of white rot fungi. In contrast, temperature was negatively related with stem breakage in Norway spruce, which may be interpreted as an inhibition of the heartrot fungus Heterobasidion at higher temperatures.In summary, drought and high N deposition increase the risk of mechanical damage to both beech and Norway spruce and thus endanger sustainable growth rates. We therefore suggest that wind damage must be taken in account in productivity calculations and carbon budgets of temperate forests.

Niche and Interspecific Association of Dominant Tree Species in Spruce–Fir Mixed Forests in Northeast China

This study focuses on the natural coniferous and broad-leaved mixed forest dominated by Picea asperata and Abies fabri in the Jingouling Forest Farm of Northeast China. Specifically, we place emphasis on examining the effects of different thinning intensities. By comparing the niche characteristics and interspecific associations of dominant tree species under various thinning intensity conditions, our aim is to gain deeper insights into the patterns of resource utilization by species and the interplay of tree species in the forest canopy. Based on plot survey data, analysis methods such as niche breadth, niche overlap index, Pearson correlation coefficient, and Spearman’s rank correlation coefficient were used to analyze the niche and interspecific relationship characteristics of the dominant tree species in the community. The results indicate that among the four selective cutting intensities, the tree species with the highest importance value in all cases is Abies fabri, with an average importance value of 30.29%. Additionally, Picea asperata exhibits the widest niche breadth among the tree species, with a value of 4.59. The selective thinning in this study resulted in a reduction of average species niche overlap in the community compared to the control plots. There were both positive and negative interspecies associations observed, but they were statistically insignificant. Few pairs showed significant correlations, with the positive-to-negative ratio of Pearson coefficients decreasing as the selective cutting intensity increased. The Spearman rank correlation analysis revealed a positive-to-negative ratio exceeding one for species pairs in the community under both light and heavy-cutting conditions, with no significant negative correlations observed. In summary, selective cutting disturbance can effectively increase the importance value of the dominant tree species, Abies fabri, in the community. However, it leads to a reduction in the niche breadth of all tree species present in the forest. Moderate selective cutting is considered a more suitable intensity, as it promotes the maintenance of biodiversity and yields higher forest management benefits in the mixed forest of Picea asperata and Abies fabri in Northeast China.

Dendrochemical indicators of tree rings reveal historical soil acidification in Swiss forest stands

The deposition of acidifying nitrogen and sulphur compounds from agriculture and fossil fuel combustion has drastically altered the chemical balance of forest soils in many regions of the world, leading to soil acidification with negative impacts on nutrient availability and thus also on tree vitality. The change of nutrient concentrations in the soil solution can be assessed by long-term investigations, however meaningful indicators, reflecting environmental changes, are needed to compare the current nutrient status with past values. We used dendrochemical indicators in stem wood of different tree species to access the impact of acidifying depositions on soil quality and tree nutrition. We selected 328 stem wood samples from 96 trees of Norway spruce (Picea abies), European beech (Fagus sylvatica), Sessile oak (Quercus petrea) and English oak (Quercus robur) from 22 forest sites, which are part of the long-term Intercantonal Forest Observation Program in Switzerland. Four time periods of 20 years were defined according to the emissions of air pollutants between 1910 and 2017. Our results showed a trend of increasing Al concentrations in tree rings of spruce peaking in the most recent time period (2000–2017). Mn and Ca concentrations in spruce and beech wood have decreased significantly throughout the time period 1910–2017. These dendrochemical indicators depended on the soil pH, with higher Al and lower Mn and Ca concentrations for soils with a low pH (pH<4.2). In oak trees the observed dendrochemical changes are confounded with dendrochemical differences between heartwood and sapwood. K and Mg showed inconsistent patterns in all three tree species, which are probably caused by translocation within the stem discs. With the use of piecewise structural equation models (SEM) we highlighted the direct and indirect influences of N deposition on element concentrations in stem wood. The data suggest a relation between increased N deposition and lower base saturation values in the forest soils for all three tree species, which were linked to higher Al concentrations in spruce and lower Mn concentrations in spruce and beech. The relation between Al concentrations in tree rings of Norway spruce and measured base saturation was used to reconstruct past soil base saturation values. It revealed a progressive soil acidification in the long-term forest observation sites. These reconstructed base saturation values were further used to validate modelled values from dynamic biogeochemical models such as SAFE/ForSAFE. This comparison pointed out possible shortcomings such as the lack of organic complexation in those models. Taken together, our analyses showed that element concentrations of Al, Mn, Ca in Norway spruce and European beech stem wood were suitable dendrochemical indicators of environmental change due to soil acidification, as they reflect both direct and indirect effects of air pollutants and chemical soil properties.

Physiological and biochemical indicators in Norway spruces freshly infested by Ips typographus: potential for early detection methods

IntoductionThe bark beetle Ips typographus currently represents the primary pest of Norway spruce (Picea abies) in Central Europe. Early detection and timely salvage cutting of bark beetle-infested trees are functional management strategies for controlling bark beetle outbreaks. However, alternative detection methods are currently being developed, and possible indicators of bark beetle infestation can be assessed through changes in the physiological, biochemical, and beetle-acceptance characteristics of trees.MethodThis study monitored infested and non-infested Norway spruce trees before and 3 weeks after Ips typographus natural attack. Permanently installed sensors recorded physiological features, such as sap flow, tree stem increment, bark surface temperature, and soil water potential, to monitor water availability. Defensive metabolism characteristics, beetle host acceptance, and attractiveness to trees were monitored discretely several times per season. The forest stand that was later attacked by bark beetles had lower water availability during the 2018–2020 seasons compared to the non-attacked stands.ResultsAfter the attack, sap flow and tree stem increment were significantly lower in infested trees than in intact ones, and bark surface temperature moderately increased, even when measured in the inner forest stand from the shadowed side. Infested trees respond to attacks with a surge in monoterpene emissions. In addition, freshly infested trees were more accepted by males in the no-choice bioassays, and a significantly higher number of beetles were caught in passive traps in the first week of infestation.ConclusionThe most promising characteristics for early detection methods of bark beetle-infested trees include tree bark temperature measured only in certain meteorological conditions, elevated monoterpene emissions, and significantly high catches in passive traps.

Energy recovery from agro-forest wastes through hydrothermal carbonization coupled with hydrothermal co-gasification: Effects of succinic acid on hydrochars and H2 production

Aiming to upgrade agro-forest wastes into value-added solid and gaseous fuels in the present investigation, hydrothermal carbonization (HTC) of spruce (SP), canola hull (CH), and canola meal (CM) was optimized in terms of operating conditions, maximizing the higher heating value of hydrochars. The optimal operating conditions were achieved at HTC temperature, reaction time, and solid-to-liquid ratio of 260 °C, 60 min, and 0.2 g mL−1, respectively. At the optimum condition, succinic acid (0.05–0.1 M) was used as HTC reaction medium to investigate the effects of acidic medium on the fuel characteristics of hydrochars. The succinic acid assisted HTC was found to eliminate ash-forming minerals e.g., K, Mg, and Ca from hydrochar backbones. The calorific values, H/C and O/C atomic ratios of hydrochars were in the range of 27.6–29.8 MJ kg−1, 0.8–1.1, and 0.1–0.2, respectively, indicating the biomass upgrading into coal-like solid fuels. Finally, hydrothermal gasification of hydrochars with their corresponding HTC aqueous phase (HTC-AP) was assessed. Gasification of CM resulted in a relatively high H2 yield of 4.9–5.5 mol kg−1 followed by that for SP with 4.0–4.6 mol H2 per kg of hydrochars. Results suggest that hydrochars and HTC-AP have a great potential for H2 production via hydrothermal co-gasification, while suggesting HTC-AP reuse.

Influences of Succession and Biogeoclimate on Forage Resources for Elk in Northern Idaho

Natural disturbance shaped forest communities for millennia, but fire suppression and timber harvest declines have altered forest structure across the western United States, reducing the abundance of forage for ungulates. We evaluated quality and quantity of forage resources for lactating elk (Cervus canadensis) and their calves in relation to season, succession, and biogeoclimate, the latter indexed by potential vegetation (PV) zones, across 36,500 km2 in Idaho's Clearwater and St. Joe River basins. In 0.2-ha macroplots (n = 359), we measured characteristics of forest overstory, biomass of current annual growth of undergrowth vegetation (kg ha-1), and nutritional content of these plants. Using biomass, digestible energy (kJ g-1), digestible protein (DP, g per100 g forage), and prior knowledge of elk diet selection and nutritional constraints, we developed 8 forage resource metrics. The greatest abundance of undergrowth vegetation (500 to 1,000 kg ha-1) occurred during the first 20 years after stand-replacing disturbance and declined as the overstory closed in wetter PV zones. Digestible energy decreased, whereas DP increased as stands aged. Evidence of nutritional limitations for lactating elk increased markedly after mid-summer; early-seral, high-elevation spruce–fir forests on productive soils provided the best opportunity for lactating elk to satisfy their requirements in late summer. Our findings demonstrate the importance of disturbance regimes that maintain early-seral communities in mosaics with mid- and late-seral stages, and suggest that implementing stand-replacing disturbance in relatively moist forest zones at mid and high elevations provides the greatest improvement in forage resources for lactating elk and their calves in summer.

Pojava ženki velikog smrekinog likotoča Dendroctonus micans (Kugelann, 1794) na vitalnim stablima kavkaske smreke u Artvinu, Turska

Dendroctonus micans (Kugelann, 1794), which was first discovered in 1966 in Turkey, has established almost in all oriental spruce forests in the Eastern Black Sea region until the late 2000s. In its expanding front it is responsible for killing spruce trees representing millions of cubic meters of wood. In recent years, oriental spruce forests have endemic population of this pest. But extreme climatic conditions that cause extreme weather circumstances may trigger suitable environment that favors D. micans outbreaks. In this study, we aimed to examine tree vitality of naturally infested and uninfested trees in the forest. Field studies were performed at a pure spruce stand in Taşlıca Forest Sub-District, Artvin Directorate of Forestry in 2016. Both infested and uninfested trees were selected in the stand closure. One core per tree was extracted from 30 naturally infested and 30 uninfested oriental spruce trees at the same stand. Core samples were taken at the second week of September. Phloem thickness, recent tree growth rates, diameter of breast height and the average number of xylem cells in a radial file formed until the sampling date were studied. Phloem thickness, recent tree growth rates and number of xylem cells were higher in infested trees. Host selection of D. micans was discussed in relation to characteristics of infested and uninfested trees.

Влияние реконструктивной рубки в лиственно-еловом древостое на корневую конкуренцию пород

The predominance of mixed forest stands in a productive forest fund, which is located in the middle taiga subzone of Northwest Russia, determines the relevance of an investigation of the growth and development characteristics of the trees. In secondary stands, created by an extensive human consumption of primary spruce stands, spruce trees are generally presented in a minor quantity. The recovery of their dominance is an urgent economic and ecological issue. Despite the unity of approaches concerning the maintenance of deciduous-spruce forests, the research characteristics on the structure of the root systems differ considerably along with age and geographical position. This article investigates a root system competition between spruce and deciduous species in a 70-year-old blueberry-type forest that was 100 thinning by a reconstructive cutting 35 years ago. The mass of fine roots and their distribution in the upper solid layers were examined by the method of soil monoliths in the mixed stands with different proportions of spruce. The numerical characteristics of the stands were determined by the results of a regular complete enumeration on the trail plots. Besides, the tree diameters were measured around the circular plots, which were made for the collection of the monoliths. The records were made on the dynamics of changes in forest floor thickness and vegetation. The relationship between the underground and elevated parts of the stands was explored. It was shown that the roots of spruce can occupy the same ecological niche as the roots of deciduous species. A correlation analysis revealed a statistically significant relationship between the mass of fine spruce roots and the competitive influence of deciduous species, the proportion of spruce in the stand, and its current volume increment. There was a significant difference in spruce root mass under joint growth with birch and aspen. Therefore, it was concluded that this phenomenon has a complex nature. Namely, the mass of the spruce roots has a direct dependency on their closeness to the maternal trees in combination with the spatial heterogeneity of the organic soil layers. The gained findings are important for the regulation of the composition and structure of the mixed deciduous-spruce stands for growing sustainable stands with a high economic value. For citation: Karpechko A.Yu., Sinkevich S.M. Influence of Reconstructive Cutting in Deciduous-Spruce Stands on Root Competition of Species. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 3, pp. 99–112. (In Russ.). https://doi.org/10.37482/0536-1036-2023-3-99-112

Clinal variation in PHY (PAS domain) and CRY (CCT domain)-Signs of local adaptation to light quality in Norway spruce.

Detection of the genomic basis of local adaptation to environmental conditions is challenging in forest trees. Phytochromes (PHY) and cryptochromes (CRY) perceive the red (R)/far-red (FR)and blue lightrespectively, thus playing a fundamental role in regulating plant growth and development. PHYO and PHYP from conifers are the equivalents of PHYA/PHYCand PHYB in angiosperms, respectively. Norway spruce shows an adaptive latitudinal cline for shade (low R:FR or FR-enriched light) tolerance and requirement of FR light for its growth. We analyzed the exome capture data that included a uniquely large data set of 1654 Norway spruce trees sampled across many latitudes in Sweden to capture the natural clines for photoperiod and FR light exposure during the growth season. Statistically significant clinal variation was detected in allele and genotype frequencies of missense mutations in coding regions belonging to well-defined functional domains of PHYO (PAS-B),PHYP2 (PASfold-2), CRY1 (CCT1)and CRY2 (CCT2)that strongly correlates with the latitudinal gradient in response to variable light quality in Norway spruce. The missense SNP in PHYO resulting in Asn835Ser, displayed the steepest cline among all other polymorphisms. We propose that these variations in the photoreceptors represent signs of local adaptation to light quality.

Enhancing Attention and Interest in Plants to Mitigate Plant Awareness Disparity.

Plant awareness disparity (PAD, formerly plant blindness) is the human inability to notice plants in everyday life. It is suggested that the main underlying factors of PAD are: 1. the inability to recognize individual plants and 2. stronger preferences for animals, which prevents building positive attitudes toward them. The presentation of individual plants should trigger more positive responses toward them than the presentation of groups of plants. Strong preferences for animals predict that the presence of an animal on a plant might enhance positive perceptions of the plant by people. We experimentally investigated the perceived attractiveness and willingness to protect (WTP) plants presented individually and in groups and with or without various pollinators in a sample of Slovak people (N = 238). In contrast to the first prediction, only one of four plants (dog rose, but not saffron, spruce, or beech tree) received higher attractiveness scores when presented individually than in a group. None of these species received higher WTP scores when presented individually, rather than in a group. The effect of the presence of pollinators on flower attractiveness and WTP was distinguished between vertebrates and invertebrates; only flowers with birds and bats increased their attractiveness scores, while flowers with invertebrates, including a butterfly, honeybee, beetle, and the syrphid fly, received similar or lower scores than the same plant species without pollinators. WTP plants significantly increased only when the scarlet honeycreeper and the cave nectar bat were present on flowers as pollinators. People showed significantly stronger preferences for items that associate 1. plants with pollinators and 2. plants with animals that distribute animal seed than for items focused solely on plants. Connecting animals and plants should help reduce PAD. This aim cannot be achieved, however, by presenting individual plants and/or plants with randomly chosen pollinators.