Picea Abies Seedlings Research Articles

Aluminium concentration versus the base cation to aluminium ratio as predictors for aluminium toxicity in Pinus sylvestris and Picea abies seedlings

Aluminium (Al) toxicity is considered an important factor in forest deterioration caused by soil acidification. A ratio of base cations (BC) to Al in the soil solution lower than 1 is widely used as an indicator for potentially adverse effects on tree health. In our view, the validity of the assumptions underlying the use of the BC:Al ratio as an indicator for Al toxicity in trees has never been evaluated properly. Here, we evaluate the importance of the base cations Ca and Mg in counteracting Al toxicity. Pinus sylvestris and Picea abies seedlings were grown on nutrient solution with a range of Al (0–0.25–0.5–1–2 mM) and base cation (0.25–0.5–2 mM) concentrations, giving BC:Al ratios of 1 at different levels of Al. Increasing concentrations of Al in solution caused growth reductions, which could not be counteracted by increasing concentrations of BC in solution with P. sylvestris and only partly counteracted with P. abies . Increased concentrations of Al in solution decreased the concentrations in shoot and root of both Ca and Mg, while increased concentrations of BC in solution increased tissue concentrations of BC. Growth reductions were, however, not a result of BC deficiencies, as growth reduction already occurred in tree seedlings that maintained adequate concentrations of Ca and Mg. All growth and uptake variables measured showed a higher or equal correlation with the absolute concentrations of Al or Al+BC in solution than with the BC:Al ratio. We conclude that Al toxicity is determined solely by the concentration of Al in solution. Shoot growth decreased significantly as dissolved Al increased at a constant BC:Al ratio of 1. In P. abies , but not in P. sylvestris , dissolved BC can positively affect uptake of BC and growth, which might partly alleviate the toxic effects of Al. Our results show that the mechanistic explanation for the effect of the BC:Al ratio is insufficient to describe Al toxicity. Care should be taken when using models based on the BC:Al ratio to predict the effect of Al on tree growth.

Mobilization of aluminium, iron and silicon by Picea abies and ectomycorrhizas in a forest soil

SummaryWeathering of soil minerals is a key determinant of ground and surface water quality and is also important in pedogenic and rhizosphere processes. The relative importance of biotic and abiotic studies in mineral weathering, however, is poorly understood. We investigated the impact of Picea abies seedlings, an ectomycorrhizal fungus and humic acid on the solubilization of aluminium (Al), iron (Fe) and silicon (Si) in an E horizon forest soil over 10 months. Elemental budgets were constructed based upon losses in drainage water, accumulation in plants and changes in the pools of exchangeable ions. Plants and mycorrhizas or both had a significant effect on the total amounts of Al, Fe and Si mobilized from the soil. Significantly larger amounts of Al and Fe were recovered in plants than those lost in drainage water, whereas the opposite trend was true for Si. The continual addition of dissolved organic matter to the soil in the form of humic acid had an effect only on mobilization of Fe, which increased due to larger plant uptake and an increase in the exchangeable pool. The mobilization of Fe and Si were positively correlated with hyphal length, soil respiration and concentrations of oxalate in the soil solution, and mobilization of Al was strongly correlated with plant weight. Scanning electron microscopy revealed that most fungal hyphae were associated with mineral surfaces with little occupation of cracks and micropores within mineral grains. Evidently ectomycorrhizas have important impacts on mineral dissolution and the chemistry of forest soils.

Impact of ectomycorrhizas on the concentration and biodegradation of simple organic acids in a forest soil

SummarySimple organic acids seem to be important in many soil processes including nutrient uptake in the rhizosphere and long‐term pedogenic processes such as podzolization. The factors regulating the concentrations of these acids in soil, however, remain poorly understood. We have investigated one set of factors, namely the impact of ectomycorrhizal (Paxillus involutus) and non‐mycorrhizal Picea abies seedlings and humic acid on the concentration and dynamics of organic acids in soil solution. We did so over 10 months in laboratory columns containing soil from the E horizon of a sandy forest soil. Several organic acids were identified in the solution extracted from the root zone including oxalic, citric, malonic, succinic, acetic, formic and lactic acids at concentrations ranging from <0.1 to 2.3 µm. Both plants and ectomycorrhizas had significant effects on the concentration of organic acids in soil solution. In contrast, omitting P from the irrigation water appeared to have little effect on the concentrations. The microbial mineralization kinetics of oxalate conformed well to a single Michaelis–Menten equation. Further, the soil with the mycorrhizas had a significantly faster mineralization of oxalic acid over a wide concentration range than did the soil without ectomycorrhizas and without plants. We conclude that the oxalate flux through the soil with both trees and mycorrhizas is much faster than is evident from measurements of solution concentration at steady state. Humic acid had little effect on the concentrations of organic acids or dynamics in the soil solution. Oxalic acid concentrations in the soil solution were correlated with hyphal length, rate of microbial mineralization, soil respiration, and shoot to root weight ratio. We conclude that both mycorrhizas and plants have a large impact on organic acid cycling in forest soils.

The use of root growth and modelling data to investigate amelioration of aluminium toxicity by silicon in Picea abies seedlings

Three-week-old Picea abies seedlings were grown for 7 days in 100 μM aluminium (Al), combined with 1000 or 2000 μM silicon (Si). Solution pH was adjusted to 4.00, 4.25, 4.50, 4.75, or 5.00. In the absence of Si, solution pH had no effect on the decrease in root growth caused by 100 μM Al. Silicon did not ameliorate toxic effects of Al on root growth at pH 4.00, 4.25 and 4.50, whereas significant, and apparently complete, amelioration was found at pH 4.75 and 5.00. An equilibrium speciation model (EQ3NR), with a current thermodynamic database, was used to predict the behaviour of Al and Si in growth solutions. When Si was not present in the 100 μM Al solutions, Al 3+ declined from 92.4% of total Al at pH 4.00 to 54.6% at pH 5.00, and there was a concomitant increase in hydroxyaluminium species as pH increased. The addition of 1000 μM Si to the 100 μM Al solutions caused a reduction in Al 3+ content over the whole pH range: at pH 4.00 Al 3+ fell from 92.4 to 83.3% in the presence of Si; and at pH 5.00 the fall was from 54.6 to 17.7%. These falls were attributed to the formation of hydroxyaluminosilicate (HAS) species. Similar, but somewhat greater, changes were observed in solutions containing 2000 μM Si. The match between root growth observations and the modelling data was not very good. Modelling predicted that change in Al 3+ content with pH in the presence of Si was gradual, but root growth was markedly increased between pH 4.50 and 4.75. Differences between root growth and modelling data may be due to the model not correctly predicting solution chemistry or to in planta effects which override the influence of solution chemistry.

Genetic variation in drought tolerance in picea abies seedlings and its relationship to growth in controlled and field environments

Drought tolerance, phenology, height‐growth and biomass were studied in 36 open‐pollinated Picea abies families in a growth chamber over two growth periods. Three different irrigation treatments were applied: well‐watered, periodic drought and lethal drought (involving watering during the first growth period and withholding water during the second). The periodic drought treatment yielded significantly smaller seedlings than the well‐watered treatment. In the lethal drought treatment 5.6% of the seedlings were still alive after 3 months without irrigation. Heritabilities for drought damage score, days to wilting and days to necrosis in the lethal drought treatment were 0.41, 0.23 and 0.20, respectively. Additive genetic correlation estimates between drought tolerance traits and growth traits in the growth chamber treatments and in four field progeny trials were weak and mainly non‐significant. High drought tolerance was correlated with early budset and, to a lower extent, late budburst. In conclusion, selection for height growth and late budburst as practised in Swedish breeding and propagation populations is not likely to reduce seedling drought tolerance.

Genetic Variation in Nutrient Utilization and Growth Traits in Picea abies Seedlings

Genetic variation in nitrogen (N) and phosphorus (P) utilization (amount of total biomass produced per unit nutrient in the needles) and growth traits in seedlings from 30 open‐pollinated families of Picea abies (L.) Karst. was estimated. Seedlings were grown under two nutrient regimens: free access to nutrients and restricted access. There was a strong treatment effect on most growth traits. With free access, families allocated relatively more biomass to the stem and less to the roots than they did with restricted access. Heritabilities for growth traits were higher with free access treatment (0.33–0.81) than with restricted access treatment (0.20–0.45). Family variance components for N and P utilization were significant (p < 0.05) with restricted access but not with free access. Genetic correlation between nutrient utilization and height traits with restricted access ranged from none to moderate ( — 0.31 to 0.56). Genetic correlations between the same trait assessed in the two treatments were strong for height and moderate for biomass.

Genetic variation in nutrient utilization and growth traits in picea abies seedlings

Genetic variation in nitrogen (N) and phosphorus (P) utilization (amount of total biomass produced per unit nutrient in the needles) and growth traits in seedlings from 30 open‐pollinated families of Picea abies (L.) Karst. was estimated. Seedlings were grown under two nutrient regimens: free access to nutrients and restricted access. There was a strong treatment effect on most growth traits. With free access, families allocated relatively more biomass to the stem and less to the roots than they did with restricted access. Heritabilities for growth traits were higher with free access treatment (0.33–0.81) than with restricted access treatment (0.20–0.45). Family variance components for N and P utilization were significant (p < 0.05) with restricted access but not with free access. Genetic correlation between nutrient utilization and height traits with restricted access ranged from none to moderate ( — 0.31 to 0.56). Genetic correlations between the same trait assessed in the two treatments were strong for height and moderate for biomass.

Genetic Variation in Drought Tolerance in Picea abies Seedlings and its Relationship to Growth in Controlled and Field Environments

Drought tolerance, phenology, height‐growth and biomass were studied in 36 open‐pollinated Picea abies families in a growth chamber over two growth periods. Three different irrigation treatments were applied: well‐watered, periodic drought and lethal drought (involving watering during the first growth period and withholding water during the second). The periodic drought treatment yielded significantly smaller seedlings than the well‐watered treatment. In the lethal drought treatment 5.6% of the seedlings were still alive after 3 months without irrigation. Heritabilities for drought damage score, days to wilting and days to necrosis in the lethal drought treatment were 0.41, 0.23 and 0.20, respectively. Additive genetic correlation estimates between drought tolerance traits and growth traits in the growth chamber treatments and in four field progeny trials were weak and mainly non‐significant. High drought tolerance was correlated with early budset and, to a lower extent, late budburst. In conclusion, selection for height growth and late budburst as practised in Swedish breeding and propagation populations is not likely to reduce seedling drought tolerance.

Effect of Air-filled Porosity and Organic Matter Concentration of Soil on Growth of Picea abies Seedlings after Transplanting

The effects of air-filled porosity (AFP) and organic matter concentration (OMC) of soil on the growth of Norway spruce [Picea abies (L.) Karst.] seedlings were studied in a greenhouse experiment. One-year-old seedlings were planted into 250 pots filled with five different growth media based on low-humified sphagnum peat and fine sand. The media were mixed to achieve five levels of OMC (1, 25, 50, 75 and 97% by mass). Five AFP levels (5, 10, 20, 30 and 40%) were applied to the mixtures of growth media during irrigation. The growth attributes of the seedlings were measured after seedlings had grown in the greenhouse for 15 weeks. The shoot height and mass growth as well as root mass were significantly higher in 20, 30 and 40% AFP than in 5 and 10% AFP (p<0.05). The longest shoots were produced in growth media with 25, 50 and 75% OMC (p<0.05). The effect of OMC on root mass, while significant (p=0.03), was less pronounced than the effect on height growth and mass of the shoots (p<0.001). The results indicate that, for good seedling growth in pots in greenhouse conditions, AFP should be 20-40% and OMC 25-75% in the growth medium.

Intraspecific variation in Heterobasidion annosum for mortality rate on Pinus sylvestris and Picea abies seedlings grown in pure culture

One-month-old Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) seedlings were inoculated in vitro with Heterobasidion annosum strains, four each of the P-, S- and F-intersterility groups. Variation among strains and between the IS groups in virulence, expressed in mortality rate, was detected during twelve months after inoculation. Most of the strains were more virulent on spruce than on pine, and mortality of spruce seedlings was significantly higher. The P strains displayed similar virulence on both hosts, while S strains caused higher mortality of spruce seedlings and significantly lower mortality of pine seedlings. Strains of the F group were less virulent, but killed significantly (P < 0.05) more spruce than pine seedlings. In the interspecific analyses with two hosts, the isolates and IS groups accounted for most of the explained variation in the host mortality

Early response of Pinus sylvestris and Picea abies seedlings to an experimental canopy gap in a boreal spruce forest

We studied the early response of size and morphology of Pinus sylvestris (Scots pine) and Picea abies (Norway spruce) seedlings to an experimental canopy gap and the consequent distribution of photosynthetically active radiation (PAR) in a boreal Norway spruce forest. Because of the asymmetric distribution of radiation in the gap and its surroundings, which was due to solar geometry at high latitudes, the highest amount of radiation was received several metres north of the gap centre. As a result, seedlings growing under the canopy at the northern edge of the gap received amounts of radiation similar to those received by seedlings growing in the southern part of the gap. Seedling size (aboveground dry biomass, height, and projected leaf area) of both species increased with increasing radiation, but shade-intolerant P. sylvestris responded more strongly than shade-tolerant P. abies. P. sylvestris seedlings reached their maximum aboveground dry biomass in the northwestern part and P. abies seedlings in the northern half of the gap. As height difference between species was small, the greater aboveground dry biomass of P. sylvestris seedlings was explained by its larger projected leaf area compared to P. abies. In addition, P. sylvestris responded to radiation with a more flexible morphology than P. abies, allowing P. sylvestris to increase its needle length with increasing radiation. Longer needles contributed to increased aboveground dry biomass, projected leaf area, and specific leaf area p. Consequently, with increasing radiation, P. sylvestris seedlings allocated proportionally more aboveground dry biomass to assimilating parts versus structural parts compared to P. abies. This allowed P. sylvestris to capture more light and compete better for resources than P. abies in gap and gap-edge environments.

Effects of Excessive Nutrient Supply and Short Day Treatment on Autumn Frost Hardiness and Time of Bud Break in Picea abies Seedlings

Contradictory results have been reported on the impact of needle nutrient concentration on frost hardiness in conifers. The aim of the present study was to test whether excessive nitrogen (N) supply would make seedlings of Picea abies (L.) Karst. more susceptible to autumn frost damage or lead to earlier bud break in the subsequent spring. Seedlings were grown in a greenhouse for one season and given a nutrient supply resulting in needle N concentrations ranging from 2.2 to 3.3%. Half of the seedlings with the lowest N fertilization were exposed to short day treatment for 3 weeks from mid August. No evidence was found in this experiment that excessive N concentrations in needles lead to increased autumn frost damage. Short day treatment resulted in less frost damage in autumn. No significant difference in time of bud break due to fertilization or day length was detected. This may have been due to a more uniform bud break caused by the storage and growth conditions.

Circadian Timekeeping for the Photoperiodic Control of Budset in Picea abies (Norway Spruce) Seedlings

Romanian populations of Norway spruce are induced to set terminal buds by four inductive cycles of 8 h light/16 h darkness. To distinguish between circadian and hourglass timekeeping for the photoperiodic control of budset, seedlings were raised in continuous light at 300 µmol m-2s-1 at 20°C for 10 weeks. They were then exposed to an extended night regime consisting of three cycles of 8 h light/40 h dark with 4-h or 1-h nightbreaks (120 µmol m-2s-1) applied to groups of plants at intervals during the extended night. Following a final cycle of 8 h light/16 h dark to maximize budset, the plants were transferred to continuous light. Budset was delayed when the night-break was applied close to the critical nightlength (CNL) of 6–7 h or about 22–23 h later in the extended night, consistent with circadian rather than hourglass timekeeping. Confidence intervals were calculated for the times to maximum effect of the night-breaks.

Nitrogen limitation in mycorrhizal Norway spruce (Picea abies) seedlings induced mycelial foraging for ammonium: implications for Ca and Mg uptake

Although many studies support the importance of the external mycelium for nutrient acquisition of ectomycorrhizal plants, direct evidence for a significant contribution to host nitrogen nutrition is still scarce. We grew nonmycorrhizal seedlings and seedlings mycorrhizal with Paxillus involutus (Batsch) Fr. in a sand culture system with two compartments separated by a 45-μm Nylon mesh. Hyphae, but not roots, can penetrate this net. Nutrient solutions were designed to limit seedling growth by nitrogen. Hyphal density in the hyphal compartment, host N status and shoot growth of mycorrhizal seedlings significantly increased in response to NH4 + addition to the hyphal compartment. Labeling the compartment only accessible to hyphae with 15NH4 + showed that the increase in N uptake in the mycorrhizal seedlings was a result of hyphal N acquisition from the hyphal compartment. These results indicate that hyphae of P. involutus may actively forage into N-rich patches and improve host N status and growth. In the mycorrhizal seedlings, which received additional NH4 + via their external mycelium, the increase in NH4 + supply less negatively affected Ca and Mg uptake than in nonmycorrhizal seedlings, where the additional NH4 + was directly supplied to the roots. This was most likely due to the close link of NH4 + uptake and H+ extrusion, which, in the nonmycorrhizal seedlings, lead to a strong acidification in the root compartment, and subsequently reduced Ca and Mg uptake, whereas in the mycorrhizal seedlings the site of intensive NH4 + uptake and acidification was in the hyphal and not in the root compartment. Our data support the idea that the ectomycorrhizal mycelium connected to an N-deficient host may actively forage for N. The mycelium may also be important as a biological buffer system ameliorating negative influence of high NH4 + supply on cation uptake.

Influence of nutrient supply on shade-sun acclimation of Picea abies seedlings: effects on foliar morphology, photosynthetic performance and growth.

Norway spruce seedlings (Picea abies Karst.) were grown in low light for one year, under conditions of adequate and limiting nutrition, then transferred to high light. Three months after transfer we measured photosynthesis, leaf nitrogen concentration, leaf chlorophyll concentration and leaf mass per area (LMA) of current-year and 1-year-old shoots; silhouette area ratio (SAR, the ratio of shoot silhouette area to projected needle area) was also measured in current-year shoots. At the foliage level, the effects of light and nutrient treatments differed markedly. Light availability during foliage expansion primarily affected LMA and SAR (morphological acclimation at the needle and shoot level, respectively). By contrast, nutrient supply in high light affected photosynthetic capacity per unit of leaf tissue (physiological acclimation at the cellular level) but did not affect LMA and SAR. The capacity for shade-sun acclimation in foliage formed before transfer to high light differed greatly from that of foliage formed following the transfer. The morphological inflexibility of mature needles (measured by LMA) limited their shade-sun acclimation potential. In contrast, at high nutrient supply, shoots that developed just after the change in photosynthetic photon flux density largely acclimated, both morphologically and physiologically, to the new light environment. The acclimation response of both current- and 1-year-old shoots was prevented by nutrient limitation. Analysis of growth at the whole-plant level largely confirmed the conclusions drawn at the shoot level. We conclude that nutrient shortage subsequent to the opening of a canopy gap may strongly limit the acclimation response of Norway spruce seedlings. Successful acclimation was largely related to the plant's ability to produce sun foliage and adjust whole-plant biomass allocation rapidly.

Piceirhiza bicolorata- the ectomycorrhizal expression of the Hymenoscyphus ericae aggregate?

The mycobionts of Piceirhiza bicolorata, a distinct ectomycorrhizal morphotype of conifers and hardwoods, have been identified by internal transcribed spacer 1 (ITS1) nuclear ribosomal DNA (rDNA) sequence comparison of the fungi involved. Samples of Piceirhiza bicolorata were obtained from seedlings of Picea abies, Pinus sylvestris, Betula pubescens, Populus tremula, Quercus robur and Salix phylicifolia. In an initial screening, the fungus amplified with universal ITS primers from ectomycorrhizal root samples of P. bicolorata shared approx. 95% ITS1 sequence identity with the ericoid mycorrhizal fungus Hymenoscyphus ericae. A total of 77 out of 88 (= 87.5%) DNA samples (i.e. 52/56 root samples and 25/32 axenic culture isolates) of P. bicolorata were successfully amplified with a taxon-selective primer designed for exclusive amplification of H. ericae-like strains. Forty-seven amplicons were sequenced, yielding 15 different ITS1 genotypes that differed by 1-14 nucleotide character state changes. An inferred ITS1 phylogeny (maximum parsimony) showed that a single major evolutionary lineage of P. bicolorata embraced the historically important H. ericae isolates in a 100% bootstrap-supported clade. The 15 P. bicolorata genotypes were positioned in four subclades, roughly corresponding to morphological groups of P. bicolorata isolates observed in axenic culture. Culture isolates of H. ericae and P. bicolorata share some common morphological features including slow, dense growth and formation of short aerial hyphal aggregates. Our results suggest that members of the H. ericae aggregate participate in the formation of the distinct ectomycorrhizal morphotype P. bicolorata. This opposes the widely accepted discrimination of ericoid and ectomycorrhizal mycobionts of the boreal forest ecosystem. The high prevalence of the P. bicolorata morphotype on pioneer seedlings of P. sylvestris, B. pubescens and S. phylicifolia at a copper mine spoil was remarkable. Hypotheses of possible nutrient mobilization and detoxification potentials of the fungal associates of P. bicolorata are discussed. We hypothesize that ericoid and ectomycorrhizal plants may share mycobionts of the H. ericae aggregate.

Influence of insecticide, wax and biofungicide treatments, applied to Pinus sylvestris and Picea abies, on the olfactory orientation of the large pine weevil, Hylobius abietis L. (Coleoptera: Curculionidae)

Abstract1 A four‐arm olfactometer was used to test the effect of permethrin ‘Gori 920®’ and the wax treatment ‘CereNat® E30’ on the response of mature adult Hylobius abietis to olfactory stimuli from seedlings of Pinus sylvestris and Picea abies.2 Also investigated in the olfactometer was the effect of Rotstop®, a biofungicide for the control of Fomes root and butt rot, Heterobasidion annosum, on the responses of mature adult female H. abietis to stump material of both P. sylvestris and P. abies.3 Hylobius abietis was significantly more attracted to untreated P. sylvestris seedlings compared to those treated with CereNat® E30 or permethrin Gori 920®. No differences in response to P. abies seedlings were found.4 With Rotstop®, no changes in the attractiveness of P. sylvestris stump material were found, but that of P. abies was significantly increased compared to untreated material.

Methyl jasmonate protects Norway spruce [Picea abies (L.) Karst.] seedlings against Pythium ultimum Trow.

The effect of methyl jasmonate (MeJA) was tested on the resistance of Picea abies seedlings against Pythium ultimum. Treatments with volatile MeJA during 3 days (25 μl 100 l−1air) protected seedlings up to 75%. This effect was unlikely to result from a direct fungitoxic effect of MeJA, as under the same conditions of treatment, growth in vitro of Pythium ultimum was not affected. Observations of possible changes on histological barriers such as lignin deposits showed no differences between control and treated plants. MeJA induced the accumulation of free salicylic acid (SA) in all parts of the seedlings, whereas bound SA only increased in hypocotyls and cotyledons. An increase in chitinase activity was detected in cotyledons already 2 days after exposure to MeJA. The results suggest that MeJA acts by stimulating defence responses of the host plant. No increase in endogenous jasmonic acid was found in spruce seedlings inoculated with Pythium nor MeJA.

Biological activity of humic substances extracted from soils under different vegetation cover

Comparisons were made between the chemical compositions of humic substances extracted from three soils covered by different vegetation and their biological activities assayed using 15‐ and 30‐day‐old seedlings of Pinus sylvestris and Picea abies. The growth, “α‐amylase and invertase activity were affected by humic fractions and by gibberellic acid (GA), indicating that humic matter had a gibberellin‐like activity. The isoenzymatic polymorphism in the electrophoretic patterns of esterase was influenced in a similar way by all humic fractions and by indoleacetic acid (IAA), which also suggested that the humic fractions exhibited an auxin‐like activity. The humic fractions extracted from the grassland, exhibiting higher amounts of phenolic and a considerable amount of carboxyl carbon, showed the best metabolic effect. The forest humic fractions, characterized by lower phenolic carbon content, appeared less effective in influencing plant metabolism, whereas the grassland‐forest humic substances proved to be even more less effective. The auxin‐ and the gibberellin‐like activities were related to a high content of phenolic and carboxylic groups. These results presented evidence that the biological activity of the humic substances was attributed to their chemical structure and to their functional groups, which could interact with hormone‐binding proteins in the membrane systems, evoking a hormone‐like response.

Growth and Biomass Partitioning of 6-Year-Old Spruces under Alkaline Dust Impact

Two-year-old seedlings of Picea abies L., P. glauca L. and P. mariana L. were planted in a sample plot subjected to high concentrations of cement dust and in an unpolluted (control) area in 1990. In 1994, the six-year-old trees were dug up in the pre-bud-break period for morphological assessment. Comparison of biomass formation and the lengths of different organs of the trees showed that alkalization of the growth substrate (pH 8.1) and the high level of dust pollution load (600–2400 g m-2yr-1) are serious factors inhibiting height growth by 61%, the length of shoots and needles by 75 and 28%, respectively, and the dry weights of roots by 88%, stems by 90%, shoots by 91% and needles by 55%. The ratio of roots to shoots dry weights increased in all species of spruces under stress. P. mariana was the most sensitive to dust pollution impact and alkalization of the environment.