Growth Of Scots Pine Seedlings Research Articles

ВЛИЯНИЕ НАНОЧАСТИЦ ЖЕЛЕЗА НА РОСТ СЕЯНЦЕВ СОСНЫ ОБЫКНОВЕННОЙ (PINUS SYLVESTRIS L.) И ДУБА ЧЕРЕШЧАТОГО (QUERCUS ROBUR L.)

The paper presents the results of a study of the effect of iron nanoparticles on the development of Scots pine ( Pinus sylvestris L.) and English oak ( Quercus robur L.) seedlings growing in the South Cis-Ural zone. It has been established that the morphobiological response of seedlings to the action of Fe nanoparticles has a species specificity. In pine seedlings, the presence of Fe nanoparticles at a concentration of 100 mmol / l had a toxic effect on the growth of Scots pine seedlings. The concentration of Fe nanoparticles 25 and 6.25 mmol / l stimulated the growth of Scots pine seedlings. With a nanoparticle content of 25 mmol / l, an increase in the length of the main root by 22.5 mm (23.1%). The number of adventitious roots in the experimental group, in comparison with the control, increased by 1.5%, the length of adventitious roots - by 10.8 mm (14.4%). Found that the seedlings of pedunculate oak are more resistant to the toxic effects of iron nanoforms. Morphometric parameters of seedlings of pedunculate oak in the experimental, as well as at a concentration of 100 mmol / l differed from those in the control group insignificantly, within 1%.

Bioecofunge-C preparation impact on growth and development of pine planting material (Pinus sylvestris L.)

Pine plantations drying has been observed during the last decade. Mass drying occurs in the temperate climate zone forests. Scots pine has been signifcantly weakened in recent years, which may further result in a change in the type of forests in Zhytomyr Polissia. This article covers the issue of growing Scots pine seedlings treated with Bioecofunge-C. A study of the biological preparation effect on the germination and growth of Scots pine seedlings in the conditions of Zhytomyr Polissia was conducted. It was proved that the germination energy of Scots pine seeds was signifcantly higher in the areas where Bioecofunge-C was applied compared to the control and amounted to 95 %. An average increase in the height of the seedlings by 34.2 % and root length by 34.9 % was noted during the cultivation of one-year-old Scots pine seedlings in the forest nursery of the Korbutiv Forestry, where the seeds were treated with the preparate. Scots pine seedlings were treated (root dosing) during the growth and development of Scots pine seedlings. The obtained results showed positive dynamics in terms of height in comparison with the control treated with water. The preparate use is promising for obtaining high-quality planting material since the treatment with Bioecofunge-C ensure the preservation, obtaining high-quality planting material and the yield of seedlings. It has been established that obtaining high-quality planting material is one of the most important components of the technologies for growing tree and shrub plants at forestry enterprises of Ukraine. However, obtaining and high-quality planting material resistant to adverse factors requires improvement of existing or development of new measures and methods. It has been proven that the artifcial restoration of the Zhytomyr Polissia forests depends on the cultivation of high-quality planting material. Key words: forest plantations, height, growth technology, planting material, seeds, growth, Zhytomyr Polissia.

Influence of plant growth regulators on Scots pine (Pinus sylvestris L.) seedling growing in the conditions of closed soil

The results of researches of ecological value of plant growth regulators on growth of Scots pine seedlings in the conditions of the closed ground — greenhouses of Sobolivsky forestry of Subsidiary enterprise «Romanovsky forestry of agro-industrial complex» of Zhytomyr regional municipal agroforestry enterprise «Zhytomyroblagrolis» of Zhytomyr regional council are given. Potassium humate, Epin (manufactured by Agriflex), Alga-600 were used in the experiments. Agrochemical analysis of soil in the greenhouses of the experimental farm was carried out. The study of the impact of growth regulators on the ecological condition of plants, their seedlings took place during the growing season of 2021. The influence of plant growth regulators on Scots pine seeds in the preparation of seed material for sowing was studied, the greatest efficiency of pre-sowing soaking of Scots pine seeds in aqueous solutions of growth regulators in the experiment with potassium humates and Epine was defined. It was found that the treatment of seedlings in greenhouses the greatest stimulating effect is achieved when using solutions of Epine and potassium humates at a concentration of 5 mg/l solution, the ecological impact on biometric indicators was assessed: height, root neck diameter of seedlings. It was found that in the needles of Scots pine treated with humate potassium content of a, β-chlorophyll is 70.4 mg / 100 g of raw weight, however, in the needles of Scots pine treated with growth regulator Alga — 600 this figure reaches 49.0 mg / 100 g of raw weight and approaching the indicators of the control area. According to the accumulation of a, β-chlorophyll, it can be predicted that seedlings treated with potassium humates and epinephrine will be more productive than others and will not cause environmental damage. It is recommended for agro-forestry enterprises, in particular, Zhytomyr Polissya, namely for the Subsidiary enterprise «Romanivsky forestry of agro-industrial complex» of Zhytomyr regional municipal agro-forestry enterprise «Zhytomyroblagrolis» of Zhytomyr regional council in closed soil conditions to obtain high-quality compliance with modern requirements for the balanced development of agricultural production as a component of environmental security of Ukraine.

Влияние предпосевной обработки семян (дражирования) на грунтовую всхожесть и дальнейший рост сеянцев сосны обыкновенной (Pinus silvestris L.)

We studied the effect of pelleting on field germination of seeds and biometric parameters (stem height, root neck diameter, root length and total biomass) of Scots pine (Pinus sylvestris L.) seedlings of the second and third years of growth in the Primorsky Territory. It was found that the germination capacity of pelleted seed was 6,8 % lower than the control samples values, but seedlings of the second year of growth obtained from seed material subjected to pelleting showed values higher than the control ones by 21,9 %. At the same time, root length exceeded the control samples by an average of 10,3 %, while the diameter of the root neck was on average 16,1 % larger, and the total biomass increased by 35,1 %. For seedlings of the third year of growth, similar indicators were higher by 30,4 %; 27,9 %; 14,7 % and 71,1 %, respectively. In the future, it is recommended to study the effect of pelleting on the subsequent growth of Scots pine seedlings.

Researching the Possibility of Using Sediments in Forest Reclamation of Disturbed Lands

The research of the physico-chemical, biological and toxicological parameters of sediments and soils reclaimed by them, as well as the analysis of the growth of Scots pine seedlings, suggests that the use of sediments as a soil ameliorant at forest reclamation sites is advisable.

Adaptation of foreign technologies of intensive cultivation of scots pine planting material in Kazakhstan

The purpose of the research was the adaptation of foreign technologies for intensive and accelerated cultivation of Scots pine planting material in Kazakhstan. Objects of research were annual seedlings of scots pine in forest nurseries of Pavlodar, Akmola, and North Kazakhstan regions. The experiments were established in 4 directions: application of dry growth regulators to soil, pre-sowing seed treatment with growth regulators, soaking seeds in stimulants and fungicide, pre-sowing watering of the soil with growth regulators. It was established that seed quality decreased significantly compared to the last year, only seeds from Pavlodar region had high indicators. Seeds from the nursery ‘Ertic Ormany’ had the highest average indicators of soil germination (58.7…67.8%). In ‘Bukhpa’, the highest germination was observed in seeds soaked with Zircon + Trichocin (3 + 2 hours). Baikal growth regulator and AridGrow slightly increased germination in the nursery of Arykbalyk branch of ‘Kokshetau’. In the forest nursery ‘Ertis Ormany’, the highest annual seedlings were obtained in variants with presowing treatment of scots pine seeds with stimulants and watering the soil with growth substances. The average height of experimental seedlings was 4.32 and 4.64 cm, respectively. The combined use of Zircon and Trichocin increased seedling growth in ‘Bukpa’ nursery to 1.42 cm, which was the highest value. It was revealed that the technologies used in neighboring countries for intensive cultivation of scots pine seedlings showed a positive effect only when using Citovit. According to other experiments, it was determined that seedlings of scots pine grown from seeds with pre-sowing treatment in Gumat+7 for 12 hours had the best growth indicators in height. Increased soil fertility through applying nitrogen, phosphorus fertilizers, soil activator AridGrow and KZ Cultury significantly accelerated growth of scots pine seedlings.

The effects of salicylic acid, oxalic acid and chitosan on damping-off control and growth in Scots pine in a forest nursery

Abstract: Modern forestry in the European Union and in Poland is in constant search of environment-friendly technological solutions. These also relate to nursery production, in which attempts are made to apply non-chemical plant-protection products. The objective of this study was to assess the effects of salicylic acid, oxalic acid and chitosan (applied in the form of Beta-chikol®) in controlling damping-off and promoting the growth of Scots pine seedlings under nursery conditions. All the substances were used in seed treatment and in the form of foliar spray, 4 times during the growing season, in the following concentrations: salicylic acid 1% and 2%, oxalic acid 0.5% and 1%, and chitosan 2%. Seedlings were inventoried three times: 3 and 6 weeks after seed sowing, and at the end of the growing season. All seedlings were counted in 1-metre segments of individual rows of the seedbed. At the end of the growing season, parameters of seedling growth like shoot length, root-collar diameter, root length and the dry mass of above-ground parts were determined. The growth of pine seedlings was found to be stimulated by both chitosan and oxalic acid, while salicylic acid proved inhibitory to growth when present at 2% concentration, and showed no detectable influence on biometric parameters at 1% concentration. Numbers of seedlings germinating per 1-metre segment were significantly greater than in the (unprotected) control, where chitosan was applied. Likewise, oxalic acid applied at both concentrations was associated with greater numbers of germinating pine seedlings than in the control, albeit the statistical significance of this difference was achieved only 6 weeks after seed sowing, and only with the 0.5% concentration. Numbers of seedlings per metre-long segment were significantly lower in response to both concentrations of salicylic acid applied. Both chitosan (applied as Beta-chikol®) and 0.5% oxalic acid resulted in seedling protection against damping-off and enhanced growth, whereas the applied concentrations of salicylic acid were presumably excessive, hence the negative impact on both germination and growth.

Early growth of Scots pine seedlings is affected by seed origin and light quality

Plants have evolved a suite of photoreceptors to perceive information from the surrounding light conditions. The aim of this study was to examine photomorphogenic effects of light quality on the growth of Scots pine (Pinus sylvestris L.) seedlings representing southern (60 °N) and northern (68 °N) origins in Finland. We measured the growth characteristics and the expression of light-responsive genes from seedlings grown under two LED light spectra: (1) Retarder (blue and red wavelengths in ratio 0.7) inducing compact growth, and (2) Booster (moderate in blue, green and far-red wavelengths, and high intensity of red light) promoting shoot elongation.The results show that root elongation, biomass, and branching were reduced under Retarder spectrum in the seedlings representing both origins, while inhibition in seed germination and shoot elongation was mainly detected in the seedlings of northern origin. The expression of ZTL and HY5 was related to Scots pine growth under both light spectra. Moreover, the expression of PHYN correlated with growth when exposed to Retarder, whereas CRY2 expression was associated with growth under Booster.Our data indicates that blue light and the deficiency of far-red light limit the growth of Scots pine seedlings and that northern populations are more sensitive to blue light than southern populations. Furthermore, the data analyses suggest that ZTL and HY5 broadly participate in the light-mediated growth regulation of Scots pine, whereas PHYN responses to direct sunlight and the role of CRY2 is in shade avoidance. Altogether, our study extends the knowledge of light quality and differential gene expression affecting the early growth of Scots pines representing different latitudinal origins.

Compensatory Growth of Scots Pine Seedlings Mitigates Impacts of Multiple Droughts Within and Across Years.

Tree seedling resistance to and recovery from abiotic stressors such as drought and warming are crucial for forest regeneration and persistence. Selection of more resilient provenances and their use in forest management programs might alleviate pressures of climate change on forest ecosystems. Scots pine forests in particular have suffered frequent drought-induced mortality, suggesting high vulnerability to extreme events. Here, we conducted an experiment using potted Scots pine seedlings from ten provenances of its south-western distribution range to investigate provenance-specific impacts of multiple drought events. Seedlings were grown under ambient and elevated temperatures for 1.5 years and were subjected to consecutive droughts during spring and summer. Growth (height, diameter, and needle) and spring phenology were monitored during the whole study period and complemented by biomass assessments (bud, needle, wood, and needle/wood ratio) as well as measurements of chlorophyll fluorescence and of needle stable carbon isotope ratio. Phenology, growth and biomass parameters as well as carbon isotope ratio and their (direct) responses to reoccurring droughts differed between provenances, indicating genotypic adaptation. Seedling growth was plastic during drought with intra- and inter-annual compensatory growth after drought stress release (carryover effects), however, not fully compensating the initial impact. For (smaller) seedlings from southern/drier origins, sometimes greater drought resistance was observed which diminished under warmer conditions in the greenhouse. Warming increased diameter growth and advanced phenological development, which was (partly) delayed by drought in 2013, but advanced in 2014. Earlier phenology was linked to higher growth in 2013, but interestingly later phenology had positive effects on wood and needle biomass when subjected to drought. Lastly, stable carbon isotope ratios indicated a clear drought response of carbon assimilation. Drought-induced reduction of the photosystem II efficiency was only observed under warmer conditions but showed compensation under ambient temperatures. Besides these direct drought impacts, also interactive effects of previous drought events were shown, either reinforcing or sometimes attenuating the actual impact. Thus, depending on amount and timing of events, Scots pine seedlings, particularly from southern origins, might be well adapted and resilient to drought stress and should be considered when discussing assisted migration under changing climatic conditions.

Influence of stand density and canopy structure on the germination and growth of Scots pine (Pinus sylvestris L.) seedlings.

Since the natural regeneration of Scots pine forests is known to be difficult, the effects of canopy structure and environmental variables such as light on germination, seedling growth, and mortality need to be well understood. The knowledge on the relationships between canopy structure, environmental variables, and seedling growth have been helpful for forest managers to formulate silvicultural prescriptions that enhance seedling recruitment. In this study, the influences of stand basal area (BA) (m2ha-1), leaf area index (LAI), light transmittance (LT), and height-to-crown base (HCB) on germination and seedling growth were explored in a naturally regenerated Scots pine forest in Kastamonu, Turkey. The number of germinants was observed following germination, and total root-collar diameter (RCD) and height of seedlings were monitored after five growing seasons following germination. BA, LAI, LT, and HCB were also examined to determine which variable has more influence on Scots pine seedlings. All variables (i.e., BA, LAI, LT, and HCB) had significant influence on the total seedling growth over a 5-year period. LT was the most significant predictor for total RCD growth and height growth of Scots pine seedlings. The data support the importance of light transmittance through the canopy, along with vertical canopy structure (i.e., HCB) when considering seedling development under a stand canopy.

Effect of buds manually removal and their damage by large pine weevil (Hylobius abietis L.) on Scots pine seedlings in Siversky Donets river valley

Large pine weevil (Hylobius abietis L.) damages different organs of Scots pine (Pinus sylvestris L.) seedlings in unclosed plantations, including foliage, buds, stem bark and roots. Simulated damage of respective organs, particularly debudding is one of the ways to evaluate qualitative and quantitative influence of such damage on tree condition.
 The aim of research was to evaluate the dependence of Scots pine seedlings mortality and height increment on artificial and large pine weevil caused bud damage.
 The growth of apical shoots of Scots pine seedlings was registered since the beginning of May to the end of June. Development of new shoots in seedlings with manually bud removal or large pine weevil damage started in beginning of May and continued in July.
 Mortality of Scots pine seedlings with 20% of lateral buds damaged did not differ from that in undamaged plants. The seedlings with apical and lateral buds manually removed as well as with apical and over 70% lateral buds damaged by large pine weevil have died in the year of treatment or damage. The seedlings with apical buds damaged as well as with apical and over 50% lateral buds damaged died in the 4th year after damage.
 Removal or damage up to 50% lateral buds did not affect the growth of Scots pine seedlings. Height increment of seedlings with apical buds manually removed or damaged by large pine weevil did not differ significantly in May and June of the year of treatment or damage. In July the height increment was statistically greater in the variant with manually removal of apical bud.
 Previously suggested scale of Scots pine seedlings bud damage satisfactory reflects the score of large pine weevil injuriousness.
 We can suggest that height increment in the next years after bud damage does not depend on damage way and intensity but mainly on ecological conditions.

Effect of wood ash mulch on growth of Scots pine seedlings after transplanting into peat soil: A pilot study

Wood ash production from power plants and the use of recycled ash for earthworks and forest peatland fertilization have increased markedly in Finland in recent decades. In this study, effects of wood-based ash on potted Scots pine seedlings were tested in a greenhouse. Seedlings were grown for one to two growing periods in peat with ash mulch thicknesses 0–8 cm. Seedlings grew well in ash thicknesses 0–4 cm during the first growing period. Seedling mortality (60%) occurred with the thickest ash mulch. Soluble nutrients in press water extracts were high compared with the control treatment. N and P levels were suboptimal also with ash mulch. During the second growing period, seedling mortality occurred (17%) already with the thinnest ash mulch. The results suggest that ash mulch around seedlings in quantities of less than 0.5 cm (or 7 kg·m<sup>–2</sup>) is feasible and is not detrimental to Scots pine seedlings. The results provide foundation for further field research on the longer-term impacts of wood ash mulch on planted seedlings on boreal forest sites and on the feasibility testing of the mulch as a supplement to or substitute for the soil preparation for seedling planting.

Influence of various sources of nitrogen on the growth of Scots pine seedlings and the IAA content in needles

One year old pine seedlings transferred from the nursery and potted in a greenhouse were watered with nitrogen solutions of different form and concentration (urea 0.36 mM and 0.90 mM, ammonium tartrate 0.36 mM and 1.79 mM, calcium nitrate 0.36 mM, 1.79 mM and 3.58 mM). After 10 months the growth and IAA content in needles were compared. Nitrogen fertilization affected shoot growth considerably, but its effects on root growth were less pronounced. The highest shoot weight was obtained after application of ammonium tartrate in 1.79 mM concentration. The lowest concentration of urea (0.36 mM) caused the same effect, as did the most concentrated calcium nitrate solution (3.58 mM). Auxine content increased in the needles after nitrogen fertilization as compared with control. The highest accumulation of IAA was found in seedlings treated with low concentrations of urea.

Increasing survival and growth of Scots pine seedlings with selection based on autumn coloration

This study evaluates the possibility of using autumn coloration of young Scots pine (Pinus sylvestris L.) seedlings as an indicator of adaptation to harsh climate conditions. One-year old seedlings from natural stands with different origins and seed orchards were classified as “red/reddish” and “green” based on the needle color after artificially increased night length in nursery and then measured after 14 years in field trials. In almost all the studied groups seedlings classified as “red/reddish” had significantly higher survival rate than seedlings classified as “green”. The survival of “red/reddish” was 14.2% higher than “green” among natural stand seed material and 56.2% among seed orchard material. During the study period the survival difference between “red/reddish” and “green” seedlings tended to increase. The seedling color had limited connection with the height growth, even though the trees classified as “red/reddish” were slightly taller than those classified as “green”. However, the total productivity over all field trials, described here as a heightsum, of “red/reddish” trees was 15% higher than productivity of “green” trees from natural stand material, and 61% higher than those from seed orchard material. It seems that controlled selection based on autumn color can be utilized within seed crops of different types with the aim to increase the adaptability of seed material to different environmental conditions.

Dark septate root endophytic fungi increase growth of Scots pine seedlings under elevated CO2 through enhanced nitrogen use efficiency

Although increasing concentrations of atmospheric CO2 are predicted to have substantial impacts on plant growth and functioning of ecosystems, there is insufficient understanding of the responses of belowground processes to such increases. We investigated the effects of different dark septate root endophytic (DSE) fungi on growth and nutrient acquisition by Pinus sylvestris seedlings under conditions of N limitation and at ambient and elevated CO2 (350 or 700 μ1 CO2 l−1). Each seedling was inoculated with one of the following species: Phialocephala fortinii (two strains), Cadophora finlandica, Chloridium paucisporum, Scytalidium vaccinii, Meliniomyces variabilis and M. vraolstadiae. The trial lasted 125 days. During the final 27 days, the seedlings were labeled with 14CO2 and 15NH4+. We measured extraradical hyphal length, internal colonization, plant biomass, 14C allocation, and plant N and 15N content. Under elevated CO2, the biomass of seedlings inoculated with DSE fungi was on average 17% higher than in control seedlings. Simultaneously, below-ground respiration doubled or trebled, and as a consequence carbon use efficiency by the DSE fungi significantly decreased. Shoot N concentration decreased on average by 57% under elevated CO2 and was lowest in seedlings inoculated with S. vaccinii. Carbon gain by the seedlings despite reduced shoot N concentration indicates that DSE fungi increase plant nutrient use efficiency and are therefore more beneficial to the plant under elevated CO2.

Relationships between canopy transmittance and stand parameters in Sitka spruce and Scots pine stands in Britain

Summary The changing emphasis within British forestry from a clearfell/replant system focussed on timber production, to multipurpose forestry encompassing biodiversity and recreation, has resulted in a need for changes to forest management. Manipulation of the forest canopy through thinnings is a powerful tool for forest managers to modify the canopy transmittance, and therefore the belowcanopy light levels. This helps to achieve specifi c objectives such as habitat management or seedling growth as part of transformation of an even-aged stand to a continuous cover forestry regime. In this study, hemispherical photography was used to assess canopy transmittance in a range of Sitka spruce ( Picea sitchensis (Bong.) Carr) and Scots pine ( Pinus sylvestris L.) stands in Britain. Speciesspecifi c relationships were developed between canopy transmittance and easily-measured stand parameters. The models that provided the best fi t to the data were based on basal area and stocking for Sitka spruce and basal area alone for Scots pine. The models indicate that a Sitka spruce stand with a basal area of 30 m 2 ha 1 should have a stocking density <450 stems ha 1 to favour growth of Sitka spruce seedlings. Similarly, a Scots pine stand should have a basal area <27 m 2 ha 1 to achieve transmittance suitable for growth of Scots pine seedlings. In conjunction with a knowledge of the light requirements of different vegetation types, these models can provide a valuable contribution to guidance on current and changing forest management practice.

Short Delay in Timing of Emergence Determines Establishment Success in Pinus sylvestris across Microhabitats

The date of emergence may have far-reaching implications for seedling performance. Seedlings emerging early in the growing season often have a greater rate of survival or grow better if early emergence provides advantages with respect to an environmental cue. As a result, the benefits of early emergence may be lost if the environmental stress creating the differences among cohorts disappears. The experimental manipulation under field conditions of the factors that constitute the main sources of stress for seedling establishment is thus a straightforward method to evaluate the impact of date of emergence on seedling establishment under realistic conditions. Two field experiments were performed to analyse the effect of emergence date on survival and first-year growth of Scots pine seedlings in natural mountain forests in south-east Spain. Two main environmental factors that determine seedling success in these mountains were considered: (1) microhabitat type (monitoring the effect of date of emergence in the three most common microhabitats where seedlings recruit); (2) summer drought (monitored by an irrigation treatment with control and watered sampling points). Overall, early emergence resulted in a higher probability of survival and better growth in the two experiments and across microhabitats. However, the reduction in summer drought did not diminish the differences observed among cohorts: all cohorts increased their survival and growth, but early cohorts still had a clear advantage. Date of emergence determines establishment success of Pinus sylvestris seedlings, even if cohorts are separated by only a few days, irrespective of the intensity of summer drought. The experimental design, covering a gradient of light intensity and soil moisture that simulates conditions of the regeneration niche of Scots pine across its geographical range, allows the results to be extrapolated to other areas of the species. Date of emergence is thus likely to have a large impact on the demography of Scots pine across its geographical range.

Effect of ectomycorrhizal fungi on nitrogen mineralisation and the growth of Scots pine seedlings in natural peat

The aim of this study was to investigate the potential of different isolates of ectomycorrhizal (EM) fungi to enhance the growth of Pinus sylvestris seedlings in five natural peat substrates with different nitrogen concentrations, and the effect of the Scots pine seedlings and fungal inoculum on the formation of dissolved inorganic and organic nitrogen in peat. Utilization of different organic nitrogen compounds by microbial community in the peat was also investigated using Biolog MT MicroPlates. Inoculation of the seedlings with EM fungi enhanced seedling growth. Piloderma croceum increased root growth especially, whereas Lactarius rufus increased needle growth and Suillus variegatus I, II and III improved both root and needle growth. All the EM fungi also significantly affected stem growth. Nitrogen concentration of the peat did not affect seedling growth as much as the EM fungi. At the lowest peat N concentration (1.17%) NH 4 + mineralisation was lower and DON (dissolved organic nitrogen) accumulation higher than at higher peat N concentrations. The EM fungal isolates had different effects on NH 4 + and DON accumulation/degradation in peat. The EM fungal isolates significantly increased NH 4 + formation in the peat, whereas L. rufus and P. croceum had an opposite effect on DON accumulation. S. variegatus I significantly decreased the DON concentrations during peat incubation. The N concentration of the peat slightly affected the utilization of amino acids and polyamines by the microbial community, whereas inoculation with S. variegatus I, II or III had no effect.

The effects of toxic metals, content of nutrients and inoculation with mycorrhizal fungi on the level of phenolics in roots and growth of Scots pine seedlings

The effects of two substrates and several strains of mycorrhizal fungi on the content of soluble phenolics in roots and growth of Scots pine seedlings was investigated. The first substrate was fertile and contaminated with copper, zinc and lead, whereas the second one displayed nutrient deficiency. The dry weights of needles, trunks, roots and the total biomass were higher in groups of seedlings inoculated with mycorrhizal fungi on fertile and polluted substrate. Inoculation of pine seedlings on this substrate resulted in a decrease in concentration of phenolics in roots and except for seedlings inoculated with Laccaria laccata negatively influenced the above-ground part: root ratio.

Effect of biological agents on survival rate and root growth of Scots Pine seedlings

Two-year-old Scots pine (Pinus sylvstris var.mongolica) seedlings were treated with Pt mycorrhiza powder, ABT root-growing powder, HRC water-absorbing agent and high-yield powder, and planted on the sandy land in Balinyouqi, Inner Mongolia (180°12′13″E and 43°13′05″N). The effect and function of these biological agents on survival rate of seedlings were tested and analyzed by measuring the fine root growth and gross root growth. The results showed that the survival rates of the seedlings treated with Pt3, ABT, and HRC biological agents increased by 29.3%, 23.6%, and 16%, respectively. The regression analysis revealed that the length of fine roots (<2 mm) was positively correlated with seedling survival rate, which means that the Pt3 powder, ABT foot-growing powder and HRC water-absorbing powder increased the survival rates of the seedlings by promoting the growth of fine roots.