Regeneration Of Scots Pine Research Articles

Comparing the effects of ground cultivation and protection against browsing upon the natural regeneration of Scots pine and birch in a Caledonian pinewood

Abstract The Caledonian pinewoods of northern Scotland represent the remnants of once extensive forests found at the western edge of the natural range of Scots pine (Pinus sylvestris L.). The surviving pinewoods are of international significance and are of high conservation and cultural value. However, for many decades, there has been concern about their long-term future because of a lack of regenerating seedlings and young trees. This problem is thought to be driven by high deer populations resulting in intensive browsing and severe damage to young trees, as well as a lack of favourable micro-sites for seedling germination. An experiment was established on the Mar Lodge estate in 2007–08 adjacent to native pinewood stands to test the effects of protection and site cultivation upon seedling numbers and growth. The experiment was located within a regeneration zone where intensive deer control had reduced numbers to <5 animals km−2. Ten years after initiation, occurrence and numbers of both Scots pine and birch seedlings were substantially increased in cultivated treatments compared with uncultivated controls. There were no effects of protection upon seedling numbers. Protection improved height growth of Scots pine, but not of birch. Cultivation had no effect upon the growth of pine seedlings but did influence the height of birch seedlings due to the rapid growth of some pre-existing seedlings in the uncultivated control. Vegetation cover had increased from ~60%to at least 80% cover 6 years after cultivation. The results suggest that site cultivation may be desirable to boost seedling germination within a Caledonian pinewood, but sustained measures to control browsing pressure are a prerequisite for satisfactory establishment of these seedlings.

Environmental controls on seedling establishment in a boreal forest: implications for Scots pine regeneration in continuous cover forestry

In nutrient poor and dry forest sites common to northern Scandinavia, Scots pine (Pinus sylvestris L.) is the most common species both in managed and natural forests. However, Scots pine is sensitive to competition during establishment. Harvesting of all trees within a given area, i.e., clear-cutting, liberates regenerating seedlings from competition with mature trees. However, recently, clear-cut-free or continuous cover forestry has been the subject of substantial debate. When choosing a management method, it is important to recognize how competitive interactions direct the success of Scots pine regeneration. We studied Scots pine regeneration at three environments: beneath the canopy of mature trees, at the canopy edge in full sunlight, and distant from the canopy with no influence of mature trees. We imposed three treatments in each of these environments: root isolation (i.e., trenching), nitrogen (N) fertilization, and control plots. Root isolation enhanced seedling performance under the canopy of mature trees. Nitrogen fertilization enhanced seedling performance to a greater extent in the clear-cut than at the forest edge. However, N fertilization had no effect under the canopy. In the N-fertilized plots, we measured higher N content in the soil under the canopy than in the open environments, indicating that not all excess N was obtained by the mature trees. N-uptake might have been limited by competition for water in the N-fertilized plots. Our results suggest that belowground competition limits the success of regeneration of Scots pine. However, N fertilization presents a tool to compensate for underground competition along canopy edges.

Формирование структурно-функциональной организации молодняков сосны обыкновенной (Pinus sylvestris L.) смешанного искусственно-естественного происхождения в условиях сосняков ягодникового и разнотравного Среднего Урала

Restoration of forests, the study of the processes of formation of their structure and productivity, is currently one of the most urgent tasks. The features of the formation of 12-year-old forest plantations and the concomitant natural regeneration of Scots pine (Pinus sylvestris L.) were studied under the conditions of berry pine forest and forb pine forest of the Middle Urals, on trial plots established in accordance with the existing requirements. For each Scotch pine (Pinus sylvestris L.) tree, the diameter at the middle height and height were measured, and the volume of the trunk in the bark was calculated. The rank distribution of trees was carried out by calculating their reduction numbers, determining the amplitude of the reduction numbers and subsequent distribution into 5 main classes. In the 12th year after planting, the survival rate in the berry pine forest was 47.0%, and in the forb pine forest - 35.3%. In the berry pine forest, taking into account the concomitant natural regeneration of Scots pine (Pinus sylvestris L.), a pine forest of artificial and natural origin is being formed, and in the forb pine forest, a pine forest of natural and artificial origin is being formed. The process of natural renewal of Scotch pine (Pinus sylvestris L.) took place over several years. Scots pine (Pinus sylvestris L.) trees of natural origin are 2-7 years younger in biological age than trees of artificial origin. Pine trees of artificial origin in the berry pine forest significantly exceed the average diameter at the middle of the height, height and trunk volume of the same trees in the forb pine forest. Pine trees of natural origin in the berry pine forest are significantly superior in average diameter at the middle of the height to trees in the forb pine forest, but they are significantly inferior to them in the average trunk height and practically do not differ in the average volume of the tree trunk. Trees of artificial origin in terms of diameter at the middle of the height, height and volume of the trunk significantly exceed trees of natural origin both in the berry pine forest and in the mixed grass pine forest. The distribution of trees by diameter and height in young forests of artificial and natural origin, both in the berry pine forest and in the forb pine forest, is characterized by a distribution close to normal. The distribution of trees of artificial and natural origin in the berry pine forest and the forb pine forest in terms of trunk volume is distinguished by left-sided asymmetry and sharpness. When distributed by rank height classes, a significant reduction in the level of variability of biometric indicators is provided. However, in natural young stands, a very high level of variability in stem volume in the bark remains. Both in artificial and natural young stands, the main (86.3-97.5%) stock of trunk wood in the bark falls on trees of I-III height classes. In the forb pine forest, artificial and natural young stands had almost the same reserve values, which confirms the formation of young pine stands of natural artificial origin. In the berry pine forest, birch renewal does not represent significant competition to pine. In the forb pine forest, birch creates serious competition for pine and, probably, the formation of deciduous-coniferous plantations and oppression of pine.

Epigeic Carabids (Coleoptera, Carabidae) as Bioindicators in Different Variants of Scots Pine Regeneration: Implication for Forest Landscape Management

Maintaining biodiversity is one of the factors determining the proper functioning of ecosystems, especially those with high human impact. Ground beetles, as bioindicators, are particularly valuable in understanding ecosystem responses and sustainability in forest and landscape management. Focusing on the regeneration of pine forests, this study aimed to describe ground beetle assemblages on Scots pine natural and artificial regeneration in northeastern Poland. This study was conducted between 2016 and 2018. Pitfall traps were set up for catching epigeic carabids on previously prepared research plots designated for natural and artificial pine regeneration. The research areas included three variants: N—natural pine regeneration, plots without soil preparation; NP—natural pine regeneration with traditional soil preparation by ploughing; and A—artificial pine regeneration with ploughing. Four plots as replicants were selected in each experimental variant, with six pitfall traps in the transects running through the centre of each study plot. In each year of the study, 11 samples were collected from each plot; overall, 33 samples per plot were collected during the three years. As a result of this study, 26,654 ground beetle individuals belonging to 89 species were caught during the three-year observation. Natural regeneration without soil preparation (N) was the most favourable in terms of the occurrence of stabilised assemblages of ground beetles. However, the remaining methods of pine regeneration, on a multi-annual scale (2016–2018), contributed to the increase in the number of ground beetles but also provided high variability in assemblage composition, diversity indices, and life-history traits. Thus, in the early stage of pine regeneration, each of the examined variants of pine regeneration can be used without fear of causing damage to carabid populations. However, further studies are required to investigate the effect of different pine regeneration types on carabid beetle assemblages over a longer period.

Влияние клена ясенелистного (Acer negundo L.) на естественное возобновление сосны обыкновенной в Барнаульском ленточном бору

The influence of ash-leaved maple (Acer negundo L.) on the natural regeneration of scots pine in the Barnaul ribbon forest in different types of forest growing conditions is considered. It was found that the ash-leaved maple forms a dense, closed undergrowth up to 10 m high in moist forest-growing conditions (A3), whereas in fresh forest-growing conditions (A2) it was noted only once. The closeness of the undergrowth of maple in the grass forest is 0,8…1,0 units, while the undergrowth with a predominance of local plant species (Siberian mountain ash, goat willow) in the grass forest has a closeness of no more than 0,5 units, in the fresh forest no higher than 0,2…0,4 units. The undergrowth of maple strongly obscures the components of the forest located under it: living ground cover and undergrowth. The shading of the living ground cover leads to its significant transformation, with a change in the floral composition and structure. Shading of the undergrowth leads to a complete absence of seedlings, self-seeding and the actual undergrowth of the common pine, interrupting the process of natural renewal. Using the obtained values of illumination under the canopy of the forest, it was found that in a grassy forest with a maple understory, the relative illumination is no more than 7,9 %, whereas in a grassy and fresh forest with an undergrowth of local species, 29,5…47,9 %. The density of pine undergrowth in a fresh forest with undergrowth of local species is 7,5…17,5 thousand units/ha, which is 3–7 times more than in a grass forest with undergrowth of local species. There is a close positive relationship between the relative illumination under the forest canopy and the density of undergrowth (r = 0,830). Ash-leaved maple acts as an aggressive undesirable breed, which limits the most important environmental factor — illumination, leading to the disappearance of pine undergrowth under the canopy of the forest.

Manipulating overstory density and mineral soil exposure for optimal natural regeneration of Scots pine

In northern boreal region the growth of forests is slow, and yield and profit are low, which is why low reforestation costs are important for profitable forestry. If natural regeneration is successful, expensive artificial forest regeneration (planting or direct seeding) can be avoided. In this study, we look at the impact of overstory density and site preparation on natural regeneration and seedling growth of Scots pine. Study stands were established in different parts of Northern Finland and in each stand following treatments: 50, 150 and 250 trees ha−1 or unthinned control, where the stand density was ≥ 250 trees ha−1, were randomly allocated to experimental plots. In addition, site preparation (disc trenching, 4000–5000 m ha−1) was carried out on two experimental plots in which tree density was either 50 or 150 trees ha−1. In the experimental stands seedling number, age and growth were monitored for 11 years. Monitoring revealed that the number of seedlings increased with decreasing tree density. Average seedling height growth was very low or even non-existent in the unthinned control and in the densest (250 trees ha−1) treatment, but increased when the density of trees decreased. The highest seedling number and the highest growth were achieved when the tree density was 50 trees ha−1 and the soil was prepared to expose mineral soil. Achieving e.g. 2000 seedlings ha−1, would need about 40% exposition of mineral soil. The required low tree density implies that not only seed supply from seed trees and site preparation is important for regeneration success in northern boreal Scots pine forests but also the reduction of competition by mature trees.

Restoring mixed forests through conversion of Norway spruce stands: effects of fencing and mechanical site preparation on performance of planted beech and natural tree regeneration

Conversion of Norway spruce (Picea abies) plantations to more diverse and resilient forest types is an important task for European forest managers in the face of climate change and increased focus on ecosystem services beyond timber production. However, there is a lack of knowledge on how to cost-effectively restore such forests. This study reports the influence of vicinity (distance) of forest type (mixed or spruce), fencing and mechanical site preparation (MSP) on the early performance of planted beech (Fagus sylvatica) seedlings and natural regeneration of other tree species following clear-cuts of Norway spruce in southern Sweden. After 6 years, we found clear effects of fencing and MSP, but not of vicinity of forest type. Fencing had a positive effect on height growth of Scots pine (Pinus sylvestris) but not on height of planted beech and naturally regenerated birch (Betula pendula, B. pubescens). There was a positive effect of MSP on survival and height growth of planted beech, and on the amount of natural regeneration of Scots pine. We conclude that establishment of beech forest is greatly accelerated by active regeneration approaches such as planting. In addition, the combination of planting beech, natural regeneration of other species, fencing and MSP is effective to promote the transition to mixed and diverse stands with both broadleaves and conifers. Fencing represented the highest cost among the treatments, and its cost-effectiveness depends on the local ungulate browsing pressure. In our study, fencing was critical to protect natural regeneration of Scots pine from browsing. Finally, natural regeneration of birch was abundant in our study and relatively unaffected by fencing and MSP treatments. With time, pre-commercial thinning of the naturally regenerated birch will be needed to maintain a diverse mixture of tree species.

Effects of site preparation and reindeer grazing on the early-stage success of Scots pine regeneration from seeds in northern Finland and Sweden

ABSTRACT The importance of sufficient soil scarification to ensure the regeneration of Scots pine on sub-dry and more fertile sites has been emphasized in many studies. Here we aimed to study, how site preparation intensity affects the early success of natural regeneration and sowing (bare seeds and seed pellets) of Scots pine with or without the reindeer grazing. The study area was located in northern Finland and Sweden where five site preparation methods were compared: unprepared control, logging machine tracks, Huminmix (mixing the mineral soil and organic layer), disc trenching and intensive disc trenching. In each of these we used direct seeding, seed pellets and natural regeneration. Results revealed that even the lightest site preparation methods can provide sufficient regeneration results while the reindeer grazing limits the optimal regeneration result. Huminmix and even the track of the logging machine could provide satisfactory regeneration results both in direct seeding and natural regeneration. This could facilitate the coexistence of forest management, reindeer herding and other land use forms in the same stands and area. The use of seed pellets needs further research, but it may have potential due to lower consumption of seeds and less need for site preparation.

Silvicultural options to promote natural regeneration of Scots pine (Pinus sylvestris L.) in Western Ukrainian forests

Scots pine (Pinus sylvestris L.) forests belong to the most relevant forest types in the Western Ukrainian Roztochia area. The promotion of close-to-nature forest management in Ukraine in the framework of the forest strategy 2 035 supports natural regeneration and the application of diverse felling methods beyond clearcutting. In the present study, natural regeneration was analysed in mixed Scots pine stands on poor and relatively rich soils, after small clearcuts, shelterwood cutting and gap fellings (with or without soil preparation), with respect to tree species composition, species abundance and height growth. It could be shown that Scots pine is the most abundant species in all the felling systems, with on average more than 100 000 plants per ha on poor soils. Other admixed tree species only occur with small shares. Natural regeneration, especially of Scots pine, was less abundant on rich soils and in shelterwood, compared to a small clearcut. After the young plants have established, their abundance declined in the second and third year due to competing herbaceous plants and thick litter.

Changes in Soil Properties and Scots Pine Tree Growth Induced by Different Soil Ploughing Prior to Afforestation: A Case Study

Numerous studies have confirmed that forests have the potential for a significant contribution to carbon sequestration, but afforestation of former agricultural land can be attempted to adopt technologies that further encourage carbon sequestration. The aim of this study was to evaluate the impact of different soil cultivation methods, including deep ploughing and soil cultivation by making microsites and furrows prior to afforestation of former agricultural land, on chemical soil properties and tree growth in 20 years old Scots pine plantations. A naturally regenerated Scots pine stand, representing the non-ploughed soil, was included as a control site. Deep ploughing, among other soil cultivation methods, significantly altered the chemical soil properties. Furthermore, significant effects were indicated in the sites afforested after cultivation by making furrows. A recent study found that, due to deep soil cultivation, higher stocks of soil organic carbon (SOC) and total nitrogen (N) were incorporated into deeper soil layers and were protected from direct environmental impact. Twenty years post afforestation in deeply ploughed sites, we still found a decreased C:N ratio and disbalanced relationship between the concentrations of SOC and total N. The SOC and total N stocks were higher in the subsoil than in the topsoil in the sites afforested after deep ploughing. Moreover, deep ploughing and soil cultivation by furrows prior to afforestation resulted in higher total SOC and total N stocks in the forest floor and mineral 0–80 cm soil layer. A higher total phosphorus (P) concentration in the subsoil and total potassium (K) in the upper mineral soil layer were obtained in the deep ploughing sites and the sites, cultivated by furrows, compared to the non-ploughed sites. Significantly higher total P stock per entire profile was found for the deep ploughing sites and the sites cultivated by furrows than in the naturally regenerated stand. Different soil cultivation methods caused no differences in tree diameter at breast height (DBH) in 20 years old Scots pine stands both in the afforested sites and in the naturally regenerated forest. However, significantly larger tree height in all afforested sites than in the naturally regenerated Scots pine stands was obtained. A lower differentiation in tree DBH was obtained in the deep ploughing sites.

Natural Regeneration of Scots Pine Requires the Application of Silvicultural Treatments such as Overstorey Density Regulation and Soil Preparation

Current management strategies for European Scots pine (Pinus sylvestris L.) forests are oriented towards the use of natural regeneration processes. They aim to maintain continuity of stand structure by preserving seed-producing and shelter trees at varying densities. Soil scarification techniques may be employed to support the natural regeneration of pine. Our study is based on data from seven study sites in the German lowlands, where the basal areas of the overstorey pine trees varied between 4 and 21 m2/ha. The soil scarification methods ranged from full surface ploughing by tractor or horse through small-scale scarification by cultivators to sites without soil scarification. Differences in the densities, spatial distributions, age structures, and above-ground development of pine seedlings were evaluated. We analysed the spatial interactions between overstorey pine trees and the densities of naturally regenerated pine seedlings as a function of the microsite types using the multitype Strauss hard-core process (MSH) method. The results show a significant decrease in height growth with increasing stand density after a period of 5 years, with seedling density and spatial patterns strongly influenced by soil scarification. The MSH pairwise interaction analyses revealed significant negative effects on seedling densities based on combinations of microsites and overstorey trees.

Large-scale assessment of artificially coated seeds for forest regeneration across Sweden

We report the results of two years’ field performance of Scots pine (Pinus sylvestris) seedlings regenerated using artificially coated seeds. The coated seeds were used for regeneration on 12 clearcut sites, covering a 1000 km latitudinal gradient across Sweden. The coating was either combined with arginine-phosphate fertilizer (10 mg N per seed) or had no additions. Interactions with environmental variables associated with sites were also assessed. Coated seeds were deployed in May–June 2017 and surveyed in August–September of 2018 and 2019. After two years, the mean establishment rate of seedlings from coated seeds was 56 ± 4% across the 12 sites. The fertilizer addition did not affect survival, and the biomass response to fertilizer varied significantly between sites. Maximum precipitation and wind speed during the first six weeks after deployment were correlated with seedling survival, regardless of fertilization treatment. Establishment increased with increasing precipitation and decreased with increasing wind speed. This highlights the importance of initial weather conditions for the seeds’ establishment. Our data suggest that Scots pine regeneration using coated seeds can be practiced in boreal forests, but also that the method is sensitive to the weather conditions at the time of deployment of the seeds.

Evaluation of the Current State of Preservation of Vaccinio uliginosi-Pinetum Kleist 1929 in Eastern Poland

The study assessed the genetic variability and the possibility of Scots pine regeneration in marshy forest. The genetic parameters were determined using the ISSR technique. The relationships between herbaceous plants, pine regeneration density, and their genetic variability were determined. On average, per 1 m2, three regenerated pine seedlings with a mean height of 27.56 cm were inventoried. Based on genetic analysis, it was found that the proportion of polymorphic loci was 60.46%. The average number of alleles at the locus was 1.345, and the effective number of alleles at the locus was 1.345. The values of the expected heterozygosity and Shannon index were 0.200 and 0.301, respectively. No species competing with pine regeneration were found. A significantly negative correlation of the number of pine regenerations with the area covered with an herbaceous plant layer and tree canopy closure was found. There was a relation to the insufficient amount of light under the stand canopy. In conclusion, the condition of marshy forests was satisfactory and the genetic variability of pine seedlings was moderate. The vegetation was typical for this habitat, but the significant presence of dry habitat species could indicate the beginning of habitat drainage. It seemed that the amount of light under the stand canopy was insufficient. Nevertheless, more light probably reached the inside of the stand in the terminal stage, as a result of upper layer tree separation, which in turn may facilitate the effective regeneration of Scots pine in this habitat.

Under-Canopy Regeneration of Scots Pine (Pinus sylvestris L.) as Adaptive Potential in Building a Diverse Stand Structure

Under-canopy natural regeneration of Scots pine (Pinus sylvestris L.) stand is able to create stands with a complex structure, which are characterised by greater resistance to extreme phenomena related to climate change. The main aim of the work was to analyse the potential of pine undergrowth, its role in the stand, and its usefulness in further breeding plans to create stands of various structure, with greater stability and tolerance to stress factors, including greater resistance to climate change. The study was carried out in north-eastern Poland, in pine stands thinned by strong (hurricane level) wind in 2002. The study area covers 225.2 ha and is located in 29 stands. Naturally regenerated pine saplings with a minimum height of 0.5 m, characterised by a high density, growing under the upper cover of the stand, with varying degrees of thinning, were qualified for the study. On average 7.820 pine saplings were recorded in the area of one hectare. Over 65% of the examined saplings were determined to be of very good or good quality, prognostic for further development and the creation of the main stand in the future. The principle of increasing the structural diversity of stands is the method of increasing the adaptability of forests to environmental changes.

Естественное возобновление лиственницы европейской за пределами ареала при минимальном количестве семенников

The study of dissemination and success of natural regeneration of European larch outside its growing area, with a minimum supply of seed plants, is presented. It was analyzed that the success of natural regeneration of larch is affected by the absence of air sacs in pollen grains, this limits their dispersion at close distances and reduces the quality of seeds of the species, due to unsatisfactory pollination, more than fifty percent are dissimilar. It was found that the distance of maximum dissemination of European larch reaches 112–114 m. The undergrowth and self-seeding of European larch was represented by different height gradations. Half (49 %) of the recorded plants represent a gradation from 2 m and more, 36,5 % up to 1 meter in height, which indicates that the process of formation of the young generation of European larch can last up to 10 years, subject to the necessary conditions (good mineralized soil). Biometric measurements show that the leading position in height is occupied by birch, and the leader among conifers in height in height is Scotch pine. The dynamics of the annual growth of European larch until 2017 has a positive trend, after which it gradually decreases, from 38,6 cm to 24,7 cm in 2020, which is caused by the lack of silvicultural care, as well as the process of the emergence of new individuals of self-seeding, which is 23,5 % of accounted plants. In general, the natural regeneration of European larch and Scots pine under conditions of simple fresh subores (B2) has a higher growth energy than that of forest crops and undergrowth of European spruce.

Effect of Extracts from Dominant Forest Floor Species of Clear-Cuts on the Regeneration and Initial Growth of Pinus sylvestris L. with Respect to Climate Change.

Climate change influences the ecological environment and affects the recruitment of plants, in addition to population dynamics, including Scots pine regeneration processes. Therefore, the impact of cover-dominant species extracts on the germination of pine seeds and morpho-physiological traits of seedling under different environmental conditions was evaluated. Increasing temperature reinforces the plant-donor allelochemical effect, reduces Scots pine seed germination, and inhibits seedling morpho-physiological parameters. Conditions unfavourable for the seed germination rate were observed in response to the effect of aqueous extracts of 2-year-old Vaccinium vitis-ideae and 1-year-old Calluna vulgaris under changing environmental conditions. The lowest radicle length and hypocotyl growth were observed in response to the effect of 1-year-old C. vulgaris and 2-year-old Rumex acetosella under increasing temperature (+4 °C) conditions. The chlorophyll a + b concentration in control seedlings strongly decreased from 0.76 to 0.66 mg g−1 (due to current environmental and changing environmental conditions). These factors may reduce the resistance of Scots pine to the effects of dominant species and affect the migration of Scots pine habitats to more favourable environmental conditions.

Growth traits of natural regeneration of Scots pine (Pinus sylvestris L.) in south-eastern Poland

Abstract In recent years, particular attention has been paid to enhancing the meaning of natural regeneration, which is a part of the implementation of the concept of sustainable development and is one of the pillars of the natural direction of forest silviculture. Since the middle of the last century, the contribution of natural regeneration in Poland has been steadily increasing. The paper presents the analysis of density and variability of growth traits of natural regeneration of Scots pine (Pinus sylvestris L.) in south-eastern Poland. The study involved four compartments, which were prepared with the use of tiller and plough (active and double mouldboard). Density of seedlings, their height and root collar diameter, were measured. Density and growth characteristics of seedlings were higher at the tiller area and furrow compared with nonscarified soil and ridge. The highest cover with herbaceous plant was reported in ridges and non-scarified soil, but in most of the analysed compartments, it had no effect on the density of seedlings. It was found that different methods for soil preparation create different conditions for germination of seeds, which is reflected in the number of seedlings and its growth traits.

The effect of planting, seeding and soil preparation on the regeneration success of Scots pine (Pinus sylvestris L.) on drained peatlands – 10-year results

Abstract We studied the effect of regeneration (planting/seeding) and soil preparation methods (no soil preparation/scalping/mounding) on the regeneration success of Scots pine (Pinus sylvestris L.) on three drained peatland Scots pine stands in northern Finland. After ten years, planting and sowing showed no differences in the total number of Scots pine seedlings (one seedling per sowing spot accepted) with the exception of the Sievi experiment. Without soil preparation the total number of Scots pine seedlings was 350–600 per ha. Scalping increased the number of Scots pine seedlings to 550–900 per ha, with the exception of seeding at Sievi. In mounded plots, with the exception of seeded plots at the Sievi site, the number of planted or seeded seedlings was 1,325–2,350 per ha. The number of crop seedlings in all the experiments and for all the soil preparation treatments reached the target of 2,000 seedlings per ha if naturally regenerated Scots pine, Norway spruce (Picea abies (L.) H. Karst.) or birch (Betula spp.) seedlings were accepted as such. Moose (Alces alces L.) damage in Scots pine crop seedlings ranged from 4% in Sievi to 65% in Simo. The proportion of planted or seeded Scots pines of the crop seedlings was 23% in unprepared plots, 30% in scalped plots and 75% in mounded plots. Mounding increased the share of Scots pine seedlings in the overall crop seedlings. Planted seedlings were taller than seeded seedlings. Planting in mounds gave the best overall results in terms of the number of crop seedlings and their height ten years after the treatment.

METODY PROWADZENIA ODNOWIEŃ NATURALNYCH SOSNY ZWYCZAJNEJ (PINUS SYLVESTRIS L.) W NADLEŚNICTWIE SKWIERZYNA

For many years, the Skwierzyna Forest District has been a leader among 35 units of the Regional Directorate of State Forests in Szczecin in terms of the area of the obtained natural regeneration of Scots pine. In the Skwierzyna Forest District in the period 2010-2018, 522.93 ha of natural regeneration was recognized, which constitutes 43% of the total regeneration, the habitat of fresh mixed coniferous forest and fresh coniferous forest as optimal for obtaining regeneration of the natural pine. In the spring date of plowing, the forest plow LPz-75 is applied, as the best for obtaining satisfactory self-seeding. The basic method of natural regeneration of pine in the Skwierzyna Forest Inspectorate is the use of a strip-like clear cutting (Ib) in the form of classic narrow sheds, with a cutting width of up to 60 m. It is noteworthy that in the woodcutting the under-eaves undergrowths, arising in forest stands close to the harvest, are left intact and later used within the naturally renovated area.

MOŻLIWOŚĆ WPROWADZANIA SIEWEM DĘBU W MONOKULTURACH SOSNOWYCH POCHODZĄCYCH Z ODNOWIENIA NATURALNEGO NA TERENIE NADLEŚNICTWA SKWIERZYNA

Oaks have an important economic and natural role in forestry. Due to the change in land use, the problem, in the long run turned out to be obtaining the desired, consistent with the habitat, species composition of crops, derived from natural regeneration of Scots pine. The aim of the work was to show biometric differences in oaks obtained from sowing and planting. The economic aspect of both ways of introducing hardwood admixtures in pine "monoliths" was also taken into consideration. The unit cost of renewing oaks by sowing is 5 times smaller than renewal by planting. The study found no biometric differences between plants. Attention was however paid to better resistance to drought from sowing oaks.