Natural 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.

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.

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.

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.

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.

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.

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.

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.

Динаміка чисельності та стан природного поновлення сосни звичайної на зрубах в умовах свіжої судіброви Київського Полісся

Динаміка чисельності та стан природного поновлення сосни звичайної на зрубах в умовах свіжої судіброви Київського Полісся

ОЦЕНКА ВОЗОБНОВЛЕНИЯ СОСНЫ ОБЫКНОВЕННОЙ (PINUS SYLVESTRIS L.) В ЕСТЕСТВЕННЫХ ЛАНДШАФТАХ

The article describes the features of natural renewal of common pine in felled areas of the forest during continuous sanitary logging, in logging areas after logging, and on land that has come out of agricultural use. The estimation of growth indicators of common pine on the accounting areas, by the diameter and height of the trunks, was made, and its vital condition was determined . Measures are planned to successfully promote the natural regeneration of Scots pine in deforestation. In the natural and artificial reproduction of pine forests, they effectively perform protective, sanitary and other environmental functions, which meets the principles of sustainable and rational forest management. It is important to pay attention to timely forestry care in stands of common pine of various origins, which will allow us to solve the problem of increasing their stability and productivity at a qualitatively new level.

Evaluation of the natural and artificial regeneration of Scots pine Pinus sylvestris L. stands in the Forest District Nowa Dęba

Abstract The main purpose of this article was to highlight the potential for enhancing positive silvicultural effects and their dependency on the management method in Scots pine Pinus sylvestris L. stands. We therefore assessed the impact of natural and artificial regeneration on vitality and health, compaction, surface coverage and seedlings height. Another important goal was to assess the severity of damage in the selected forest sites. A comparative analysis was carried out based on results from field work conducted in the autumn 2010 in the Forest District Nowa Dęba. As part of this field work, also the breeding quality of the analyzed pine renewals was assessed. The obtained results indicate that natural regeneration of Scots pine under the conditions of a fresh coniferous forest as well as a fresh mixed coniferous forest is the most reasonable management practice. In wet mixed coniferous forests however, the naturally regenerating Scots pine seedlings are of lower silvicultural quality and growth parameter values compared to those in artificially regenerated stands. In fresh mixed broadleaved forests, naturally regenerated Scot pine trees showed slightly lower silvicultural quality and vitality than artificially regenerated trees. Our results indicate furthermore that there are indeed conditions under which the restoration of Scots pine in the Nowa Dęba Forest District using natural regeneration is preferable. We also found that the employed method of renewing has a significant impact on pine growth parameters in the moist mixed coniferous forest habitat. Naturally renewing pines are characterized by a lower overall viability, but at the same time natural regeneration provides a larger number of individuals with the best viability (1st vitality class), which can be a valuable selection basis for trees used in breeding.

Which Selective Logging Intensity is Most Suitable for the Maintenance of Soil Properties and the Promotion of Natural Regeneration in Highly Continental Scots Pine Forests?–Results 19 Years after Harvest Operations in Mongolia

Scots pine (Pinus sylvestris L.) forests are one of the main vegetation types in the Asian forest-steppe zone. However, over-harvesting currently threatens the natural regeneration and sustainability of these forests. In this study, we examine the long-term effects of different logging intensities on soil properties and natural regeneration in a natural Scots pine forest in the West Khentii Mountains (Mongolia), 19 years after selective logging. Our experimental design included five treatments: clear cut (CC), treatments with high (HI), medium (MI), low (LI) intensities, and a reference parcel with no logging impact at all (RE). We described and quantified the harvest events and applied ANOVA and LMM modeling to analyze and explain the long-term impacts of the logging intensities on soil properties and natural regeneration. We found that logging has a significant negative influence on the physical and chemical properties of the soil because it increases soil compaction and reduces soil nutrients. The most critical impacts of logging were on soil bulk density, total porosity, organic matter, and total nitrogen and phosphorus. The LMM modeling showed that organic matter (OgM), total nitrogen (TN), available K (AK) and pH values are especially impacted by logging. Our study revealed that the values for all of these variables show a linear decrease with increasing selective logging intensity and have a level of significance of p < 0.05. Another finding of this study is that selective logging with low and medium intensities can promote natural regeneration of Scots pine to numbers above those of the reference site (RE). High intensity logging and clear-cuts, however, limit the regeneration of Scots pine, reduce overall seedling numbers (p < 0.05), and create conditions that are suitable only for the regeneration of deciduous tree species. This underlines the risk of Scots pine forest degradation, either by replacement by broad-leaf trees or by conversion into non-forest ecosystems.

Föhrenverjüngung: Plastizität und Akklimatisation in einem trockeneren Klima

Pine regeneration: plasticity and acclimation in a dryer climate Increasing summer drought might limit the natural regeneration of Scots pine stands at low elevations of the Rhone valley. Common garden experiments at the forest-steppe ecotone have shown that emergence and establishment of Scots pine primarily depend on spring precipitation and, to a minor degree, on summer drought and rising temperatures. Scots pine seedlings acclimated rapidly to drought periods by favouring root to shoot growth. In the second year, the saplings were already adapted to drought so that most of them survived an extended spring and summer drought, as recorded at Sion twelve times during the last 154 years. Only an extreme summer drought – no water from June to September – killed 14.7% of the Scots pine saplings. Surprisingly, they were even able to acclimate to such extreme drought events: after the same extreme summer drought in the third year, mortality dropped below 5%. In general, the Scots pine was very plastic, i.e. seedlings and saplings changed their phenotype depending on environmental conditions. But we also found genetic adaptation: Scots pine originating from regions with pronounced summer drought, including populations from lower elevations in the Rhone valley, produced more biomass than those from moister regions in all treatment combinations. Black pine reacted similarly to the treatments like Scots pine, but it grew faster and more saplings survived the first extreme summer drought. These results show that Scots pine from low elevations of the Rhone valley is one of the most drought-tolerant provenances in Europe. Thanks to its high phenotypic plasticity and the ability of seedlings and saplings to acclimate to drought on a short time scale, natural regeneration of Scot pine at low elevations of the Rhone valley is likely to occur also under future conditions, but maybe less frequent than today.

Effects of Reforestation and Site Preparation Methods on Early Growth and Survival of Scots Pine (Pinus sylvestris L.) in South-Eastern Poland

Successful tree regeneration is a key process in ensuring forest sustainability and one of the most crucial investments made in silviculture. This study compared the effects of three reforestation methods (planting, direct seeding, and natural regeneration) and three mechanical site preparation methods (double mould-board forest plough (FP); active plough (AP); and forest mill (FM)) on biometric parameters, survival, and density of Scots pine (Pinus sylvestris L.) seedlings in the first 4 years of growth in a clear-cut area in south-eastern Poland. Planted seedlings were higher, thicker in root collar, and had higher survival rates after the fourth growing season than trees from natural regeneration and direct seeding. Site preparation methods did not affect the density of planted seedlings. After natural regeneration and direct seeding, seedling density was lower and less homogeneous (plots with no seedlings) in FM soil preparation in comparison to other methods. The survival of pines in all reforestation methods was not affected significantly by site preparation methods. Our results indicate that the best mechanical site preparation method for planting is FM, as this is the one that least disturbs the soil environment. For direct seeding the best results were achieved after AP preparation. Natural regeneration of Scots pine was most effective after FP use, and in relatively wet years also after AP use.

Genetic Variability of Natural Regeneration of Scots Pine in Eastern Poland Determined by ISSR Markers

Genetic Variability of Natural Regeneration of Scots Pine in Eastern Poland Determined by ISSR Markers

Alternative approaches to assessing the natural regeneration of Scots pine in a Mediterranean forest

In modelling regeneration patterns, parametric regression is recommended because it can account for the spatial and temporal correlation present in the data, whereas decision trees allow more complex interactions and can be used to reduce the number of variables. The establishment of seedlings after regeneration fellings is key to guaranteeing the development and persistence of the forest. Depending on the objective pursued, data available or type of forest, a number of different methods have been employed to assess the relationship between seedling establishment and both environmental and stand factors. Most authors have conducted their analyses using parametric regression or point pattern analysis. We analysed the way in which light, stand conditions, edaphic and topographic variables affect the regeneration of Pinus sylvestris L. in Central Spain. We used different methods to analyse the same data set. The strengths and weaknesses of each method were discussed. We used two parametric approaches: generalized linear mixed model regression using a negative binomial followed by the variant explanatory variables reduction prior to regression as well as three nonparametric approaches not commonly employed in forest regeneration: nonmetric multidimensional scaling, regression trees and random forests algorithm. The parametric regression identified a larger number of variables associated with the regeneration process and the inclusion of a random effect in the model allowing the consideration of the spatial variability among plots. However, decision trees captured the complex interaction among variables, which typical parametric methods were unable to detect. Different statistical methods gave similar insights into the underlying ecological process. However, different statistical premises with inference implications can be noticed. This may give misinterpretation of the model depending on the nature of the data. The choice of a given method should be made according to the nature of the data and the achievement of desirable results.

Effect of soil scarification on natural regeneration of mature scots pine (Pinus sylvestris) stands in Greece

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 <p>The natural regeneration of Scots pine stands at the Sarakatsana location in the Pieria Mountains improved considerably after the removal of the dense ground vegetation followed mechanical soil scarification. The experimental design consisted of replications on scarified and non-scarified soil. The results four years after the experiment was set up showed that regeneration reached 59 seedlings m-2 in scarified and 7 seedlings m-2 in non-scarified soil. Soil scarification seems to have had a positive effect on the emergence and survival of naturally regenerated Scots pine. The negligible number of dead seedlings in the first two measurements could be due to the favourable site and/or good climatic conditions. Although the mother stand appears to be in a critical condition due to age and increased necrosis as a result of fungal attacks, there is still considerable potential for regeneration in terms of fructification and seed production. The study findings indicate that there can be new growth of Scots pine forest with the shelterwood method of natural regeneration in combination with soil scarification.</p>
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