Forestry and Forest Melioration

Natural regeneration of oak stands in the Left-Bank Forest-Steppe after regeneration felling

V. P. Tkach — 2023-12-26

Introduction

Natural seed regeneration of oak stands in the Left-Bank Forest-Steppe of Ukraine has recently received considerable attention. This is due to the negative trend of reducing the area of natural oak forests. Therefore, one of the important aspects of forest management in oak forests during their reproduction is the effective use of natural regeneration of oak and other valuable species, as well as the activities to promote it.

The study aims to identify the features of the natural regeneration of English oak (Quercus robur L.) and other valuable species on clear-cuts after the strip-gradual regeneration felling.

Materials and Methods

The study was conducted in the forests of Kharkiv Forest Research Station in fresh fertile site conditions in 105–110-year-old oak stands of vegetative origin with a relative density of stocking of 0.72–0.84 and 80–100% of Q. robur in the composition.

Strip-gradual regeneration felling (continuous cutting of trees in strips 25 m wide) was carried out in the stands in combination with natural regeneration-promoting activities. All clear-cuts were left for further natural regeneration. The success of natural regeneration was evaluated according to the scale developed in URIFFM. The numbers of plants in young stands were assessed on circular accounting sites of 10 m²and the main mensuration characteristics were determined.

Results

The fructification intensity significantly affects the number of developed acorns and, accordingly, the success of the natural regeneration of oak forests. In the 13-year-old stand developed after strip-gradual regeneration felling in the year of good acorn harvest, the number of English oak trees was 12.6 thousand per ha (75% of the total). In the 8-year-old stand developed after strip-gradual regeneration felling in the year of a very good acorn harvest, the number of English oak trees was the largest – 19.3 thousand stems per ha (85% of the total). In the 4-year-old stand developed after strip-gradual regeneration felling in the year of medium acorn harvest, the number of English oak trees was 17.2 thousand per ha (60% of the total number). In the 6- and 7-year-old stands developed after strip-gradual regeneration felling after a year with a poor acorn harvest, the number of English oak trees was generally sufficient and amounted to 7.0–8.2 thousand per ha (58–84% of the total number). In the 2-year-old young stands developed after strip-gradual regeneration felling after a year with a very poor acorn harvest, even in combination with regeneration-promoting activities, the number of English oak trees was only 0.7 thousand per ha (8% of the total number).

The success of natural regeneration according to the scale developed in URIFFM in the clear-cuts after the strip-gradual regeneration felling in weakened coppice oak stands after years of medium, good, and very good acorn harvest was assessed as “good”. The natural regeneration success was assessed as “satisfactory” in clear-cuts with additional acorn sowing in places without oak saplings. In the clear-cut area after a year of very low and low oak harvests without additional acorn sowing the natural regeneration success was assessed as “insufficient”. Measures to ensure the successful seed natural regeneration of oak forests are proposed.

Conclusions

The success of the natural regeneration of oak forests largely depends on the intensity and periodicity of oak fructification, as well as on the previous implementation of certain forestry activities. These points should be taken into account to promote the natural seed regeneration of oak stands in the Left-Bank Forest-Steppe of Ukraine.

1 Fig., 3 Tables, 30 Refs.

Growth dynamics of artificial modal pine forest stands in Prydonetskyi Steppe and use of forest site capacity

O. B. Prihodko — 2023-12-26

Introduction

In today's environment, the issue of developing regulatory and information materials for evaluation and forecasting of the growth of modal stands is relevant, taking into account zonal features. Such standards will allow evaluation of forest ecosystem functions and control the efficiency of forest management. Scots pine (Pinus sylvestris L.) is one of the most resilient tree species in the steppe conditions. The pine stands in Prydonetskyi Steppe have certain features and require detailed research.

The study aimed to reveal the features of the growth and productivity of artificial modal pine stands in Prydonetskyi Steppe in Ukraine.

Materials and Methods

To develop growth tables, information from the compartment database “Forest fund of Ukraine” of the Ukrainian State Forest Management Planning Association Ukrderzhlisproekt for Izyum Forest State Enterprise, Lyman Forest State Enterprise, and Kreminna Forest and Hunting State Enterprise, mensuration data on 26 sample plots in pine stands and observations on four monitoring plots were used. In addition, five sample plots were used, which were laid during the forest management planning in Lyman Forest State Enterprise in Donetsk region, with felling and measuring 15 model trees. The sites were located mainly in fresh poor (A₂) and relatively poor (B₂) forest site conditions, as well as dry poor (A₁) and fresh relatively rich (C₂) site conditions. The efficiency of the use of forest cite capacity of forest lands by modal stands was quantitatively assessed using an indicator of productivity of native stands according to I. Turkevych.

The forests of the studied enterprises are dominated by Scots pine stands, which grow on 58% of the forest areas covered with forest vegetation. Most often pine stands have a medium density of stocking and II and I site classes. The prevailing forest types are fresh poor pine, relatively poor oak-pine, and dry poor pine types. Average tree heights were approximated using the Mitscherlich function. The transition from relative to absolute values was based on the basic height values of the modified scale of Orlov for 80-year-old stands of seed origin. An allometric function was used to model the average diameter, including the age and height of the stand. The growing stock was calculated using Mitscherlich formula depending on the height and relative density of the stocking. The dynamics of the relative density of stocking was modeled using a second-order polynomial.

Results

The height growth of modal pine stands of artificial origin occurs within one site index class of the general site index scale, although at a younger age, they tend to slow growth. The stands of the Prydonetskyi Steppe had a slightly more intensive growth in height at the age of 20–30 years with its subsequent slowing down, smaller diameters due to a bigger relative density of stocking, and, accordingly, a bigger growing stock compared to the modal pine stands of Dnieper Northern Steppe according to V. Lovynska. Middle-aged and premature modal pine stands are characterized by a relatively high degree of forest site capacity use compared to fresh poor pine site conditions in the Steppe. The lowest values of forest site capacity were found in the first and second age classes (41–61%).

Conclusions

The studied modal pine forests of fresh poor site condition grow mainly according to the II site class and had rather high productivity, taking into account the unfavorable forest site conditions. This is evidenced by their growing stock, which at the age of 90 was about 330 m³ ·ha^-1 and a relatively high degree of use of forest site capacity – 74%. Quantitative maturity of artificial pine stands of Prydonetskyi Steppe occurs at the age of 60. The developed regional growth tables objectively characterize the dynamics; they consider regional features of growth and formation of modal pine stands of Prydonetskyi Steppe and can serve as a basis for solving scientific and practical forestry tasks.

2 Figs., 4 Tables, 17 Refs.

Possibilities for forming uneven-aged stands in the forest fund of the Zakarpattia region

A. V. Kichura — 2023-12-26

Introduction

The studied forests subordinated to the State Forest Resources Agency of Ukraine are located mainly in the mountainous area. These forests, by analogy with the mountain forests of other territories, require nature conservation-oriented forestry management, taking into account the constant, particularly negative, influence of the mountain environment factors on them. Such orientation can best be ensured by growing uneven-aged stands, which optimally meet mountain conditions.The study aimed to evaluate the possible area of uneven-aged stands in the analyzed forest fund and to examine the prerequisites for their origin, further development, and rational use by the requirements of sustainable development.Materials and Methods

The object of the research was the uneven-aged stands located in overmatured forests in Zakarpattia region, subordinated to the State Forest Resources Agency of Ukraine. For the study, data from the State Forest Cadastre and forest management materials (as of 01.01.2011 and 01.01.2021) were used.

Results and Conclusions

As a result of a comprehensive forestry-mensuration analysis of the forest fund of Zakarpattia region subordinated to the State Forest Resources Agency of Ukraine, the area of overmatured stands of beech, spruce, and fir was evaluated. They are uneven-aged or can be so, given their age and biological ability to develop uneven-aged stands. These stands cover a significant part: their area is 40.5 thousand ha (7.4%), and their total stock is 15.7 million m³ which is 8.6% of the investigated forest stock.

Prerequisites for the emergence and development of uneven-aged stands in forests with a special use regime, a large part of which are non-commercial forests, are more favorable than in commercial forests (26.2 thousand ha; 9.98 million m³ vs. 14.4 thousand ha; 5.7 million m³). In non-commercial forests, there are many times better prerequisites for the appearance and therefore for the further development of uneven-aged stands, in comparison with the commercial forests (32.0 thousand ha; 12.4 million m³ vs. 8.5 thousand ha; 3.3 million m³).

In general, free growth and development of the uneven-aged stands is possible on 32.0 thousand hectares of non-commercial forests. In the commercial forests, uneven-aged stands on 8.5 thousand ha have a dubious prospect of their further growth, which is related to the mode of use and exploitation. A possible solution to the problem can be achieved by changing this regime or by implementing the selective felling system.

7 Tables, 11 Refs.

Condition of pine stands in the recreational and health-improving forests in Left-Bank Polissia

S. I. Musienko — 2023-12-26

Introduction

In the past years, considerable information from Europe and North America has been accumulated about recreational and health-improving forests. In Ukraine, several studies were devoted to this topic. However, much less is known about the resources of these forests, which limits their effective use. Therefore, the assessment of stand characteristics of recreational and health-improving forests of various natural zones and the estimation of the extent to which the forests use the forest site capacity are urgent issues.

Materials and Methods

Forest mensuration characteristics of pine stands in recreational and health-improving forests in Left-Bank Polissia were analyzed based on the materials of the database “Forest Fund of Ukraine” of the Ukrainian State Forest Management Planning Association Ukrderzhlisproekt (as of 2017). The effectiveness of the use of forest site capacity was assessed by comparing the stocks of modal pine stands with those of highly productive stands.

Results

The area of pine stands in recreational and health-improving forests of the Left-Bank Polissia is about 47,000 hectares. Among the pine forests, stands of artificial origin predominate, covering 75% of the total area. The stock of these stands is estimated at 11.5 million m³. The proportion of pine stands belonging to forest areas in green zones around settlements (forestry part) is the largest and amounts to 61%. The productivity of natural stands is somewhat higher than that of artificial ones. This is primarily due to their higher average age. In general, among all studied pine forests, regardless of origin, the largest stock (345 m³·ha^-1) was recorded for pine stands within the forest areas in green zones around settlements (forestry part), and the smallest one (246 m³·ha^-1) for pine stands belonging to forest areas within cities, towns, and other settlements.

Modal pine stands lag behind highly productive stands in all age classes. For example, at the age of 100, the difference in stock between these stands is 29%.

The level of use of forest site capacity by modal pine stands ranged from 40% (at the age of 20) to 74% (at the age of 90–100) in comparison with local highly productive stands. In general, the weighted average value of the use of forest site capacity is relatively low and amounts to 67%.

Conclusions

The conditions of the studied region are generally favorable for the successful growth and development of pine stands with recreational and health-improving functions. This is evidenced by the significant predominance of pine trees that grow according to the first and higher site classes and have a relative density of stockings of 0.7–0.8. A decrease in the relative density of stocking for pine stands after reaching 80–90 years of age was revealed, regardless of location.

The weighted average values of the use of forest site capacity by modal pine stands in the forest areas in green zones in Left-Bank Polissia are relatively low and amount to 67%, compared to local highly productive stands.

6 Figs., 7 Tables, 14 Refs.

Features of the further natural regeneration in the oak stands in Sumy region

M. Н. Rumіantsev — 2023-12-26

Introduction

Natural regeneration of oak forests is one of the most important issues in forestry. Identifying the features of the appearance and successful further growth of advance seedlings, analysis of their quantitative and qualitative condition will contribute to the development of appropriate measures for seed reproduction of highly productive, biologically stable natural oak stands, forecasting their further development and preservation of genetic potential.

The research aims to evaluate the quantitative characteristics of advance growth of valuable species, their distribution by height and age groups, and the placement pattern on the plots of 1–3-year-old open-grown oak stands for its further use during the regeneration of oak forests by natural or combined (in combination with man-made) ways.

Materials and Methods

The natural regeneration (advance growth) of valuable species was assessed for the autumn period of 2018–2020 on sample plots laid out in 1–3-year-old open-grown oak stands in Trostyanets Forestry, Okhtyrka Forestry and Krasnopillia Forestry branches of the State Specialized Forest Enterprise “Forests of Ukraine”, territorially located in the forest-steppe part of Sumy region.

For the assessment, circular subplots (10 m² each) were laid out on diagonal lines through cutting sites. On each plot, 30 subplots were laid out. The seedlings of valuable species were counted by species, age groups, and height groups.

The success of natural regeneration was evaluated according to the scale developed in URIFFM. During the assessment, the number of seedlings was compared in terms of age, height groups, and abundance. Fructification success was estimated quantitatively in points according to Kapper’s scale. Data samples were processed by the methods of variation statistics using the Microsoft Excel software package.

Results

The studied oak stands 1–2 years before felling (in 2016 and 2017) had very poor and poor oak fructification (1 and 2 points, respectively, by the Kapper’s scale). This greatly affected the available natural regeneration of the English oak.

Six tree species were found in the advance growth composition: English oak, common ash, Norway maple, field maple, small-leaved lime, and Scots elm. The number of natural regeneration of English oak was 0.2–1.2 thousand stems?ha^-1, and its proportion in the composition of the regeneration was 2–9% of the total number; Common ash amounted to 0.5–6.0 thousand stems?ha^-1 (7–40%), Norway maple – 1.1–5.5 thousand stems?ha^-1 (26–61%), field maple – 0.7–3.2 thousand stems?ha^-1 (7–42%), small-leaved lime – 0.1–0.9 thousand stems?ha^-1 (1–6%), and Scots elm – 0.5–1.5 thousand stems?ha^-1 (4–32 %). A greater number of oak seedlings was registered in the plots where the proportion of oak in the composition of a mother stand was 70–80% and ash – 20–30%. Regeneration success according to the scale developed in URIFFM in all plots of open-grown stands aged 1–3 years was assessed as “poor”.

Conclusions

Both the identified features of the distribution of advance growth of valuable species by height and age groups and their placement pattern should be taken into account in the future when choosing a method of oak forest regeneration.

3 Figs., 5 Tables, 21 Refs.

Application of GIS technologies for accounting plus trees

I. B. Zhadan — 2023-12-26

Introduction

Nowadays, an important forest genetic resources (FGR) conservation activity is the systematization of information on gene pool conservation units in electronic databases. It should be noted, however, that the existing international databases mainly relate only to units represented by populations (stands), which are visualized as polygons on the map. As the scientists from the Department of New Information Technologies in URIFFM have implemented the website “Geoportal: Forests of Ukraine”, it became technically possible to add information on plus trees to its functionality and combine data on tree locations and their characteristics in a united electronic database.

The study aimed to improve the organization of information on plus trees, their accounting, survey, and use as improvement units by applying free software (Python, JavaScript) and the PostgreSQL relational database with the PostGIS module.

Materials and Methods

In 2021, one of the work stages was to develop software and methodology for forming the Plus Trees database and to provide a user manual. In particular, a data schema was created to store both attribute and geographical information on tree improvement units in Ukraine. In addition, attribute and geographical information of forest inventory are used. The database of plus trees contains basic information from plus tree Passports or selection/inventory data from the reports.

Results

The proposed database consists of several panels. The first panel contains elements for setting coordinates and entering plus tree numbers. The second panel is intended for selecting a species name of trees. The third panel of the data entry form contains mandatory attributes (total height of a plus tree and its diameter at a height of 1.3 m). The fourth panel contains other tree characteristics.

During the testing of the developed database structure and the working out of the instruction, the information on plus trees in seven regions of Ukraine (Kharkiv, Poltava, Sumy, Dnipro, Zaporizhzhia, Luhansk, and Donetsk) was entered, which is about 25% of the country’s plus tree pool. In addition, the design of the web pages was finalized in parallel with the data entry.

The developed software can be useful to both scientists and forest managers. Its use will simplify the search for plus trees in forest stands for their inventory, and survey, as well as in cases where it is necessary to collect seeds or cuttings for the seed orchards or progeny tests creation in forest enterprises or at forest seed centers. For scientists, it will provide an opportunity to systematize, analyze, and generalize information, in particular, to improve methodical approaches to the selection of the plus trees.

Conclusions

A data schema was created to store both attribute and geographic information on forest tree species tree improvement units in Ukraine. The schema considers the complex structure of coordinated units and includes the developed algorithms for data verification which will allow the effective use of the proposed database for the plus tree accounting.

8 Figs., 1 Table, 20 Refs.

Comprehensive assessment of Scots pine clone seed orchard progenies by growth characteristics and resistance traits in the Forest-Steppe zone of Kharkiv region

V. Dyshko — 2023-12-26

Introduction

Clonal seed orchards (CSOs) are the main and most promising objects of the permanent forest seed base. The prospects of using seed material obtained from CSOs are assessed by testing their seed progenies. During the test, the main attention is paid to the intensity of growth in height and diameter, trunk shape, and health condition of the trees; however, unfortunately, the traits that would directly or indirectly indicate disease resistance are not taken into account.

Heterobasidion annosum s. l. infects pine stands and causes significant wood losses and a decrease in the protective properties of forests. The absence of objective criteria for assessing the degree of resistance of Scots pine to this pathogen prompts the search for markers of tree resistance to this disease. An important role in ensuring the resistance of Scots pine to unfavorable environmental factors, including root rot, can be played by the weight of seeds, the density of needles on shoots, the parameters of the conductive system of needles in the mid-section, the width of layers of latewood, and the intensity of the release of oleoresin from micro-wounds. A comprehensive assessment of CSOs progenies, taking into account the traits that predict the resistance to root rot, will allow the identification of the most promising ones for cultivation in local conditions.

The study aimed to improve the existing integrated approach to the evaluation of Scots pine seed progenies using methods of diagnosing trees for resistance to root rot and selecting the most promising ones in the forest-steppe zone in Kharkiv region.

Materials and Methods

The study was conducted in Scots pine variety tests established in Guty Forestry (Slobozhansky forest office, Kharkiv region, Ukraine), where the CSO progenies from Kharkiv, Kyiv, and Volyn regions grow. The progeny grown from seeds harvested in Guty Foresry were used as a local control (Guty-control) for all of the variants, and those grown from seeds harvested in the state forest enterprises of the corresponding regions were used as regional controls (Kharkiv-control, Kyiv-control, Volyn-control). The height, diameter, straightness of the stems, and health condition of trees in variants were determined.

The prospects of using the seeds of CSO progenies in the local environment of Kharkiv region were assessed using the scale of the comprehensive assessment presented in the variety testing method (total points 5–20) and with the addition of traits of H. annosum s. l. resistance (total number of points 5–45).

Results

A comprehensive assessment of the variants according to the scale of the forest species variety testing method by growth and condition showed that four CSO progenies with a total score of 10–15 points were promising in the study area. The variants 'Kyivskyi-3' and 'Prykhylkivskyi-2' were the best (total score of 15 points). To assess the potential of using seeds from CSOs in areas vulnerable to the risk of root rot infection, we considered additional traits of resistance, namely seed weight, the density of needles on shoots, parameters of the conductive system of needles at the mid-section, width of latewood layers, and intensity of oleoresin release from micro-wounds. The results of the scoring indicate that the best candidates for reforestation in such areas are the varieties from Kharkiv, Kyiv, and Volyn regions.

Conclusions

The use of annosum resistance traits for the integrated assessment of Scots pine allowed the identification of differentiation between variants in terms of resistance to root rot and to identify the most promising ones for cultivation in Kharkiv region. The effectiveness of using these traits as resistance markers requires further confirmation. The results of the comprehensive assessment indicate the feasibility of using seeds from CSO to create sustainable and productive forests in the forest-steppe zone in Kharkiv region.

2 Figs., 3 Tables, 31 Refs.

Selection and conservation of Scots pine plus trees in Chernihiv Polissia and forest-step part of Ukraine

L. I. Tereshchenko — 2023-12-26

Introduction

Most modern methods of forest tree improvement are based on the method of selecting the best trees for further propagation and use. Currently, there are 4.600 plus trees in the State Register of Ukraine, of which more than 1.300 are Scots pine trees. Current tasks are monitoring their condition as well as their evaluation and involvement in seed production programs. Plus trees are intended for vegetative and seed reproduction and the creation of progeny tests, clone archives, and forest seed orchards on their basis. Assessment of the breeding value of the Scots pine plus trees after a long period from the time of selection is of great significance in improving forest selection methods.

The research aimed to analyze the primary and present characteristics of Scots pine plus trees as objects of conservation in situ in Chernihiv Polyssia, the Right-Bank, and Left-Bank Forest-steppe, and improve approaches to the selection of plus trees, as well as provide suggestions for increasing the selection efficiency.

Materials and Methods

The results of the present survey of 80 plus trees of Scots pine (Pinus sylvestris L.) selected more than 35 years ago in the stands of Chernihiv, Kharkiv, and Cherkasy regions are presented. Growth and quality characteristics, selection category, condition, and reproduction intensity were determined. The data obtained during the survey have been compared to the data from the Passports of plus trees at the year of selection.

Results

The study showed no clear trend like changes in the growth variables of plus trees. According to the survey results, 95% of the Scots pine plus trees in Chernihiv region retained their advantages in height, and 92% of them in diameter 36–48 years after their selection. In Kharkiv region, the values for the Scots pine plus trees were 73% and 55% respectively.

Most plus trees had high-quality trunks; in particular, the value was 95% in Chernihiv region, 94% in Cherkasy region, and 73% in Kharkiv region. The average length of the knotless part of plus trees’ stem from their total height was 70%, 56%, and 43% respectively. The least quality trunks were surveyed in plus trees in Kharkiv region. There is a tendency for the plus tree condition to deteriorate with age.

Approaches to the selection of Scots pine plus trees were analyzed, and it was proposed to measure at least 10 trees surrounding a candidate plus tree or the five best trees selected within 100 m from it on plots with hilly terrain and in a mixed stand. To confirm the uniqueness of the candidate tree, it is advisable to attach its photo in addition to a detailed description.

Conclusions

The percentage of the excess of the plus trees growth variables over the average values of the surveyed stands have decreased with age to 3–9% in height and to 3–13% in diameter. The majority of surveyed plus trees had high-quality trunks. The tree height and trunk straightness were determined as the most important indicators for the selection of plus trees.

Approaches to the selection of Scots pine plus trees were analyzed and proposals for improving the selection criteria were provided. It is recommended to reduce the requirements for plus trees in terms of self-pruning in Forest-Steppe conditions compared to Polissia. It is proposed to create an electronic database of detailed protocols for the plus tree selection and characteristics of their genotypes, as well as to conserve all selected plus trees in ex situ.

2 Figs., 4 Tables, 19 Refs.

Protection of young Scots pine plantations against browsing by ungulates in the Kyiv Polissia

O. I. Khromulyak — 2023-12-26

Introduction

In the forests of the Kyiv Polissia, Scots pine (Pinus sylvestris L.) predominates. This species is the most important winter forage for ungulates. Intensive browsing of pines by ungulates leads to significant economic losses due to reduced wood quality and tree mortality. Analysis of the impact of ungulates on plant composition, tree regeneration, and forest resilience is crucially important for determining management strategies, especially in the face of increasing animal populations. There is a necessity to implement silvicultural practices adapted to the presence of ungulates to reduce the damage caused by them.

The research aims were to determine the effectiveness of the use of the Cervacol Extra repellent to protect Scots pine plants against browsing by ungulates in Kyiv Polissia.

Materials and Methods

The effectiveness of the Cervacol Extra repellent for protecting pine plants from ungulate browsing has been studied in 2020–2021. The research was conducted in the Staropetrivske Forestry in Kyiv Forest Research Station in the Kyiv region. Data on the population of ungulates in the forest fund of the Kyiv Forest Research Station were taken from the materials of the hunting service as of autumn 2020. On the research territory, there are dense populations of ungulates: roe deer (Capreolus capreolus L.) – 25.6 heads per 1,000 hectares, moose (Alces alces L.) – 0.9 heads per 1,000 hectares, fallow deer (Cervus (Dama) dama L.) – 0.9 heads per 1,000 hectares, and red deer (Cervus elaphus L.) – 3.1 heads per 1,000 hectares. The annual increase in the population averages 15%.

The research was carried out in two plots of 30 ? 20 m. For each plant of the test treatment and control the following criteria were assessed: (i) damage to the leading shoot, (ii) damage to the leading shoot and lateral shoots, (iii) no damage. The proportion of damaged shoots of each plant – up to 50% and more than 50% – and the number of plants that lost the ability to regenerate, were determined. The proportion of damaged pines with varying degrees of damage was calculated from their total number on each experimental plot for two variants (1 - with treatment, 2 - without treatment). To improve the properties of the data and to equalize their distribution, the arcsine square transformation was applied to the proportions of the number of damaged pine plants from their total number on the plot according to each evaluation criterion. One-way ANOVA was used to determine a significant difference between the experimental treatments. For all statistical analyses, a significance level of ? = 0.05 was used.

Results

Treating pine plants with the Cervacol Extra repellent in late autumn positively affected their protection from ungulate browsing in winter. The numbers of plants with various degrees of shoot damage and plants that lost the ability to regenerate demonstrate significant differences between the groups (p < 0.05). This confirms the hypothesis of the high effectiveness of Cervacol Extra repellent for protecting pine plants from ungulate browsing.

Conclusions

Wild ungulates, in particular Capreolus capreolus, Alces alces, Cervus (Dama) dama, and Cervus elaphus, cause significant damage to young Scots pine trees in Kyiv Polissia. Treatment of pine plants with Cervacol Extra repellent in late autumn has a positive effect on their protection from ungulate damage. In this way, the percentage of damaged plants due to ungulate browsing can be reduced to 6%.

3 Figs., 1 Table, 24 Refs.

Some features of the growth of English oak in experimental plantations planted in different dates in Kharkiv Forest Research Station with the containerized seedlings fertilized with different types of fertilizers

M. Н. Rumiantsev — 2023-12-26

Introduction

Recently, various types of fertilizers and microbial preparations have been used as growth intensifiers for the planting stock of the main forest-forming species, including English oak (Quercus robur L.). However, there is almost no data on the growth characteristics of forest plantations established with containerized seedlings that have been fertilized with various fertilizers during cultivation and microbial preparations.

The study aimed to compare mensuration characteristics of English oak in experimental plantations established with containerized seedlings, grown with the use of different types of fertilizers and microbial preparations, as well as to confirm the possibility of establishing oak forest plantations in the summer using container seedlings.

Materials and Methods

To confirm the possibility of significantly extending the spring planting period for containerized oak seedlings, including the summer period, experimental plantations were established in 2014. The study site is situated in the Derhachy Forestry in Kharkiv Forest Research Station, Kharkiv region. The oak plantations were established on an area of 3.0 hectares in spring (March 25), summer (July 10 and August 19), and autumn (October 30). To lay out the plantations, the containerized seedlings that have been fertilized with various fertilizers and biological products during cultivation were used.

Mensuration characteristics of oak seedlings in the experimental plantations have been estimated and analyzed according to the generally accepted forestry and forest mensuration methods following some regulatory materials.

Results

The oak plants had a higher survival rate in all experimental treatments compared to the control. For example, the oak survival rate was from 87% to 93% in the experimental treatments and 78% in the control. English oak trees in the 5-year-old plantations established with containerized seedlings in summer (July 10 and August 19) and autumn (October 30) were significantly inferior to the plantations created in spring (March 25) in terms of growth characteristics.

The plantations created in autumn (October 30) and fertilized with different types of fertilizers were superior to the plantations established with containerized seedlings without fertilization in all characteristics. The difference was 1–16% in diameter, 0–22% in height, and 1–48% in height increment.

The coefficients of variation in diameter and height ranged from 17% to 24%, indicating an average and increased variability of the studied variables. The coefficients of variation in height increment ranged from 26% to 38%, demonstrating increased and high variability. In general, significant variability in growth is characteristic of young stands.

Conclusions

English oak trees in most treatments of 5-year-old experimental plantations created in summer were inferior in growth to the treatments established in spring with seedlings grown in the previous year. However, oak trees in the plantations established in the summer exceeded in growth almost all plantation treatments established in the autumn by seedlings grown in the planting year.

Our results indicate the possibility of significantly extending the terms of spring planting of oak plantations with containerized planting stock and even creating plantations in the summer, provided it is treated with antitranspirants.

1 Fig., 2 Tables, 19 Refs.

Evaluation of pheromone traps for bark beetles and their predators in pine forests in the Kharkiv region

A. D. Vorobei — 2023-12-26

Introduction

Pine stands of many regions have been affected by outbreaks of bark beetles with the dominance of Ips acuminatus (Gyllenhal, 1827) and Ips sexdentatus (B?rner, 1776). In many countries, pheromone traps are produced and used to monitor and suppress native and alien bark beetles. In Ukraine, pheromone traps for catching bark beetles are not produced. The effectiveness of various trap designs and the number of lures for pine bark beetles have not been previously studied in Ukraine. In 2023, within the framework of the FAO project TCP/RER/3801, State Specialized Forest Protection Enterprise ‘Kharkivlisozahyst’ received three types of pheromone traps produced by the Spanish company Sanidad agricola econex s.l. and pheromones intended for the capture of I. acuminatus and I. sexdentatus.

The study aimed to compare the species composition and abundance of bark beetles and their predators by captures in the different pheromone trap-lure combinations.

Materials and Methods

The research was carried out in June – August 2023 in pure mature pine stands in the Vasishcheve subunit (State Specialized Forest Enterprise “Forests of Ukraine”, Branch “Zhovtneve Forestry”). Three types of pheromone traps were placed randomly in six locations of a homogeneous stand, the distance between which was about 50 meters. Type A traps (Funnel) contain 8 funnels, Type B traps are Theyson, and Type C traps are Crosstrap® mini. Depending on the experimental design, the traps contained blades with pheromones of Ips acuminatus or Ips sexdentatus. Blades for I. acuminatus contained 2 and 3 dispensers (commercial names 4C and 5C, respectively), and blades for I. sexdentatus contained 3 and 4 dispensers (commercial names 4C and 5C, respectively). In control treatments, respective traps (A, B, and C) were left empty (without blades). Trapping experiments were carried out from 20 June through 8 August 2023. Trapped insects were collected every 7 days, dried, and sorted. Bark beetles, longhorn beetles, and predators were identified at the species level, and some other insect groups at the family level at least.

Results and Conclusions

Five bark beetle species (Curculionidae: Scolytinae), five longhorn beetles (Cerambycidae), five predator species from Histeridae, Cleridae, Nitidulidae, Monotomidae, and Tenebrionidae, as well as several species of Staphylinidae, Carabidae, and Elateridae were captured in traps of three types (A – Funnel; B – Theyson; C – Crosstrap® mini) with pheromones of Ips acuminatus and I. sexdentatus. Target species – Ips acuminatus and I. sexdentatus – accounted for 51% and 31% of all captured beetles, respectively. Their numbers, seasonal dynamics, and proportions depended on the trap type, pheromone, and blade. The highest number of I. acuminatus beetles was captured in Crosstrap® mini traps (C type), and that of I. sexdentatus was found in Theyson traps (type B). An increase in dispenser number provides more captures of I. acuminatus and has no significant influence on captures of I. sexdentatus. The number of Th. formicarius was the lowest in trap B (Theyson) and the highest in trap С (Crosstrap® mini). The number of Th. formicarius captured in traps A and C with the pheromone of I. acuminatus was higher than in the traps with the pheromone of I. sexdentatus. Differences in the captured Th. formicarius beetles in the traps with more dispensers with the pheromone of I. acuminatus are significant, whereas in the traps with the pheromone of I. sexdentatus they are nonsignificant.

12 Figs., 14 Refs.

Pest and disease incidence of Ulmus sp. in forest shelter belts along the Kyiv–Kharkiv highway

O. A. Kuznetsova — 2023-12-26

Introduction

Starting from the 1960s, Ulmus sp. trees in many regions were significantly affected by Dutch elm disease (DED). Publications indicate that the species composition of Ulmus sp. varies with longitude as well as their requirements for ecological conditions. We hypothesized that the susceptibility of elm species to biotic damage also depends on the geographical location of the stands. Therefore, our research was started in the forest protection belt along the highway from Kyiv to Kharkiv, where three Ulmus species with various types of damage are widely represented.

The research aimed to assess the infestation of different Ulmus species by bacteriosis, Dutch elm disease, butt rots, and bark beetles in the fragments of the Kyiv – Kharkiv highway within individual administrative regions.

Materials and Methods

In June – September 2023, 2,250 trees of the genus Ulmus were examined in 96 test plots in forest belts along the M 03 highway, passing from the West to the East through the territory of Kyiv, Poltava, and Kharkiv regions. The sample plots were located at the parts of the shelter belt with the dominance of one or several Ulmus species, particularly U. glabra Huds., U. laevis Pall. and/or U. pumila L.

The infestation type for each inspected tree was identified by visual signs. The pathogens of DED were identified from symptomatic shoots using mycological methods (incubation on Malt Extract Agar, Biolife Italiana) as well as using primers ITS PCR ITS1-F та ITS4. Species-specific primers mtsr1 (5?-AGTGGTGTACAGGTGAG-?3) and mtsr2 (5?-CGAGTGGTTAGTACAATCC-?3) were used for differentiation O. ulmi and O. novo-ulmi. For identification Ophiostoma novo-ulmi and its hybrids or subspecies, specific primers for gens col1 (SSPP) and cu (CU1 і CU2) were used.

The incidence of each cause of elm damage was estimated as the proportion of trees with certain symptoms or signs from the total amount of inspected trees (for each Ulmus sp. or stand fragment).

Results and Conclusions

The part of U. glabra decreased from Kyiv to Kharkiv regions. U. laevis was more represented in Poltava region while U. pumila was in Kharkiv region. The main factors for the weakening of elms were bacteriosis (on average 10.6–13.4 % of trees) and DED (4–10.2% of trees), to a lesser extent – butt rot (2.5–4.5 % of trees). Within the observable height of the trunks, bark beetle exit holes and galleries were found on 4.5–9.9 % of trees. The proportion of damaged trees depended on elm species and the location of shelter belt fragments. U. pumila was the most affected with 47.2, 32 and 33 % of trees with the presence of different types of damage in the fragments of shelter belt within Kyiv, Poltava, and Kharkiv regions, respectively, including 11.3; 10.7 and 9.3%, respectively, particularly affected by DED. For the first time in the study region, the presence of Ophiostoma novo-ulmi subsp. americana and its aggressive hybrid Ophiostoma novo-ulmi subsp. americana ? novo-ulmi (pathogens of DED) was confirmed by molecular methods. Bacteriosis of all elm species was most widespread in a fragment of shelter belt within Kyiv region, and least widespread within Kharkiv region.

9 Figs., 3 Tables, 22 Refs.

Dynamics and causes of changes in the health condition of pine stands in Cherkasy region during 1992–2021

I. M. Ustskyi — 2023-12-26

Introduction

The increasing temperatures during the growing season in combination with periodic droughts (especially in the last decade) cause the spreading of forest diseases. The research aimed to determine the specificities of pathological processes in the forests in Cherkasy region and the impact of climate changes in 2008–2021 on their health condition.

Material and Methods

Climatic changes were assessed by analyzing temperature and precipitation for the growing seasons of 2008-2021 according to the data of six climate stations in the region and the fluctuation of groundwater levels according to the data of the Institute of Hydrology (Kyiv). Based on the ratio of precipitation and evaporation, moisture coefficients were calculated according to Vysotsky and Ivanov. Changes in the health condition state of pine stands in Cherkasy region for 1992–2018 were analyzed based on forest pathology information from State Specialized Forest Protection Enterprise ‘Kyivlisozakhyst’ and Ukrainian Research Institute of Forestry and Forest Melioration.

Results

From 1994 to 2012, the area of forest stands in which pathological processes were detected gradually and unevenly increased. As of 2021, the area of such stands was about 21,000 hectares. Among them, the largest area is occupied by pine stands (64%) of VII–IX age classes (61%), with a relative density of stocking of 0.7 (62%). The main causes of pine forest deterioration in 2018 were hydrological and climatic factors (74%), while in 2021 there were a variety of diseases. Particularly, the semi-parasitic plant Viscum album ssp. austriacum (Wiesb.) Vollm. on 11.3 thousand ha, root rot on 2.9 thousand ha, needle-eating insects on 2.9 thousand ha were spread, and 0.7 thousand ha were damaged by windstorms. From 2018 to 2021, the area of pine stands with pathological processes has been increased more than five times. The precipitation and temperature during the growing season on the spread of forest pathological processes had direct medium and weak correlations with forest decline area. Changes in the moisture coefficient indicate a tendency to an uneven increase in aridity in the growing seasons of 2008–2021. Groundwater in the right-bank part of Cherkasy region is mainly located at a depth inaccessible to pine root systems.

Conclusions

Pathological processes in the forests in Cherkasy region are widespread in pine forests of VII–IX age classes (61%), with a relative density of stocking of 0.7 (62%). While as of 2018, the main causes of deterioration were hydrological and natural phenomena, as of 2021 they were diseases (root rot), stem pests, and a semi-parasitic plant (Austrian mistletoe). During these years, the moisture regime during the growing season corresponded mainly to the conditions of the dry steppe. The water regime of forest stands in these conditions depends mainly on surface moisture.

4 Figs., 4 Tables, 9 Refs.