Current State of Pineries in Zhytomyr Polissia Under the Influence of Environmental Factors

Recently, there has been a massive drying of conifers all over the world. In North America and Siberia, there are millions of hectares of shrunken plantings; in Europe, pines and firs have been drying up over the past two decades. Furthermore, considerable damage is caused to woody plants by phyto-pest and phyto-diseases, since mass reproduction of Ips typographus Linnaeus, Ips acuminatus Gyllenhal has been observed in Europe in recent years, Dendroctonus micans Kud – in North America, Polygraphus proximus Blandford – in East Asia. Nematodes also cause significant damage to pine forests. Among phyto-diseases, Heterobasidion annosum (Fr.) Bref. harmfully affects Pinus sylvestris L. The appearance of foci of shrunken trees in different parts of the globe indicates the global nature of processes associated with cyclical planetary processes and climate change. This study describes climate changes in the research region for 1961-2020. According to the analysis, it was found that for 2009-2020, considerable damage to pine plantations in Zhytomyr Polissia is caused among needle-eating insects – Panolis flammea Denis & Schiffermuller, Diprion pini L., Neodiprion sertifer Geoffroy; among other pests – Aradus cinnamomeus Panz, Dendrolimus pini L., Bupalus piniarius L. The greatest harmful effect that pineries have recently sustained has been caused by Diprion pini L. It was also found out that among phyto-diseases suffered by the pine forests, significant damage has been done by Heterobasidion annosum (Fr.) Bref., with the damaged area of 13.0-14.2 thousand hectares. Hydrothermal analysis was performed for 2009-2020. The influence of solar activity on the number of phyto-pest and diseases is analysed. This paper provides the estimate of the amount of CO2 emissions is given for 2009-2020. It was found that since 2014, the amount of carbon dioxide emissions has decreased from 1.5 million tonnes to 0.6 million tonnes. Correlation analysis of all indicators indicated a high mutual influence between the area of trees damaged by insect pest, root sponge, the Wolf number, and CO2 emissions to the environment. Mathematical dependences are obtained to predict the influence of the W number on damage to pineries by forest pests and diseases in the conditions of Zhytomyr Polissia

Studies on the role of improvement perimeters in preventing and combating soil erosion

Work conducted over the course of a year have had as primary purpose the effect of ecological reconstruction through afforestation and other works (support fences, cross and longitudinal works în ravinees) in improvement perimeters Diviciori 1 (compartment 73) and Diviciori 3 (compartment 49). Forest vegetation was installed 30 years ago in 73, according to afforestation formula 7PiN-2Pa (Fr) -1 seadbucktorn and 50 years in 49, according to the afforestation formula: 5PiN-2Pi-3Mo. Stands were led using silvotechnic works were just regarding hygienization, in the first years. However, in the recent past, the trees have suffered due to abiotic factors that favorized the emergence of disease and pests (Lophodermium ssp. and Diprion pini). So as to obtain more relevant scientific data, test surfaces were placed following the methods used in the agricultural field, modified as to fit the forest field, so the data could be statistically processed and allow the recommendation of adequate technical solutions regarding the ecological reconstruction of the damaged terrains. Eight test areas were placed in the forests and limitrophe to them, the collected data concerning the volume of rainfall, the quantity of runoff on each surface, respectively material collected in the designated tanks. Therefore the collected data has been processed in the laboratory, ultimately uncovering the quantity of eroded material and comparing it between the two compartments and the limitrophe land, having the following values: 0.0912 t/ha in 49, 0.1718 t/ha outside 49, 0.0939 t/ha in 73 and 0.1657 outside 73. Keywords: Improvement perimeter, runoff plots, erosion, rainfall, forest bottom

The influence of stand and habitat characteristics on the occurrence of pine sawflies Diprion pini L. and Gilpinia virens (Klug) (Hymenoptera, Diprionidae) in selected areas of northern Poland

Pine sawflies (Hymenoptera: Diprionidae) belong to the most common pests of Scots pine Pinus sylvestris L. in the area of the Regional Directorates of State Forests in Toruń and Gdańsk. The two most destructive species, Diprion pini L. in the area of Puszcza Bydgoska and Gilpinia virens (Klug) in Bory Tucholskie, were investigated in this study. Our main aim was to characterise the two species in the Bydgoszcz Forest District in RDSF in Toruń and Kaliska in RDSF in Gdańsk, respectively, based on data gathered during outbreaks between 1991 and 2011. For this purpose, a geometric database was created, containing information about the year of outbreak, number of larvae observed after tree felling as well as selected stand and site features including stand age and species composition, stocking index, canopy closure, site index, humidity and fertility. By analysing the occurrence of both species in relation to stand and site features, we were able to determine their environmental requirements, which are quite different from one another. D. pini preferred older stands, with a stocking index between 0.8–0.9, growing on fresh and dry coniferous sites, while species composition (share of pine), canopy closure or site index did not have any influence on its abundance. G. virens preferred middle-aged pure pine stands, with relatively open canopies, on fresh coniferous sites and poorer soils. The stocking index did not affect its occurrence.

Масові розмноження звичайного соснового пильщика (Diprion Pini L.) у лісовому фонді Житомирської області

Оцінено параметри динаміки масових розмножень звичайного соснового пильщика (Diprion pini Linnaeus 1758: Hymenoptera; Diprionidae) у лісовому фонді Житомирської області. Визначено наявність трьох спалахів (1993-1995, 2000-2002 і 2010-2012 рр.) із найбільшою площею осередків у 2000-2002 рр. Доведено, що початку масового розмноження звичайного соснового пильщика сприяли підвищення температури повітря, ранній початок вегетаційного періоду та збільшення його тривалості. Це створило умови для успішного розвитку двох поколінь і росту чисельності наприкінці вегетаційного періоду, коли пошкодження личинками хвої є найнебезпечнішим для сосни. Показано, що площа осередків масового розмноження звичайного соснового пильщика визначалася структурою лісового фонду. На прикладі лісового фонду ДП "Малинське ЛГ" проаналізовано зміни вікової структури та складу порід соснових насаджень за даними лісовпорядкувань 1997 та 2010 рр. Встановлено, що площа осередків шкідника у 2010-2012 рр., порівняно зі спалахом 2000-2002 рр., зменшилася внаслідок збільшення віку насаджень, які втратили принадність для цього виду, та зменшення площі чистих соснових насаджень, зокрема розташованих біля зрубів суцільних санітарних рубок і рубок головного користування. Доведено високу ймовірність нового зростання чисельності звичайного соснового пильщика найближчим часом. Уточнення прогнозованої площі осередків має бути проведено за даними останнього лісовпорядкування, яке візьме до уваги зміни в лісовому фонді, зокрема пов'язані з катастрофічним поширенням осередків "короїдного всихання".

Diprion pini L. (Hymenoptera, Symphyta, Diprionidae) population dynamics in the Low Dnieper region

Pine sawflies (Hymenoptera, Symphyta, Diprionidae) are the most spread foliage browsing insects of pine forests in Europe, especially monovoltinous European pine sawfly Neodiprion sertifer (Geoffroy, 1785) and common pine sawfly Diprion pini (Linnaeus, 1758), which develops in one or two generations per year depending on weather. The outbreaks of both pine sawflies are the most frequent and intensive in the Steppe zone of Ukraine, especially in the Low Dnieper region, where pine forest (Pinus sylvestris Linnaeus and Pinus pallasiana D. Don) was planted on moving sands in the sixties of the 20th century. This research is aimed at the evaluation of the parameters for D. pini outbreak dynamics in the Low Dnieper region. Outbreak severity, specific foci area and mean score of stand threat by D. pini were evaluated from the regional statistical reports. In the regional scale for 1979–2017, notable outbreaks of D. pini were registered in 1982, 1993, 2002, 2006 and 2017. An interval between maximums was from 4 to 11 years, in average 9 years. The growth of foci area in 1979–1998 as compared to 1999–2017 as well as correlation between pine stand area and annual area of this pest’s foci in different forests was not statistically significant. Graphical analysis of dynamics of D. pini focal area for 2010–2017 was done based on individual threat levels. Our study confirms the fact of three outbreaks for this period in three forest and hunting enterprises (FHE), two outbreaks in one FHE and one outbreak in one FHE. An interval between the outbreaks makes three or six years. The causes of such shortening of interval are discussed.