The analysis of regeneration processes on post-agrogenic lands allows establishing patterns and features of succession processes in phytocenosis, to identify the most appropriate measures to promote natural regeneration and to establish the possibility and feasibility of the production of forestry crops on lands left out of agricultural use. A study of forest regeneration processes in areas of fallow land for agricultural purposes adjacent to the floodplain of the Oredezh River in Gatchina district of Leningrad region. On the prepared study plots (0.25 ha) in different elements of the slope relief, the natural regeneration of pine and spruce and living ground cover was also taken into account. The soils on the objects of the study are agricultural soils of different thickness, from 30 to 45 cm. In two areas the soil is turfy, well-cultivated, concealed podzolic, ferrous illuvial soil on sands. On plots No. 3–5, the soil is turfy, well-cultivated, concealed podzolic, ferrous illuvial, clayey, on a red loam. The purpose of the study was to identify the nature of forest regeneration processes in areas of fallow land for agricultural purposes. It has been established that the composition of the emerging undergrowth depends on a number of factors: the type of soil, the taxation characteristics of the adjacent forest, the forest vegetation subzone, and the living ground cover. In these soil conditions on the deposits, young mixed undergrowth with a predominance of spruce and pine after a meadow stage of ruderal vegetation is formed.

Growing spruce and pine wood on land being out of active agricultural use is important for many European regions. The study of the qualitative characteristics of coniferous wood makes it possible to predict target indicators of the obtained raw materials. The influence of xylem structural elements on the density of spruce pine wood on the postagrogenic lands of the boreal zone of Russia was studied. The objects of the research were spruce-pine stands growing on old arable land in the Gatchina district of the Leningrad region. Depending on the share of the species, various anatomical indicators of the macro-structure of wood influence the formation of the spruce and pine wood density. For the spruce part of the forest stand, the width of the annual increase makes a greater contribution to the formation of indicators of wood density. For the pine part of the forest stand the density of the wood correlates with the proportion of late xylem. With a different proportion of the species, the influence of macro-structural elements on the density of wood changes. Conducted analysis of variance showed a significant effect of the forest stand composition on the anatomical macro-structure of spruce and pinewood.

The aim of the study is to analyse the empirical data collected in 2017, explaining the distribution of mechanically damaged trees left after the commercial thinning, in order to characterize the potential impact of the change of soil scarification working direction on the intensity of damage to the trees left in the felling during the following pre-commercial thinning. The study found that extraction or leaving logging residues in the felling area did not significantly affect the productivity of the soil scarification, but in areas where logging residues were extracted, the depth of the furrows increased significantly, implying a better quality of soil preparation in these areas. The study did not identify the correlation between strip-road patterns (combined or uncoupled ends) with damage intensity, but the research hypothesis was confirmed that the number and proportion of damaged trees is significantly increasing at the ends of the technological corridors. A bigger increase of proportion of damaged trees at the end of strip-roads was found in pine stands. When modelling the effect of soil preparation and logging design on the proportion of damaged trees, species specific parameters should be used – the proportion of damaged trees at the corridor ends in pine stands is 68%, in spruce stands – 45% compared to the rest of the stand. The rest of the stand can be characterized by production statistics or by the results of the study – the average proportion of damaged trees in spruce stands is 4.9% and in pine stands – 0.8% of the remaining trees.

Forestry in Latvia in the 20th century was strongly focused on the establishment and management of pure Scots pine and Norway spruce stands trying to avoid any admixture of other tree species. Knowledge on the economic feasibility of the mixed stands’ management is still rather poor in Latvia, while at the same time the establishment of mixed stands of Norway spruce and birch species has become an attractive management objective in Finland and Sweden. This paper used the data from the Latvian National Forest inventory to quantify the amount of birch stands with the second layer of spruce, as the first step to justify the development of recommendations for alternative management options in this type of stands. According to the results, there are 121 752 ha of birch stands with the second layer of Norway spruce, and most of those are located in Hylocomiosa, Oxalidosa, Myrtillosa mel. and Myrtillosa turf.mel. site types. The mean standing volume of birch stands with Norway spruce understorey was higher than in birch stands with no spruce understorey, and Hylocomiosa, Oxalidosa, Myrtillosa mel. were the most productive site types both in terms of total standing volume and that of the Norway spruce growing in the second layer. Analysed data also revealed that the management of birch stands already now differs strongly in state and private forests, in the latter being more focused on selective fellings. It is possible to develop and test alternative management methods of birch stands with the second layer of Norway spruce to maximise yield and reduce expenses of forest regeneration.

Impact of abiotic (wind, summer drought) and secondary (bark beetle (Scolytinae)) or primary (cervids (Cervidae)) biotic factors affect the survival of Norway spruce (Picea abies (L.) Karst.) that is an economically important tree species. Norway spruce is mostly regenerated via planting – thus with significant investment. Therefore it is important to improve the resistance of Norway spruce stands as much as possible. Aim of the study was to characterize damages in Norway spruce stands by cyclonic wind storm and the regeneration of the stands, destroyed by the storm. Data from 4491 Norway spruce dominated stand, destroyed by the storm of 2005, from State Forest service database were obtained. Areas of post-storm sanitary clearcuts ranged from 0.1 to 7.6, mean 0.9 ± 0.02 ha. Most of the clearcuts were larger than 0.5 ha, demonstrating a relatively large size of gaps created by this natural disturbance. Changes of dominant trees species after the storm were statistically significantly affected by the forest type and type of regeneration. Overall, it happened in 55% of the former Norway spruce areas and was predominantly in cases, where natural regeneration was practiced. No indications of measures to increase stability of future stands against wind damages were found.

The aim of the paper is to present the spatial diversity of water resources in the Kuyavian-Pomeranian Voivodship during the drought in 2015. The region’s area is characterized by the lowest average annual precipitation in Poland, the lowest water resources and high water demand associated with intensive plant production. Hydrological research was carried out in September 2015 in 145 measurement points on various rivers. Despite the low precipitation recorded in August 2015 at the majority of meteorological stations, the volume of the specific discharge from the Kuyavian-Pomeranian region was characterized by high variability. The largest specific discharges were recorded for rivers located in the northern part of the region whose sources are located in the Pomeranian Lake District, i.e. Brda and Wda (over 2 dm3 sE−1 kmE−2) and the Masurian Lake District (Drwęca over 1 dm3 sE−1 km E−2). The smallest specific discharges (less than 0.5 dm3 sE−1 kmE−2) were recorded in the catchments located in the Kuyavian region (Tążyna, Zgłowiączka and Noteć) in the southern part of the Kuyavian-Pomeranian Voivodship and from the Osa River catchment. These areas are intensively used for agricultural purposes. The use of surface water resources as a potential source of irrigation water for crops can only be taken into account in connection with groundwater resources.

The urbanization and increasing growth of planet’s population accumulates significant volume of disposed waste as well as increases risks on human health and environmental safety. Landfill systems are the dynamic, living in space and time, potentially harmful entities that must be managed in as careful and smart way as possible. There are many studies related to landfill emissions such as leachates and methane. However, there is a need for advanced understanding of landfill hydrological regime and risks related to climate change and associated changes of hydrological cycle. The comprehensive studies about the urban hydrology are available; however, application to landfill management is fragmentary and inconsistent in several aspects. Landfill in long term has an impact on hydrological cycle. The heterogeneous land surface is one of aspects; however, there are still unanswered questions about the urban environment impact on water balance components. The aim of this study is to describe fundamentals of landfill hydrology in urban hydrological response unit context as well as evaluate the potential risks to environment and human health related to landfill geomorphology and hydrological balance in temporal climate conditions. The landfill hydrological cycle has similarities with urban hydrological cycle; however, there are additional components related to landfill specification, e.g., irrigation or leachate recirculation as well as total produced leachate.

In this article, the topic under discussion is the development of deformations in semi-rigid knee joints made of dowel type fasteners and consequences expected regarding overall deformations of timber portal frame structure. The use of semi-rigid connection resolves the problem of transportation, but development of small rotation in connection reduces the stiffness of the connection that becomes significant during service life. It is assumed that the rotational stiffness modulus Kφ (kNm∙radE−1) is the relevant characteristic of semi-rigid connection. Timber portal frame structure (span 30 m) designed with dowel type fasteners located around two circles has been subjected to different loading trials by using Dlubal software (RFEM). Results of a numerical study of portal frame model demonstrate the importance of characteristics of semi-rigid knee joints for design. It is found that developing deformations in the semi-rigid knee connection produce up to 90% bigger vertical displacement at an apex point and 96% bigger horizontal displacement comparing with the rigid knee joint model.

The global population has begun to rise exponentially; therefore, the demand for bioresources including food and fibre is increasing. An increasing demand for food and fibre necessitates more sustainable use of natural resources especially for soilbased ecosystem services. In this context, Functional Land Management was developed to optimize agricultural soilbased ecosystem services to meet both agricultural and environmental targets simultaneously. The aim of the research is to evaluate unmanaged agricultural land use change impact on primary productivity function in three parishes in Latvia by using Functional Land Management framework. Evaluation of primary productivity function was accomplished for both sectors agriculture and forestry by using profit and working hours as a proxyindicators. Production of vegetables and perennial plantations has higher supply of primary productivity function comparing to other land uses. Land use changes affect all soil functions that we expect from our land, especially primary productivity function. After applying land use changes, an increase in profit is higher in Liezere parish for both areas on mineral soils (7.1%) and areas on organic soils (5.2%); while an increase in working hours is higher in Usma parish: 36.6% in areas on mineral soils and 1.0% increase in areas on organic soils. Shortterm benefits are received from agricultural land, while forest land provides long-term return which increases over time but can only be obtained after reaching the age of felling. Before applying land use changes or changes in management practices we have to consider other soil function and national commitments.

Nowadays, with the rapid development of robotics and automation, there is a need for more powerful, more compact data processing equipment that also emits more heat. Various electronics cooling solutions are already in use, others are in development. Each cooling solution has its advantages and disadvantages. Active cooling usually dissipates heat more efficiently, but passive cooling is more reliable, especially when the electrical system is exposed to aggressive environmental influences. The possibility of using graphene in the manufacture of electrical equipment components is widely studied. Graphene could significantly improve the efficiency of passive cooling because its thermal conductivity is much better than copper.