Research in many countries across the world, including Latvia, shows that youth participation in national defence is a topical issue. So far, scholarly research focusing on the promotion of youth participation in national defence and the provision of career support at school age and after finishing school is scarce. Therefore, the aim of the research was to establish the basis for young people’s military career in national defence. Research results show that there is both theoretical and legal basis for young people to start a military career, already during school years. Based on the broad meaning of the concepts career and career development, young people’s self-development, self-management and self-actualisation in various fields of human activity over one’s lifetime emerge as topical issues. Such activities of various kinds may follow one another in succession or take place simultaneously, in parallel, in accordance with dual career theories. The beginning and development of young people’s military career in Latvia can occur in the context of various activities already present and available in the near future: 1) participation in the Latvian Youth Guard as a type of non-formal education, 2) acquisition of National defence training at school in the context of formal education, 3) upon reaching legal age, voluntarily joining the Latvian National Guard, which is a component of the National Armed Forces of the Republic of Latvia.

Dialogue (discourse) is the main indication leading us to the conclusion that mediation is constructive. Discourse, the main form of dialogue, allows to achieve a positive result of mediation – an agreement between the participants of the conflict, as well as to learn dialogue communication skills. The aim of this study is to determine the types of dialogue used in mediation, the usage of recognized dialogue, and to find methods for assessing the dialogue (discourse) skills that need to be taught to the participants of the conflict, as well as future mediators and to evaluate the effectiveness of mediation. The research was conducted based on the theoretical methods of analysis of modern concept of dialogue and empirical testing methods (using questionnaires) of the participants of the conflicts and future mediators. Methods of mathematical statistics were used, when processing and analysing the results of the questionnaires. As a result of this work, the types of dialogue used in mediation are identified; recommendations on the choice of components and barriers of dialogue to be considered by the mediator when training participants in the conflict and future mediators are made, as well as recommendations on assessment the effectiveness of mediation are offered.

Dead wood is a significant component in forested ecosystems. In Fennoscandia and Baltic countries, set-aside forest areas, also called woodland key habitats (WKHs), have been created for nature conservation purposes in the production forest landscape. We performed a comparative study on dead wood substrate availability in different WKH types in Latvia. We measured standing trunks and downed logs to estimate biological quantities and qualities for coarse woody debris substrate. In this study, we found out that dead wood availability ranges, on average, from 38.2 to 149.5 m**3 haE−1. This study showed that moderate quantity and quality of dead wood has been found in different types, but the fine quality coarse woody debris was scarcely presented. In general, WKHs provide moderate and high level of qualities and quantities of structural features in the production forest landscape.

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.

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.

A demand for wood resources is increasing. In addition to drainage and appropriate regeneration and thinning, the forest soil fertilization may increase the future harvest rates. Therefore, the improved growth of forest stands raises in priority among the research topics related to forestry. The objective of the study is to evaluate the impact of nitrogen fertilizer on soil water and throughfall water chemical composition to elaborate recommendations for the forest fertilization. The trials were conducted in a birch stand and in three coniferous stands. Nitrogen containing mineral fertilizer (ammonium nitrate) was distributed in the study sites, while the control plots were left without any treatment. The water samples were collected a season before and a season after the soil treatment. The pH level, total nitrogen, potassium and phosphate were determined in throughfall and soil water samples. The chemical properties of throughfall water differed depending on the forest stand type. The concentration of nitrogen was higher in throughfall water samples collected from the birch stand. The mean concentration of total nitrogen was 1.6 ± 0.3 mg LE−1 in the throughfall water samples from the birch stand compared to 1.03 ± 0.11 mg LE−1 in the throughfall water samples from the coniferous stands. Although the forest soil was enriched with the nitrogen fertilizer, there was a significant increase in concentrations of potassium and phosphate in soil water samples from certain stands. It can be explained with changes in pH level that occurred after the forest soil treatment with ammonium nitrate. There was also a significant increase in total nitrogen concentrations in soil water samples at the depth of 30 cm from the treated plots of the coniferous stands – 15 ± 6 mg LE−1, compared to 1.5 ± 0.03 mg LE−1 in the samples from the control plots. However, the concentrations decreased within two months and remained at a steady rate – slightly above the control level.

Forests offer a wide variety of ecosystem services, including cultural or recreational services. In that sense, state-owned forest lands hold the biggest responsibility to acknowledge and provide these services, where it is economically and ecologically viable. Suitability analysis has been extensively used to provide information on species conservation measures, and it is possible to apply similar techniques for potential supply of recreational services. A simple weighted overlay analysis was conducted to locate forest land areas most suitable for potential recreational activities. Several criteria were selected for the analysis, including forest stand parameters such as forest stand age, forest stand type and species, topographical diversity and remoteness. Basis for the weighting of the selected criteria were obtained from the social surveys, previous research work done in Latvia and the Baltics, and European scale scientific data on recreation preferences. The analysis showed that 20% of the total model area analysed provide substantially high recreation potential. Furthermore, these preliminary data can be used for surveying and facilitating community involvement processes. Local tourism and nature leisure activities can be promoted by exploring possibilities of alternative forestry planning options, utilizing such multifunctional assessments of recreational supply.

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.

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.

Global scale environmental problems and economic issues are the main aspects what point out exigency to do research in the construction of renewable building materials. Renewable building materials are those materials that can be regenerated quickly enough and in theory, their production could be carbon-neutral. In order to evaluate the thermal efficiency of renewable materials in the framework systems of building envelope structures, test samples were made with the filling of renewable materials. The aim of the work is to find out the thermal conductivity coefficient of these natural composites and to compare them. Different size test samples were created for determination of thermal conductivity coefficient: 1.type as reference value: (width x height x depth) 290 x 290 x 30 mm; 2.type as experimental construction value (imitation of real wall construction): (width x height x depth) 980 x 980 x (165; 250; 345) mm. In this research as renewable insulating materials were used: maple leaves, legume (Galega orientalis), the composition of hemp shives (Bialobrzeskie) and sapropel with lime. A renewable insulating materials (also known as eco-thermal insulating) as alternative building materials discussed in this research work meets the requirements of the normative documents of the Republic of Latvia on sustainable construction principles. The analysis of results indicates significant difference among investigated materials – 0.040 W mE−1KE−1 lowest obtained value of thermal conductivity coefficient.