One of the most often mentioned competence in the surveyed literature is problem solving. It is also one of the key skills for the sustainable development of society. The article includes analysis of pedagogical approaches like project-based, problem-based learning and enquiry-based learning, as well as describes the use of design thinking as one of the problem solving approaches in higher education. As mathematics studies at universities play an important role in developing problem solving skills, an empirical study was carried out to identify the pedagogical approaches used by mathematics teachers and to illustrate the development of problem solving skills in mathematics studies at universities in Latvia. It includes a survey of mathematics teachers in Latvia aimed at identifying their experience in implementing different pedagogical approaches to mathematics and assessing the extent to which these methods help develop problem solving skills. The answers of mathematics teachers show that problem solving skills are developed at the middle level, which means only for the use in a certain situation (that is slightly different from previously known). The most effective approach to promoting problem-solving skills is the so-called context approach, which means focusing on the practical task related to a specialty. In the empirical study self-assessment method is used and the results are based only on respondents’ opinion.

Latvia University of Life Sciences and Technologies, Latvia Precision of the forest inventory planning is still one of the most important problems in the forestry nowadays. The aim of this research was to estimate the sample tree height results of the combined forest inventory (LiDAR CFI) and LiDAR (Light Identification Detection and Ranging) height data by calculating an average value from sample tree neighbouring pixel values in the ripening Scotch pine forest stands, comparing the results with the measurements of the height in the area. For the update of LiDAR calculated data and LiDAR CFI height results, the increment algorithms of the Latvian State Forest Research Institute ‘Silava’ were used, comparing the results with the sample plot measurements. Both results showed a close correlation – in the case of LiDAR CFI with R2 =0.82, LiDAR data with R2 =0.93, demonstrating a standard deviation: 2.40 and 2.75, accordingly and standard error: 0.11 and 0.13, accordingly. The results indicate that both technologies can be used in the forest management, offering reliable information about the forest inventory. Positive values were reached by minimizing the human error factor, which is problematic for the field inventory.

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.

The capercaillie Tetrao urogallus L. is a typical bird species inhabiting structurally diverse coniferous forests. To increase the habitat quality of capercaillie leks, experimentally the habitat restoration in degraded ecosystems has been practiced. The main habitat restoration events are related to the reversion of hydrological regime and understorey layer management. The aim of this study was to find out how the management of lek sites – mowing of Ledum palustre L. and ground vegetation – promotes the regeneration of the vegetation typical of the capercaillie leks. Three sample plot blocks of 10x30 m have been established, which have been divided into 3 variants of 10x10 m. The first is a control plot, in the second plot an entire ground vegetation mowing was performed, while in the third plot – the ground vegetation mowing in a 3 m wide strip was carried out. The vegetation was determined using the BraunBlanquet recording form before the management – in August 2015, and after the management – in August 2017. The condition of the habitat of capercaillie is inadequate before management, since Ledum palustre prevails in the ground vegetation. Both types of ground vegetation management have had a significant impact on the projective cover of Ledum palustre. After mowing the entire area, it has decreased by half, but after mowing in a strip, it has decreased by 30%. The ground vegetation mowing in a strip enhances positively the regeneration of dwarf shrubs and herbaceous vegetation.

Conifer tree stumps are a prospective source of bioenergy, but there are considerable uncertainties and risks associated with this forestry practice, and environmental consequences of stump harvesting are little studied in the Baltic countries. One of the major concerns is related to the risk of nutrient leaching that may cause pollution of watercourses and decline of tree growth in the next forest generation. The main aim of the present study was to estimate the effect of stump harvesting on general soil and soil solution parameters in three clear-cut areas located in Hylocomiosa site type (dominant tree species prior to clearfelling – Picea abies L. (Karst.)) over a period of 6 years after the stump removal. Two types of treatments were compared: whole-tree harvesting with only above-ground biomass removed (WTH) and whole-tree harvesting combined with the stump removal (WTH+SB). We found no acidification effect of soil and soil solution. Soil C and N stocks six years after harvesting were similar in the plots with and without stump removal, and demonstrated similar pattern of change in both studied treatments (WTH and WTH+SB). Nutrient content and patterns of change varied with the site and year, suggesting that the effects are rather site- than treatment-specific.

Resorts in the Republic of Lithuania are residential areas with natural healing factors (mineral water, healing mud, health-friendly climates, recreational areas and water bodies) and a special infrastructure enabling them to use these factors. Currently, there are 4 resorts in the country: Birštonas, Druskininkai, Neringa and Palanga. The purpose of this article is to carry out an analysis of the anthropogenic landscape of the resorts of the Republic of Lithuania in 2007-2018. During the preparation of the article, the following scientific methods were used: literature analysis, determination and evaluation of the current situation, grouping method, comparison method, analytical and statistical analysis methods, logical analysis, graphical method. The analysis showed that the anthropogenic landscape of the three resorts increased: in Druskininkai – by 362.65 ha or 18.17%, in Neringa – by 113.43 ha or 52.78%, in Palanga – by 190.74 or 15.09%. The anthropogenic landscape of Birštonas has decreased by 41.11 ha or 5.03%. Over the past decades, with the intensification of anthropogenesis and its accompanying urbanization, the importance of the natural environment has become more and more understood, and landscape research, which is associated with the assessment of naturalness and its problems, is becoming more and more relevant.

This study is important to contribute morphometry researches and give an example of how to accomplish studies about lakes. The aim of the study is to use the latest technology to determine the morphometric parameters and their variability compared to the previous research results. Research focuses not only on local water body morphometry and bathymetry, and their influencing factors, but also deals with methodological issues regarding measurements of morphometric characteristics and data interpretation as well as state of the art visualization of results. On many occasions, there is a lack of research on morphometry of water bodies or they have taken place in the last century, which has led to the use of obsolete research methods in modern morphometry studies that do not produce the results of a high level of detail. The aim of the study is to use the latest technology to determine the morphometric parameters and their variability compared to the previous research results. The study consists of analysis of the literature on morphometry, methodology used in bathymetry studies, history of research, research methods used in the previous studies. The research object is Lake Kisezers including its morphometry, bathymetry, and influencing factors. The results of the study show that morphometric parameters of Kisezers differ from the results of previous studies. The results of the study confirm that Lake Kisezers is exposed to various influencing factors, mainly anthropogenic. The main factor influencing morphometry and hydrological regime in Kisezers is the water level fluctuations influenced by Riga Hydroelectric Power Plant.

Society aims to develop frames for recognizing important geological and geomorphological sites and features or landscapes within their national and even transnational boundaries. Earth heritage sites educate the general public and preserve cultural and environmental matters. New trends of sustainable development, importance of site conservation are demanding that landforms and landscapes, rocks, minerals, fossils, soils should be protected legally, as they give understanding about the evolution of Mother Earth in local and regional context to generations. The Geopark concept was developed in cooperation with UNESCO and followed a large number of requests to UNESCO from all over the world, from geological institutions and geoscientists and non-governmental organizations, and it became extremely popular and influential to preserve those geological heritage areas, nowadays still recognized only nationally or not at all. This paper aims to give comprehensive overview of existing geoparks in the Baltic Sea Region, as well as analyse aspiring geoparks and unpublished initiatives of potential geopark (Livonia and Vooremaa) eventual establishment in frames of cultural and landscape preservation context. Criteria, requirements and earlier studies are given in context. The geoparks should mainly contain cultural and educational purpose while targeting the least possible damage in preservational aspect.