One of the most challenging issues in forest inventory based on remote sensing data is identification of tree species. Hyperspectral remote sensing data provides information which considerably facilitates tree species recognition. The objective of the research is to evaluate different hyperspectral data analysis methods to classify tree species in Latvian forest conditions. The study site is a forest in the central part of Latvia, Jelgava district (56º39’ N, 23º47’ E). The area consists of a mixed coniferous and deciduous forest. During research 598 trees were analyzed in 70 sample plots. Remote sensing data are 64 hyperspectral bands in the 400 - 970 nm spectral range. Two different classification techniques: linear discriminant analysis (LDA) and artificial neural networks (ANNs) were used. In LDA species classification was done by stepwise and using principal components of hyperspectral bands. In stepwise LDA 18 hyperspectral bands were used. LDA using principal components and ANNs used all 64 hyperspectral bands. The best results show stepwise LDA where 82.4% of the data were correctly classified. Scots pine was classified 94.8%, Norway spruce 83.5%, Silver birch 77%, European aspen 71.4% and Black alder 56.3%. Classification with ANN’s best results showed for Scots pine, Norway spruce and Silver birch – respectively 81%, 84%, 86%. With LDA using principal components Scots pine’s classification showed best results with 85.1% correctly classified trees.

The objective of this study is to elaborate the mathematical model describing the bark proportion (BP) in stems of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies [L.] Karst), silver birch (Betula pendula Roth.) and aspen (Populus tremula L.), as well as to analyze the vertical variation of the BP for the aforementioned species. The study material consists of data of 372 sample trees sampled in three regions of Latvia – Western (Kurzeme), Eastern (Latgale) and North-eastern (Vidzeme) during the years 2011 – 2014. The BP for each tree was calculated as a difference between the under-bark and over-bark stem volume. In this study, we compared the performance of three power regression models in predicting of BP using breast height diameter (DBH), tree height (H) and total volume (TV) as independent variables. The best fit to data was achieved by using tree height for the prediction of BP. Our results confirm that the highest proportion of the bark is at the upper part of the stem (relative height 95%) for all trees species. Pine stems have a lower BP of up to 30% relative height comparing to other species, while the spruce has the lowest bark percentage at the stem base relative to other tested species There were no significant differences found in BP among the stands from different regions for all studied species, indicating no need for derivation of separate equations for each region and ascertaining the possibility of use of the average BP values for the whole country.

The regeneration of European hornbeam (Carpinus betulus L.) has been assessed in the National Gene Reserve Forest near Lukne in the south-western part of Latvia, which is the northernmost point of hornbeam distribution in Europe. In the studied stand, six sampling plots and four transects were established to assess stand structure and the effect of irradiation parameters on stand regeneration. Successful regeneration of hornbeam was shown by its presence in all height and diameter classes. Nevertheless, in the smallest height and diameter classes, an increased abundance of other shade tolerant species (maple (Acer platanoides L.) and lime (Tilia cordata Mill.) was observed. Norway spruce (Picea abies Karst.) mainly formed a scattered second forest floor and, apparently, competed with hornbeam. Light parameters, particularly, the diffuse radiation, had a significant effect (p=0.05) on the distribution and abundance of hornbeam understory. The threshold values of irradiation parameters for hornbeam were notably higher compared to other species. The number and height of hornbeam saplings correlated tightly with the amount of available light. Nevertheless, under sufficient light conditions hornbeam showed good vitality, thus suggesting suitability of growing conditions.

In Latvia, two European ash (Fraxinus excelsior) genetic resource forests (GRF) have been designated in Skrīveri and Bērvircava. However, as the degree of damage of ash by the pathogenic fungus Hymenoscyphus fraxineus has increased, many stands have died and many do not comply anymore with minimum requirements for GRF. The aim of the present research was to evaluate and examine the quality of ash GRFs. In each forest unit, one 20×20 m plot was established, and the first (E3) and second (E2) layer projective cover of each species was determined in August 2014. All undergrowth and advance regeneration species were counted and the degree of ash damage by H. fraxineus was determined along a diagonal 25×1 m transect in each plot. In total, 101 plots were established. Quality evaluation was carried out according to the basic criteria for selection of GRF as well as based on criteria cited in other research. Their variation was established by using principal component analysis. Ash in layer E3 was better maintained in Skrīveri, but ash regeneration there was worse, as well as a higher degree of damage by H. fraxineus was observed. Ash regeneration density is significantly influenced by its cover on layers E3 and E2 as well as by tree species dominating the growth. The most valuable GRFs have been maintained in Skrīveri where 50% of units were rated of average quality and few of bad quality. In Bērvircava, 56% of forest units were of bad and very bad quality.

Wind is an important natural disturbance factor in a forest ecosystem. It creates gaps in a forest canopy, providing microenvironmental conditions, suitable for forest regeneration and affects the species composition of ground vegetation. Most of the studies analysing consequences of wind-storm have addressed short-term changes or influence the stand structure, but the aim of our study is to analyse ground-vegetation long time after windstorm in hemiboral forests. Data on ground vegetation cover have been collected in areas affected by the storm of 1967, where due to salvage-logging 200-400 m wide clearcuts were created. Sample plots (1×1 m) were placed in different distance from the edge of former clearcuts and projective cover of ground vegetation assessed using Braun-Blanquet method in Myrtillosa mel. forest type on 5 sites in north-western part of Latvia. Results reveal that in all sites species belonging to boreal, boreal-temperate and temperate biome were present, but their proportions varied between sites. In total 82 species of vascular plants were found, most frequent among them Maianthemum bifolium (L.) F.W.Schmidt (species characteristic to Norway spruce forests), Vaccinium myrtillus L. and Vaccinium vitis-idaea L. (associated with Scots pine forests) as well as Molinia caerulea (L.) Moench and Deschampsia caespitosa (L.) P.Beauv. (both characteristic to wet soils). Results suggest, that even 47 years after the storm microenvironmental conditions in the sites are not stable. Ellenberg’s indicator values reveal, that most of the sites are in semi-shade, cool and moist conditions, placed on acidic, nitrogen-poor (in few sites – also nitrogen rich) soils.

Thinning of young forest stands is a contribution to the future of the stand development. Our study focuses on damage of the remaining trees and soil. Now it is common to see thinning of young stands with heavy forest machines, but most of these operations take place in commercial thinning. This study is focused on precommercial thinning to evaluate different mechanized thinning methods in relation to the damage done to the remaining trees and soil in deciduous tree stands. Data were collected in four stands where the average diameter of trees at breast height was 6.2 cm, the height of average trees - 9.5 m, but number of trees per hectare was more than 2900. The stands regenerate naturally. Damage was evaluated separately after harvester and forwarder operations. The study proves that forwarding makes much less damage to the remaining trees than harvesting. According to the study data, the traditional method results in the largest number of damaged trees, because operators need to cut all trees closer than 1.5 m from the target tree. Both schematic thinning methods result in significantly less damage. A statistically significant difference (p is less than 0.001) was found in a proportion of damaged remaining trees between all of the applied working methods. The smallest amount of damage is associated with complex symmetrical thinning method. The most damage appears during harvesting. The aim of this study was to compare three working methods of biofuel production in pre-commercial thinning using harvester John Deere 1070D with accumulating felling head Bracke C16.b in grey alder (Alnus incana) pure stand.

Scots pine (Pinus sylvestris L.) is the most common wood species in Latvia. It is classified as not durable, therefore additional protection against microorganisms is needed prior its use outdoors. Presently Cu-containing wood preservatives are commonly used, but the biggest drawback is the poor Cu fixation, therefore raising concerns about the impact on the environment. Three types of specimens were used to carry out the experiments – untreated, Latvian originated Scots pine; Scots pine commercially treated with preservatives that belong to a group of Cu-boron-triazole (CBA) products; and Scots pine, impregnated with micronized-Cu solution using a standard full cell process. In order to make sure that all of the specimens are equal in their components, elemental analysis was performed and content of nitrogen (1.2 – 2.5 g kgE-1), carbon (485.5 g kgE-1), oxygen (456.0 g kgE-1) and hydrogen (55.6 g kgE-1) was determined. The treated specimens were leached according to the European standard EN 84. For micronized-Cu impregnated Scots pine the total Cu content in leachates obtained by atomic absorption spectroscopy was 0.15 mg gE-1 of wood, and 0.06 mg gE-1 of absolute dry matter with CBA preservative impregnated Scots pine wood. Subsequently, according to the European standard EN 113, treated Scots pine blocks were exposed to brown-rot fungus Coniophora puteana and to white-rot fungus Trametes versicolor for 16 weeks. Mass loss for wood treated with micro-Cu was 48.4% (484 g kgE-1) and 1.5% (15 g kgE-1) respectively, but for CBA – 49.5 % (495 g kgE-1) and 1.2% (12 g kgE-1). Both samples proved to be inappropriate for outdoor use (use class 3).

This article deals with conception and particularity of management process and functions of non-governmental organisations (hereinafter referred to as NGO), as well as peculiarities of management functions of NGO. Empirical research results of implementation of NGO management functions in Kaunas District have been presented, the major advantages and disadvantages of implementation of NGO management functions in Kaunas District have been pointed out. With reference to the data of theoretical analysis and empirical research, the directions towards development of problematic areas of NGO management functions have been indicated and justified, highlighting the elimination of drawbacks to the implementation of management functions.

Recently economic development has been an issue of intense research and discussion in an academic society. Many facets of countries’ economic development were examined, including foreign trade. As a foundation of international cooperation, this indicator is relevant in observing one’s internal development and external ties. In case of Latvia, this topic is heavily influenced by economists, and the geographical perspective is quite underdeveloped. In this research, the economic ties of Latvia were explored through the analysis of its main export groups in sectors of agriculture, forestry and fisheries throughout the first decade of the 21st century. With the aim of establishing clear ties between Latvia and its major export markets, the statistics of foreign trade was analysed using frequency analysis. It can be reported that in general Latvian export markets are closely located and consist of the Baltic Sea Region countries such as Denmark, Germany, Russia and others. Despite the differences in commodity group destinations, it can be clearly stated that a division of trade flow still exists, separating it into two directions - Eastern and Western, where the former allocates the majority of Latvian processed commodities and more sophisticated goods, and the latter consumes raw materials and less transformed materials. This arguably shows a difference in demand in Western and Eastern markets, where the first mostly requires materials for its own industry, while the latter procures them for consumption on the local market, again pointing to a complexity of reforms required for the Latvian economic focus turning towards Western markets.

The objective of the paper research is to assess the role of the implementation of the local development strategies (LDS) elaborated by the local action groups (LAGs) in the regional development and addressing social problems in Latvia. The paper examines the role and place of LDS in territorial development planning in Latvia, carries out thematic analysis of the projects implemented under the LDS as well as tries to assess the LEADER approach impact on regional development and addressing of social issues on the local level. The authors use unpublished data on LEADER projects and apply quantitative and qualitative analysis methods. Most of LEADER projects have been implemented to facilitate the development of infrastructure related to recreation and quality leisure time as well as culture and sports. Rural inhabitants have noticed positive changes in their local territory introduced by the LEADER approach. Though, in order to enhance the role of LAGs and LDS in addressing regional development and social problems at local level, it is advisable that the potential interaction of the activities provided by all regional planning documents is observed when determining priorities at regional level (presently the place and role of the LDS has not been formally defined), while implementation of the LDS should pay more attention to long-term effects and even accomplishment of target priorities.