Antibiotic resistance of Staphylococcus is increasing worldwide. New antibiotics are used in big amounts in the meat production more and more. As a zoonosis, Staphylococcus aureus (S. aureus) is found in various species of animals and people, especially in those, who are working on commercial swine farms and slaughterhouses. The aim of the study was to find out the occurrence of S. aureus in different age groups of pigs on commercial swine farms in Latvia. Microbiological samples (n=702) including nasal, rectal, milk and air samples were collected during October 2013 from three closed farms of different sizes and several age groups of pigs and investigated with microbiological standard methods. S. aureus was found in all swine farms. The occurrence of S. aureus in Latvian pig farms was 41% and the highest occurrence of S. aureus was among 3-3.5 month old piglets. S. aureus was 1.8 times more frequently found in nasal than in rectal samples, and only in 28.38% of pigs S. aureus was in both - nasal and rectal samples. S. aureus was found also in sow milk in 13% of samples and in 3 samples of air (n=23).

The changes of areas of eight tree species in Lithuania during the past century were analysed. Aiming to apply the different approaches in forest studies, the Exponential smoothing method for forecasting the changes of the tree areas for the 25 years was used. The data dating from 1922 was analyzed as a time series. The descending trend was identified for Scots pine (Pinus sylvestris L.) and European ash (Fraxinus excelsior L.) and increasing trend – for Norway spruce (Picea abies (L.) H. Karst.), common oak (Quercus robur L.), birch species (Betula pubescens Ehrh. and Betula pendula Roth), black alder (Alnus glutinosa (L.) Gaertn.), European aspen (Populus tremula L.) and grey alder (Alnus incana (L.) Moench). The Exponential Trend with Multiplicative Seasonality (ET-MS) model was fitted for almost all investigated tree species with exception of European ash. For the latter species, the Damped Trend with Multiplicative Seasonality (DT-MS) model was chosen. Mean absolute percentage error of the model in all cases did not exceed 2%.

Latvia is one of the forest-richest countries in Europe. Very often in young forest stands of spruce admixture of coniferous or deciduous trees are taking place. During the growth trees suffer from influence of different risk factors. Damages in mixed stands depend on chosen mode and intensity of economic activities. Forest management cannot be imagined without creating the infrastructure (roads, ditches, etc.). However, the development of infrastructure may cause an effect of fragmentation and lead to changes in the forest structure. The aim of the research is to analyze influence of forest spatial features on the sanitary state of mixed stands of spruce. In 2011 and 2012 mixed stands of spruce younger than 40 years were investigated in all regions of Latvia. Nineteen stands were measured and surveyed and 80 sample plots were arranged. With the help of Geographical Information System (GIS) data base of the State Forest Service of Latvia the forms of forest plots (regular or irregular), as well as location of neighbouring infrastructural objects and location of mixed stands in forests were stated. In unnaturally created regular form plots damages of risk factors usually tend to be larger than in those, which have been created naturally. With the credibility of 95%, linear connection between occurrence of damages caused by browsing and intensity is relevant (r=0.937 is greater than r0.05=0.575), as well as occurrence and intensity of damages caused by Lophophacidium hyperboreum Lagerb. (r=0.999 is greater than r0.05=0.575).

Climate in Latvia has been changing in last decades, and it is predicted to continue changing; therefore, it is important for forestry sector to understand how these climatic changes might affect tree growth and survival. In order to assess climate suitability effect on Scots pine (Pinus sylvestris L.) provenances in Latvia, height and survival data from a Scots pine provenance trial located in three geographically distant places in Latvia were analysed together with several climatic indices. Provenances in the corresponding trial originated from Latvia, Poland, Germany, Belarus, Russia and Ukraine. Thirty year average climate data values from 1961 – 1990 for the 64 origins of provenances were acquired from the WorldClim project. Correlation analysis between provenance average values for height and survival and climate index values for the origins of the provenances confirm that there is a relation between these amounts, and the relation differs between the three site locations, indicating that suitability of climate is an important factor affecting the results of provenance trials. Cluster analysis confirmed that provenances from distant origins might have a very similar growth and survival rates; therefore, geographical location of the provenance origins cannot be considered as the only influential factor on these rates and the results from provenance trials have to be analysed together with climate data in order to make conclusions about the suitability of the provenances.

In Latvia, Picea abies and Pinus sylvestris as the commercially most valuable species make more than half of all woodlands. It has been found that about 23% of spruce stands are infected by root rot, caused predominantly by fungal pathogen Heterobasidion annosum s.l. To restrict the spread of root rot in coniferous forests of Latvia, the Joint Stock Company ''Latvijas valsts meži'' collaborated with Latvian State Forest Research Institute ''Silava'' in 2006 and launched a project for testing the Rotstop biological preparation, containing a suspension of Phlebiopsis gigantea spores. This project had a general task to accomplish Rotstop using technology approbation in Latvia and develop control system. Starting with the year 2008, preparation was used for stump treatment during thinning operations. When analysing the field data, a conclusion made in other studies was confirmed - P. gigantea colonizes pinewood more intensively even in case of improper stump treatment. It implies that the quality of stump treatment is decisive when using Rotstop for rot control in spruce stands.

Invention of light weight cellular wood material (CWM) with a trade mark of Dendrolight is one of the most important innovations in wood industry of the last decade. Currently CWM has been used as core material for sandwichpanels. These three layer panels are used in furniture industry and have wide non-structural applications. The aim of the research was to define the thermal properties of CWM and evaluate various wall envelopes where solid wood cellular material is used. There were 4 specimens of cellular wood material manufactured with nominal dimensions thickness 120 mm, length and with 600 mm to determine thermal conductivity and thermal transmittance according to standard EN 12667:2002. The specimens were manufactured of four layer 112 mm thick Scots pine (Pinus sylvestris L.) CWM double faced with 4 mm thick high-density fiberboard (HDF). Adhesive used in the bonding process was polivinilacetate Cascol 3353. Each direction (parallel, perpendicular) was represented by two specimens. Common procedure to evaluate the energy efficiency of building envelope is to calculate thermal transmittance in static conditions. The influence of the cellular material orientation to its thermal properties was investigated. Coefficient of thermal conductivity was determined for both material directions of CWM (l0 =0.0977 W∙m-1∙K-1 l90=0.148 W∙m-1∙K-1), combining the test method of EN 12667:2002 and calculation method of standard EN 6946:2008. To calculate thermal transmittance of various wall envelopes calculation software in JavaScript environment was created. Various compositions of external walls were assessed, thermal transmittance of these structures were calculated according to standard EN 6946:2008.

When the measurements of power consumed by cutting mechanism electromotor are made, the mechanical cutting power cannot be obtained, because they are different physical processes. However, determination of electricity power is relatively simpler. Therefore, both powers are determined in the study, in order to evaluate coherence between them. Computer numerical control machine was used for climb-sawing of aspen (Populus tremula L.) wood with a circular saw. Mechanical cutting power was calculated from measurements of cutting force, but the electric ones – from measurements of current and voltage. As a result, changes of both powers and of specific cutting work, on what the analytical calculation of cutting power is based, were obtained depending on length of the cutting trajectory. It is found out, that mechanical cutting power is greater than electric power, and it is useful to use for the analytical calculation, based on determination of the specific cutting work, wear coefficient of the cutter that depends not only on the duration of work of cutter, but also on feed speed and the length of the cutting trajectory.

The majority of natural Lithuanian rivers were regulated during intensive land reclamation period. Straightening of rivers caused unfavourable conditions for biodiversity. Four tributaries of the Merkys River in the South Lithuania were selected to explore changes in biodiversity patterns and determine the relationships between flow energy distribution in beds and ecological status of selected rivers. The research has shown that variation of cross sections area was usually 1.2 to 2.3 times higher in natural beds as compared to regulated ones. The range of rivers flow energy, estimated by Froude number, values were characterized as higher in natural (0.0 to 0.35) streams than in regulated (0.0 to 0.20) ones. This is the reason why the biggest number of macroinvertebrate taxa during the research period was recorded in natural riverbeds and the lowest - in the fields of the regulated segments. The assessing the abundance of fish revealed that total fish density in natural river sections was four times higher than in regulated ones. The research has approved the importance of naturalness for biodiversity and rehabilitation of regulated rivers in Lithuania.

The purpose of this article has been to present a range of products which can be obtained from agricultural production and used for energy purposes. The domestic demand for plant material to be converted to biocomponents was assessed, including the demand for oilseed rape seeds and other grain used to make bioethanol in Poland. One of the ways to limit the adverse effect of fossil fuels on the environment is by using renewable resources. Agriculture is the producer of biomass used to make biocomponents for liquid fuels and raw materials for substitution of solid fuels. The EU, wishing to stimulate production of biomass for energy purposes, has brought to life several legal acts which force the use of biofuels in the European Community. Farmers who produce substrate for bio-fuel production were offered subsidies to energy crop plantations, at first paid from the state budget, and in 2007 – 2009 provided under the Common Agricultural Policy (CAP), which increased the farmers’ revenues from farming. The decisions approved of while reviewing the CAP are to improve – via the market mechanism – the production and export potential of the whole EU. This is to be achieved, for example, by abolishing the subsidies to energy crops, which ceased to be paid in 2010. Such subsidies improved (artificially) the profitability of energy crop plantations, while causing a relative decrease in food production in Europe. By participating in the CAP, Poland is obliged to undertake certain measures in the domestic policy that will comply with the decisions made on the EU level.

The value of farm diversification is unquestionable especially in terms of additional income generation, income stability and easing the employment difficulties of agricultural producers; its importance has recently been in the focus of agricultural and rural policies. The research purpose was to describe the situation of farm diversification in Hungary and to analyse the characteristics of diversified farms, as well as to determine which factors influence the extent and direction of diversification. The research method is based on statistical data analysing and questionnaire survey. Contrary to the above my analyses showed that the share of diversified farms is rather low in the small-scale, semi-commercial and part-time farms; its wide scale distribution is hindered by several factors. Based on the analyses I found that in private farms and in corporate farms it is characteristic that farm diversification activities are closely connected to the main activity of the farm, but they are of different type. I could state that the share of diversified farms is more significant in the labour-intensive farms and primarily in commercial farms. The share of young farmers and farmers in active age, qualified and with a full-time job is higher in the diversified and organic farms.