Researching new remote sensing and data processing methods is very important subject in forestry. The objectives of research are to explore methods to determine single tree characteristics using LIDAR and adapt them for Latvian forest conditions. Different algorithms and mathematical relations for automatic calculation of tree species, coordinates, height and diameter at breast height are described. Within the project four different clustering methods for tree identification were evaluated. The first method's construction is based on reflection point count in certain height range. The second and third methods are searching for global and local maximums on height axis of LIDAR data collection. In the fourth method segmentation of aerial photography is done by using the user selected sample data. Tree tops were s discovered by searching similarly coloured regions. Field measurements were used for the calibration of LIDAR data and analysis. Sample plots were fitted in the study area with different species composition, age and density. The total number of measured trees in sample plots is 1844. Results show that height can be found mainly for I, II, III craft class trees with average error 2.5%. Stem diameter estimation error of pine is 28%, spruce 17%, birch 4.2% and second storey trees 5.4% using linear equations D = 0.6616*H + 4.6969 (for coniferous trees) and D = 0.7756*H + 3.7132 (for deciduous trees). Dividing trees in classes of coniferous and deciduous can be done by using near infra red photography. The total number of first storey trees identified by LIDAR is 91%, by aerial photographic method 94%.

This paper introduces the first test results to use laser scanning and high resolution digital colour infrared aerial image data to estimate average tree crown density at a sample plot level. General methodological framework based on two-phase sampling schemes, non-parametric estimators and satellite images as the auxiliary data sets was adopted for the use with airborne data sources. More than 400 circular sample plots were established and measured in a special research forest area near Kaunas, the central part of Lithuania. The tree crown density was visually estimated for every coniferous tree belonging to the 500 square m plot together with other conventional forest parameters. Two variants of digital colour infrared aerial images (ground sampling density 15 and 40 cm), LiDAR point clouds, based on 1 point/square m scanning density and two phase sampling approach with non-parametric k-nearest neighbour and most similar neighbour estimators were used to test the accuracies of tree crown density estimation at a sample plot level. Reliable estimates were found to be possible on pure coniferous stands only. Average tree crown density was estimated with the root mean square error around 17.5-18% at a sample plot level, bearing in mind average crown density around 64% for the whole study area. The estimates were unbiased. Integration of laser scanning based variables with the ones available from digital aerial images resulted in lowest estimation root mean square errors. Laser scanning based variables used as the auxiliary data set independently resulted in better estimation errors than the variables available from digital colour infrared images.

The purpose of using electrosurgical devices in veterinary practice is to reduce bleeding during the cut increasing temperature locally, causing coagulation and apoptosis of proteins. There is a lack of data on the extent and depth of these thermal damages and whether these effects on the different tissues are the same. Because of that, the aim of this study was to investigate which of the different electrosurgical devices causes highest heating effect on the skin tissue of rabbits (Oryctolagus cuniculus). The research was carried out at the Latvia University of Life Sciences and Technologies, Faculty of Veterinary Medicine. It included 50 rabbits, on average 2 years old, clinically healthy, with similar weight and condition. We formed five experimental groups: skin tissue cut with CO2 laser (n=10), an electrocoagulator (n=10), a tissue welding device (n=10), a radiofrequency apparatus (n=10) and a scalpel as control group (n=10). In order to evaluate the thermal effects of electrosurgical instruments on tissues, we performed contactless thermography. There were taken 3 images for each animal, totally 150 skin thermo-grams. From the obtained results we conclude that the most pronounced thermal effect on rabbit’s skin was caused with laser and an electrocoagulator. All electrosurgical devices caused a significantly higher (p is less than 0.01) increase in skin temperature compared to a surgical scalpel at the moment of tissue incision. During the study, it was found that the gentlest electrosurgical devices were used on rabbit skin tissue were a radiofrequency device.

In majority of cases, a positive effect can be observed upon application of Laser Agnis-L01 in treatment regimen of bone fractures. Positive effect of the laser was observed in 66.7%, no change in 22.2% and negative effect in 11.1% of the rabbits in experiment. To accelerate healing of bone fractures, we recommended the following parameters in treatment regimen with Agnis L01: impulse power 1.5 W, impulse frequency 250 Hz, modulation frequency 50 Hz and duration of treatment episode 240 seconds, 5 squares of treatment, 1 dosage per day, 10 treatment episodes. The treatment should start from day 4 after occurrence of fracture. Efficacy of laser treatment depends on individual properties of animal. Treatment of bone fractures is complex, laser treatment could be an element of the treatment regimen.