The purpose of the study was to test a simple light meter (luxe meter) as a tool for determining light conditions in the fertile beach forest understory, as well as, evaluating its usefulness in understanding the determinants of changes in the phenology of fertile beach forests undergrowth species. Field research was conducted during the period from 10 March to 10 November 2014. A permanent plot (100 m²) was located in the fertile beech forest Dentario glandulosae-Fagetum, the Świętokrzyskie Mountains (southern Poland). Phytosociological relevés were done (for seven months of the growing season; every four weeks on average) on the permanent plot using the Braun-Blanquet method. In addition, phenological phases of herbaceous species of undergrowth which occurred in every relevé were noted.

   In the centre of the permanent plot and in the nearby glade measurements of illuminance, E, were performed once a week, using a hand-held light meter. The measured illuminance (in lux) values were converted into photosynthetic photon flux density PPFD (in mmol·m^-2 ·s^-1 ) and irradiance I (in W·m^-2 ). The changes of the absolute values of the indices of light conditions and the overstory light transmission (in %) were analyzed. The illuminance values measured using a simple light meter accurately reflected changes in fertile beech forest understory light conditions depending on vegetation variability, cloudiness and wind speed. A significant negative correlation was found: r_s = -0.93 at p = 0.003 (t = -5.51) between the percentage coverage of tree layer (based on the Braun-Blanquet scale) and the overstory light transmission (obtained from the illuminance measurements). Statistically significant relations between the percentage coverage of tree layer and the number and percentage coverage of geophytes and hemicryptophytes in a particular phenophase were also found.

Keywords: fertile beech forest, luxe meter, permanent plot, percentage coverage, Poland.

   Forest roads are usually single-lane roads built to unique technical standards with the purposes of accessing to forests and performing forestry in addition to other activities. With this study, in Karacaoren Forest Sub-District Directorate, evaluation of technical efficiency which consists of different variables of forest roads by scoring system was aimed to allow the function of the forest roads to be optimally performed over long time periods. Eleven different variables were evaluated to determine the technical efficiency of the forest roads in the study; these variables are the following: the road platform width, ditch width (condition), road expansion in curves and hairpin turns, superstructure, culvert condition, road-shadow condition, cut-fill slope stability, platform degradation, road inclination, and growth of plants on the road platform (the presence of bushy plants).

   The technical efficiency for each 100 m section of the forest roads was firstly evaluated in case area using the variables. Forest roads that the efficiency status was determined according to technical standards were recorded in the ArcGIS database. Finally, effects of topography (the slope, aspect) and soil characteristics on the technical efficiency variables were analyzed and mapped using SPSS and ArcGIS software.

    Our results showed that the “ditch width (condition)” and “platform width” variables were mostly not suitable accord-ing to the standards and the “plant growth” and “fill side slope stabilization” variables on the road platform were in good condition. The slope of the study area had a significant (p < 0.05) influence on the platform width, while the aspect of the study area had a significant (p < 0.05) influence on the ditch condition, the platform degradation condition, and the plant growth on the road platform. In general, the soil depth had some impact (p < 0.05) on the platform width, the cut side slope stability, and the plant growth on the road platform. The soil stoniness also affected (p < 0.05) the platform width, the cut side slope stability, and the plant growth on the road platform. However, the platform width, the cut side slope stability, and the platform degradation condition were all affected (p < 0.05) by erosion in the study area. Based on these results it concluded that the forest roads should be planned in sunny areas with slopes less than 51%, on “shallow soils” with “little stony” stoniness, and with “none to very little” erosion levels.

Keywords: Forest road, technical efficiency variables, GIS, SPSS, topography, soil characteristics.

   Increasing occurrence of natural and human-caused disturbances threatens sustainability of forest ecosystems, their ability to regenerate and maintain biological diversity. Simultaneously, forest tree species penetrate into abandoned agricul-tural lands, the areas of which have noticeably increased during the last decades. The aim of this study was to evaluate and compare the development of regenerating forest tree communities in terms of their growth, competition and species composition in ecosystems affected by various environmental stressors such as windthrows, insect pests, fungal diseases, traditional clearcuttings and agricultural land-use legacy. Lithuania, being located in the transition between the boreal and continental biogeographical regions of Europe, has been considered a favourable research area as both conifer and broadleaved tree stands as well as mixed ones are common here. Research methods used included inventory of vegetation and assessment of quantitative characteristics and sanitary condition of six regenerating forest tree species – Scots pine, Norway spruce, silver birch, pedunculate oak, common ash and black alder – in 7–8 circular research plots (50.24 m² each) per study site with total 17 study sites. Results of the study demonstrated that forest regeneration takes place in all disturbed ecosystems, although high variation in space and time was present. Species composition of the regenerating forest ecosystems depends on those prevailing before disturbance, although, pioneer species out-compete the others. The most intensive forest regeneration takes place in those forest ecosystems which were subjected to direct human impact, i.e., clear cuttings, and less intensive regeneration, particularly, that with the target species, takes place on sites cleared of windthrows and where sanitary fellings were applied. Although non-target species depending on habitat type usually prevail on cutting sites, numbers of saplings of target species are sufficient for the regeneration of high productivity forest ecosystems and development of the new ones given the competing species will be controlled by silvicultural measures. The pioneer herbaceous species established on areas affected by disturbances affect regeneration and species composition of the future forest communities.

Keywords: ecosystem disturbance; regeneration; abandoned agricultural lands; clearcutting; sanitary fellings; windthrows.

   The initial survival and growth of seedlings following out-planting affect the success of plantation activities. Due to transplanting shock, mortality is usually higher and the growth rate is lower in the first growing season following out-planting. In this study, the influence of leaf removal on the initial survival and growth of containerized black pine (Pinus nigra Arnold) seedlings was observed. Thirty seedlings were randomly assigned to one of four treatments: 0%, 25%, 50%, and 75% removal of the existing needles. Height growth, root-collar diameter (RCD) growth, increase in dry stem mass and dry root mass, and mortality were observed during the first growing season following out-planting. All seedlings survived the first growing season. Removal of needles did not affect the height growth, RCD growth, or dry stem mass of the seedlings. However, there was a statistically significant relationship between the removal of needles and the dry root mass; the dry root mass increased with increasing removal of needles. The initial results show that better root development is associated with needle defoliation. However, long-term observations of the seedling responses are recommended.

Keywords: Black pine, defoliation, dry mass, growth, survival.