Invazija žljezdastoga pajasena (Ailanthus altissima (Mill) Swingle) u urbanim i ruralnim područjima Vukovarsko-srijemske županije

Three-of-heaven (Ailanthus altissima (Mill.) Swingle) is considered as one of the most invasive plant species worldwide in rural and urban environment. Although tree-of-heaven is commonly observed throughout the city of Osijek (Croatia), its prevalence and frequency has not been documented. This study has been conducted from May to September 2022 in the streets of Osijek to determine the distribution, abundance and competitive advantage of this species. A survey was performed by sampling randomly selected 20 quadrats in each city district, having together 140 phytocoenological records, and presence-absence of tree-of heaven was recorded in each plot. Where present at urban habitats, the number of threes were recorded and categorized approximately by the diameter at breast height (dbh). Habitats were distinguished as follows: alleys, abandoned private areas, public areas, ruderal sites, cracked walls and road edges. Risk assessment analysis were prepared by combining quantitative (number of trees per plots) and qualitative (four categories: biological characteristics and dispersal abilities, ecological amplitude and distribution, ecological impact, and difficulty to control) data. There was e recorded a total of 189 tree-of-heaven, occurring both as solitary plants or in developed stands. The habitat types with the highest rate of tree-of-heaven are abandoned private areas (34%) followed by public areas (31%). Out of the total, 55% of the recorded tree-of heaven are young individuals belonging to the very small and small diameter classes, and are mainly present on abandoned private and public areas. Ecological impact and biological characteristics are primary course of its landscape spread.

The influence of elevation on the forest development and also on more structural elements is evident. The aim of this paper is to research the impact of elevation on the relationship between diameter at breast height (DBH), tree height (H), crown length (L) and stem volume (V). In the area of the Pelister National Park in North Macedonia, 22 experimental plots (EPs) were established in the even-age Pinus peuce Gris. stands with an average age of 90 years. The EPs were of a circular form and covered an area of 500 m2 each; 6 of them were established at 1150 meter above sea level (m asl), 7 at 1350 m asl and 9 at 1550 m asl. DBH, tree height, and crown length of 481 trees were measured in all EPs. The DBH – H model was prepared in accordance with Prodan, as well as nonlinear (polynomial) regression for the relation between DBH and L and nonlinear (power) regression for the relation between DBH and V. The stem volume was calculated with a formula by Parishko for Pinus peuce Gris. The quadratic mean of DBH, average Loray height, average crown ratio, and the density of the stands were also calculated. The relationship between DBH and H, L, and V was examined with Pearson correlation and root mean square deviation (RMSE). The differences between averages of H, L, and V from the EPs were tested with analysis of variance (ANOVA) with an elevation class (1150, 1350 and 1550 m asl) as single factor. The density of stands was 490, 429 and 409 trees per ha on 1150 m, 1350 m and 1550 m asl, respectively. The average DBH was 39.8 cm, 46.5 cm and 45.5 cm, and Loray height was 23.9 m, 24.1 m and 22.6 m at 1150 m, 1350 m and 1550 m asl, respectively. Crown ratio (CR) pointed out different results on the different elevations, with the average value of 40.5%, 43.7%, and 39.3% at 1150 m, 1350 m, and 1550 m asl, respectively. Differences between average structural elements at different elevations can be confirmed with ANOVA with a significance of p<0.05 and F of 3.4 for H, the significance of p<0.05 and F 3.2 for L data and p<0.05 and F of 9.7 for the value of V. In that way, the regression model for H is higher at a lower elevation, the tree has a longer crown length at lower elevation and also has a bigger volume at lower elevation. From the results, it can be concluded that the elevation has an influence on the relationship between DBH on the one hand and H, L and V as structural elements on the other hand. It can be said that at higher elevation trees have a smaller average height, DBH, and volume and have longer crown length than trees at lower elevation.

Among the woody and shrubby weeds colonising non-crop areas in the Apulia Region (South Italy), Ailanthus altissima (tree of heaven), an exotic invasive species, is one of the worst, because of its fast growth and root-sucker production. It reaches the heart of protected areas and spreads everywhere in urban and peri-urban areas creating dense stands. As there are no official monitoring protocols for weed mapping, a method based on real-time global positioning system (GPS) on satellite maps was set up. Due to this method, the distribution, spread, size, density and harmfulness of A. altissima were assessed across the wide urban area of Bari (South Italy) by mapping all the individual plants and areas/stands of plants. In Bari, along a total of 76 km of roads mapped, 170 very large (diameter >18 cm), 231 large (diameter 8–18 cm), 130 medium (diameter 3–8 cm), 53 small (diameter < 3 cm) single plants, and 70 high, 63 medium and 13 low density areas were detected. This indicated that A. altissima (tree of heaven) was very widespread in the study area. Moreover, 35 types of damage or potential risks were recorded covering functional, environmental, health and safety and aesthetic aspects and then classified according to frequency and location. The real-time GPS method proved to be very useful for providing a speedy and accurate record of the data.

The purpose of this study is 1) to determine differences in the characteristics of the spatial thinking ability of students in urban and rural school environments and 2) to determine differences in the characteristics of the spatial thinking ability of the students in the urban and rural school environments in terms of the type of gender. This research uses experiment methods with a population of class XI students of Social Science both in urban and rural schools with a total sample of 31 students from each school. Spatial thinking skills are measured through the test of problem solving using the satellite imagery of Google Earth as a tool of representation. Spatial thinking skills assessment is based on the components of spatial thinking. It includes understanding concepts of spatial, the use of representation tools, and reasoning process. The data analysis uses statistical for different test with SPSS 25.0 for windows. The results showed, first, spatial thinking ability character’s between students in the urban and rural environments are significantly differences. So, the character of environment, i.e., urban and rural is not always consistent in influencing the spatial thinking ability of the students. Second, no differences in the spatial thinking ability in the statistics between male and female students. However, the students in urban environment have the characteristics of spatial thinking better than the students in the rural environment. Female students in urban environment have more powerful character of spatial thinking skills, though it is not proven in male students.

Background and Objectives: The aim of this study was to determine the effects of different stand densities and thinning regimes on stem quality parameters, mainly branch characteristics, of Scots pine (Pinus sylvestris L.) trees. The study provides some input to the discussion about Scots pine stem quality responses to different forest management practices in relatively young stands. Materials and Methods: Total tree height, height to the lowest live and dead branch, diameter at breast height (DBH), and diameter of all branches from the whorls located up to 6 m from the ground were measured. The linear regression models to predict branch diameter, as the main parameter for the stem quality assessment, were developed based on stand density and stem parameters. Results and Conclusions: DBH, branch diameter and number of branches up to 6-m stem height were significantly higher in the stands with the lowest density. These stem parameters showed a relatively clear downward trend from the lowest to the highest stand densities. The main identified variables which significantly affected stem quality, were branch diameter and diameter of the thickest branch in the bottom part of the stem, at least up to 3-m stem height. For practical use, the best fitted model was estimated when stand density, DBH, and branch diameter up to 3-m height were included in a single equation. The developed model for branch diameter could be used as a forest management tool for managing stem-wood quality.

贵州雷公山秃杉种群生活史特征与空间分布格局

This paper is concerned with a quantitative and comparative analysis of wind velocities in urban and rural environments. It is undertaken to provide a route to the classification of wind energy in a rural and urban setting. This is a common problem and the basis of a significant focus of research into wind energy. In this paper, we use a non-Gaussian statistical model to undertake this task, and, through a further modification of the data analysis algorithms used, extend the model to study the effect of wind turbulence, thereby introducing a new metric for this effect that is arguably superior to a more commonly used and qualitatively derived measure known as the Turbulence Intensity. Starting from Einstein’s evolution equation for an elastic scattering process, we consider a stochastic model for the wind velocity that is based on the Generalised Kolmogorov Feller Equation. For a specific ‘memory function’ - the Mittag-Leffler function - it is shown that, under specified conditions, this model is compatible with a non-Gaussian processes characterised by a L´evy distribution that, although previously used in wind velocity analysis, has been introduced phenomenologically. By computing the L´evy index for a range of wind velocities in both rural and urban environments using industry standard cup anemometers, wind vanes and compatible data collection conditions (in terms of height and sampling rates), we show that the intuitive notion that the ‘quality’ of wind velocity in an urban environment is poor compared to a rural environment is entirely quantifiable. This quantifies the notion that a rural wind resource is, on average, of higher yield when compared to that of the urban environment in the context of the model used. In this respect, results are provided that are based on five rural and urban locations in Ireland and the UK and illustrate the potential value of the model in the consideration of locating suitable sites for the development of wind farms (irrespective of the demarcation between an urban and rural environment). On this basis, the paper explores an approach whereby the same model is used for evaluating wind turbulence based on the Fractal Dimension using the ‘polar wind speed’ obtained from three-dimensional data sets collected in urban environments. Index Terms

This study aims to estimate stand density and stand volume in Cryptomeria japonica and Chamaecyparis obtusa stands from high-resolution satellite data and verify the reliability and uncertainty of the data. Sixty circular sample plots of 0.04 ha each were established. Their stand densities were estimated from the number of tree crowns derived from high-resolution satellite data using the watershed method. Stand densities derived from field surveys in the sample plots were compared with those obtained from high-resolution satellite data by stand age class. As a result, there was a positive correlation between them for sample plots of 41 years of age and over (R = 0.82); however, there was no correlation between them for sample plots of 40 years and under. Individual diameters at breast height (DBH) were estimated from crown areas obtained from high-resolution satellite data for the two species. Using the estimated DBH, individual tree heights were predicted from the height–diameter curves. Stand volumes were estimated from the sum of individual volumes, which were derived from volume formulas having two variables, i.e., DBH and height. Stand volumes derived from the field survey were compared with those obtained from high-resolution satellite data. The correlation coefficient between them for stands of 41 years of age and over was 0.78.

Adoption of better management practices is crucial to lessen the impact of anthropogenic disturbances on tallgrass prairie systems that contribute heavily for livestock production in several states of the United States. This article reviews the impacts of different common management practices and disturbances (e.g., fertilization, grazing, burning) and tallgrass prairie restoration on plant growth and development, plant species composition, water and nutrient cycles, and microbial activities in tallgrass prairie. Although nitrogen (N) fertilization increases aboveground productivity of prairie systems, several factors greatly influence the range of stimulation across sites. For example, response to N fertilization was more evident on frequently or annually burnt sites (N limiting) than infrequently burnt and unburnt sites (light limiting). Frequent burning increased density of C4 grasses and decreased plant species richness and diversity, while plant diversity was maximized under infrequent burning and grazing. Grazing increased diversity and richness of native plant species by reducing aboveground biomass of dominant grasses and increasing light availability for other species. Restored prairies showed lower levels of species richness and soil quality compared to native remnants. Infrequent burning, regular grazing, and additional inputs can promote species richness and soil quality in restored prairies. However, this literature review indicated that all prairie systems might not show similar responses to treatments as the response might be influenced by another treatment, timing of treatments, and duration of treatments (i.e., short-term vs. long-term). Thus, it is necessary to examine the long-term responses of tallgrass prairie systems to main and interacting effects of combination of management practices under diverse plant community and climatic conditions for a holistic assessment.

Indian Earth Observation Satellite Cartosat‐1 data were evaluated for the estimation of biophysical variables, including as tree height, crown diameter, canopy density and canopy gap, that are crucial for the estimation of stand volume, biomass and generation of site index (an indicator of site quality of growing stock). Investigations were carried out at a site covering the major dominant forest species grown in India. Cartosat‐1 stereo data were analysed in conjunction with differential global positioning system (DGPS) measurements to generate a digital elevation model (DEM) and an orthoimage, which were used to estimate the biophysical variables. Analysis using grey‐level co‐occurrence texture measures was performed for separation of forest species, homogeneity of the classes of forest stands, stratification and measurement of crown area, canopy gap and stand density. Field measurements of tree height, diameter at breast height (DBH), stand density, age and crown diameter were conducted for each stand. Empirical models for the estimation of DBH were developed and validated with Cartosat‐1‐derived height and crown diameter. Measured and estimated values were found to be in close proximity to each other. A local contrast co‐occurrence measure (contrast, mean and variance) was suitable for the estimation of average crown diameter, stand density and canopy gap area for each forest stand class. The texture image provided information on structural attributes (i.e. stand density, crown diameter and canopy gap of the forest tree stands). The results presented in this study show that the Cartosat‐1‐derived DEM and orthoimage have potential for the estimation of stem volume, growing stock conditions, and biomass and site index for important timber species.

Towards a systematic understanding of the dynamic fate of polychlorinated biphenyls in indoor, urban and rural environments

Epiphytic bryophytes are known to perform essential ecosystem functions, but their sensitivity to environmental quality and change makes their survival and development vulnerable to global changes, especially habitat loss in urban environments. Fortunately, extensive urban tree planting programs worldwide have had a positive effect on the colonization and development of epiphytic bryophytes. However, how epiphytic bryophytes occur and grow on planted trees remain poorly known, especially in urban environments. In the present study, we surveyed the distribution of epiphytic bryophytes on tree trunks in a Schima superba Gardn. et Champ. urban plantation and then developed count data models, including tree characteristics, stand characteristics, human disturbance, terrain factors, and microclimate to predict the drivers on epiphytic bryophyte recruitment. Different counting models (Poisson, Negative binomial, Zero-inflated Poisson, Zero-inflated negative binomial, Hurdle-Poisson, Hurdle-negative binomial) were compared for a data analysis to account for the zero-inflated data structure. Our results show that (i) the shaded side and base of tree trunks were the preferred locations for bryophytes to colonize in urban plantations, (ii) both hurdle models performed well in modeling epiphytic bryophyte recruitment, and (iii) both hurdle models showed that the tree height, diameter at breast height (DBH), leaf area index (LAI), and altitude (ALT) promoted the occurrence of epiphytic bryophytes, but the height under branch and interference intensity of human activities opposed the occurrence of epiphytic bryophytes. Specifically, DBH and LAI had positive effects on the species richness recruitment count; similarly, DBH and ALT had positive effects on the abundance recruitment count, but slope had a negative effect. To promote the occurrence and growth of epiphytic bryophytes in urban tree planting programs, we suggest that managers regulate suitable habitats by cultivating and protecting large trees, promoting canopy closure, and controlling human disturbance.

For this paper, we sampled a fenced and an unprotected portion of a dry gallery forest (the Beza Mahafaly Reserve) in southwestern Madagascar for structure and floristic composition. Seedling plots were also sampled to assess invasion and regeneration. A total of 923 plants 22.5 cm diameter at breast height (DBH) were censused in 25 transects. Sixty-nine species and 43 genera were represented. In plant density, diversity, and size classes of individuals, the forest is similar to many continental tropical dry forests in Africa and the Neotropics. Over 80 percent of those species identified were native, as were 26 percent of the genera. Unlike many insular forests, Beza Mahafaly is not being invaded by fast-growing exotic species. There were no noticable differences in density, diversity, size classes, or proportion of native species between transects within and outside of the protected reserve. Two distinct microhabitats were noticed. Individual plants were more dense on drier' soils; whereas, large trees >25 cm DBH were over twice as frequent on wetter soils. The floristic composition also differed, with only two species of tree, Tamarindus indica and Azima tetracantha, being common to both habitats. The distribution and density of lemur populations within the forest appear to be directly related to microhabitat differences.

Research Highlights: Stand density was connected with wood quality and lumber production to develop a predictive model to better estimate tree value. Background and Objectives: The available standing wood volume in British Columbia (BC), Canada has consistently decreased since 1990. Better understanding the link between stand growth conditions, knot characteristics, the sawmilling process and product quality is essential in making informed forest management decisions and efficiently utilizing wood. The overall objective was to investigate and predict the impact of tree growth as affected by stand density on knot characteristics, lumber volume and value recoveries for two conifer species, two types of sawmills and three economic scenarios. Materials and Methods: Seventy-two amabilis fir and western hemlock trees were harvested from three stands located on Vancouver Island, BC. Sawlogs were scanned using an X-ray computed tomography (CT) scanner and images were processed to extract knot characteristics and reconstruct three-dimensional (3D) log models. The effects of three diameter at breast height (DBH) classes (30, 40 and 50 cm) and three stand densities on knot characteristics, including knot volume, number of knots, average knot area and knot/tree volume ratio, as well as the simulated lumber volume and value recoveries from two types of sawmills (i.e., Coastal and Interior) under three economic scenarios (i.e., baseline, optimistic, and pessimistic) were investigated. Results: As expected, the knot characteristics of both species increased with the DBH. The difference of knot distribution between amabilis fir and western hemlock suggests that the latter is more sensitive to growth site conditions. The sawmilling simulations revealed that the Coastal mill produced a lower lumber volume due to the type of products manufactured and the primary breakdown patterns being used. Conclusions: The developed linear mixed effects models based on the knot characteristics and tree features could predict the value of a standing tree and can be used for estimating preharvest stand value of similar Coastal Hem-Fir forests.

Impact of exotic plantation on native Grassland Biodiversity: A 30-Year analysis in Tanzania’s southern highlands