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Forest canopy cover is one of the most significant structural parameters of the forest stand that can be estimated using of aerial and satellite remote sensing. Even though sub-pixel analysis can be used to estimate the index on low-resolution imagery, high-resolution imagery provides more accurate details on forest canopy variability for ecological and forestry applications. However, the high variability of the images demands a more advanced approach to canopy cover measurement than the visual interpretation of single images or stereo pairs. These traditional methods are inefficient and limited in providing a comprehensive and accurate canopy cover assessment. An improvement of the method could involve classifying high spatial resolution images, separating and extracting the areas corresponding to canopy gaps, and generating canopy cover maps. This study offers valuable insights and reveals key differences between three methods for estimating canopy cover: ground measurements, visual photo interpretation and automatic extraction from classified images using pixel and object-based methods. The texture analysis approach was used for separating the "shadow" objects corresponding to gaps in the canopy from the shades cast on the lower trees. The sample plot-based visual interpretation of the images revealed comparable results between ground and satellite image canopy cover values (correlation coefficient of 0.74 for all plots), with lower correlations (r = 0.39) for uneven-aged stands. The results encourage the use of the texture analysis method, with satisfying accuracy (forest canopy cover differences of maximum 0.06 between ground, photo interpreted and extracted datasets). The method could be further integrated with complementary data like LIDAR or hyperspectral images. [ABSTRACT FROM AUTHOR]

Ecological patterns of species distribution can reveal essential information on the spatial and functional relationship between species or species and their environment. Various approaches can be used to assess species associations, and our study aimed to compare three methods at different scales: the co-occurrence indices for binary presence–absence data, principal component analysis (PCA) on species abundance and point process analysis. Our goal was to gain a deeper understanding of the species' co-occurrence patterns and notice if the three methods capture roughly the same spatial distribution trends. Our observational study of the analysed sapling community displayed several positive relationships between species (e.g., the association between ash and linden). However, many relationships were inconsistent across different scales. Furthermore, attraction between species was more prevalent than repulsion. Overall, there is a positive association trend, with more relationships being significantly positive across all scales. This trend is consistent with other recent studies of tree–species interaction. Nonetheless, the results suggest that the scale significantly influences spatial patterns of associations. Positive associations tend to be more prevalent on larger scales, while negative associations are more commonly found on smaller scales, regardless of the analysis method used. While the PCA results are less consistent, the point process analysis allowed us to detect more refined patterns of species associations based on the distance of their interaction. In addition, the binary presence–absence analysis provided solid results, with a coarser spatial perspective but with significantly less sampling effort. [ABSTRACT FROM AUTHOR]

In the context of forecasted climate change scenarios, the growth of forest tree species at their distribution margin is crucial to adapt current forest management strategies. Analyses of beech (Fagus sylvatica L.) growth have shown high plasticity, but easternmost beech populations have been rarely studied. To describe the response of the marginal beech population to the climate in the far east sites of its distribution, we first compiled new tree ring width chronologies. Then we analyzed climate–growth relationships for three marginal beech populations in the Republic of Moldova. We observed a relatively high growth rate in the marginal populations compared to core distribution sites. Our analyses further revealed a distinct and significant response of beech growth to all climatic variables, assessing for the first time the relationship between growth and vapor pressure deficit (VPD) which described how plant growth responds to drought. These results highlight that accumulated water deficit is an essential limiting factor of beech growth in this region. In conclusion, beech growth in the easternmost marginal population is drought-limited, and the sensitivity to VPD will need to be considered in future studies to update the forest management of other economic and ecologically important species. [ABSTRACT FROM AUTHOR]

In Romania, the productivity of the new clones of hybrid poplar has not been tested in recent years. This case study aims to fill a gap on the productivity map of the new poplar clones, estimating, by biomass measurements, the productivity of two clones (AF2 and AF8) with different planting densities (from 1333 trees·ha−1 to 2667 trees·ha−1). The short-rotation woody crops (SRWCs) were established in homogeneous conditions, in North-East (NE) Romania and the northern part of Suceava County. Using a specifically developed method, biomass production was estimated using destructive methods, with 190 poplar trees being harvested, measured, and weighed to compute the accumulated biomass for each growing season The biomass production of the crops with 1667 trees·ha−1 planting density highlighted significant differences in productivity in favour of the AF2 clone after five growing seasons. The crops shared similar annual growth patterns, and the stem biomass represents approximately 73–80% of the total biomass of the trees. The second research question concerning planting density influence on productivity showed fluctuations of biomass accumulations at different planting densities (1333 trees ha−1, 1667 trees ha−1 and 2667 trees ha−1) for a 5-year rotation. The outcomes emphasized the influence of the annual weather conditions—primarily the rainfall in May–June—on poplar growth, showing that productivity also depends on the genotype, density and biotic disturbances. [ABSTRACT FROM AUTHOR]

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On June 25, 2021, the Faculty of Forestry celebrated such an extraordinary professor. The “Ștefan cel Mare” University of Suceava awarded the title of PROFESSOR EMERITUS to the Professor doctor engineer Radu Leontie Cenușă. This distinction was awarded for his generous teaching and scientific career with an impressive number of projects, books, articles or communications recognized and appreciated by the forestry scientific community. A project characteristic of the optimistic spirit of the professor was the rebirth of the scientific journal “Bucovina Forestieră” under his coordination as editor-in-chief. Also, this honorary title was rewarded both for the role of forest school creator that the Professor had in supporting the idea of re-establishing the higher forestry school in Bucovina and the role in strengthening the Faculty of Forestry for training foresters in the spirit of respect to the forest. In his lecture, Professor Radu Leontie Cenușă made a new demonstration of eloquence and energy, his cultivated speech, although rational, sharing the specific emotion of those who truly promote the professionalism and honesty put at the forests’ interest. We thank the professor for the example given in these years and we wish him good health and continued strength! [ABSTRACT FROM AUTHOR]

Global climate change is one of the biggest threats to the environment, with direct consequences for the terrestrial life and the human activity. Thus, the analysis of public knowledge regarding the importance, causes and effects of climate change is entirely justified. The public knowledge about the phenomenon of climate change is influenced by the information available on the most accessible sources of information such web sources, TV shows and news. On the other hand, the perceptions of climate change are depending on many other individual cognitive factors such the level of education, the professional background or the direct experience with climate-change related events. The main questions asked in this study were: How the human perceptions on climate change are shaped? What role has the media in shaping the perceptions on climate change? To address these questions, we have considered a pool of 76 respondents, with education in forestry, from three counties situated in North - Eastern part of Romania. On the other hand, we have performed a search on several Romanian news portals using the keywords related with global change for the period 2009-2012. We have found 42 references about extreme weather events and their consequences (drought, floods, extreme precipitation, etc.), but only 19% of them were related directly to the global climate change. While the mass-media contribution to the formation of beliefs in climate change was difficult to prove, the professional background and the TV consumption habits appears to better discriminate the respondents. We conclude that the beliefs in climate change may be a kind of fashion amongst the forest engineers. While their perceptions on climate change are formed individually using different TV and internet sources, they seem to be shaped at the end by the professional milieu of the respondents. [ABSTRACT FROM AUTHOR]

This paper describes a permanent research platform (PRP) designed and implemented in "Codrul secular Slătioara" and its surroundings (2205.85 ha), having also the role of introductory paper for future research articles based on data collected from this platform. "Codrul secular Slătioara" is known as one of the largest temperate mountainous intact forests of Europe and, in 2017, it was included in UNESCO World Heritage List, as part of the "Ancient and Primeval Beech Forests of the Carpathians and Other Regions of Europe". Moreover, the PRP overlaps other three scientific reserves, the share of strictly protected forests exceeding 70%. This platform has a multiple role, being developed for research, conservation and educational activities. The PRP was designed for an ecological analysis of the intact forest ecosystems. It contains 193 circular sample plots, each of them of 500 m2, and it is structured on two levels. The first level contains 58 sample plots corresponding to a square grid of 500 × 500 m, stretching over the entire forested area, and the second level contains 135 plots, placed according to a square grid of 100 × 100 m, covering 136 ha within the core area of the UNESCO site. We measured the characteristics of 8296 living trees, 1743 standing dead trees, 1900 dead wood trunks, 3214 saplings, and the abundance–dominance indices of flora species. Thus, we identified 14 tree species, 17 shrub species, and 248 other cormophyte species forming the herbaceous layer. In terms of volume, the main tree species are Norway spruce, silver fir and European beech. The tallest species are Norway spruce (56 m) and silver fir (51 m). The average volume of living trees is 659 m3·ha−1, with a maximum of 1441 m3·ha−1. The mean total dead wood volume is about 158 m3·ha−1, with sample plots where the total dead wood volume exceeds 600 m3·ha−1. After presenting the results of preliminary data processing, the paper describes the main research topics to be further considered, based on the PRP, and the foresights related to the PRP's monitoring and development. [ABSTRACT FROM AUTHOR]

Masting is the highly variable and synchronous production of seeds by plants. Masting can have cascading effects on plant population dynamics and forest properties such as tree growth, carbon stocks, regeneration, nutrient cycling, or future species composition. However, masting has often been missing from forest models. Those few that simulate masting have done so using relatively simple empirical rules, and lack an implementation of process-based mechanisms that control such events. Here we review more than 200 published papers on mechanistic formulations of masting, and summarize how the main processes involved in masting and their related patterns can be incorporated in forest models at different degrees of complexity. Our review showed that, of all proximate causes of masting, resource acquisition, storage and allocation were the processes studied most often. Hormonal and genetic regulation of bud formation, floral induction, and anthesis were less frequently addressed. We outline the building blocks of a general process-based model of masting that can be used to improve the oversimplified functions in different types of forest models, and to implement them where missing. A complete implementation of masting in forest models should include functions for resource allocation and depletion, and for pollination, as regulated by both forest structure and weather in the years prior to seed production. When models operate at spatio-temporal scales mismatched with the main masting processes, or if calibration data are not available, simulation can be based on parameterizing masting patterns (variability, synchrony, or frequency). Also, observed masting patterns have the potential to be used as “reality checks” for more process-based forest models wishing to accurately reproduce masting as an emergent phenomenon. [ABSTRACT FROM AUTHOR]