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Keywords: carbon, forest reference levels, forest management, harvesting scenarios, yield curves, UNFCCC, prirastne krivulje, UNFCCC
Published in DiRROS: 19.10.2020; Views: 1277; Downloads: 899
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Abstract: In the presented research, we studied the forest edge structure of urban and peri-urban forests on the outskirts of Ljubljana (Slovenia) consisting of a number of patches covering the collective surface of 1884 ha. They differ from each other according to the degree of fragmentation and by the share of the interior forest area. On the basis of LiDAR data, we conducted an analysis of the edges of the persistent forest patches and estimated them with regard to the land use they bordered on. The horizontal estimation of forest edges and the changes of forest edges, in the last decades, were estimated using digital orthophoto images of cyclic aerial surveys of Slovenia, from 1975 to 2018. The data, provided by LiDAR, were used to obtain an accurate estimate of forest edges and the metrics of their vertical canopy structure. On the basis of the canopy height model (CHM), we determined the height classes, the heights of the tallest trees, and indices of canopy height diversity (CHD) as variables subjected to a k-means cluster analysis. To determine the forest edge and trees stability, their heights and diameters at breast height (DBH) were measured and their canopy length and h/d (height/diameter) dimension ratios were estimated. In the study area of the Golovec forest patch, more than half of the forest edge segments (56%) border on residential buildings. After the construction of buildings, 54% of the newly formed forest edges developed a high and steep structure. Unfavorable h/d dimension ratio was estimated for 16% of trees, more among the coniferous than among the deciduous trees. Similar characteristics of newly formed forest edges bordering on built-up areas were determined in other sub-urban forest patches, despite the smaller share of such forest edges (19% and 10%, respectively). Tools and methods presented in the research enable the implementation of concrete silvicultural practices in a realistic time period and extend to ensure that adequate forestry measures are taken to minimize possible disturbances.
Keywords: forest ecosystem services, forest edge stability, forest edge structure, LiDAR, urban forests
Published in DiRROS: 26.05.2020; Views: 1892; Downloads: 1030
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Abstract: The conservation and sustainable use of forests and forest genetic resources (FGR) is a challenging task for scientists and foresters. Forest management practices can affect diversity on various levels: genetic, species, and ecosystem. Understanding past natural disturbance dynamics and their level of dependence on human disturbances and management practices is essential for the conservation and management of FGR, especially in the light of climate change. In this review, forest management practices and their impact on genetic composition are reviewed, synthesized, and interpreted in the light of existing national and international forest monitoring schemes and concepts from various European projects. There is a clear need and mandate for forest genetic monitoring (FGM), while the requirements thereof lack complementarity with existing forest monitoring. Due to certain obstacles (e.g., the lack of unified FGM implementation procedures across the countries, high implementation costs, large number of indicators and verifiers for FGM proposed in the past), merging FGM with existing forest monitoring is complicated. Nevertheless, FGM is of paramount importance for forestry and the natural environment in the future, regardless of the presence or existence of other monitoring systems, as it provides information no other monitoring system can yield. FGM can provide information related to adaptive and neutral genetic diversity changes over time, on a species and/or on a population basis and can serve as an early warning system for the detection of potentially harmful changes of forest adaptability. In addition, FGM offers knowledge on the adaptive potential of forests under the changing environment, which is important for the long-term conservation of FGR
Keywords: forest monitoring, forest genetic monitoring, forest genetic diversity, silviculture
Published in DiRROS: 20.02.2020; Views: 2045; Downloads: 1287
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Abstract: Forest understory vegetation is largely influenced by disturbances and given local abiotic conditions. Our research focuses on the early response of understory vegetation to various forest management intensities in Dinaric fir-beech forests in Slovenia: (i) control, (ii) 50% cut of stand growing stock, and (iii) 100% cut of stand growing stock. Apart from identifying overstory removal effects, we were interested in fine-scale variation of understory vegetation and environmental determinants of its species composition. Vegetation was sampled within 27 karst sinkholes, which represent a dominant landform in studied forests. Within each sinkhole, five sampling plots, varying in slope aspect (centre, north, east, south, west), were established (135 in total), where pre-treatment (in 2012) and post-treatment (in 2014) floristic surveys were conducted. The sampled understory species were characterized in terms of Ellenberg's indicator values (EIVs) and plant functional traits (plant height, seed mass, specific leaf area, leaf dry matter content). Diversity metrics (species richness, total cover, Shannon index) increased in plots where the silvicultural measures were applied. Tree species richness also increased in 100% cutting. A redundancy analysis revealed that species composition was related to environmental variables, which are directly influenced by management interventions (overstory canopy cover, microclimate maximum daily temperature, soil properties thickness of organic soil layer) as well as by topographic factors (slope inclination and surface rockiness). EIVs for light were significantly affected by treatment intensity, whereas soil-related EIVs (moisture, reaction, nutrients) depended more on the within-sinkhole position. Canopy gaps, compared with uncut control plots, hosted a higher number of colonizing species with a higher plant height and smaller seeds, while leaf traits did not show a clear response. We found a negative correlation between pre-treatment species (functional) richness and post-treatment shifts in floristic (functional) composition. Plots with higher richness exhibited smaller changes compared with species-poor communities. Incorporating different perspectives, the results of this study offer valuable insights into patterns of understory vegetation response to forest management in fir-beech forests.
Keywords: canopy gap, microsite environment, Ellenberg indicator values, plant functional traits, compositional resistance, karst topography, fir-beech forest
Published in DiRROS: 06.12.2019; Views: 2494; Downloads: 1563
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Abstract: In recent decades, the conservation of biodiversity has become one of the main areas under consideration in managing forests in an ecologically sustainable way. Forest management practices are primary drivers of diversity and may enhance or decrease forest biodiversity, according to the measures applied (thinning options). We have focused on three beech (Fagus sylvatica L.) forests across a latitudinal gradient in Italy, characterised by different structures resulting from dissimilar management. We tested the short-term effects of differently-based silvicultural intervention vs. stands where no silvicultural practices were applied on biodiversity indicators and related proxies: deadwood amounts, microhabitat density, floristic richness and life form abundance. In each study area, the occurrence of the above indicators and proxies was evaluated before and after the implementation of crop tree thinning (CTT) and thinning from below (LT) methods, comparing them with control areas where no interventions were performed. After two years, the management options resulted in different responses of the investigated parameters. The CTT increased deadwood amounts in comparison with the LT ones, while stumps increased significantly after the LT thinning. Microhabitats increased significantly where intervention was not undertaken. On the contrary, they remained unaltered after the LT treatments. CTT thinning created favourable conditions for the development of microhabitats and their proliferation in the long term. Two years after the application of the CTT thinning treatment, all forest stands demonstrated a significant increase in their floristic richness and herb layer cover. Significant differences were also found in both the frequency and cover of life forms in relation to silvicultural treatment. These findings provide a better understanding of short-term effects of silvicultural treatment useful for maintaining biodiversity in mountain beech forests.
Keywords: deadwood, microhabitats, understory vegetation, mountain forests, sustainable forest management, Italian forests
Published in DiRROS: 04.10.2018; Views: 2669; Downloads: 1743
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