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Determining Harvester Productivity Curves of Thinning Operations in Birch Stands of Central Europe
Silver birch (Betula pendula Roth) is a popular tree species forming stands in nearly the whole of Europe. In Poland, birch is one of the most representative broadleaved species growing on rather poor soils, very often as a mix species with Scots pine (Pinus sylvestris L.). In Central Europe, birch forms trunk often with sweeps, and at the older age with thick branches. Due to that, a harvester thinning operation in birch stands can be challengeable when trying to process logs from the top part of trees, which can finally impact on productivity. The objective of this research was to determine harvester productivity for birch with particular attention to production of logs from the top part of a tree. The research was carried out in stands of North and North-West Poland. All together 21 tests were completed in 16 stands, in which 9 harvesters were used (8 different models). The mean diameter of harvested trees was 23.7 cm with the mean height of 21.7 m. Obtained productivity without delays was on average 21.98 m3 h-1 and varied from as low as 5.14 to maximum 44.66 m3 h-1, and depended mainly on harvested tree size. It was also confirmed that top diameter of the last log depended on diameter at breast height (DBH). The model developed based on that relationship can be used for prediction of biomass volume from birch stands when harvesters are used for thinning.
Quality of Pellets Obtained from Whole Trees Harvested from Plantations, Coppice Forests and Regular Thinnings
The Influence of Various Silvicultural Treatments and Forest Operations on Tree Species Biodiversity
Abstract Purpose of Review Biodiversity is one of the most important features of forest ecosystems. One of the goals of Sustainable Forest Management is to reduce biodiversity disturbance, which can occur as a consequence of timber harvesting. The aim of this review was to define which silvicultural systems and forest operations can have an influence on forest tree biodiversity by summarising the findings of nearly 60 papers published in the last ten years (2013–2022). Recent Findings In natural forest ecosystems characterised by a high level of structural complexity, such as uneven-aged tropical forests, selective logging and retention forestry are, in general, suitable forms of intervention that have a limited impact on tree biodiversity. Forest operations, in particular, should be of low intensity and try to simulate as much as possible small-scale natural disturbances. Thinning has proved to be a valid treatment for managing tree biodiversity. However, it is important to shape the magnitude of thinnings according to the management aims. Limited removal is recommended in interventions for maintaining the current structure, and more extensive removal is appropriate in cases when a change in species composition is expected, e.g. in the conversion of planted coniferous stands to uneven-aged mixed or broadleaved stands. In addition, coppicing is suitable for maintaining tree biodiversity due to its effectiveness in fostering the presence of light-demanding tree species. Findings show that it is important to establish the right rotation age, considering that an excessively short period between coppicing interventions can be detrimental to functional biodiversity. Skid trails and landing sites represent suitable areas for the initial establishment of natural regeneration. However, generally, the level of biodiversity on these sites declines with time as a consequence of soil compaction, thus highlighting the importance of the forest infrastructure network planning. Summary In uneven-aged tropical forests, selective logging and retention forestry are the most suitable options for maintaining tree biodiversity. Thinning and coppicing help to manage biodiversity, whilst intensive thinning helps to change species composition. Skid trails and landing sites can support natural regeneration. Recommendations and management options were developed, as well as possible future research directions. The authors recommend that future studies should investigate how much tree biodiversity depends on different levels of harvesting technology applied within the same silvicultural treatment.
Forest Accessibility and Road Network Density: A Global Overview with a Special Focus on Europe
Abstract Purpose of the Review Forest accessibility and road network density are important concerns not only for forest managers, but also for everyone who benefits from forests, whether for professional or personal use. A well-planned forest road network, integrated with the forest ecosystem, is a fundamental element of rational and efficient forest management. This review aims to describe the current state of forest road density and overall forest accessibility in Europe, as well as relevant global examples. Recent Findings When a forest road network is distributed adequately across an area, it can support many, if not all, tasks outlined in forest management plans, with high efficiency and minimal costs during construction and maintenance. Collecting data on forest accessibility and primary forest road density at the national level in many countries is a complex task. Diverse terrain conditions, economic factors, and forest management practices have led to variability in the data. A common thread, however, is the optimistic outlook on the use of modern technologies for road network planning and data acquisition. Summary Efficient forest management, especially harvesting operations, relies on a road network with appropriate density, load-bearing capacity, and alignment. Primary forest transport infrastructure helps reduce timber extraction costs by minimising extraction distances and shortening the travel time from the forest stand to the market. As such, forest road density and accessibility are crucial elements in planning forest operations. Despite differences in terrain conditions, harvesting systems, and economic contexts across Europe and globally, research consistently highlights the need to improve the efficiency of road network planning. Future research on forest accessibility should focus on integrating valuable data collection with scientific research and ensuring effective knowledge transfer to forest practitioners.