Currently, fossil fuels are used to produce fuels and electricity, which are finite sources and have a negative impact on the natural environment. An excellent alternative to these fuels is biofuels, such as bioethanol from waste forest biomass. Pine needles are one of the most important available forest biomass materials with s significant impact on local understory vegetation. Forest waste biomass, which is a rich source of lignocellulose, can be used in various ways, such as for the eco-economical production of bioethanol. The aim of this study was to analyze the possibilities of bioethanol production from pine needle biomass obtained from forest land following different soil preparations and logging residue management. The pine needle dry matter yield, chemical components of pine needle biomass (cellulose, hemicellulose, lignin), and the amount of ethanol yield per hectare were evaluated. The highest average yield pine needle equal to 6.17 Mg∙ha⁻¹ was observed. Bioethanol yield per hectare from this biomass was the highest for plowing with the LPZ-75 plow and was 1.08 m³∙ha⁻¹. The discussed results were confirmed by detailed statistical analysis. To sum up, the researched pine needle biomass turned out to be an interesting raw material with the potential for bioethanol production.

The increasing demand for renewable energy has led to a surge in biomass harvesting from forest ecosystems. However, intensive biomass extraction, especially logging residue (LR) removal and mechanical site preparation (MSP), may affect long-term forest productivity. This study aimed to assess the effects of three MSP methods (plowing and planting in furrows, disc trenching, bedding and planting in raised beds) and three LR management strategies (complete removal, leaving residues, and comminution) on above- and belowground biomass production in Scots pine (Pinus sylvestris L.) stands 17 years after planting. The experiment was conducted in northwestern Poland on Albic Brunic Arenosols with low fertility. The experiment consisted of 27 plots in a randomized complete block design. The tree measurements included diameter at breast height (DBH), tree height, stand density, basal area, stand volume and biomass, which were analyzed using two-way ANOVA. Significant differences in DBH and tree height were detected between the MSP methods. Furrowing resulted in the greatest growth, whereas bedding produced the lowest DBH and height. Among the LR treatments, tree height was lowest for comminution. However, no significant differences were found in stand biomass, basal area, or stand volume across the treatments. These findings suggest that the MSP and LR management methods have short-term effects on tree growth but do not significantly influence long-term stand productivity. These results highlight the importance of performing long-term experimental trials to assess the sustainability of forest management practices.

Biological invasions are one of the most important threats to biodiversity. However, spread mechanisms have been described in detail only for some widespread taxa. Here, we aim to characterize the unique phenomenon of ×Sorbaronia ′Mitschurinii′ (Rosaceae) spread into temperate Scots pine forests. We assessed the surroundings of an abandoned ×Sorbaronia ′Mitschurinii′ plantation, established in 1986 near Ośno Lubuskie (W Poland). Around the plantation we established 66 study plots in 30 m intervals along eight transects, in a systematic design. Using generalized linear mixed-effects models we analysed how the distance from the propagule source (i.e. abandoned plantation), maximum age of ×Sorbaronia shrubs assessed using dendrochronological techniques, and light availability determined the density and biomass of the studied plant. We found that its mean aboveground biomass in the plantation was 7.22 ± 0.66 Mg ha⁻¹, and decreased with distance from the propagule source: 6.83 Mg ha⁻¹ 30 m from the abandoned plantation, 1.38 Mg ha⁻¹ at a distance of 90 m, and 0.11 Mg ha⁻¹ at a distance of 180 m, almost disappearing at further distances (but present at the maximum distance of 450 m). The density and aboveground biomass of ×Sorbaronia ′Mitschurinii′ increased with increasing maximal age of the studied plant and its light availability. The ×Sorbaronia ′Mitschurinii′ plantation acted as a strong propagule source, as it reached a density of 100 ind. 100 m⁻² after five years, forming a dense shrub layer, capable of reproducing. We conclude that alien species planted at high density and left with no management control might transform into invasion hotspots under favourable circumstances. The study highlights the importance of scientific awareness of similar cases of overlooked invasion sources, as management to limit their spread is still possible.