The Possibility of Using Non-Native Spruces for Norway Spruce Wood Replacement—A Case Study from the Czech Republic

Scots pine (Pinus sylvestris L.) represents one of the most important commercial coniferous tree species, providing valuable timber. Due to climate change, it is experiencing serious problems in some areas, therefore, finding a suitable substitute for its wood is currently a challenge. In this study, we compared the wood quality of three different non-native pine species and Scots pine growing at the same site to ensure identical growing conditions. Black pine (Pinus nigra J. F. Arnold), a pine species native to Southern Europe, lodgepole pine (Pinus contorta Douglas ex Loudon), and ponderosa pine (Pinus ponderosa Douglas ex C. Lawson) native to North America were compared to Scots pine for selected quantitative (productivity) and qualitative (physical and mechanical) properties. Significant differences between pine species were found in all quantitative dendrometric parameters, except average diameter at breast height. The stand volume ranged from 157 m3 ha−1 for lodgepole pine to 356 m3 ha−1 for Scots pine. For qualitative characteristics, wood density, shrinkage, and compressive strength were used to find differences among species in choosing the best alternative. The highest wood density was obtained for Scots pine (458 kg m−3), followed by black pine with 441 kg m−3. The density of the remaining pine species was significantly lower. Scots pine also exceeded the tested species in compressive strength (44.2 MPa). Lodgepole pine achieved the second highest value (39.3 MPa) but was statistically similar to black pine (36.5 MPa). The tested pine species exhibited similar values in shrinkage, which were statistically insignificant, ranging from 14.3% for lodgepole pine to 15.1% for Scots pine. Based on applications and preferred characteristics, black pine or lodgepole pine could serve as the Scots pine substitute in some areas. And vice versa, ponderosa pine did not attain the Scots pine wood quality.

The Potential of Non-Native Pines for Timber Production—A Case Study from Afforested Post-Mining Sites

Zeidler,

Borůvka,

Tomczak

et al. 2024

Wood Quality of Pendulate Oak on Post-Agricultural Land: A Case Study Based on Physico-Mechanical and Anatomical Properties

Tomczak,

Mania,

Cukor

et al. 2024

Oak is one of the most economically important hardwood tree species in Europe, and its prevalence will increase due to progressing global climate change, according to predictive models. With the increasing demand for timber and with the need for a balance between carbon emissions and sequestration, it is essential to address the afforestation of agricultural land. Therefore, this research aimed to investigate the physico-mechanical properties and anatomical structure of pendulate oak (Quercus robur L.) wood—specifically focusing on the trunk’s cross-section—in post-agricultural areas compared with the forest land in the western part of Poland. Wood density, bending strength, modulus of elasticity, and other parameters were analyzed from 1626 wood samples. The analysis of physico-mechanical properties reveals that, historically, agricultural land use has an almost negligible impact on wood quality. Despite significant differences in small vessel diameter and fiber length favoring trees from post-agricultural land, the physico-mechanical properties remain consistent. Large vessel measurements show comparable diameter and length in both land types. These findings suggest that post-agricultural land can serve as an effective alternative for high-quality pendulate oak wood production for industrial purposes. However, wood from post-agricultural land may exhibit a decrease in modulus of rupture by over 30% and potentially lower density above the trunk’s halfway point. This observation hints at the fact that oak trees in post-agricultural areas could be cultivated in shorter rotation periods compared to forest land.

How the Spruce Ageing Process Affects Wood

Jelonek,

Klimek,

Naskrent

et al. 2024

Climate change and the gradual phaseout of the spruce from Central Europe inspired us to study the effects of the ageing process of trees on wood properties. This study was conducted in old tree stands with significant involvement of the spruce (Picea abies (L.) H. Karst) in the ages between 122 and 177 years. The study material (samples) was collected from the selected trees to study wood properties such as density, resilience to compressive strength, resilience to bending strength, and modulus of elasticity. The results and findings of this study indicate that the spruce currently reaches the optimal technical quality of wood tissue at approximately 60 years of age. It is approximately 20 years earlier than the planned cutting age for the species. This could be due to water stress which led to adaptive changes in the wood tissue and earlier technical maturation of the wood in the studied trees. Significant radiant variabilities of wood properties of the Norway spruce were observed. It was determined that wood density does not fully reflect its mechanical properties, and it can be considered an indicator of the technical quality of wood tissue, but only within a limited scope. The results obtained may not only be applied in optimising the use of wood from spruce stands. They can also indicate the need to change the approach to managing spruce stands and their conversion towards broadleaf species.