Journal of Forest Science - In Press

Variation in wood density between mature sessile oak and English oak trees growing in different vegetation zonesOriginal Paper

Vladimír Gryc, Kyriaki Giagli, Sergei Mikhailov, Marko Stojanović, Dimitrios Tsalagkas, Hanuš Vavrčík, Petr Horáček

Wood density is a fundamental functional trait influencing ecological adaptation, hydraulic safety, and timber utilisation in temperate hardwoods. This study investigated variation in wood density (12% moisture) across mature stands of two economically and ecologically vital European oak species, sessile oak [Quercus petraea (Matt.) Liebl.] and English oak (Quercus robur L.), growing in their characteristic vegetation zones in the Czech Republic. We assessed wood density at two heights (at 1.3 m and at the crown base) across six trees per plot and examined its relationship with tree-ring width and height. Results demonstrated statistically significant interspecific differences, with Q. petraea consistently exhibiting higher wood density (721 kg·m−3) than Q. robur (662 kg·m−3) at 1.3 m. Q. petraea showed a statistically nonsignificant higher density of 710 kg·m−3 at the crown base and an overall average of 717 kg·m−3, while Q. robur had densities of 701 kg·m−3 and 669 kg·m−3, respectively. Radial density profiles revealed species-specific patterns, with Q. robur showing a more uniform density distribution than the pronounced pith-to-bark gradients observed in Q. petraea. Regression analysis indicated that tree-ring width explained only 12–13% of the variance in density, so other anatomical factors, such as latewood proportion and tree-ring structure (number and cell size), should be examined as anatomical drivers of wood-density variation.

Leaf area index and soil water content responses to pre-commercial thinning in Norway spruce plantations under climate changeOriginal Paper

Jakub Černý, Zdeněk Vacek, Jan Cukor, Dominik Báňa, Stanislav Vacek

Global climate change (GCC) and increasing drought frequency pose a threat to the stability of European forests, particularly those of Norway spruce [Picea abies (L.) Karst.] plantations. We investigated how different pre-commercial thinning (PCT) intensities affect leaf area index (LAI) and its relationship to soil water content (SWC) in young spruce stands in northeastern Czechia. Three permanent research plots in a 13-year-old monoculture were subjected to mild PCT, heavy PCT, or left as an unthinned control in winter 2019/2020. Thinning caused an immediate decrease in LAI, with averages of 8.3 ± 1.1 m2·m–2 (mild), 3.8 ± 0.5 m2·m–2 (heavy) and 11.1 ± 1.1 m2·m–2 (control) in 2020. By 2023, LAI in the mildly thinned stand had largely converged with the control, whereas the heavily thinned stand maintained significantly lower LAI. The strongest relationship between LAI and SWC occurred in the heavily thinned plot (R2 = 0.715 in 2021), while correlations were weak or transient in the mildly thinned and control plots. These results indicate that PCT intensity influences both the magnitude and duration of LAI reduction and is associated with differences in stand water dynamics. Appropriately adjusted thinning may therefore modestly affect water availability and could contribute to adaptive management of spruce forests under GCC.

Soil macroarthropod dynamics in response to environmental disturbances in a forest remnant ecosystem: A case study at Cibodas Botanical GardenOriginal Paper

Anita Rianti, Fenky Marsandi, Taufikurrahman Taufikurrahman, Musyarofah Zuhri, Muhammad Efendi, Hari Prayogi, Setyawan Agung Danarto, Hidayatul Fajri, Vivin Silvaliandra Sihombing, Dian Anggraini Indrawan

Disturbing the remaining forest ecosystem in the Cibodas Botanical Garden (CBG) has affected the dynamics of the soil macroarthropod communities. This study was conducted in three remaining forest locations in the CBG with different levels of disturbance. Soil macroarthropod samples were collected using the pitfall trap method with 30 traps and analysed using the Shannon-Wiener diversity index, Pielou's evenness, Simpson's dominance, and Margalef's species richness to assess the dynamics of the soil macroarthropod community. This study analysed how these communities respond to different levels of disturbance in the garden, namely Jalan Akar/JA (low), Wornojiwo/WJ (moderate), and Ciismun/CI (high), which were influenced by tourism activities and local environmental conditions. The results showed that individuals from the Hymenoptera group accounted for 60.05% of the total number of soil macroarthropods found. Site WJ, which experienced moderate disturbance, had the highest number of individuals and species richness of soil macroarthropods. In contrast, site CI, which experienced high levels of disturbance, had a lower number of individuals and lower species richness, diversity and evenness indices. Site JA, which experienced low levels of disturbance, exhibited higher diversity and evenness indices. These results demonstrate that disturbance affects the presence of soil macroarthropods at their respective levels of disturbance. However, analysing the spatial distribution of soil macroarthropods in each studied taxon using the Morisita index revealed that they were dominantly clustered and exhibited varied distribution patterns. The study concludes that maintaining minimal disturbance is essential to preserve soil biodiversity and ecological balance in managed forest ecosystems such as the Cibodas Botanical Garden.