WOOD RESEARCH Volume 71, Number 1, 2026
YASİN KARAŞİN, BÜLENT TOPRAK, MUHAMMED ALİ AYDIN, and MEHMET ALİ ÜNLÜ

THE EFFECTS OF RAINWATER-HARVESTING V-SHAPED MICROCATCHMENTS AND PLANT-SUPPORTIVE AMENDMENTS ON SOIL MOISTURE AND EARLY ESTABLISHMENT OF FRAXINUS ANGUSTIFOLIA VAHL. UNDER SEMI-ARID MEDITERRANEAN CONDITIONS

This study assessed the effectiveness of V-shaped rainwater-harvesting micro catchments and selected plant-supportive amendments on soil moisture dynamics, survival, and early growth performance of narrow-leaved ash (Fraxinus angustifolia Vahl.) during three consecutive growing seasons (2022–2024) in western Türkiye. By the end of the first growing season, mean seedling survival was approximately 63% across treatments. However, complete mortality (100%) occurred in conventional terrace control plots by the second growing season, indicating plantation failure under this method. In contrast, V-shaped micro catchments maintained survival rates of 65% in the second year and 57% after three years. Volumetric soil water content (0–20 cm) measured during the peak drought period (July–September) was consistently higher in micro catchments than in terrace controls. In September 2024, soil moisture in the micro catchment control (C-V) reached 8.17% at the upper position and 5.88% at the lower position, compared to 3.83% and 1.53%, respectively, in terrace plots. Relative diameter increment (RDI) differed significantly among treatments (p < 0.0001), with the straw-based lignocellulosic superabsorbent polymer increasing stem diameter growth by approximately 40% compared with other micro catchment treatments. Relative height increment (RHI) was up to 2.3 times greater in micro catchment plots than in terrace controls. These findings demonstrate that integrating structural rainwater harvesting with wood- and plant-derived water-retaining amendments substantially enhances soil water availability, seedling survival, and early stem growth of F. angustifolia, thereby improving hardwood plantation establishment and resilience under semi-arid Mediterranean environments

WOOD RESEARCH Volume 70, Number 3, 2025
MELİS ÇERÇİOĞLU, MUHAMMED ALİ AYDIN, YASİN KARAŞİN, BURAK BAHAR, and DERYA EŞEN

Effects of mulching on selected properties of soil and young stone pine (Pinus pinea L.) seedlings under semi-arid conditions

Evaporation is a primary source of soil moisture loss, and mulching can effectively reduce this loss, thereby conserving soil moisture. This study examined the effects of wood-materials mulching with various particle sizes and application depths (5-cm thick coarse sawdust, 5-cm thick wood chips, and 10-cm thick wood chips) on some soil properties, including moisture, bulk density (BD), pH, electrical conductivity (EC), organic matter (OM), and CaCO₃, as well as on stone pine (Pinus pinea L.) seedling root collar diameter (RCD), height, sturdiness index (SI), and survival rates. One-year-old containerized stone pine seedlings, a drought-tolerant and economically valuable native conifer species, were planted with a spacing of 3 x 3 m in Aliaga, Izmir, Türkiye. Ten months after treatment (July 2024), no significant differences in soil bulk density and moisture were observed among treatments. The 10-cm-thick wood chips treatment showed significantly greater organic matter content compared to both the control and the 5-cm-thick coarse sawdust treatments. Although large numerical differences were seen in mean pine survival rate and height growth, these differences were not statistically significant, likely due to high data variability. The 10-cm-thick wood chips and 5-cm-thick coarse sawdust treatments demonstrated relatively higher seedling survival rates, while the control treatment showed the lowest seedling survival. However, the control seedlings exhibited significantly greater root RCD than mulch treatments, with the 5-cm-thick coarse sawdust treatment ranking second in promoting seedling RCD. Early results did not indicate enhanced pine survival and growth due to mulching. However, future data collection is recommended to provide further insights.