Soil and Water Research - In Press
Effect of logging residues management on the distribution of potentially toxic elements in soils of large-scale clearcuts resulting from bark beetle forest damageOriginal Paper
Lenka Pavlů, Marek Kučírek, Václav Tejnecký, Ondřej Drábek, Petra Vokurková, Luboš Borůvka, Martin Valtera, Věra Fadrhonsová, Radek Novotný
This research focuses on the effects of large-scale clearcuts resulting from salvage logging after spruce (Picea abies) forest dieback caused by an extreme bark beetle infestation, and on the effect of logging residues management (chopping vs. clearing) on the distribution of potentially toxic elements (PTEs) in soil. Pseudo-total contents of Cd, Cr, Cu, Ni, Pb and Zn were determined in soil samples collected separately from the organic (F+H) and mineral (0–10, 10–20, and 20–30 cm depths) soil layers. The distribution of elements was influenced mainly by sampling locality and position in the soil profile. In general, the contents of Cd, Ni and Cr were higher in the mineral layers, whereas Pb was more concentrated in the FH layer. A significant effect of logging residues management on the distribution of PTEs was observed only for Pb and Zn. We expect that the relative decrease of Pb and increase of Zn contents in the “chopped” treatment was mostly due to the higher input of mineral soil and wood residues to the FH layer. Since the stand was harvested relatively recently, the effects of soil preparation have probably outweighed those of spreading or removing logging residues
The response of medium and trace elements in degraded alpine meadow soils to vegetation characteristics and soil physicochemical propertiesOriginal Paper
Haowei Xu, Yuhong Tong, Li Zhou, Huizhen Li
Alpine meadows, one of the most widespread and important vegetation types on the Qinghai-Tibet Plateau, are facing severe degradation. This study examines how degradation affects soil medium and trace elements in the eastern Qinghai-Tibet Plateau, along with their relationships with plant traits and soil properties. Results indicate that alpine meadow degradation significantly reduces vegetation coverage, height, biomass, soil water content (SWC), and the levels of soil organic carbon (SOC), nitrogen (N), and phosphorus (P), while increasing soil bulk density (BD), pH, and potassium (K) content. Soil Ca, Zn, and Mo decrease with degradation, whereas Mg, Fe, Mn, Cu, Ni, and Co increase, with Ca, Fe, and Mn showing the strongest changes. Correlation and redundancy analyses indicate that aboveground biomass, SWC, SOC, N, and P positively correlate with Ca, Mo, and Zn, while pH, BD, and K associate with Mn, Fe, Ni, Co, Mg, and Cu. Therefore, alpine meadow degradation significantly influences the distribution of certain soil physicochemical properties and medium and trace elements in the eastern Qinghai-Tibet Plateau. Meanwhile, these medium and trace elements are also affected by specific soil physicochemical properties. Future grassland restoration should consider not only macronutrients and basic soil properties but also key elements like Ca, Fe, and Mn. This study provides foundational data for the ecological restoration of degraded alpine meadows.
Multi-objective optimization and synergistic mechanisms of expansive soil improvement using organic fertilizer, slow-release fertilizer, and rice strawOriginal Paper
Yonggang Huang, Hongri Zhang, Xinzhong Wang, Yuexing Wu, Xianliang Tan, Kang Xiong
This study systematically investigated the synergistic improvement of expansive soil using organic fertilizer (OF), slow-release fertilizer (SRF), and rice straw (RS) through Box-Behnken design (BBD) and response surface methodology (RSM). Key findings include: The quadratic models demonstrated high statistical significance (root density: R² = 0.765, F = 25.84; shear strength: R² = 0.885, F = 18.65; swelling rate: R² = 0.20, F = 15.23; all P < 0.001) with low prediction errors (root content: ± 0.08 mg/cm³; shear strength: ± 0.58 kPa; swelling rate: ± 0.38%); The combination of 12.30% OF + 0.7 kg/m³ SRF + 0.4% RS achieved 58% improvement in shear strength, 32% improvement in root content, 42.7% reduction in swelling rate; OF exhibited negative linear effects on root density (β = –0.18, P = 0.002) with > 10% dosage reducing root growth by 9.0%; SRF showed positive linear impacts on shear strength (β = +0.25, p=0.001) and root density (β=+0.12, p=0.023); RS enhanced shear strength below 0.5% (β=+0.08, P = 0.042) but impaired root density due to pore clogging (β = –0.15, P = 0.008). The optimized formulation, validated by triplicate center-point tests (coefficient of variation ≤ 2.1%), is recommended for slope stabilization while limiting OF to ≤ 10% to prevent performance degradation. This data-driven approach provides actionable insights for balancing agricultural waste utilization and geotechnical performance in expansive soil improvement.
Rainfall pattern impact on runoff and sediment of the sloping cropland in Northeast ChinaOriginal Paper
Xu Fan, Wei Hu, Zhongzheng Ren, Yuan Chen, Qingsong Shen, Xingyi Zhang
Rainfall is a major contributor to water erosion of sloping cropland in Northeast China. Identifying how rainfall and slope gradient (S) influence runoff depth (RD) and sediment yield (SY) is crucial for preventing water erosion. Field measurements from runoff plots were collected from 2023 to 2024, and K-means clustering was applied to clarify the rainfall patterns. Response of RD and SY to the rainfall pattern and S were analysed. Key factors impacting RD and SY were explored. The results showed that three rainfall patterns were identified for 34 erosive rainfall events: A (41.2%, medium duration, medium rainfall intensity, and medium rainfall amount (RA)). B (50.0%, short duration, high rainfall intensity, and low RA) and C (5.4%, long duration, low rainfall intensity, high RA). Furthermore, the cumulative RD and SY increased with S for the same rainfall pattern. The cumulative RD and SY responded similarly to rainfall patterns for the same S. The contribution of the rainfall pattern to the cumulative RD and SY decreased in the order of C, A, and B. In addition, rainfall duration (D) and maximum 30 min rainfall intensity was the key factors affecting RD and SY for rainfall pattern A, respectively. Rainfall erosivity (R) was the key factor affecting RD and SY for rainfall pattern B and C. R and RD was dominant factor influencing the RD and SY for all rainfall events, respectively.