Shield tunnelling through densely populated urban areas inevitably disturbs the surrounding soil, potentially posing significant safety risks to nearby buildings and structures. The constitutive models currently employed in numerical simulations for tunnel engineering are predominantly confined to the assumptions of isotropy and coaxiality, making it challenging to adequately capture the complexity of the mechanical response of the soil surrounding the tunnel. Based on the proposed non-coaxial and anisotropic elastoplastic Mohr-Coulomb yield criterion, this study carries out numerical simulation analyses of soil disturbance induced by urban shield tunnelling. Herein, the anisotropic parameters n and /1 jointly determine the shape of the anisotropic yield surface. The results demonstrate that rotation of the principal stress axes is observed in most areas of the soil surrounding the tunnel face, with the phenomenon being particularly pronounced at the crown and the invert of the tunnel. As the anisotropic parameter n decreases, the maximum surface settlement above the tunnel axis increases. The influence of anisotropy on higher-stress unloading coefficients is significant, resulting in the development of a wider plastic zone around the tunnel. As the coefficient of lateral earth pressure at rest K0 increases, the maximum surface settlement gradually reduces. Under the influence of anisotropic parameter /1 or non-coaxial parameter k, the maximum surface settlement exhibits an approximately linear relationship with K0. However, the anisotropic parameter n has a significant influence on the trend of the maximum surface settlement with respect to K0, which leads to a non-linear relationship. Neglecting the effects of soil anisotropy, noncoaxiality, and the coefficient of lateral earth pressure at rest may lead to design schemes that are potentially unsafe. The results of this research can provide engineers with design bases for construction parameters and soil disturbance control while shield tunnelling in sandy pebble soil.
The majority of European forests are managed and influenced by natural disturbances, with wind being the dominant agent, both of which affect the ecosystem's carbon budget. Therefore, investigating the combined effect of wind damage and different soil preparation practices on forest carbon pools is of great importance. This study examines changes in carbon stocks in the soil and biomass of two 5-year-old Scots pine stands (namely Tlen1 and Tlen2), which were established approximately 2 years after a large-scale wind disturbance in northwestern Poland. These neighboring sites differ in terms of the reforestation methods applied, particularly regarding soil preparation: ploughing disc trenching at Tlen1 and partial preparation through local manual scalping at Tlen2. Using nearby forest soils as the best available reference for the pre-windthrow state, it was estimated that the total carbon stock in the soil (up to 50 cm depth, both organic and mineral) was depleted by approximately 17 % at Tlen1 and 7 % at Tlen2. The between-site differences were around 18 %, which nearly doubled when considering only the top 20 cm of the soil profile. In contrast, the total biomass, as well as the carbon stock in biomass, were significantly higher at the site with soil prepared using moderate ploughing (Tlen1) compared to the area with partial soil preparation (Tlen2). Our findings indicate that ploughing disc trenching, aimed mainly at weed removal and improving soil properties, significantly enhanced Scots pine seedlings' growth, survival, and development during the first four years after planting. Finally, when both carbon stock estimates are pooled together, regardless of the chosen technique, the growing biomass in the investigated stands did not fully compensate for the carbon losses caused by mechanical soil preparation. However, in the short term, the overall change in the ecosystem's carbon balance was only slightly negative and comparable between the two sites.
Wild boar ( Sus scrofa ) is a widespread megaherbivore that can intensively disturb large areas of its habitat both in its native and non-native ranges, when populations reach high densities. The main problem is its rooting habit, which entails intensive disturbance of the topsoil and herbaceous layer. The extent of concomitant habitat degradation varies across ecoregions; some ecosystems are rather resilient, although the damages are long-lasting in others. In mown meadows, a secondary problem is the inability to resume mowing due to the uneven soil surface of rooted patches. This can lead to both economic loss and a loss of management-dependent biodiversity. We assessed the short-term effects of rooting on vegetation cover and composition in central European permanent hay meadows and tested the utility of manual soil surface resmoothing to enable the continuation of mowing. We found that rooting increased bare soil surface but vegetation recovery occurred within a year. Similarly, high resilience was found for species composition. We could not detect any difference between rooted and intact grassland patches after 1 yr. This short-term perturbation of the composition could be associated with a temporary decrease in grassland specialist species and an increase in ruderal and pioneer species. Soil surface resmoothing was an additional disturbance, but vegetation cover returned to the level of intact grasslands within a year. Vegetation composition needed a slightly longer time (2 yr) to recover than that without resmoothing. We thus recommend the application of manual resmoothing in hay meadows with high short-term resilience to rooting, but a risk of long-term degradation (e.g., shrub encroachment) if mowing is not resumed. In hay meadows with lower resilience (because of, e.g., steep slopes), resmoothing should be applied with caution and may be supplemented with seeding to support the recovery of the vegetation and prevent soil erosion. (c) 2025 The Society for Range Management. Published by Elsevier Inc. All rights are reserved, including
Fire has important effects on soil properties and functioning in terrestrial ecosystems that have been explored by many studies. Limited information exists on the alterations in soil parameters over time caused by fire disturbance in semi-arid climates. This study is designed to examine the influence of fire disturbance on the change of soil physical, chemical, and biological properties over time in a semi-arid region. In the summer of 2007, a severe natural fire occurred in the Pideh region of northern Iran, dominated by hawthorn (Crataegus melanocarpa M.B.) and berberis (Berberis integerrima Bunge), which destroyed almost 80 % of the shrubs and the majority of the co-dominant plants over a vast area. For this research, 12 soil samples (0-10 cm depth) were taken in summer (August) in different years (i.e., 2010, 2013, 2016, 2019, and 2022) from the burnt area. Furthermore, a total of 12 soil samples were collected during the summer (August) of 2022 from unburned regions to serve as a control. Soil biological parameters were studied by conducting soil samplings in the summer (August) and autumn (November) of every year. To evaluate soil N mineralization, soil samplings were done in summer (August and September) and autumn (November and December). Our results indicated that the occurrence of fire increased soil bulk density, with a concomitant decline in soil organic matter (SOM), porosity, aggregate stability, particulate organic carbon and nitrogen (POC and PON), as well as available nutrients such as ammonium (NH4+) and nitrate (NO3-) levels. Additionally, microbial parameters (respiration and biomass) and enzymes (urease, acid phosphatase, arylsulfatase and invertase), experienced a decrease in areas affected by the fire over time of 2010 to 2022. Unburnt (2022) and burnt (2022) sites had higher density and biomass of the three earthworm groups. Acari, Collembola, nematodes, protozoans, fungi and bacteria were significantly affected by fire disturbance in the different seasons, and years, and declined in the order unburnt sites > burnt sites 2022 > burnt sites 2019 > burnt sites 2016 > burnt sites 2013 > burnt sites 2010, respectively. Fire has complex effects on soil, involving interactions among physical, chemical, and biological properties that may persist for a prolonged period. After fifteen years of fire disturbance, soil characteristics were different in the burned (2022) and unburned areas. This research offers valuable insights into the impact of fire on soil characteristics over time, as well as a comparison with an unburned area. Therefore, it is essential to adopt soil management practices to minimize soil disruption in burned areas and facilitate the full recovery of soil ecosystems after fire damage.
Animal logging is one of the most ancient wood extraction methods and it is still applied in different parts of the world, including industrialised countries. Animal logging is often imagined as a low-impact method and sometimes, or rather often, it is recommended as a best-management practice. However, the literature findings depict a more complex scenario, and the goal of the present review is to shed light on the topic of environmental sustainability of logging operations performed by animals. Usually, animal logging causes less pollutant emissions and less damage to the residual stand in comparison to ground-based mechanised extraction methods. However, when applied in commercial forestry interventions such as coppicing, animal logging showed levels of soil compaction in line with those of ground-based machinery like tractors, skidders and forwarders. Specifically developed trials revealed that in the animal skid trails a strong disturbance to the soil microarthropod community occurred. Furthermore, the soil features in the animal trails seemed to get worse over time after logging, thus suggesting the possible presence of strong localised erosion along these trails. Despite the strong need to further investigate this topic, concerning the ecological aspects of forest soil which were generally neglected by the literature, the use of animal logging can be recommended in the case of small-scale forestry with wooden material sparsely located throughout the logging site. In the case of commercial logging on steep slopes instead it is recommended to replace animal logging with cable-based extraction systems.
A review of the status of research on high mountain soils and their alterations caused by changes in the cryosphere in the European Alps is given. Soils of high mountain environments are not only exposed to atmospheric warming, rising CO2 levels, and changing precipitation patterns but also to climate-driven changes in the cryosphere. The massive reduction of glacier coverage as well as snow cover and (perma) frost extent can affect soils in various ways. We performed a comprehensive literature analysis and considered both the direct impacts (changes in surface coverage or ground thermal conditions) and indirect impacts (changing hydrosphere, lithosphere/geomorphodynamics, or biosphere) of cryosphere changes on soil. All considered studies had a multidisciplinary character: around 34% of the articles covered two spheres (cryosphere, pedosphere), 40% covered three spheres (cryosphere, pedosphere, and an additional sphere), and 26% covered more than three spheres. Most studies focused on initial soil formation in glacier forefields. The impact of changing geomorphodynamics on soils is underrepresented in literature, even though it is one of the major consequences of changes in the cryosphere. We therefore finally discuss possible consequences of changing geomorphodynamics due to changes in the cryosphere for high mountain soils.
Permafrost, an important source of soil disturbance, is particularly vulnerable to climate change in Alaska where 85% of the land is underlained with discontinuous permafrost. Boreal forests, home to plants integral to subsistence diets of many Alaska Native communities, are not immune to the effects of climate change. Soil disturbance events, such as permafrost thaw, wildfires, and land use change can influence abiotic conditions, which can then affect active layer soil microbial communities. In a previous study, we found negative effects on boreal plants inoculated with microbes impacted by soil disturbance compared to plants inoculated with microbes from undisturbed soils. Here, we identify key shifts in microbial communities altered by soil disturbance using 16S rRNA gene sequencing and make connections between microbial community changes and previously observed plant growth. Additionally, we identify further community shifts in potential functional mechanisms using long read metagenomics. Across a soil disturbance gradient, microbial communities differ significantly based on the level of soil disturbance. Consistent with the earlier study, the family Acidobacteriaceae, which consists of known plant growth promoters, was abundant in undisturbed soil, but practically absent in most disturbed soil. In contrast, Comamonadaceae, a family with known agricultural pathogens, was overrepresented in most disturbed soil communities compared to undisturbed. Within our metagenomic data, we found that soil disturbance level is associated with differences in microbial community function, including mechanisms potentially involved in plant pathogenicity. These results indicate that a decrease in plant growth can be linked to changes in the microbial community and functional composition driven by soil disturbance and climate change. Together, these results build a genomic understanding of how shifting soil microbiomes may affect plant productivity and ecosystem health as the Arctic warms.