The coupled thermo-hydro-mechanical response caused by fire temperature transfer to surrounding rock/soil has a significant impact on tunnel safety. This study developed a numerical simulation model to evaluate the effects of fire on tunnel structures across different geological conditions. The heat transfer behavior varied with the mechanical properties and permeability of the geotechnics, concentrating within 1.0 m outside the tunnel lining and lasted for 10 days. Significant differences in pore water pressure changes were observed, with less permeable geologies experiencing greater pressure increases. Tunnel deformation was more pronounced in weaker geotechnics, though some tunnels in stronger geologies showed partial recovery post-fire. During the fire, thermal expansion created a bending moment, while a negative bending moment occurred after the fire due to tunnel damage and geotechnical coupling. The entire process led to irreversible changes in the bending moment. The depth of tunnel burial showed varying sensitivity to fire across different geological settings. This study provides important references for fire protection design and post-fire rehabilitation of tunnels under diverse geological conditions.

This study investigates the effects of incorporating date palm wood powder (DPWP) on the thermal, physical, and mechanical properties of lightweight fired earth bricks made from clay and dune sand. DPWP was added in varying proportions (0 %, 5 %, 8 %, 10 %, 12 %, and 15 % by weight of the soil matrix) to evaluate its influence on brick performance, particularly in terms of thermal insulation. Experimental results revealed that adding DPWP significantly reduced the thermal conductivity of the bricks, achieving a maximum reduction of 56.41 %. However, the inclusion of DPWP negatively impacted the physical and mechanical properties of the samples. Among the tested bricks, those with 8 % and 10 % DPWP achieved a desirable balance, maintaining satisfactory mechanical strength within acceptable standards while achieving thermal conductivity values of 0.333 and 0.279 W/m & sdot;K, representing reductions of 37.29 % and 47.46 %, respectively. To further validate these findings, prototypes of the DPWP-enhanced fired bricks and commercial bricks were constructed and tested under real environmental conditions during both summer and winter seasons, over a continuous 12-h daily period. The DPWP-enhanced prototypes demonstrated superior thermal performance, with temperature differences reaching up to 3 degrees C compared to the commercial bricks. These findings highlight the potential of DPWP as a sustainable additive for improving the thermal insulation properties of fired earth bricks, thereby promoting eco-friendly and energy-efficient building materials for sustainable construction practices.

Wildfires are increasingly recognized as a critical driver of ecosystem degradation, with post-fire hydrological and soil impacts posing significant threats to biodiversity, water quality, and long-term land productivity. In fire-prone regions, understanding how varying fire intensities exacerbate runoff and erosion is essential for guiding post-fire recovery and sustainable land management. The loss of vegetation and changes in soil properties following fire events can significantly increase surface runoff and soil erosion. This study investigates the effects of varying fire intensities on runoff and sediment yield in the Kheyrud Educational Forest. Controlled burns were conducted at low, moderate, and high intensities, along with an unburned plot serving as the control. For each treatment, three replicate plots of 2 m2 were established. Runoff and sediments were measured over the course of 1 year under natural rainfall. In addition, key soil physical properties, including bulk density, penetration resistance, and particle size distribution (sand, silt, and clay fractions), were assessed to better understand the underlying mechanisms driving hydrological responses. The results revealed that bulk density and penetration resistance were lowest in the control and highest for the high-intensity fire treatment. A significant correlation was observed between bulk density, penetration resistance, and both runoff and sediment production. However, no significant correlation was found between runoff and soil texture (sand, silt, and clay content). Fire intensity had a pronounced effect on runoff and sediment, with the lowest levels recorded in the control and low-intensity fire treatment, and the highest in the high-intensity fire treatment. The total annual erosion rates were 0.88, 1.10, 1.57, and 2.24 tons/ha/year for the control, low-, moderate-, and high-intensity treatments, respectively. The study demonstrates that high-intensity fires induce substantial changes in soil structure and vegetation cover, exacerbating runoff and sediment loss. To mitigate post-fire soil degradation, proactive forest management strategies are essential. Preventive measures-such as reducing fuel loads (e.g., removing uprooted trees in beech stands), minimizing soil compaction and vegetation damage during logging operations, can help reduce the ecological impact of wildfires. These findings provide a scientific basis for adaptive management in fire-prone forests, addressing urgent needs to balance ecological resilience and human activities in wildfire-vulnerable landscapes.

This study explored the effects of forest fires on soil microbial activity in forest soils classified by rock origin (igneous, metamorphic, and sedimentary) and stratified by subsoil depth (topsoil, subsoil). Microbial activity, indicated by average well color development (AWCD) and Shannon diversity indices, was higher in undamaged topsoils compared to fire-damaged ones. In contrast, fire-damaged subsoils, particularly in metamorphic and sedimentary soils, exhibited increased microbial activity over time due to organic matter decomposition. A significant increase in substrate utilization was observed in undamaged soils across all rock types (*p < 0.05, **p < 0.01) in topsoil, with sedimentary rock exhibiting the highest microbial diversity based on Shannon indices. The dehydrogenase activity followed a similar pattern, with reduced activity in fire-damaged topsoil but higher activity in damaged metamorphic and sedimentary subsoils. Principal component analysis (PCA) linked microbial indicators (AWCD, Shannon index) to mineral compositions like orthoclase and hornblende, highlighting the role of soil chemistry in shaping microbial responses to fire. These insights advance the understanding of fire-induced changes in soil microbial functions across diverse geological contexts.

明确不同野火数据产品的一致性与不确定性是开展产品分析应用的前提与基础。FireCCI51和MOSEV是国际上广泛使用的两套野火数据产品，泛北极多年冻土区是全球野火发生的集中区与重要碳库，分析该区野火数据产品的一致性可对未来提升野火产品的数据精度、降低泛北极碳通量估算等具有重要意义。本研究运用空间分析方法，从燃烧面积与燃烧区空间位置等方面，识别了FireCCI51和MOSEV两种数据产品在泛北极多年冻土区的一致性，进而分析了两者一致区与不一致区的地理环境特征。结果表明：(1)2001～2019年FireCCI51产品的燃烧面积均大于MOSEV，且两者燃烧面积的百分比差异在7%～60%无规律波动；(2)两种产品识别的燃烧区的空间分布一致性介于27.68%～47.14%，一致区主要分布在燃烧区集中分布的地区，例如加拿大中部地区、俄罗斯中、东西伯利亚地区及其南部延伸的大兴安岭地区，不一致区除了分布在这些地区之外，还在俄罗斯南部和西西伯利亚地区分布较多；(3)高程、气候类型和植被类型均对两套数据产品的一致区分布造成一定影响。在较低海拔和常湿冷温气候地区两种产品的一致区面积占比较多，在相对较高海拔...

明确不同野火数据产品的一致性与不确定性是开展产品分析应用的前提与基础。FireCCI51和MOSEV是国际上广泛使用的两套野火数据产品，泛北极多年冻土区是全球野火发生的集中区与重要碳库，分析该区野火数据产品的一致性可对未来提升野火产品的数据精度、降低泛北极碳通量估算等具有重要意义。本研究运用空间分析方法，从燃烧面积与燃烧区空间位置等方面，识别了FireCCI51和MOSEV两种数据产品在泛北极多年冻土区的一致性，进而分析了两者一致区与不一致区的地理环境特征。结果表明：(1)2001～2019年FireCCI51产品的燃烧面积均大于MOSEV，且两者燃烧面积的百分比差异在7%～60%无规律波动；(2)两种产品识别的燃烧区的空间分布一致性介于27.68%～47.14%，一致区主要分布在燃烧区集中分布的地区，例如加拿大中部地区、俄罗斯中、东西伯利亚地区及其南部延伸的大兴安岭地区，不一致区除了分布在这些地区之外，还在俄罗斯南部和西西伯利亚地区分布较多；(3)高程、气候类型和植被类型均对两套数据产品的一致区分布造成一定影响。在较低海拔和常湿冷温气候地区两种产品的一致区面积占比较多，在相对较高海拔...

明确不同野火数据产品的一致性与不确定性是开展产品分析应用的前提与基础。FireCCI51和MOSEV是国际上广泛使用的两套野火数据产品，泛北极多年冻土区是全球野火发生的集中区与重要碳库，分析该区野火数据产品的一致性可对未来提升野火产品的数据精度、降低泛北极碳通量估算等具有重要意义。本研究运用空间分析方法，从燃烧面积与燃烧区空间位置等方面，识别了FireCCI51和MOSEV两种数据产品在泛北极多年冻土区的一致性，进而分析了两者一致区与不一致区的地理环境特征。结果表明：(1)2001～2019年FireCCI51产品的燃烧面积均大于MOSEV，且两者燃烧面积的百分比差异在7%～60%无规律波动；(2)两种产品识别的燃烧区的空间分布一致性介于27.68%～47.14%，一致区主要分布在燃烧区集中分布的地区，例如加拿大中部地区、俄罗斯中、东西伯利亚地区及其南部延伸的大兴安岭地区，不一致区除了分布在这些地区之外，还在俄罗斯南部和西西伯利亚地区分布较多；(3)高程、气候类型和植被类型均对两套数据产品的一致区分布造成一定影响。在较低海拔和常湿冷温气候地区两种产品的一致区面积占比较多，在相对较高海拔...

Background and AimsPrescribed burning is a widely used management technique, often employed to restore grasslands affected by woody plants encroachment. However, its interaction with pre-existing plant species in influencing soil properties remains unclear.MethodsWe conducted a diachronic soil survey to assess the evolution of several soil properties in the mid-term (up to 18 months) after burning, including physico-chemical parameters and microbial biomass carbon on soils under vegetation patches of different plant functional types and life forms. Vegetation patches included Ericaceae and legume shrubs, ferns, and biocrusts dominated by lichens. Soil samples were taken pre-burning, immediately after burning and 9 and 18 months after.ResultsOur findings indicate that while some soil properties returned to pre-burning levels in the mid-term (i. e., soil cations and NH4+), others, such as available phosphorous (P Olsen), exhibited a significant decline that persisted even 18 months later. Furthermore, soils under legumes initially displayed higher levels of soil carbon and nitrogen compared to other vegetation patches, but this distinction diminished over time. This was likely due to legumes' susceptibility to fire damage, in contrast to the greater resilience of Ericaceae shrubs.ConclusionOur study highlights the complex vegetation patch-dependent effects of prescribed burning on soil properties. While legumes initially enhance soil carbon and nitrogen, their contribution decreases over time due to fire sensitivity. Some soil parameters recover in the mid-term, but nutrients like available phosphorus continue to decline. Fire management strategies should consider plant diversity and recovery time to mitigate soil fertility loss.

Extreme weather events are increasing the frequency and intensity of forest fires, generating serious environmental and socio-economic impacts. These fires cause soil loss through erosion, organic matter depletion, increased surface runoff and the release of greenhouse gases, intensifying climate change. They also affect biodiversity, terrestrial and aquatic ecosystems, and soil quality. The assessment of forest fires by remote sensing, such as the use of the Normalised Difference Vegetation Index (NDVI), allows rapid analysis of damaged areas, monitoring of vegetation changes and the design of restoration strategies. On the other hand, models such as RUSLE are key tools for calculating soil erosion and planning conservation measures. A study of the impacts on soils and vegetation in the south of Salamanca, where one of the worst fires in the province took place in 2022, has been carried out using RUSLE and NDVI models, respectively. The study confirms that fires significantly affect soil properties, increase erosion and hinder vegetation recovery, highlighting the need for effective restoration strategies. It was observed that erosion intensifies after fires (the maximum rate of soil loss before is 1551.85 t/ha/year, while after it is 4899.42 t/ha/year) especially in areas with steeper slopes, which increases soil vulnerability, according to the RUSLE model. The NDVI showed a decrease in vegetation recovery in the most affected areas (with a maximum value of 0.3085 after the event and 0.4677 before), indicating a slow regeneration process. The generation of detailed cartographies is essential to identify critical areas and prioritise conservation actions. Furthermore, the study highlights the importance of implementing restoration measures, designing sustainable agricultural strategies and developing environmental policies focused on the mitigation of land degradation and the recovery of fire-affected ecosystems.

The extent of wildfires in tundra ecosystems has dramatically increased since the turn of the 21st century due to climate change and the resulting amplified Arctic warming. We simultaneously studied the recovery of vegetation, subsurface soil moisture, and active layer thickness (ALT) post-fire in the permafrost-underlain uplands of the Yukon-Kuskokwim Delta in southwestern Alaska to understand the interaction between these factors and their potential implications. We used a space-for-time substitution methodology with 2017 Landsat 8 imagery and synthetic aperture radar products, along with 2016 field data, to analyze tundra recovery trajectories in areas burned from 1953 to 2017. We found that spectral indices describing vegetation greenness and surface albedo in burned areas approached the unburned baseline within a decade post-fire, but ecological succession takes decades. ALT was higher in burned areas compared to unburned areas initially after the fire but negatively correlated with soil moisture. Soil moisture was significantly higher in burned areas than in unburned areas. Water table depth (WTD) was 10 cm shallower in burned areas, consistent with 10 cm of the surface organic layer burned off during fire. Soil moisture and WTD did not recover in the 46 years covered by this study and appear linked to the long recovery time of the organic layer.