To study the failure mechanism of high ductile coagulation (HDC) under sulfate attack in cold saline soil area, cement-based cementing material (cement: fly ash: sand: water reducing agent: water = 1:1:0.72:0.03:0.58) and 2 % polyvinyl alcohol fiber (PVA) were used to prepare HDC sample, to increase the density and ductility of concrete. a 540-day sulfate-long-term immersion test was performed on HDC specimens under two low-temperature curing environments and different sulfate solution concentrations (5 %, 10 %). Using a combination of macro and microscopic methods, according to the principle of energy dissipation, To study the relationship between the evolution of energy (total damage energy U, dissipated energy Uds, elastic strain energy Ues) and the deterioration of strength and the change of pore structure during the compression process of HDC. According to the characteristics of stress-strain curves during HDC compression, the damage evolution characteristics of characteristic stress points during HDC compression are summarized, establish energy storage indicators Kel to evaluate the degree of internal damage of HDC. The results show that during the compression damage process of HDC after long-term soaking in sulfate solution under low temperature environment, Uds and Ues of HDC at characteristic stress points both increase first and then decrease, Kel are reduced first and then increased. The development trend of elastic strain energy and dissipative energy of HDC in 10 % sulfate solution is more drastic than that in 5 % sulfate solution. Compared with the other three groups, the D group energy storage level rises and falls more violently, and the HDC has a smaller ability to resist damage under this condition. Through the study of the correlation between macro and micro changes of HDC in cold saline soil areas and energy evolution, to provide a reference for the stable operation of highly ductile concrete in cold saline soil areas.

Forest management and tree felling in the stand change the structural characteristics, which causes changes in the microclimate conditions. The microclimate is a key in sustainable forest management because soil temperature and moisture regimes regulate nutrient cycling in forest ecosystems. The aim of this research was to determine the changes in air and soil temperatures in pedunculate oak forest stands in different stages of shelterwood that stimulate natural regeneration. The research was conducted in pedunculated oak forests in Spa & ccaron;va area. The microclimatic parameters were measured in a mature old forest stand without shelterwood cutting and in stands with preparatory cut, seed cut, and final cut. The intensity of shelterwood had an impact on the amplitudes and values of air and soil temperatures. The highest average air temperature was in the stand with a preparatory cut. Extreme values of air and soil temperatures were measured in the stands with a final cut. The highest air and soil temperature amplitudes were in the stand with a final cut, with the exception of most of the winter, when the highest soil temperature amplitude was in the stand with a seed cut. The highest number of icy, cold, and hot days was in the stand with a final cut. SARIMA models establish that the difference between microclimatic parameters is not accidental.

During the landfilling and resource utilization of solidified soil, it is inevitable that the material will be influenced by the surrounding water environment. Processes such as soaking and infiltration of both clean water and contaminated liquids can have an impact. This paper investigates the strength and structural stability of soil contaminated with a high concentration of lead or copper that has been solidified with red mud-carbide slag-phosphogypsum (RCP-Pb or RCP-Cu, respectively) in strongly acidic water, weakly acidic water, and pure water, as well as in two different modes of soaking and infiltration. The unconfined compressive strength, apparent and microscopic morphology, mineral composition, and functional groups of solidified soil before and after the action of different water solutions were compared, and the water and acid resistance of solidified soil was comprehensively analyzed. The results indicate that under the influence of a strongly acidic water environment, the strength of RCP-Pb and RCP-Cu can decrease by up to 26.4% and 18.5%, respectively, compared to the standard solidified specimens. Conversely, in a weakly acidic environment, the strength of the specimens can increase by a maximum of 21.1% and 32.8%, respectively. Under the two different water environment modes of action, RCP-Pb exhibits a greater increase in strength (39.8%) under soaking conditions, while RCP-Cu shows a greater increase (44.4%) under water infiltration. Based on the microscopic images, the pore counts in specimens in weakly acidic and pure water environments are greater than those in standard solidified specimens, while the porosity is less than that in standard solidified specimens. The surface of the particles exhibited increased roughness. A noticeable finding is that, under the infiltration of a strongly acidic water environment, the porosity of RCP-Pb increases to 20.22%, and the pore counts of RCP-Cu rise to 534. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses revealed that as the acidity of the water environment increased, the CaCO3 content significantly decreased. However, hydration products such as calcium silicate hydrate (C-S-H), calcium aluminate hydrate (C-A-H), calcium aluminosilicate hydrate (C-A-S-H), and ettringite (AFt) did not show significant differences. Consequently, the specimens maintained a stable strength and structure even under such a water environment.

Due to Paleo-clay's unique properties and widespread distribution throughout China, it is essential in geotechnical engineering. Rainfall frequently causes the deformation of Paleo-clay slopes, making slope instability prediction crucial for disaster prevention. This study explored Paleo-clay's strength degradation and slope stability under soaking and wet-dry cycles. Using Mohr-Coulomb failure envelopes from experiments, curve fitting was used to find the patterns of Paleo-clay strength degradation. Finite element simulations and the strength discounting method were used to analyze the stability and deformation of Paleo-clay slopes. The results indicate that wet-dry cycles impact them more than soaking. Paleo-clay's cohesion decreases exponentially as the number of wet-dry cycles and soaking times rise, but the internal friction angle changes very little. After 10 wet-dry cycles and 24 days of soaking, iron-bearing clay's cohesion decreased to 17% and 44% and reticular clay's to 32% and 48%. Based on the study area characteristics, three slope types were constructed. Their stability exhibited exponential decay. Under soaking, stability remained above 1.4; under wet-dry cycles, type I and II stability fell below 1.0, leading to deformation and failure. All types showed traction landslides with sliding zones transitioning from deep to shallow. Practical engineering should focus on the shallow failures of Paleo-clay slopes.

It is assumed that climate change (global warming) worsens the living conditions for conifers and at the same time favours the cultivation of deciduous trees, including oaks. In fact, in Poland, for example, many more oaks are now being planted as forest-forming tree species than in the 1980s and 1990s. However, the monitoring of the health status of European forests (according to the International Co-operation Project) does not confirm these optimistic assumptions, and oak has been cited as one of the most damaged tree species in terms of defoliation in recent decades. The prospects for oak cultivation in European forestry are therefore a combination of abiotic conditions and biotic damage factors. This review article focuses in particular on the new threats posed by pathogenic organisms causing emerging diseases. These include newly identified bacteria responsible for the so-called Acute Oak Decline (AOD), oomycetes (especially those specialised in damaging fine roots, such as Phytophthora quercina T.Jung) and semi-parasites of the genus Loranthus. At the same time, the pressure from commonly observed insects and fungi described in connection with the complex syndrome of oak decline, which is divided into predisposing, inciting, and contributing factors (according to Manion's disease spiral), has not abated. Therefore, international, interdisciplinary research (such as that proposed in Oakland) is needed, using modern technologies (RS remote sensing) based on the comparison of satellite images (from different years), not only to inventory the most valuable oak stands in Europe (microrefugia) but also to identify trends in changes in their condition and biodiversity. As RS has its limitations (e.g., resolution), aerial monitoring should be complemented by quantitative and qualitative inventory from the ground, e.g., monitoring of the presence of soil microorganisms using effective molecular biological methods (e.g., Next-Generation Sequencing NGS).

Ecosystem multifunctionality means that the ecosystem has the ability to provide multiple functions simultaneously. The study of the ecosystem multifunctionality provides an important basis for the understanding of the ecosystem function and management. Despite the plant community restoration is an important driver of changes in biodiversity and ecosystem multifunctionality, we still little know about the scaling effects the relationship between different dimensions of biodiversity and ecosystem multifunctionality. In this study, we investigated the relative contributions of different dimensions of plant diversity (e.g., species diversity, functional diversity and phylogenetic diversity) changes in ecosystem multifunctionality under different restoration stages (10, 30 and 40 years) in a human-damaged Liaodong oak (Quercus wutaishanica) plant communities in northern China. The results found that (1) ecosystem multifunctionality index was significantly higher in the middle (30 years) and late (40 years) stages of restoration than the early stage (10 years) of restoration. (2) Species richness and phylogenetic diversity were significantly higher in the early stage (10 years) of restoration than in the middle (30 years) and late (40 years) stages of restoration, however, functional dispersion was significantly higher in the later stages (40 years) of restoration than in the early (10 years) and middle stages (30 years) of restoration. (3) Ecosystem multifunctionality is primarily driven by photosynthetic traits of dominant species. The results of this study deepen the under-standing of the relationship between plant diversity and ecosystem multifunctionality in the forests of northern

Studies have reported the important role of soil properties in regulating insect herbivory under controlled conditions or at relatively large scales. However, whether fine-scale variation of soil properties affects insect herbivory under natural conditions in forests is still unclear. We selected a ca. 300 ha Quercus variabilis forest area where the leaf damage was mainly caused by Lampronadata cristata (Lepidoptera: Notodontidae) and set 200 10 x 10 m plots within the area. We examined insect herbivory (percent leaf area damaged) on Q. variabilis and correlated it to soil properties and tree characteristics. Insect herbivory decreased with soil sand percentage and bulk density and increased with DBH and tree height. Effects of soil sand percentage and bulk density on insect herbivory were partly mediated by DBH and tree height. Our results indicated that soil physical properties may have significant effects on insect herbivory by directly influencing insect herbivores that need to complete their life cycle in the soil, or by indirectly affecting insect herbivores through influencing DBH and tree height which reflects the total leaf biomass available to the insect herbivore. This study may help to understand the complex relationship between soil and plant-insect interactions in forest ecosystems.

Forests provide multiple ecosystem services including water and soil protection, biodiversity conservation, carbon sequestration, and recreation, which are crucial in sustaining human health and wellbeing. Global changes represent a serious threat to Mediterranean forests, and among known impacts, there is the spread of invasive pests and pathogens, often boosted by climate change and human pressure. Remote sensing can provide support to forest health monitoring, which is crucial to contrast degradation and adopt mitigation strategies. Here, different multispectral and SAR data are used to detect the incidence of ink disease driven by Phytophthora cinnamomi in forest sites in central Italy, dominated by chestnut and cork oak respectively. Sentinel 1, Sentinel 2, and PlanetScope data, together with ground information, served as input in Random Forests to model healthy and disease classes in the two sites. The results indicate that healthy and symptomatic trees are clearly distinguished, whereas the discrimination among disease classes of different severity (moderate and severe damage) is less accurate. Crown dimension and sampled spectral regions are a critical factors in the selection of the sensor; better results are obtained for the larger chestnut crowns with Sentinel 2 data. In both sites, the red and near infra-red bands from multispectral data resulted well suited to monitor the spread of the ink disease.

Heatwaves and soil droughts are increasing in frequency and intensity, leading many tree species to exceed their thermal thresholds, and driving wide-scale forest mortality. Therefore, investigating heat tolerance and canopy temperature regulation mechanisms is essential to understanding and predicting tree vulnerability to hot droughts. We measured the diurnal and seasonal variation in leaf water potential (Psi), gas exchange (photosynthesis A(net) and stomatal conductance g(s)), canopy temperature (T-can), and heat tolerance (leaf critical temperature T-crit and thermal safety margins TSM, i.e., the difference between maximum T-can and T-crit) in three oak species in forests along a latitudinal gradient (Quercus petraea in Switzerland, Quercus ilex in France, and Quercus coccifera in Spain) throughout the growing season. Gas exchange and Psi of all species were strongly reduced by increased air temperature (T-air) and soil drying, resulting in stomatal closure and inhibition of photosynthesis in Q. ilex and Q. coccifera when T-air surpassed 30 degrees C and soil moisture dropped below 14%. Across all seasons, T-can was mainly above T-air but increased strongly (up to 10 degrees C > T-air) when A(net) was null or negative. Although trees endured extreme T-air (up to 42 degrees C), positive TSM were maintained during the growing season due to high T-crit in all species (average T-crit of 54.7 degrees C) and possibly stomatal decoupling (i.e., A(net) 0). Indeed, Q. ilex and Q. coccifera trees maintained low but positive g(s) (despite null A(net)), decreasing Psi passed embolism thresholds. This may have prevented T-can from rising above T-crit during extreme heat. Overall, our work highlighted that the mechanisms behind heat tolerance and leaf temperature regulation in oak trees include a combination of high evaporative cooling, large heat tolerance limits, and stomatal decoupling. These processes must be considered to accurately predict plant damages, survival, and mortality during extreme heatwaves.

This paper presents experimental studies on a compacted expansive soil, from Nanyang, China for investigating the at-rest lateral earth pressure sigma(L) of expansive soils. The key studies include (i) relationships between the aL and the vertical stress sigma(V) during soaking and consolidation, (ii) the influences of initial dry density p(d0) and moisture content w(0) on the vertical and lateral swelling pressures at no swelling strain (i.e. sigma(V0) and sigma(L0)), and (iii) evolution of the sigma(L) during five long-term wetting-drying cycles. Experimental results demonstrated that the post-soaking sigma(L)-sigma(V) relationships are piecewise linear and their slopes in the passive state (sigma(L) > sigma(V)) and active state (sigma(L) < sigma(V)) are similar to that of the consolidation sigma(L)-sigma(V) relationships in the normal- and over-consolidated states, respectively. The soaking sigma(L)-sigma(V) relationships converge to the consolidation sigma(L)-sigma(V) relationships at a threshold aV where the interparticle swelling is restrained. The sigma(L0) and sigma(V0) increase monotonically with p(d0); however, they show increasingthen-decreasing trends with the w(0). The extent of compaction-induced swelling anisotropy, which is evaluated by sigma(L0)/sigma(V0), reduces with an increase in the compaction energy and molding water content. The sigma(L) reduces over moisture cycles and the stress relaxation in the sigma(L) during soaking is observed. An approach was developed to predict the at-rest soaking sigma(L)-sigma(V) relationships, which requires conventional consolidation and shear strength properties and one measurement of the sigma(L)-sigma(V) relationships during soaking. The proposed approach was validated using the results of three different expansive soils available in the literature. (c) 2024 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).