Site Conditions Research Articles

Application research on nonlinear partitioned analysis of soil-structure interaction method of seismic response for seawater-seabed-structure.

The analysis of seismic response in marine engineering structures is pivotal for guaranteeing their seismic safety. Such analyses are intricate due to the complexity of fluid-structure and soil-structure interactions. This paper introduces a unified computational framework for wave motion within a water-saturated seabed-bedrock system, employing the Davidenkov model and a modified Massing rule to characterize the nonlinear properties of the saturated seabed. A comparative analysis is conducted between the nonlinear responses of marine sites subjected to linear and nonlinear free-field inputs, with a specific focus on the seismic response of bridges under seawater-seabed-structure interaction. The study demonstrates that the modulus of a nonlinear saturated seabed diminishes, leading to a decrease in the wave impedance ratio between the saturated seabed and bedrock. Consequently, the reflection and transmission coefficients from the bedrock to the saturated seabed increase, amplifying the seismic response. For deepwater bridges, under harder site conditions, the abutment's bottom response is largely insensitive to increasing water depth, whereas the shear at the abutment's base diminishes with increasing water depth. The proposed method is validated through two case studies, with an examination of the impact of saturated sites on the analysis results.

Optimized agricultural management reduces global cropland nitrogen losses to air and water.

Nitrogen (N) losses from croplands substantially contribute to global N pollution. Assessing the reduction in N losses through improved N management practices is complex due to varying site conditions, such as land use, climate, soil properties and local farming methods. In this Article, we conducted a meta-analysis to evaluate the effects of improved practices on N loss reduction, analysing data from 1,065 studies with 6,753 pairs of observations comparing standard and optimized practices. Without considering site-specific conditions, optimized management practices can reduce N2O emissions by 3-39%, NH3 emissions by 15-68%, N run-off by 21-37% and N leaching by 19-52%. After considering local conditions and current practices, average reductions on a global scale were 31% for N2O, 23% for NH3, 18% for N run-off and 17% for N leaching. The effectiveness of N loss reduction was mainly influenced by optimized management practices and, to a lesser extent, site conditions. The results of this study underscore the importance of implementing optimized, site-specific management to effectively reduce N losses from global croplands.

Evaluating Quoddy Region archaeological site vulnerability to sea-level rise and erosion through the integration of geographic information system modeling and surveys

Modeling archaeological site erosion often depends on regional site databases that record sites accurately but with variable precision. This study examines the impact of sea-level rise (SLR) on 10 archaeological sites in the Quoddy Region of Maine through comparing models and field observations. Sites were categorized as low, mid, or high priority for field excavation based on exposure to tides. These model results were compared to field reports of site condition to evaluate the accuracy of modeling SLR as an indicator of erosion and to evaluate the application of models in developing prioritization protocols for site investigations. Models for current sea level scenarios broadly underestimate the degree of erosion reported by field observations because not all site locations were recorded at the precision required for analysis. This study emphasizes the importance of field audits for sites recorded in databases to enable large-scale modeling for the prioritization of urgently threatened sites.

A real−world pharmacovigilance study of FDA Adverse Event Reporting System events for pralsetinib

BackgroundPralsetinib, a selective oral inhibitor of rearranged during transfection (RET) fusion proteins and oncogenic RET mutants, has shown significant efficacy in treating RET fusion-positive non-small cell lung cancer and thyroid cancer. However, since pralsetinib was approved in the United States in September 2020, there have been limited reports of post-marketing adverse events (AEs). In this study, we aimed to analyze the AE signals with pralsetinib on the basis of the United States Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) to provide instructions in clinical practice.MethodsAll AE reports were obtained from the FAERS database from the first quarter (Q3) of 2020 to the second quarter (Q2) of 2024. Various signal quantification techniques were used for analysis, including reporting odds ratios, proportional reporting ratios, Bayesian confidence propagation neural network, and multi-item gamma Poisson shrinker (MGPS)-based empirical Bayesian geometric mean.ResultsOut of 8,341,673 case reports in the FAERS database, 1,064 reports of pralsetinib as the “primary suspected (PS)” AEs were recorded, covering 26 system organ classes and 256 preferred terms. Of the reports, 62.5% were from consumers rather than healthcare professionals. The most common systems were general disorders and administration site conditions (n = 704), investigations (n = 516), and gastrointestinal disorders (n = 405). A total of 95 significant disproportionality preferred terms (PTs) conformed to the four algorithms simultaneously. AEs that ranked the top three at the PT level were hypertension (n = 80), asthenia (n = 79), and anemia (n = 65). Of the 95 PTs with significant disproportionation, unexpected significant AEs such as increased blood calcitonin, increased myocardial necrosis marker, and bacterial cystitis were observed, which were not mentioned in the drug’s instructions. The median onset time of pralsetinib-associated AEs was 41 days [interquartile range (IQR) 14–86 days]. The majority of the AEs occurred in 30 days (42.86%).ConclusionOur pharmacovigilance analysis of real-world data from the FEARS database revealed the safety signals and potential risks of pralsetinib usage. These results can provide valuable evidence for further clinical application of pralsetinib and are important in enhancing clinical medication safety.

Comparative Study on Ground and Roof-Mounted Solar PV Systems

Solar photovoltaic (PV) systems are integral to sustainable energy solutions. The choice between ground-mounted and roof-mounted systems significantly impacts efficiency, cost, and installation feasibility. This study provides a comparative analysis of these two solar PV installation types to inform stakeholders and guide decision-making. This study aims to guide stakeholders, including policymakers, investors, and energy planners, in making informed decisions regarding solar PV system installations. By highlighting the strengths and weaknesses of each approach, this review contributes to the broader understanding of solar PV deployment strategies and their implications for sustainable energy development. A systematic literature review was conducted to gather data from various sources including academic journals, ScienceDirect, Google Scholar, PubMed, SpringerLink, Academia, and research gate. Key criteria for comparison included energy production efficiency, initial and ongoing costs, installation complexity, and long-term maintenance. The review revealed that ground-mounted systems generally offer higher energy production due to optimal tilt and orientation adjustments, and often result in lower maintenance costs due to easier access. Conversely, roof-mounted systems are usually less costly to install as they utilize existing infrastructure and may benefit from lower regulatory hurdles. However, they are constrained by roof space and orientation limitations and may face higher maintenance costs due to accessibility issues. Ground-mounted solar PV systems typically provide greater efficiency and easier maintenance but at higher installation costs. Roof-mounted systems are more cost-effective in terms of installation but may present limitations in energy production and maintenance. The choice between these systems should be guided by specific site conditions, budget constraints, and long-term energy goals.

Variation in Annual Ring and Wood Anatomy of Six Tree Mangrove Species in the Nicoya Gulf of Costa Rica

There is limited information regarding the adaptation of anatomical features and growth ring formation to ecological site conditions in Costa Rican mangrove trees. We used the methods and principles of ecological anatomy to explore the relationship between wood properties (e.g., ring formation, anatomical characteristics) and ecological factors for six mangrove tree species growing in three sites in the Gulf of Nicoya in Costa Rica. We found that variations of ecological conditions affected the growth ring formation of Avicennia bicolor, Avicennia germinans, Pelliciera rhizophorae and two species of Rhizophora but not Laguncularia racemosa. Site conditions affected the anatomical features of the mangrove tree species. Ray dimensions (height and width) were the factors most affected, which were followed by the frequency, diameter, and length of vessels. The fiber dimensions, green density, specific gravity, and carbon content were also affected by the site conditions. The plasticity in ray (increasing of ray dimension) and vessel elements (multiple vessels) facilitate efficient hydraulic conductivity amidst negative growth conditions and physiological restrictions for mangrove trees. We hypothesize that soil salinity, freshwater inputs and intertidal flooding influence these changes. Laguncularia racemosa presented the most changes in anatomical features across the different sites, followed by Pelliciera rhizophorae, with identical changes between Avicennia and Rhizophora spp. Finally, site salinity and wave energy affected the highest number of anatomical changes in mangrove tree species, including 38 changes in the wood structures in site 1.

Reduced predation and energy flux in soil food webs by introduced tree species: Bottom‐up control of multitrophic biodiversity across size compartments

Abstract The introduction of non‐native tree species has become a global concern and may disrupt native communities and related ecosystem functions. Soil food webs regulate organic matter decomposition and nutrient cycling in forests with their feeding activities, but evaluating consequences of the introduction of tree species on soil invertebrates is challenging due to the complex trophic structure and wide range in body size of soil invertebrates. Here, we employed an energetic food web approach and estimated the energy flux in soil food webs using a four‐node model including soil meso‐ and macrofauna decomposers and predators. We examined pure and mixed stands of native European beech (Fagus sylvatica), introduced Douglas fir (Pseudotsuga menziesii) and native range‐expanding Norway spruce (Picea abies) across site conditions. Compared to native forests, introduced tree species reduced total fresh mass of macrofauna predators by 92% at sandy sites but not that of decomposers, suggesting trophic downgrading in soil food webs by Douglas fir. The energy flux in mixed forests was intermediate between respective monocultures, suggesting that tree mixtures mitigate potential negative impacts of introduced tree species on food web functioning. Across size classes, soil macrofauna responded more sensitively to changes in environmental conditions than soil mesofauna. Additionally, total energy flux positively correlated with species richness, pointing to the significance of soil biodiversity for trophic functionality. The energy flux through mesofauna outweighed that through macrofauna when considering energy loss to predators, highlighting the importance of mesofauna for decomposition processes in forest soil food webs. Overall, the study emphasizes the critical role of tree species composition, site conditions and soil biodiversity in driving energy flux through soil food webs and maintaining forest ecosystem functions. Read the free Plain Language Summary for this article on the Journal blog.

Self-Compacting Mixtures of Fair-Faced Concrete Based on GGBFS and a Multicomponent Chemical Admixture—Technological and Rheological Properties

The use of superplasticizers in a self-compacting concrete mix without the addition of a foaming agent in practice leads to a well-known problem associated with increased air entrainment and promotes the formation of harmful large bubbles, high-void content, and ununiform appearance. This paper presents research on the properties of cement paste consisting of Ordinary Portland Cement (OPC), powder based on ground granulated blast furnace slag (GBBS), and superplasticizer. The methodology of this study was the estimation of flow diameter and flow time, as well as the evaluation of the rheological characteristics. The influence of ground granulated blast furnace slag and polycarboxylate plasticizer on the flowability and viscosity of cement paste was studied. The effect of superplasticizer (SP) based on polycarboxylate esters (PCE) anti-foaming agent (AFA) based on a glycol ester and air-entraining admixture (AEA) based on an amphoteric surfactant on flowability, viscosity, rheological properties and the strength of the cement paste was evaluated. It was found that the increase of slag content in cement paste (25%) with the presence of superplasticizer (0.64%) significantly changes the flowability and viscosity. It was stated that the addition of 0.04% anti-foaming agents increases flowability (20%) and reduces viscosity (44%) of cement paste. It was stated that the addition of small dosages of glycol ester-based anti-foaming agent (0.02 and 0.04%) significantly changes the rheological properties, decreases the shear yield stress by 2.1–2.8 times, the plastic viscosity by 2.4–2.6 times and apparent viscosity 1.6–2.5 times, improves the compressive strength at the age of 1 and 7 days by 2.5 and 1.4 times, respectively. The addition of air-entraining admixture led to a decrease in the plastic viscosity by 1.2–1.4 times. It was stated that the presence of air-entraining admixture assists in increasing the apparent viscosity by 1.7–2.4 times. It was shown that the presence of complex admixtures of various origins, purposes, and mechanisms of action would assist in predicting the behavior of concrete mixtures under the conditions of the building site and reduce the consumption of polycarboxylate esters due to the enhancing plasticizing effect of anti-foaming agent and air-entraining admixture.

Analysis of Adverse Reactions Associated with the Use of Crataegus-Containing Herbal Products

Background/Objectives: Products from various parts of Crataegus species are traditionally applied as a cardiotonic. In Europe and the USA, mainly Crataegus monogyna Jacq. (Lindm.) and Crataegus laevigata (Poir.) DC (synonym Crataegus oxyacantha L.) are used, but worldwide, other Crataegus species are also used. Phytotherapeutic preparations with a standardised content of flavonoids and/or oligomeric procyanidins are commercially available. The products are generally considered as safe and are at most associated with minor and atypical adverse reactions. The aim of this study was to critically assess the information about the safety of Crataegus-containing products in humans. Methods: A scoping review of the literature about adverse reactions associated with Crataegus-containing products was performed. Next, individual case safety reports (ICSRs) were assessed, which were included in VigiBase (the World Health Organisation’s global database of adverse event reports for medicines and vaccines) and in the database of the Netherlands Pharmacovigilance Centre Lareb. The findings are discussed in relation to the literature. Results: The scoping review yielded 23 clinical studies with single-herb and 14 with multi-herb preparations, from which only a few minor gastrointestinal and cardiac events had been reported. A total of 1527 reports from VigiBase, from 1970 to 2023, were analysed, as well as 13 reports from Lareb. The most frequently reported adverse reactions belonged to the system organ classes ‘gastrointestinal disorders’, ‘skin and subcutaneous tissue disorders’, ‘general disorders and administration site conditions’, ‘cardiac disorders’ or ‘nervous system disorders’. In 277 reports of VigiBase, a single-herb product was the only suspect for causing the adverse reaction(s). Of these, 12.6% were graded as serious. Conclusions: The results of our study provide deeper insight in the adverse reaction profile of Crataegus-containing products and should contribute to their safe application in the treatment of less severe forms of cardiac failure.

Pinus densiflora var. ussuriensis Forest Alliance

The Pinus densiflora var. ussuriensis forest is a unique pine forest type in Northeast China. The species grows normally under extremely adverse conditions because it has a strong tolerance to poor soils and drought. It also benefits the ecological environment significantly through water conservation, soil improvement and windbreak and sand fixation, thus making it an important pioneer species for improving site conditions. This paper systematically analyzes the geographical distribution, ecological and community characteristics, species composition and classification of Pinus densiflora var. ussuriensis forests in China through field surveys and literature review. The main findings are: (1) Based on the dominant species of each layer, Pinus densiflora var. ussuriensis forests can be divided into two categories of associations: Pinus densiflora var. ussuriensis - Rhododendron dauricum - Carex callitrichos association and Pinus densiflora var. ussuriensis + Quercus mongolica - Lespedeza bicolor - Carex caespitosa association. (2) According to sample plot surveys, a total of 134 vascular plant species, belonging to 59 families and 104 genera, were recorded in natural Pinus densiflora var. ussuriensis forests. Amongst them were one fern species, two gymnosperm species and 131 angiosperm species. (3) The composition of life forms in Pinus densiflora var. ussuriensis forests is dominated by terrestrial herbs, with fewer woody plants and with vines making up the smallest proportion. (4) The Pinus densiflora var. ussuriensis forests located on the hillocks of Xingkai Lake are in decline. If the soil in this area continues to increase in wetness, this community may eventually evolve into a broad-leaved mixed forest.

Three-Dimensional Numerical Analysis of Seismic Response of Steel Frame–Core Wall Structure with Basement Considering Soil–Structure Interaction Effects

In recent years, numerous studies highlighted the crucial role of the soil–structure interaction (SSI) in the seismic performance of basement structures. However, there remains a limited understanding of how this interaction affects buildings with basement structures under varying site conditions. Based on the three-dimensional (3D) numerical analysis method, the influence of the SSI on the seismic response of high-rise steel frame–core wall (SFCW) structures situated on shallow-box foundations were investigated in this study. To further investigate the effects of the SSI and site conditions, three types of soil profiles—soft, medium, and hard—were considered, along with a fixed-foundation model. The results were compared in terms of the maximum lateral displacement, inter-story drift ratio (IDR), acceleration amplification coefficient, and tensile damage for the SFCW structure under different site conditions, with both fixed-base and shallow-box foundation configurations. The findings highlight that the site conditions significantly affected the seismic performance of the SFCW structure, particularly in the soft soil, which increased the lateral deflection and inter-story drift. Moreover, compared with non-pulse-like ground motion, pulse-like ground motion resulted in a higher acceleration amplification coefficient and greater structural response in the SFCW structure. The RC core wall–basement slab junction was a critical region of stress concentration that exhibited a high sensitivity to the site conditions. Additionally, the maximum IDRs showed a more significant variation at incidence angles between 20 and 30 degrees, with a more pronounced effect at a seismic input intensity of 0.3 g than at 0.2 g.

IEA Wind Task 49: Reference Site Conditions for Floating Wind Arrays

Abstract The commercial-scale deployment of floating offshore wind (FOW) projects is expected to take place in a diverse range of sites that may differ significantly from existing fixed-bottom projects. FOW farms are particularly sensitive to the water depth and the meteorological and oceanographic (metocean) and geotechnical conditions at the project site due to the wave-induced system motions and loads as well as the anchoring system constraints imposed by the seafloor conditions. Uncertainty around the site conditions will permeate through all aspects of project design, leading to suboptimal and overly conservative designs, increased costs, and adversely affected performance. As FOW expands into a global industry, metocean and geotechnical conditions will increasingly vary for projects located in different geographic regions or in far-from-shore, deep-water sites. This study represents the outputs of work package 1 of International Energy Agency Wind Task 49, which focuses on the integrated design of floating wind arrays. The primary goal of this study is to establish the type of parameters and constraints required to characterize FOW array reference sites; provide a realistic and publicly available set of reference site conditions to the FOW community as a baseline set of data for individual research projects; identify and categorize any critical gaps in the existing data or methodologies required to define reference site characteristics; and inform and support the design of reference FOW arrays. A building block concept was developed for synthesizing reference sites for the design of FOW arrays. The building blocks include three classes of site conditions focusing on the techno-economic design of FOW projects: metocean conditions, seabed conditions, and coastal infrastructure. All reference site data produced and collected in this study are publicly available.

Impacts of prescribed fire and mechanical shredding of aboveground vegetation for fire prevention on ecosystem properties, structure, functions and overall multi-functionality of a semi-arid pine forest

Ecosystem multi-functionality is a key concept when measured to protect forests from natural and anthropogenic disturbances, such as fire prevention techniques, must be adopted. Despite this importance, scarce studies have analysed the impacts of prescribed burning and aboveground vegetation management on ecosystem functions and overall multi-functionality. To fill this gap, this study has evaluated the changes in some ecosystem properties and structure (associated with soil characteristics and plant diversity, respectively), in important forest functions, and the overall ecosystem multi-functionality in a Mediterranean pine forest of Castilla La Mancha (Central Eastern Spain) under three site conditions: (i) undisturbed ecosystem; (ii) forest subjected to mechanical shredding of aboveground vegetation (hereafter “AVMS”); and (iii) forest treated as above and then with prescribed fire (“AVMS + PF”). The results of the study have shown that neither the PF nor AVMS have significantly modified the structure, properties and functions as well as the overall multi-functionality of the forest ecosystem. These slight impacts of the treatments are due to the low fire severity of the prescribed burning and the long time elapsed from the vegetation management. Among the studied ecosystem functions, organic matter decomposition (driven by the enzymatic activities and soil basal respiration), water cycle (influenced by soil water content and water infiltration), carbon stock (linked to soil organic matter) and biomass production decreased, when species richness and plant diversity increased. The study is useful to indicate the feasibility of forest management actions for fire prevention in delicate forest ecosystems of the Mediterranean environments.

Climate Change Impact on the Stability of Soil Slopes from a Hydrological and Geotechnical Perspective

Climate change (CC) is expected to cause significant changes in weather patterns, leading to extreme phenomena. Specifically, the intensity of precipitation extremes is continuously escalating, even in regions with decreasing average precipitation levels. Given that CC leads to long-term shifts in weather patterns and may affect the precipitation characteristics (i.e., frequency, duration, and intensity) directly related to groundwater table fluctuations and soil erosion phenomena, it has the potential to significantly affect soil slope instabilities. In turn, slope stability and the structural integrity of nearby structures and infrastructure will be affected. Accordingly, the present paper focuses on the impact of CC on the geohazard of soil slope instability by considering both hydrological aspects, i.e., the impact on rainfall intensity on the groundwater table and the geotechnical aspects of this complex problem. The findings reveal that the impact of CC on potential slope instabilities can be detrimental or even beneficial, depending on the specific site and water conditions. Therefore, it is essential to do the following: (a) collect all the available data of the area of interest, (b) assess their variations over time, and (c) examine each potentially unstable slope on a case-by-case basis to properly mitigate this geohazard.

The impact of long-term organic horticultural systems on energy outputs and carbon storages in relation to extreme rainfall events

Enhancing resilience of agroecosystems of Mediterranean area is a challenge that involves both researchers and different stakeholders and, in this context, increasing crop diversity by redesigning agricultural systems can be considered among the most important tools. Therefore, the response of agroecological practices to climate change effects was tested in a long-term experiment on organic horticultural crops (MITIORG), which is characterized by a soil hydraulic arrangement in ridges, strips and the use (with different management options) of cover crops within cash crops rotations. The main objective of this study was to show how powerful is the sustainability assessment of agroecological practices by converting crops yield and biomass into energy outputs and carbon storages, in diversified horticultural systems. The obtained outputs (expressed in energy and carbon equivalents) were evaluated and analyzed considering the site-specific meteorological data in more than 10 horticultural cropping cycles, from autumn-winter 2014-15 to autumn-winter 2020-21. The Ridge and Strips (RS) system 1 (RS1 - cover crops as living mulch on ridges and break crops in strips, both with no-till termination) showed an enhancement of about 18% of energy output and carbon (C) storages compared to RS2 (ridges and strips with green manured cover) when extreme precipitation events occurred. Moreover, RS3 (ridges and strips without cover crops) recorded a reduction of about 5 and 9% of energy output and C storage, respectively, compared to the mean of RS1 and RS2 in periods with extreme events. Our results highlighted that using more diversified agroecological systems improved their overall average outputs, ensuring greater resilience during extreme weather events, since at least part of crop productions was safeguarded. Therefore, it is important to combine techniques that allow long-term resilience, such as choosing and well managing cover crops (agroecological service crops), according to site and systems specific conditions.

Influence of environmental conditions on the growth of Pleurotus ostreatus in sand

Pleurotus ostreatus, a saprotrophic fungus, has been proposed for the remediation of organic contaminants in soils and more recently for modifying the hydraulic and mechanical behaviour of granular soils. The in situ performance of fungal-based biotechnologies will be controlled by the fungal growth and associated biochemical activity that can be achieved in soil. In this study, the influence of environmental conditions (temperature, degree of saturation), substrate type (lignocellulose and spent coffee grounds) and concentration on the mycelium growth of P. ostreatus in sand are investigated. Furthermore, the evolution of growth/survival indicators (respiration, ergosterol concentration) and enzymatic activity (laccase, manganese peroxidase) are investigated. Temperature was shown to have a strong influence on the growth of P.ostreatus in sand: growth was observed to be delayed at low temperatures (e.g. 5 °C), whereas growth was prevented at high temperatures (e.g. 35 °C). No growth was observed at very low degrees of saturation (Sr=0% and 1.2%), indicating there is a critical water content required to support P.ostreatus growth. Within the mid-range of water contents tested radially, growth of P.ostreatus was similar. However, growth under saturated soil conditions was restricted to the air-water atmosphere due to the requirement for oxygen availability. Low substrate concentrations (1%–5%) resulted in high radial growth of P.ostreatus, whereas increasing substrate content further acted to reduce radial growth, but visual observations indicated that fungal biomass density increased. These results are important for understanding the feasibility of P.ostreatus growth under specific site conditions and for the design of successful treatment strategies.

Novel method to estimate horizontal variability of shear wave velocity through multichannel analysis of surface waves

Scale of fluctuations (SOFs) of spatially variable soil properties have been regarded as one of the important parameters for performing reliability-based design in geotechnical engineering. However, the information required to estimate the SOFs in practice is limited, especially in the horizontal direction. In this study, the potential use of Multichannel Analysis of Surface Waves (MASW) to estimate the SOFs of shear wave velocity (VS) in horizontal direction is investigated through a series of numerical investigations. 2D random field models with a vertically increasing trend of VS were first simulated with different levels of variability controlled by the coefficient of variation (COV) and SOF. Afterwards, a large number of numerical MASW tests were performed using a 2D finite difference method, where the survey lines were progressively shifted. Results show that the COV of VS can be determined from the scatter of the dispersion curves, whereas the horizontal SOF of VS can be appropriately estimated from the phase velocity profile presented in the wavelength form. Additionally, in-situ MASW tests were conducted to estimate the horizontal SOF, and the obtained results align with those estimated by different methods. It is highlighted that the accuracy of the estimation depends on survey length. The interpretation using a long array reflects an averaged site condition of the survey area, thus losing the variability information. Favorable predictions are produced when survey length is shorter than 1.0 SOF. However, it should be noted that use of short survey length may limit the depth of investigation.

Assessment of the heartwood contribution to carbon accumulation in Pinus sylvestris L. trees under different forest site conditions

Assessment of the heartwood contribution to carbon accumulation in Pinus sylvestris L. trees under different forest site conditions

Plant Species Diversity and Composition Differ Significantly Between the Boundaries of Kettle Holes and Field Borders.

The boundaries around habitat islands in agricultural fields are rather unexamined, although they may be an important part of agroecosystems in some regions. In this study, we surveyed field boundaries in northeastern Brandenburg both at outer field borders and around kettle holes, which are typical habitat islands in the region. We examined, described, and compared the plant species diversity and composition at both the inner and outer field boundaries in the arable fields (crop edge) as well as in permanent vegetation (field margins). Diversity was assessed and compared with Hill diversity values, using the iNext framework. Non-metric multidimensional scaling and permutational analysis of variance were used to compare species composition at different field boundaries and to search for variables that drive species composition at the local scale. The results revealed that both species diversity and composition differed significantly between the inner and outer boundary along the crop edges and at the field margins. Local site conditions, namely a moisture gradient, influenced the species composition of the field margins, resulting in differences between the inner and outer field margins. Mitigated through crop growth and cover, the moisture gradient influenced also the species composition of the inner and outer crop edges, despite the management practices on the fields were the same.

Investigating Sampling Bias in Seismological Research Through Secondary Variable: Insights from VS30 Datasets of Mainland China, Japan, Türkiye, and Taiwan

Abstract Sampling bias is an inevitable issue in seismological research, especially in collecting seismic site condition data due to operational constraints. It impacts data representativeness and subsequent model performance. Previous researches give insufficient consideration to this issue. Some researches worked on raw data directly. Some others used conventional declustering methods that rely on data spatial distribution and proved to be ineffective. This study investigates sampling bias in seismological research by employing a debiasing method that incorporates secondary variables, focusing on VS30 datasets from mainland China, Japan, Türkiye, and Taiwan. Quantifying analysis showed that, when considering topographic slope as the secondary variable, the sampling biases in the mainland China and Taiwan dataset are more pronounced. When examining the secondary variable of geology age, the sampling biases in the Japan and Türkiye datasets that are not readily discernible through visual inspection of spatial distributions become apparent. By investigating the sampling bias of the Türkiye and mainland China dataset using semivariogram as the secondary variable, this study reveals hidden bias within the Türkiye dataset, despite its well-distributed appearance. This finding further illustrates the limitations of relying solely on spatial distribution to detect sampling bias. In addition, the study examined the impact of sampling bias on resulting models. The topographic slope-based VS30 proxy models of debiased data in the four regions demonstrate significant effects of debiasing on modeling outcomes. Notably, the debiased models exhibit a homogenized trend comparing to original models in the low topographic slope range, indicating the possibility of a globally consistent relationship.