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Macrobenthic bioturbation is vital to facilitate nutrient turnover in estuarine ecosystems and drives spatial heterogeneity in the sediment matrix. In this study, we compared the sediment physico-chemical properties, microbial community structure and functional genes in vertically-stratified sediment samples from bioturbated (burrows of Parasesarma bidens and Tubuca arcuata) and non-bioturbated area in mangrove ecosystems (the Hanjiang River Estuary, Southern China). The result indicated that bioturbation by P. bidens and T. arcuata had significantly different effects on sediment properties, with the action of P. bidens enhancing nutrient accumulation while T. arcuata promoted N 2 O emission. Burrow microhabitats harbored distinctive microbial communities although the dominant phylum and genera shared considerable similarity with the control sediment surface with Woeseia dominating in vertical profiles across different habitats. Co-occurrence network analysis revealed that crab bioturbation promoted formation of less complex but more functionally-specialized microbial communities. Crab bioturbation enhanced nutrient metabolism and separated clusters in dendrogram demonstrated the species-specific effect between P. bidens and T. arcuata. Our work verified the significance of bioturbators in regulating biogeochemical processes and highlighted the species-specific bioturbation effect between two dominant mangrove crabs (P. bidens vs. T. arcuata)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Microplastic pollution has become an increasing concern. Vertical transport of microplastics is one of the major research questions concerning the distribution and fate of microplastics in the marine environment, and biologically mediated vertical transport is particularly significant. However, studies on the effects of different types of benthic organisms on the vertical distribution of microplastics in sediments are still scarce. The results of this study revealed that when exposed to environmentally relevant concentrations of fluorescent polystyrene microbeads (200 µm), Manila clams (Ruditapes philippinarum) exhibited prolonged acclimation period, yet subsequent burrowing behavior (burrowing rate and burrowing velocity) was unaffected. The condition index, clearance rate, and oxygen consumption rate of the clams similarly exhibited no stress response after 14 days of exposure. We determined that microplastics were rapidly transported to deeper layers (6-8 cm below the surface) in the sediment under bioturbation. This study elucidates the mechanisms of microplastic transport, showing that clam behaviors such as burrowing, movement, and ingestion contribute to this process. The results suggest that a biologically based management strategy may be a more environmentally friendly means of mitigating microplastic pollution in seawater., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Marine soft sediments play crucial roles in global biogeochemical cycles and biodiversity. Yet, with organisms often hidden in the sediment, they pose challenges for effective monitoring and management. This study introduces a novel approach utilizing sediment microtopography as a proxy for ecosystem functioning and biodiversity. Combining field sampling, benthic chamber incubations, and advanced Structure-from-Motion photogrammetry techniques, we investigated the relationships between microtopographic features and various ecological parameters across diverse subtidal habitats. Our findings reveal strong associations between sediment microtopography and environmental variables, benthic fluxes, biodiversity metrics, and community functional traits, with microtopography consistently explaining more than 50% of the variance in the data. This research demonstrates the potential of sediment microtopography as a cost-effective and scalable tool for assessing soft-sediment ecosystem dynamics and informing conservation strategies. By providing insights into the links between habitat structure and ecological processes, this study advances our understanding of marine benthic ecology and opens new possibilities for habitat assessment applications worldwide., (© 2024 The Author(s). Ecological Applications published by Wiley Periodicals LLC on behalf of The Ecological Society of America.)

In this study, the effects of bioturbation induced by sandworms and crabs on polycyclic aromatic hydrocarbons (PAHs) desorption from sediments were investigated through microcosm experiments and fugacity fraction calculations, with a focus on phenanthrene (Phe), pyrene (Pyr), and benzo[a]pyrene (BaP) as representative compounds. The results indicate that crab-induced bioturbation leads to PAHs desorption rates that are 2.63 to 3.52 times higher than those observed with sandworm activity. Crabs typically forage by overturning surface sediments, whereas sandworms excavate burrows downward and exert less impact on the surface sediment integrity. Interestingly, with increasing organism density, bioturbation from sandworms inhibit the PAHs desorption, whereas crab-induced bioturbation consistently enhanced PAHs desorption rates. Fugacity fraction calculations demonstrate that the trend of desorption was the greatest for Phe, followed by Pyr, and smallest for BaP, which highlights that larger molecular weights correlate with stronger hydrophobicity and more difficulty in desorption. This study provides valuable insights into the desorption mechanisms and transport dynamics of PAHs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Aquaculture systems are of increasing concern as an important source of atmospheric methane (CH 4 ) and nitrous oxide (N 2 O). However, the role of animals in regulating CH 4 and N 2 O emissions from aquaculture systems remains unclear. Here, we established mesocosm trials to investigate impacts of bioturbation of different aquaculture species (i.e., clam, shrimp, and crab) on CH 4 and N 2 O fluxes in a mariculture pond. Across the initial, middle, and final culturing stages, mean CH 4 flux in mesocosm without animals was 4.81 ± 0.09 µg CH 4 m ‒2 h ‒1 , while the existence of clam, shrimp, and crab significantly increased CH 4 flux by 35.3 %, 80.6 %, and 138 %, respectively. Bioturbation significantly decreased dissolved oxygen (DO) concentration by 5.19‒44.8 % but increased porewater CH 4 concentration by 14.1‒59.9 %, indicating that lowered DO caused by animal respiration promoted CH 4 production in sediment. Moreover, bioturbation of animals significantly increased ebullitive CH 4 fluxes by 41.0‒216 %, contributing 57.4‒77.2 % of the increased CH 4 emission in mesocosms with animals. However, shrimp and crab significantly reduced N 2 O flux by 30.3 % and 42.5 %, respectively, primarily due to lowered DO conditions suppressing nitrification and limiting NO 3 ‒ supply for denitrification. By contrast, clam significantly increased N 2 O emission by 181 % because its filter-feeding behavior excreted more NH 4 + and NO 3 ‒ into overlying water and thereby facilitating N 2 O production. The N 2 O concentration in overlying water was 1.72‒2.83-fold of that in porewater, and the calculated diffusive N 2 O can either evade as water-air fluxes or diffuse downwards into sediments to be consumed. Overall, our study advocates that aquaculture-related climate mitigation strategies should place more attention on the divergent impacts of animal bioturbation on CH 2 O efflux. This implied that N 2 O might be primarily produced in overlying water rather than sediments, and the produced N 2 O can either evade as water-air fluxes or diffuse downwards into sediments to be consumed. Overall, our study advocates that aquaculture-related climate mitigation strategies should place more attention on the divergent impacts of animal bioturbation on CH 4 and N 2 O emissions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The transformation mechanism of muddy carbonate rock by the coupling of bioturbation and diagenesis was studied based on core, cast thin section and physical property data of Cretaceous strata in the Mesopotamia Basin, the Middle East. There are 3 ways of biological transformation of rocks: (1) The living creatures transformed formations mechanically to make the rocks looser and intergranular pores increase. (2) After formation, burrows were backfilled with coarse-grained debris, and then unsaturated fluid infiltrated into the burrows during the penecontemporaneous period, resulting in dissolution. (3) Chemical alteration occurred in abandoned burrows and dolomitization produced a large number of intercrystalline pores. The coupling of bioturbation and dissolution occurred mainly in the penecontemporaneous phase, and was controlled by rock type, sea level decline, burrow abundance, infillings, and water environment etc. As the burrows had better physical properties than the matrix, unsaturated fluid preferentially migrated along the burrows, leading to dissolution and expansion of the burrows first and then dissolution of the matrix. The coupling of bioturbation and dolomitization occurred mainly in the burial phase. The rich organic matter and reducing bacteria in the burrow provided material basis, reducing conditions and alkaline environment for dolomitization. The metasomatism in the penecontemporaneous period had little effect on the physical properties of the burrows. When the burrows were separated from the deposition interface, equimolar metasomatism occurred in the burrows in a closed environment, forming euhedral fine-crystalline dolomite with intercrystalline pores. The transformation degree of bioturbation to muddy carbonate reservoir depends on rock type, density, connectivity, infillings and structure of the burrows. With the increase of the carbonate mud content, the improvement to rock physical properties by bioturbation becomes more prominent. When the burrows are filled with coarse-grained debris or fine-crystalline dolomite, the greater the density, the higher the connectivity, and the lower the tortuosity of burrows, the better the physical properties of the muddy carbonate rocks are.

Abstract Microsites created by soil‐disturbing animals are important landscape elements in arid environments. In the Pre‐Namib, dust‐bathing behavior of the near‐endemic Hartmann's mountain zebra creates unique rolling pits that persist in the landscape. However, the ecohydrological characteristics and the effects of those microsites on the vegetation and on organisms of higher trophic levels are still unknown. In our study, we characterized the soil grain size composition and infiltration properties of rolling pits and reference sites and recorded vegetation and arthropod assemblages during the rainy season of five consecutive years with different amounts of seasonal rainfall. We further used the excess green vegetation index derived from drone imagery to demonstrate the different green up and wilting of pits and references after a rainfall event. In contrast to the surrounding grassland, rolling pits had finer soil with higher nutrient content, collected runoff, showed a higher infiltration, and kept soil moisture longer. Vegetation in the rolling pits was denser, dominated by annual forbs and remained green for longer periods. The denser vegetation resulted in a slightly higher activity density of herbivorous arthropods, which in turn increased the activity density of omnivorous and predatory arthropods. In times of drought, the rolling pits could act as safe sites and refuges for forbs and arthropods. With their rolling pits, Hartmann's mountain zebras act as ecosystem engineers, contributing to the diversity of forb communities and heterogeneity of the landscape in the Pre‐Namib.

Grizzly bears are an integral part of the northern Rocky Mountains ecosystem, where their foraging and denning leaves a measurable impact on the landscape. The purpose of this project was to evaluate the erosional effect of grizzly bears on relict solifluction tread and riser environments in the alpine tundra of Glacier National Park, Montana, USA. Grizzly bear excavation sites and material removed from vegetated risers and deposited downslope by bears was classified into either recent or decaying (i.e., not the current season) excavations, measured, and the volume of each excavation was calculated to determine the magnitude of disturbance by grizzly bears in this alpine environment. Grizzly bear activity was found at only one of four sample sites, where grizzlies removed 1.1727 m3 of material (new excavations = 0.6974 m3, old excavations = 0.4754 m3). The width of treads and risers was also measured to determine if there were differences in the dimensions of solifluction features where bear activity was observed. Although one of the study sites did have statistically wider treads and narrower risers than the other study sites, no grizzly bear activity was observed at that site, suggesting that excavations are related to factors intrinsic to solifluction features. A conceptual model of the degradation of turf was developed based on observations of vegetation and soil removed by bears, illustrating how foraging activity in a tread and riser environment may produce micro-scale changes in the landscape over time.

Dung beetles are recognized as providers of important ecosystem functions, most of which are derived from the removal of vertebrate dung from the soil surface. These insects occur in nearly all terrestrial biomes but are most diverse in the humid tropics. Several of the ecological functions attributed to dung beetles are related to their direct and indirect interactions with plants. Among these functions, the secondary dispersal of seeds defecated by mammals has received the most attention in tropical forests. Nonetheless, while several aspects of secondary seed dispersal by dung beetles are relatively well understood, others remain understudied or have not been addressed at all. Thus, a broad generalization about the effects of secondary seed dispersal by dung beetles on plant fitness remains somewhat elusive. Furthermore, other effects of dung beetle activity on tropical plants have received very little attention. A few studies have shown that through their behaviors of dung burial and soil-excavation, dung beetles can shape seed bank structure and dynamics. Also, though numerous greenhouse studies and field experiments in agricultural lands and temperate grasslands have shown that dung beetle activity increases plant nutrient uptake and yield, it is uncertain whether such effects are common in tropical forests. Here, we review and synthesize our current knowledge on how dung beetles affect tropical forest plants by dispersing defecated seeds, shaping the structure and dynamics of seed banks, and influencing the performance of understory seedlings. We focus on the Neotropics, where most studies on the effects of dung beetles on tropical forest plants have been carried out, but we also show results from other regions and biomes, to present a more general picture of these beetle-plant interactions. Throughout the review we emphasize aspects that need more research to allow generalizations and point out those questions that remain unanswered. We hope that this review will stimulate more research about the fascinating interactions between dung beetles and plants in tropical ecosystems.

The rapid reorganization of global biodiversity has triggered an intense research effort to understand its consequences for ecosystem functioning. However, efforts to monitor biodiversity change and evaluate the outcomes for ecosystem states and processes are currently poorly aligned. While most monitoring programs evaluate ecosystem status by reporting measures of taxonomic diversity, it is not the number of species but rather the exhibited traits of these species that regulate function. Trait-based approaches assume that trait diversity and variability relate to changes in functions across environmental gradients, but this relationship remains to be explored for most marine benthic ecosystems. Using macrozoobenthic communities from the Dutch Wadden Sea as a model, we compiled information on traits related to animal-sediment relationships. This trait information was then combined with species’ abundance data from a 19 years-long database to calculate different taxonomic and functional metrics that reflect macrozoobenthic diversity, function, and community structure. Finally, we compared how these taxonomic and functional metrics change along with sediment texture gradients. Our analyses showed that the structure of macrozoobenthic communities and various diversity metrics all changed with sediment gradients. The observed changes in the communities’ species composition were associated with directional shifts in the relative presence of specific functional traits with increasing sediment grain size, from communities dominated by small body size, deposit-feeding, and short life span to communities characterized by large to medium body size, suspension-feeding, and long life span. We observed limited functional redundancy and high sensitivity of functional trait-based measures to changes in the community composition along sediment gradients. Our findings suggest that a trait-based approach provides valuable information about the ecological function of marine macrozoobenthic species complementary to traditional biodiversity measures (e.g., species richness, Simpson diversity, etc.). Hence, these measures may be used to characterize changes in ecosystem functioning in time and space using traditional monitoring datasets.

Endogenous water pollution and excessive nitrogen in ponds have always been prominent problems threatening aquaculture. To solve this problem, a 70-day indoor simulation experiment was conducted. The snail Bellamya purificata was stocked at four different densities: 0, 15, 30, and 60 individuals/tank, represented as CON (control), LD (low density), MD (medium density), and HD (high density), respectively, to investigate the effects of B. purificata on the nitrogen occurrence forms and bacterial communities in the sediment. At the end of the experiment, the nitrate concentration was significantly higher, while the total nitrogen content was significantly lower in the MD group than in the other three groups. Ammonia monooxygenase activity was significantly lower in the CON group than in the other three groups, and hydroxylamine oxidase activity was significantly higher in the HD group than in the other three groups. The CON and MD groups showed the highest and lowest values in nitrate reductase activity, respectively. The hydroxylamine reductase activity decreased significantly with increasing density. Through 16S ribosomal RNA (rRNA) high-throughput sequencing, significantly affected bacterial communities by B. purificata were found. Alpha diversity results showed that, a significantly lower Shannon index was observed in the MD group than in the other three groups. The LD and MD groups showed the highest and lowest Chao1 index values, respectively. Phyla Nitrospinae and family Nitrosomonadaceae were significantly enriched in the HD and MD groups, respectively. Redundancy analysis (RDA) indicated a significant correlation between differential bacterial taxa and TN content. Predicted functional analysis based on FAPROTAX (Functional annotation of prokaryotic taxa) database showed that functional groups aerobic ammonia oxidation and aerobic nitrite oxidation were significantly enriched in the MD group. Overall, B. purificata significantly altered the bacterial community composition, increased hydroxylamine oxidase and ammonia monooxygenase activities, enhanced the bacterial nitrification process, and promoted the transformation of total nitrogen to nitrate. Moreover, B. purificata stocked at 30 and 60 individuals/tank appeared to have a significant promotion effect on the bacterial community and nitrogen occurrence forms in the sediment. Hence, co-culturing B. purificata may be a feasible and effective ecological restoration method to alleviate excess nitrogen and reduce water eutrophication.

Bioturbation can influence petrophysical properties (e.g., porosity, permeability) of sedimentary rocks and, in consequence, reservoir quality. The impact can be positive, negative, or neutral, requiring detailed ichnological analysis. Ophiomorpha, a branched cylindrical burrow with diagnostic peloidal wall, may be present in bioturbated reservoirs that exhibit properties of both super-permeability and reduced porosity/permeability. However, no mechanistic understanding of how Ophiomorpha positively or negatively impacts petrophysical properties has yet been established. This study presents high-resolution X-ray microtomographic analysis of how the features of Ophiomorpha (i.e., peloidal wall vs. burrow fill) influence porosity distribution in deep-water deposits (Neogene Tabernas Basin, SE Spain). The results show that the peloidal burrow wall exhibits the lowest porosity (up to six orders of magnitude lower than burrow fill or host sediment), while surrounding sediment shows variable values. Abrupt porosity changes within the fill material likely relate to burrow-associated diagenesis. A refined understanding of the features of Ophiomorpha and their associated porosity distribution help to constrain understanding of their diverse impacts on reservoir properties.

Saltmarshes are important global carbon (C) sinks, but the considerable uncertainty in the C budget and the underlying mechanisms limit the estimation of greenhouse gas emissions (GHG, e.g., CO2 and CH4) in the context of global climate change. To ascertain the mechanistic understanding, we assessed how crab burrows morphology and greenhouse gas effluxes changed in response to interactions of fiddler crab burrow density, soil organic matter content (high vs low), and presence/absence of Spartina alterniflora (vegetated saltmarsh vs nearby unvegetated mudflat) on the coast of New England (USA). The crab burrow volume in the vegetated saltmarsh was smaller than that in the mudflat, and crab burrow volume greatly correlated with soil CO2 efflux, indicating that crab activities could enhance coastal wetland CO2 efflux. Soil CO2 and CH4 effluxes rates were significantly positively correlated with crab burrow density, organic matter content, and vegetation types. Specifically, the higher soil organic matter content and crab burrow density greatly increased soil heterotrophic respiration in the saltmarsh. Overall, with crab disturbances, soil CO2 and CH4 efflux increased by 32.1% and 47.9%, respectively. This study highlights that fiddler crab burrowing activity plays an important role in the C sequestration of coastal blue C ecosystems (BCEs).

A novel 3-dimensional numerical model resolving dynamic interactions between environmental drivers and benthic fauna was applied to an idealized domain as analogous to typical tidal embayments. The aim is to derive insights into the role of benthic fauna in guiding long-term (decadal to centennial) coastal morphological evolution at a system scale. Three major functions by benthic fauna on sediment dynamics, namely bio-destabilization, bio-deposition and bio-stabilization, were incorporated. Results indicate that each of the three functions is able to guide a unique and profound long-term change of the embayment morphology. Bioturbation-induced sediment mixing and bio-destabilization may result in net sediment export out of the embayment, whilst bio-deposition and bio-stabilization tend to alter the embayment toward a net sediment import environment. Benthic fauna is able to modify large-scale hydro-morphology toward a state favorable for living. A combined effect of the three functions is not just a simple neutralization of the opposing impacts between sediment stabilization and destabilization. Rather, it leads to a unique response of the embayment morphology due to interactions between different benthic functional groups. Comparison with a real tidal embayment (Jade Bay from the Wadden Sea) justified a general validity of the model results in terms of statistics in both morphology and benthic fauna, and suggested an equal importance of interactions between benthic fauna and bed morphology and between different benthic functional groups in guiding morphological development of complex coastal systems.

Burrowing crabs are widely distributed and have large populations in estuarine wetlands. Crab excavation can have potentially significant bioturbation effects on the vertical structure of sediments, and the processes of nutrients deposition and mineralization. However, the effects of crab micro activities on the geochemical cycling processes of the whole estuarine ecosystems are not clear, specifically the contributions of burrowing crabs to sediment and nutrients turnover in coastal ecosystems. Due to the lack of knowledge on crab burrowing behavior and borrow morphology, it is difficult to accurately estimate the excavation and turnover volumes of crabs. Therefore, this study examined the bioturbation activity of the crab Helice tientsinensis in western Pacific estuary ecosystems by analyzing their burrow morphology and local sediment properties. The common burrow shapes of Helice tientsinensis were J- and Y-shaped burrows. Burrow morphological characteristics such as total burrow depth, curve burrow length, burrow volume, and opening diameter significantly differed among tidal zones. Crab carapace size, water depth, soil hardness, and bulk density were the main factors driving burrow morphology. Sediment excavation by crabs was ~50 times greater than the deposition of sediment into crab burrows. The net transported amounts of sediment (31.66–33.18 g·d-1·m-2) and nutrients (total nitrogen: 0.075–0.090 g·d-1·m-2, total carbon: 3.96–4.55 g·d-1·m-2, and organic matter: 0.44–0.77 g·d-1·m-2) were mainly from the belowground sediment to the surface. These results highlighted the important role of crabs in sediment and nutrients cycling within coastal estuary ecosystems.

Bioturbation is recognized as a deterministic process that sustains the physicochemical properties of the freshwater ecosystem. Irrigation, ventilation, and particle reworking activities made by biotic components on sediment beds influence the flow of nutrients and transport of particles in the sediment–water interface. Thus, the biogenic disturbances in sediment are acknowledged as pivotal mechanism nutrient cycling in the aquatic system. The macroinvertebrates of diverse taxonomic identity qualify as potent bioturbators due to their abundance and activities in the freshwater. Of particular relevance are the bioturbation activities by the sediment-dwelling biota, which introduce changes in both sediment and water profile. Multiple outcomes of the macroinvertebrate-mediated bioturbation are recognized in the form of modified sediment architecture, changed redox potential in the sediment–water interface, and elicited nutrient fluxes. The physical movement and physiological activities of benthic macroinvertebrates influence organic deposition in sediment and remobilize sediment-bound pollutants and heavy metals, as well as community composition of microbes. As ecosystem engineers, the benthic macroinvertebrates execute multiple functional roles through bioturbation that facilitate maintaining the freshwater as self-sustaining and self-stabilizing system. The likely consequences of bioturbation on the freshwater ecosystems facilitated by various macroinvertebrates — the ecosystem engineers. Among the macroinvertebrates, varied species of molluscs, insects, and annelids are the key facilitators for the movement of the nutrients and shaping of the sediment of the freshwater ecosystem. [ABSTRACT FROM AUTHOR]

The research was carried out at the cremation cemetery of the Lusatian culture in Wtórek, Ostrów Wielkopolski district, Wielkopolska province, Poland. Contrary to the so-far-studied topics related to the CT imaging of burnt bones and their virtual exploration, we concentrated on the analysis of the structures formed by the soil fauna activity in the fills of urns and additional vessels, and reconstruction of the dynamics of the ecosystem variability within the cemetery area based on thereof. We also demonstrated the impact of macrofaunal activity on stratigraphy and bone fragmentation. From the total of 222 excavated burials in 18 urns and one additional vessel, the remains of macrofauna or its bioturbation activity were identified. Out of 19 vessels subjected to CT examinations, traces of macrofaunal activity were demonstrated in 13: in five vessels animal bioturbative activity was not observed and in one, observations was impossible (due to significant metal-related artifacts). In two vessels both macrofaunal remains and traces of activity were identified. Discovered bioturbations were associated with specific species or genera. Nests or their parts of the genus Geotrupes sp. beetles were the most frequently observed traces of macrofaunal activity. Tunnels and aestivation chambers of earthworms and chambers of the genus Harpalus sp. beetles filled with Setaria sp. caryopses were discovered. The chitinous parts of other insects and the humerus bones of the vole of the genus Microtus sp. were also identified. It was shown, especially due to the non-destructive method, that rodents activity had the most destructive effect on the bone stratigraphy as well as on the movement and fragmentation of the burnt bones. The chances of visualizing bioturbations decreased with time since their creation. The process of disappearance of traces of macrofaunal activity concerned both traces of rodent activity and nests set up by Geotrupes sp. and other species. [ABSTRACT FROM AUTHOR]

The physical and geochemical character of the post‐depositional changes present in the Early‐Middle Jurassic carbonate‐dominated units (Samana Suk, Shinawari, Chiltan and Loralai formations) of the Indus Basin, Pakistan have been addressed. The study is based on 11 sections along a N‐S transect on the western margin of the Indian Plate to provide an insight into the nature of cementation and dolomitization behavior by using an integrated petrographic and geochemical analysis. The carbonates located in the northern proximity are dominated by the eogenetic signatures of hardgrounds, biogenic micritization, and iron‐containing burrows. The pattern and yellowish‐brown coloration of the burrows is distinct, and shows a positive relationship with the Fe, Si, Al, K, Mn concentrations, and meteoric phase. The transition from the Early to Middle Jurassic is marked by a correspondent increase in the dolomitization and bioturbation but its intensity decreases from north to the south. The packing index and marine phreatic environments generally increase towards the south. The planar‐s to planar‐e protodolomite and dolomite proper have particularly targeted the micritic facies and allochems, courtesy of retaining high‐magnesian calcite waters, and the geochemical analysis also reveals some dedolomitization, associated with sequence boundaries. The pore occluding cements of the Samana Suk and Chiltan formations are Fe deficient and have low Sr and Mn levels, as compared to the Shinawari Formation. The latter has an elevated concentration of Fe, Mg, Si, Al, Sr, Mn, and the Fe + Mn versus Sr relationship and Mn* values suggest that cementation dominantly occurred in the oxic‐dysoxic zones of sub‐tropical climate. [ABSTRACT FROM AUTHOR]

Cementation factor has a crucial role in evaluating volumetric reserves for heterogeneous clastic reservoir. Bioturbation is a prominent source of heterogeneity existing in hydrocarbon-bearing formation across the world. The effect of bioturbation on the petrophysical properties of the clastic has not been comprehensively understood yet, especially its effect on cementation factor estimation. The precise description of such properties is beneficial in developing better volumetric estimates and optimizing field development planning. The present work discusses an approach to characterize cementation factor in bioturbated clastic Bhuj Formation, Kachchh Basin, India. In order to ascertain the cementation exponent for bioturbated media, an improved triple-porosity model is proposed by quantifying the total porous volume into three components, namely matrix 1, matrix 2 and bioturbated region. An equivalent resistance model is then developed by identifying the series and parallel relation between the two matrix components and the burrow. The experimental observations of electrical response indicated large variation in resistivity in vertical cores compared to horizontal cores. The decreased resistivity is due to the vertically aligned burrow which due to their enhanced porosity provides less tortuous path for current to flow. The triple-porosity model is validated with different porosity value of matrix 1, matrix 2 and burrow, and a cementation factor of 2.8 for higher bioturbated samples and 3 for lower bioturbated samples is obtained. This validates the previous understanding of enhanced flow and storage property and thereby produces a consistent way to evaluate total cementation factor. The correct estimation of cementation factor helps in precise evaluation of water saturation in bioturbated reservoirs. [ABSTRACT FROM AUTHOR]

The intensity, extent, and ecosystem-level impact of bioturbation (i.e. Agronomic Revolution) at the dawn of the Phanerozoic is a hotly debated issue. Middle Cambrian fan-delta deposits in southwestern Saskatchewan provide insights into the paleoenvironmental extent of the Agronomic Revolution into marginal-marine environments. The studied deposits reveal that several environmental stressors had direct impact on trace-fossil distribution and bioturbation intensities in Cambrian fan deltas. Basal and proximal subaerial deposits are characterized by very coarse grain size and absence of bioturbation. Mid-fan and fan-toe deposits were formed under subaqueous conditions and are characterized by rapid bioturbation events in between sedimentation episodes when environmental stressors were ameliorated, providing evidence of a significant landward expansion of the Agronomic Revolution. Transgressive marine deposits accumulated after the abandonment of the fan-delta system display high levels of bioturbation intensity, reflecting stable environmental conditions that favored endobenthic colonization. The presence of intense bioturbation in both subaqueous fan delta and transgressive deposits provides further support to the view that Cambrian levels of biogenic mixing were high, provided that stable environmental conditions were reached. Our study underscores the importance of evaluating sedimentary facies changes to assess the impact of environmental factors prior to making evolutionary inferences. [ABSTRACT FROM AUTHOR]

Radioactivity levels of 210Pb and 226Ra were detected in a sediment core obtained using a multi-corer from the polymetallic nodule area inside the Clarion-Clipperton Zone (CCZ), a contract area of the China Ocean Mineral Resources Association (COMR) in the eastern Pacific Ocean. The profile of excess 210Pb (210Pbex) shows that the specific activity of 210Pbex has three parts with different distributions at depths of 0–16 cm (I), 17–36 cm (II), and 37–48 cm (III). When the I section of nonlocal mixing was excluded, using a steady-state diffusion mode, the bioturbation coefficients of the core were estimated to be 24.2 cm2/a at 17–36 cm deep and 5.9 cm2/a at 37–48 cm deep, which were greater compared to previously published results. This is most likely owing to bioturbations caused by various organism species in the two sections. [ABSTRACT FROM AUTHOR]

Many important ecosystem functions are underpinned by below‐ground biodiversity and processes. Marine sediments, one of the most abundant habitats on earth, are essential to the mineralisation of organic matter. However, they are increasingly polluted by urban activities leading to the loss of biodiversity and the functions they provide. While traditional sediment remediation strategies are focussed on microbial and engineering solutions, we propose that the reintroduction of below‐ground ecosystem engineers (bioturbators) is important to rehabilitate polluted sediments and drive recovery of their functions in urban coastal ecosystems.We tested this notion by introducing bioturbators to nutrient polluted sediments to assess their survival, as well as their capacity to drive biodiversity and oxygenation and their potential to remediate nutrient pollution. Polychaete worms Diopatra aciculata and clams Katelysia sp. were added to mesocosms (ex‐situ), and the worms also added to experimental plots in‐situ. Potential for remediation was assessed with measures of nutrient content.All animals survived when introduced to polluted sediments and showed no evidence of sub‐lethal effects. Worms oxygenated sediments and reduced organic matter content by up to 50% in‐situ. The worms also drove shifts in the receiving communities at all locations and increased the number of taxa at one location. On the other hand, the effects of clams were variable, showing opposite effects in organic matter content at different sites and levels of pollution.Synthesis and applications. Global seafloor habitats are becoming increasingly degraded and novel strategies that combine biodiversity restoration with remediation are urgently needed to return function. Tube‐building bioturbators can stimulate nutrient processing in sediments proving multiple functional outcomes, but these effects are dependent on the receiving environment. In areas with medium levels of pollution, they can kick‐start recovery in a feedback loop whereby bioturbation increases oxygenation and nutrient remediation, shifting sediment biodiversity and contributing to further recovery. This can drive long‐term changes in sediment communities, particularly in urban areas where unvegetated sediments are conspicuous. [ABSTRACT FROM AUTHOR]

Forest soils are shaped by various processes, like runoff, erosion, sedimentation and bioturbation. A better understanding of the interactions between abiotic and biotic soil-forming processes, including wild boar (Sus scrofa) rooting (i.e., subsurface foraging), enhances adequate management of forest ecosystems. We hypothesized that intense soil sedimentation influences wild boar rooting occurrence and that wild boars modify the outcome of the sedimentation process by redistributing soil layers. This study was conducted in the Babat Valley, Hungary. We estimated the availability of sedimented and non-sedimented patches and the occurrence of boar rooting. Surveys and samplings were done along transects, over consecutive months, where the impact of rooting on the physical and chemical characteristics of soil was measured by comparing them between control and rooted sites. We found that non-sedimented, steep areas were preferred areas for rooting. Sedimentation processes have a higher impact on soil chemical characteristics and soil layer composition than wild boar rooting. We conclude that mitigation of soil degradation can be more effective by reducing adverse abiotic processes rather than wild boar population control. [ABSTRACT FROM AUTHOR]

In recent decades, contourites—as sediments deposited or reworked by bottom currents— have begun to be considered important targets for deep-sea petroleum exploration and exploitation. The incidence of bioturbation, a common feature in contourite deposits, on petrophysical properties has never been approached in detail, however. Here, detailed comparative analysis of the impact of ichnological features on contourite rock properties is initiated through the application of different techniques: (a) X-ray micro-computed tomography (Micro-CT), (b) mercury intrusion porosimetry, and (c) analysis of impregnated thin sections. These three techniques were employed to study two types of contourite deposits, namely clastic (Miocene Morocco) and calcareous ones (Eocene–Miocene Cyprus). The results evidence the suitability of a multi-technique approach. Particular strengths and weaknesses may be encountered for each method depending on the type of material, the ichnological features, and the particular objectives. Trace fossils analysed in calcareous contourites show a neutral effect. In contrast, the burrow lining of Macaronichnus in the clastic contourites has a positive incidence on porosity. The appearance of this ichnotaxa could invigorate the reservoir capacity of bioturbated contourite deposits. Thus, we suggest that detailed analyses must be conducted focusing on ichnological features other than the ones traditionally considered. Still, this is a preliminary effort, and more detailed studies are needed to support the obtained results, and eventually extrapolate them to further contourite deposits. [ABSTRACT FROM AUTHOR]

Different sea cucumbers have different preferred habitats and seasonal changes, which is still lack of detailed research. This study selects two common tropical sea cucumbers (Holothuria edulis and Stichopus chloronotus) to explore the reasons that affect their habitat selection and seasonal changes, so as to provide support for the spatial planning of sea cucumbers reserve in coral reef area. The study area is a compound distribution area of living coral reefs and sandy bottom in the north of Wuzhizhou Island. The survey time is January, April–September, 2019. Three fixed transects (G, H, and Q) were selected to reveal the population ecological characteristics of them in the typical dry season (January, April, May, and June) and rainy season (July, August, and September). The variation range of density for H. edulis and S. chloronotus were 2.0–8.9 inds./10 m2 and 0.2–0.7 inds./10 m2, respectively. The population density in rainy season was significantly higher than that in dry season (P<0.05). H. edulis tends to be distributed in deeper water. The distribution of H. edulis was significant positively correlated with the sand coverage and sand continuity in G transect (P<0.05), and significant negatively correlated with live coral coverage in three transects (P<0.01). The shift from dry season to rainy season is a key factor affecting their habitat preference. In dry season, the preferred habitats of S. chloronotus are small rock (SR), sand (S), and small coral reef (SCR), while the H. edulis is S, SR, and dead coral rubbles (DCR). In rainy season, the preferred habitats of S. chloronotus are shift to SCR and SR, while the H. edulis is SCR, DCR, and sand. [ABSTRACT FROM AUTHOR]

Bioturbation by non-native common carp (carp) can facilitate an ecosystem phase shift from clear to turbid water in shallow lakes and ponds, with negative effects on abundance of aquatic animals and plants. Management of carp often involves reducing populations below a threshold biomass at which important components of the aquatic ecosystem, like submerged aquatic vegetation (SAV), recover. To evaluate control targets for a nuisance carp population in Malheur Lake in SE Oregon, USA, we conducted a mesocosm experiment in a small wetland within the lake's drainage basin. We stocked 200-m2 enclosures with individual or multiple carp of different age classes at target biomasses of 50, 100, and 300 kg ha−1. We measured turbidity, total suspended sediments, nutrients, chlorophyll- a , and surface coverage of SAV four times within a single growing season. Turbidity increased through time and soluble P was higher in 300 kg ha−1 carp treatments compared to the control, but few changes were observed for any of the other variables at any biomass. Results suggest that with well established SAV, a maintenance carp biomass threshold of <200 kg ha−1 will not result in a phase shift from a clear- to turbid-water state in the short-term. Invasive common carp are difficult to eradicate so management often entails reducing their population to a level that helps restore one or more components of the aquatic ecosystem. We conducted an enclosure experiment in a small wetland to determine the threshold biomass for carp at which water clarity, nutrients, and submerged aquatic vegetation would, or would not, be affected by carp. [ABSTRACT FROM AUTHOR]

Context: Understanding how ecosystems function to deliver services is essential if we are to limit the impacts off human activities. Aim: We hypothesised that increased densities of whelk, Pyrazus ebeninus, and crab, Macrophthalmus setosus, up to four times (given their large body-size and ecological roles, e.g. consuming deposits and disturbing sediments) would affect the macrofaunal community and how it functions in a south-eastern Queensland mudflat. Method: The biota and physical environment of the field-deployed cages (three density treatments, caged and control plots) were sampled up to 90 days. Results: After 90 days, the redox discontinuity layer was deeper and sediment organic matter was higher in all density treatments. This is consistent with enhanced burrowing, surface disturbance, mucus and pellet production. However, no significant changes in the taxonomic composition of the unmanipulated portion of the macrofaunal resident assemblage were observed. Conclusion: Whereas some communities change structurally when perturbated and then revert, this community remained in the new manipulated configuration for at least 90 days. Implications: Limited understanding of the ecological relationships in these systems, such as the processes operating to support this large increase in deposit-feeding biomass constrains evidence-based management. These systems may be able to, at least temporally, support enhanced biomasses and levels of ecosystem services. Experiments in south-eastern Queensland found that the mudflat community was unresponsive to increased densities of native crabs and whelks; the assemblage simply absorbed the four-fold increases in their abundance. A deeper redox layer and elevated organic matter content were also observed. Results suggest that these systems may have the capacity to support enhanced macrofaunal biomasses and ecosystem service delivery. [ABSTRACT FROM AUTHOR]

The dolomitic calcrete profiles from the Boyevaya Gora and Tuyembetka sections, both represented by the uppermost Permian (Changhsignian) red continental deposits from the Orenburg Cis-Urals, were studied by sedimentological, mineralogical, and geochemical methods. Сalcrete from the Boyevaya Gora section formed on sandy-silty flat alluvial fan/sheetflood sediments, under the setting of slow subsidence of the territory. Calcrete from the Tuyembetka section developed on relatively elevated mudflat/playa under a stable tectonic regime. The subtropical semi-arid climate was reconstructed based on the geochemical indices from the illuvial paleosol horizons. The presence of anhydrite in the calcrete profiles indicates the saline conditions of soil waters. Cryprocrystalline idiomorphic grains (1–3 μm) and the low Mn2+ partitioning ratio between the Ca- and Mg-position in dolomite (0.7–1.8) suggest its primary origin and a rapid crystallization from the soil waters. Free organic radicals and phosphorus-associated anion centers in the pedogenic dolomite identified by the electron paramagnetic resonance (EPR) analysis assume a biogenic contribution to the formation of dolomite. Fossilized fungal hyphae and bacteriomorphs along with the fragments of plant roots were detected by scanning electron microscopy (SEM) in both calcretes. The bacterial origin of dolomite from the studied calcretes was discussed.

Abstract Different conceptions of disturbance differ in the degree to which they appeal to mechanisms that are general and equivalent, or species‐, functional group‐, or interaction‐specific. Some concepts of disturbance, for example, predict that soil disturbances and herbivory have identical impacts on species richness via identical mechanisms (reduction in biomass and in competition). An alternative hypothesis is that the specific traits of disturbance agents (small mammals) and plants differentially affect the richness or abundance of different plant groups. We tested these hypotheses on a degu (Octodon degus) colony in central Chile. We ask whether native and non‐native forbs respond differently to degu bioturbation on runways versus herbivory on grazing lawns. We ask whether this can explain the increase in non‐native plants on degu colonies. We found that biopedturbation did not explain the locations of non‐native plants. We did not find direct evidence of grazing increasing non‐native herbs either, but a grazing effect appears to be mediated by grass, which is the dominant cover. Further, we provide supplementary evidence to support our interpretation that a key mechanism of non‐native spread is the formation of dry soil conditions on grazing lawns. Thus, ecosystem engineering (alteration of soil qualities) may be an outcome of disturbances, in which each interacts with specific plant traits, to create the observed pattern of non‐native spread in the colony. Based on these results, we propose to extend Jentsch and White (Ecology, 100, 2019, e02734) concept of combined pulse/ disturbance events to the long‐term process duality of ecosystem engineering/ disturbance.

Bivalve aquaculture benefits from non-chemical, operational-scale pest management tools to sustain or increase production. Mechanical methods to control a bioturbating pest (burrowing shrimp Neotrypaea californiensis) have been tested in Washington State (USA), providing a roadmap for other regions affected by native or widespread pests. These shrimp smother and bury ground-cultured oysters on tidal flats even when the shrimp are at low densities. Therefore, control methods with high efficacy are required, also considering non-target effects and costs to implement. From 2002 to 2023, 55 mechanical control trials were carried out, plus two shell-addition trials from earlier research. Methods included: 1) surface barriers, 2) shrimp removal, 3) sediment disruption, and 4) physical conditions intended to cause direct mortality (e.g. electricity, heat). Data were compiled through a meta-analysis framework, in which effect size was calculated as the log response ratio of treated relative to reference plots. Most surface barriers were not effective because they were penetrated by shrimp or insufficiently anchored; an exception was application of five inches (12.7 cm) of gravel. Shrimp removal was effective with a water-jet technique developed to collect shrimp for bait at low tide, but efforts to deploy multiple jets with a towed mechanized device were unsuccessful. Sediment disruption through surface compaction was the most common farm-scale approach but insufficiently reduced shrimp densities, whereas consolidating sediment with vibration to 1 m depth had high efficacy but has been applied only in small plots. Effect sizes were not available for any field trials of direct mortality methods, but energy required to kill shrimp was calculated from laboratory studies (1–50 kW-hr m−3 in water, and higher energy required in saturated sediment). Across all field methods, efficacy improved with effort (person-hours per area). Sediment showed reduced penetrability and increased muddiness following treatment. Non-target effects on infauna included both positive and negative effect sizes, consistent with a community change following a reduction in shrimp density. In the six studies measuring epibenthic species, no overall positive response to control of shrimp occurred, even though the reason for control is to protect surface-dwelling species from bioturbation by shrimp. This outcome illustrates the importance of pairing efficacy in terms of reduction of shrimp and improvement of farming. The vertical position of N. californiensis below nearly a meter of water-saturated sediment, along with an innate tolerance to pressure and anoxia, has placed them out of reach of most attempted mechanical methods. Although progress has been made in recent years, mechanical control options remain limited that can be carried out without permits and that economically reduce shrimp to densities compatible with benthic shellfish aquaculture at a farm scale. • Synthesized results from 57 mechanical control trials against a native bioturbator pest in bivalve aquaculture. • Effective methods involved thick, impenetrable surface barriers or techniques that penetrated 1 m into sediment. • Efficacy in pest reduction increased with effort. • Non-target infauna showed positive and negative responses to control. • Efficacy and costs have not reached levels suitable for farm-scale use. [ABSTRACT FROM AUTHOR]

• Formation histories of krotovinas in a Chernozem profile were reconstructed. • Examining soil mixing at the level of single-grain luminescence. • The direction, frequency, and active time of bioturbation were investigated. Krotovinas, the infilled burrows created by small mammals through bioturbation, represent a distinct pedogenic process and provide valuable records of soil and landscape history. Traditionally, macro- and micromorphological features are analyzed to investigate the origin of burrow fills, and ages are often estimated using 14C dating. However, in some environments, morphological features can be misleading and material for 14C dating is insufficient. This study explores the potential of luminescence techniques to address these issues. We studied a Chernozem profile with typical krotovinas, forming from fluvial sediment in northeast China. Three krotovinas of different depths and colors (two black and one yellow) were sampled, along with their respective supposedly undisturbed counterparts from the surrounding soil. We conducted single-grain (SG) luminescence dating of the K-feldspar fraction and multigrain (MG) luminescence dating of both quartz and K-feldspar fractions. Significant differences in luminescence ages between samples inside and outside the krotovinas at both MG and SG levels suggest the presence of vertical bioturbation. Comparisons of SG distributions among samples indicate that the yellow krotovina at ca. 70 cm was the result of upward transportation from a lower layer and was formed after the end of the Last Glacial Maximum. The two black krotovinas at ca. 80 and 160 cm are genetically linked, and probably formed in a single, rapid, simultaneous filling event occurring no earlier than 2.7 ka. This study highlights the unique role of luminescence dating in elucidating formation processes of krotovinas and the soils in which they are found. [ABSTRACT FROM AUTHOR]

Shallow lentic freshwater aquatic systems are globally important emitters of methane (CH4), a highly potent greenhouse gas. Previous laboratory studies indicated that bioturbation by chironomids can reduce CH4 production and increase CH4 oxidation by enhancing oxygen transport into sediment. Thus, reduction in chironomid density by application of biocides for mosquito control, such as Bacillus thuringinesis var. israelensis (Bti), have the potential to affect CH4 emissions. We evaluated the effect of a 41% reduction in chironomid larvae abundance due to Bti applications on CH4 dynamics in the aquatic and aquatic-terrestrial transition zones of 12 floodplain pond mesocosms (FPMs) (half treated, half control). We evaluated short-term (2 months) and seasonal effects by measuring CH4 emissions, dissolved concentrations, and oxidation rates in spring, summer, autumn, and winter. On average, CH4 emissions from the aquatic-terrestrial transition zone of the treated FPMs were 137 % higher than those of the control FPMs. The lack of differences in mean oxidation rates between the treated and control mesocosms suggests that a reduction in bioturbation and the associated decreased oxygen transport into the sediment promoted CH4 production in the treated FPMs. Our findings point to potential effects of Bti on CH4 biogeochemistry through alterations of the chironomid abundance, and highlight the underestimated role of invertebrates in biogeochemical cycling in these ecosystems.

Bioirrigation is a process corresponding to animal-induced transport of porewater solute or exchange between interstitial and overlying waters. How and why the burrowing macrobenthos complete this process remain unclear. Here, we used two infaunal-behavior observation devices to investigate the ventilation behaviors of the benthic polychaete Perinereis aibuhitensis Grube, a species that is widespread along the Asian coast with a wide temperature range, at various temperatures (5°C, 10°C, 15°C, 20°C, and 25°C). The two typical movement behaviors of P. aibuhitensis, axial crawling and radial undulation, as well as associated parameters, were delimited and quantified. We found that the radial undulation frequency of P. aibuhitensis and the associated pumping rate (PR) increased significantly with temperature (T, 5-25°C); this relationship can be described by the regression equation PR = −0.0067T2 + 0.29T - 0.52 (R2 = 0.749, P < 0.05; n = 15). The relationship between axial crawling velocity (ACV) and temperature (T, 5-25°C) can be expressed by the regression equation ACV = -0.0001T3 + 0.0059T2 - 0.063T + 0.28 (R2 = 0.997, P

The fossil record of deep-marine environments is notoriously poor in comparison with that of their shallow-marine counterparts. Notably, deep-marine deposits are typically host to diverse and abundant trace-fossil assemblages, providing evidence of the ancient deep-sea benthos. To analyze the early colonization of the deep sea, we constructed a global dataset of trace-fossil occurrences from a survey of EdiacaranâDevonian stratigraphic units. This analysis highlights the importance of the Ordovician radiation as a pivotal time in the colonization of the deep sea. Ediacaran deep-marine trace fossils consist of very simple trails and burrows. Global and alpha ichnodiversity, as well as ichnodisparity, were extremely low. Nonspecialized grazing trails reveal the exploitation of microbial mats. These strategies persisted in the Cambrian, although with an increase in ichnodiversity (both global and alpha) and ichnodisparity. An increase in the complexity of morphologic patterns, as illustrated by the undermat mining ichnogenus Oldhamia, is apparent during the Cambrian. The face of the deep sea started to change during the end of the Cambrian and beginning of the Ordovician with the protracted expansion of farming and trapping strategies. The main architectural designs of deep-marine trace fossils (e.g. regular networks, delicate spiral burrows, guided meandering graphoglyptids) were established in the deep sea by the Early Ordovician, recording the first appearance of the Nereites Ichnofacies. Lower to Middle Ordovician deep-marine ichnofaunas are moderately diverse, and fodinichnia commonly dominates rather than graphoglyptids. A significant ichnodiversity and ichnodisparity increase occurred in the Late Ordovicianâearly Silurian, with ichnofaunas recording higher proportions of graphoglyptids and evidencing the establishment of a deep-marine ecosystem of modern aspect. The distinction between the Nereites and Paleodictyon ichnosubfacies, with the former characterized by the dominance of feeding traces in muddy turbidites and the later by the dominance of graphoglyptids in sandy turbidites, can also be tracked back to the Ordovician radiation. This trend of increased colonization of the deep sea continued through all the Silurian and the Devonian. However, colonization of carbonate turbidites may have lagged behind that of siliciclastic turbidites. The progressive increase in abundance and diversity of graphoglyptids resulted in an increased role of gallery biodiffusers. This faunal turnover in the deep sea was coincident with an increase in oxygenation in slope and base-of-slope settings, which is thought to have been a driver of Ordovician biodiversifications. The formation of permanent open burrows in the deep sea may have increased bioirrigation in the uppermost zone of the deep-sea sediment, therefore increasing ventilation and potentially generating a feedback loop between bioturbation and oxygenation, with the endobenthos engineering its environment.

In order to comprehensively explore the regulatory effect of bioturbation on the assembly and overall metabolic characteristics of Daqu microbial community. This study used metatranscriptomics and metabolomics to investigate the composition of the microbial community, physicochemical properties, and overall metabolic profile of Daqu before and after bioturbation by Bacillus velezensis. The results demonstrated that the acidity, moisture, amino acid nitrogen, and starch content of Daqu exhibited a significant increase following bioturbation. The symbol microorganisms of Daqu have also changed significantly, from the original Aspergillus chevalieri , Rasamsonia emersonii , Aspergillus ruber , Aspergillus glaucus , Aspergillus wentii and Aspergillus cristatus to Paecilomyces varioti , Trichomonascus ciferrii and Staphylococcus gallinarum. Correlation analyses and integration pathways indicated that altered microbial community abundance also promoted the metabolism of starch, ethanol, fatty acids, and pyrazine, resulting in a significant enhancement of Daqu 's saccharification and liquefaction power, as well as the content of some volatile and non-volatile metabolites, with pyrazines increased by 24.50%. The application of fortified Daqu to Baijiu fermentation can significantly enhance the content of various pyrazines in Baijiu. These results are helpful to elucidate the mechanism of biochemical changes, microbial assembly and flavor production of Daqu after biodisturbance. • Utilizing Bacillus velezensis, which is a high producer of pyrazines, to make fortified Daqu. • Bioturbation of functional strains improved the quality of Daqu. • Multi-omics coupling to analyze the effects of bioturbation on Daqu microbiota, enzyme profiles and metabolism. [ABSTRACT FROM AUTHOR]

To understand complex channel meandering dynamics and shape evolution in tidal flats, we analyzed tidal stream migration characteristics in the non-vegetated Gochang tidal flat over 9 years using Google Earth imagery. Large channels with tens of meters stream width migrated furthest, followed by creeks and small gullies with less than a meter of width. While annual migration speeds were fastest in large channels, normalizing by channel width revealed an opposite trend: small gullies migrated the fastest relative to their size, while large channels migrated the slowest. This unique pattern, compared to vegetated tidal flats, is likely driven by the interaction of three factors: (1) the non-vegetated Gochang flat's weak sediment cohesion, especially in the fine-grained upper intertidal zone; (2) strong hydraulic forces from typhoons and storms; and (3) the significant particle size gradient between upper and lower zones. The efficient reworking and re-deposition even in large channels highlight the importance of considering dynamic tidal migration as an advection term alongside bioturbation. This is crucial for sedimentological and biogeochemical studies, including tidal flat sedimentation rate calculations and carbon cycle research. • Tidal channels in non-vegetated monsoon flats migrate dynamically. • Small gullies outrun larger channels in migration. • Migration speed increased with distance from entrance. • Weak sediment cohesion, strong monsoon energy, and finning landward grain size explain the migration patterns. • Sedimentation rate on this dynamic tidal flat need to be rethought. [ABSTRACT FROM AUTHOR]

Bioturbation promoted by benthic macrofauna impacts the biogeochemical processes in the sediment and water column, being an important process in estuaries, which are depositional ecosystems of high ecological importance. Functional diversity provides clear connections between biota and environmental variables, enabling researchers to comprehend the structure and functioning of ecosystems. The functional approach is still an emerging field of studies for estuaries, especially in the context of weather events such as the ENSO – El Niño. We investigated the functional diversity on a sandflat in the Patos Lagoon Estuary, regarding the bioturbation related traits of the benthic macrofauna, during and following the 2002/2003 El Niño event. Our study evidenced that the decrease in salinity caused by the high precipitation during the El Niño was the most influential factor affecting the functional diversity of the macrofauna. This led to assemblages with less potential for bioturbation, decreased stability, and higher prevalence of opportunistic traits. We also found that despite using bioturbation related traits for our analysis, the proportions of sand, silt, and clay in the sediment were not the main drivers of changes in the functional indices or trait composition, presenting less influence than the seasonal variation of temperature. [Display omitted] • Changes in salinity due to the El Niño were the most influential environmental factor affecting the functional diversity. • Although the traits studied related to bioturbation, sediment composition had a minor influence over functional diversity. • Sediment reworking and irrigation, with different taxa as the most influential, both varied similarly due to the ENSO. [ABSTRACT FROM AUTHOR]

This study investigates the impact of biogenically influenced permeability and burrow connectivity on gas production, particularly in sedimentary strata with Thalassinoides burrow networks. Using multipoint statistics models, the study examines two distinct Thalassinoides configurations: as connected networks and as isolated volumes. The study assesses various permeability levels across millidarcy, microdarcy, and nanodarcy scales in both Thalassinoides cells and the host rock matrix cells in a 1-m cube model. A series of 12 fluid flow simulation cases, spanning these configurations and permeability scales, are analyzed to explore the interplay between permeability contrasts and burrow connectivity, and their collective impact on gas production. The results reveal that both the level of permeability and the contrast in permeability between the burrow fillings and the host rock matrix, along with the pattern of burrow connectivity, significantly influences gas flow dynamics. In scenarios with high permeability contrast (of three orders of magnitude), a connected burrow network can have divergent effects on gas production, either enhancing or inhibiting it. Conversely, in systems with low permeability contrast, the impact of burrow connectivity on gas flow is minimal. In these cases, the permeability of the host rock matrix emerges as the predominant factor influencing gas production efficiency, thus overshadowing the role of burrow connectivity. This research advances our understanding of the complex interplay between burrow structures and gas reservoir dynamics and has significant implications for optimizing extraction strategies and reservoir management in gas production from sedimentary strata. • Multipoint statistics method effectively facilitates the modeling of burrowed strata within geocellular grids. • Models represent gas reservoirs, encompassing a diverse range of permeabilities and various patterns of burrow structures. • Fluid flow simulations yields critical insights into the key factors that influence gas flow dynamics within bioturbated reservoirs. • Burrow network can either enhance or inhibit gas production from sedimentary strata. • Permeability of the matrix can overshadow the role of burrow connectivity depending permeability contrast. [ABSTRACT FROM AUTHOR]

[Display omitted] • Plateau pika bioturbation decreased AHN. • Plateau pika bioturbation decreased AAN, AN, UN and ASN. • AAN to plateau pika bioturbation were more sensitive than AN, ASN and UN. The small semi–fossorial herbivore bioturbation has been verified to affect available soil nitrogen in grasslands, but the effects of small semi–fossorial herbivore bioturbation on soil organic nitrogen (SON) fractions that are main compositions of soil total nitrogen and sources of soil available nitrogen remain poorly known. The plateau pika (Ochotona curzoniae) bioturbation creates numerous bare patches, which intersperse within vegetated surfaces in grasslands. In this study, plateau pika was considered as an example animal to examine the differences of SON fractions between bare patches and vegetated surfaces under the small semi–fossorial herbivore bioturbation across six sites. This study demonstrated that acid – hydrolysable nitrogen (AHN) was 27.58% lower in bare patches than in vegetated surfaces. Amino acid nitrogen (AAN), ammonium nitrogen (AN), amino sugar nitrogen (ASN) and unknown nitrogen (UN) in bare patches were 35.23%, 17.07%, 17.70% and 19.87% lower than those in vegetated surfaces, respectively. The contribution of AAN to AHN was 5.3% lower in bare patches than in vegetated surfaces, but the contributions of AN, ASN and UN to AHN were 2.42%, 1.11%, and 1.77% higher, respectively. The response of AAN to plateau pika bioturbation was more sensitive than AN, ASN and UN. These findings verify the plateau pika bioturbation leads to a lower potential capacity of soil nitrogen supply in bare patches than in vegetated surfaces, and present a possible pattern of SON fractions in relation to small semi–fossorial herbivore bioturbation in grasslands. [ABSTRACT FROM AUTHOR]

Using a mesocosm experiment, we investigated the individual and interaction effects of two earthworm species with contrasting behaviour on soil structure and water transfers. The anecic species Amynthas zenkevichi (Thai, 1982) and the polyhumic endogeic species Pontoscolex corethrurus (Müller, 1857) were incubated in repacked soil columns alone or together for three months under laboratory conditions. The volume of belowground casts, empty burrows and lateral soil compaction were assessed using X-ray computed tomography. The production of surface casts and the amount of food ingested were also recorded. The soil moisture at 7 cm depth and water evaporation of the whole column were monitored regularly. Soil water infiltration was assessed using the Beerkan method at the end of the experiment. A. zenkevichi burrows were less numerous (25 vs. 85), more continuous (41 vs. 0 cm3), more connected from the surface to the bottom of the columns (17 vs. 0 cm3) and more compacted laterally (243 vs. 92 cm3) than those of P. corethrurus. Conversely, P. corethrurus burrows were more abundant in the top 5 cm of the columns and more backfilled by casts than those of A. zenkevichi (36 vs. 5 %). Both species ingested buffalo dung provided at the soil surface and produced surface casts at similar rates. Interactions resulted in an increase in surface activity of more than 40 % and a decrease in the depth and continuity of burrow systems. The water infiltration rate was increased by 3.5 times (compared to the control soil without earthworms) by A. zenkevichi burrows and was not modified by interactions. P. corethrurus increased the cumulative water evaporation by 10 % and decreased soil moisture by 3 % (compared to the control soil without earthworms), whereas A. zenkevichi had marginal effects on these parameters. Globally, interactions led to a slight positive synergistic effect on soil resistance to water loss by evaporation, which was likely related to the increase in surface casting activity. To conclude, this study stresses the importance of considering interactions between earthworms in soil and the need to confirm our findings under natural conditions. • The two species had contrasting belowground activities but similar surface activities. • Anecics had a larger impact on water infiltration than endogeics. • Only the endogeics increased soil water evaporation and decreased soil moisture. • Interactions increased surface activity and decreased the depth of burrows. • The two species together had a positive effect on soil resistance to water loss by evaporation. [ABSTRACT FROM AUTHOR]

The redox conditions in the littoral limnic sediments may be affected by the penetration of plant roots which provide channels for oxygen transport into the sediment while decomposition of the dead roots results in consumption of oxygen. The goal of this work was to study the impact of environmental parameters including penetration of roots of Cyperus articulatus L. into the sediments on cycling of the redox-sensitive elements in Lake Kinneret. We measured roots content, porosity, and chemical parameters including pH, sulfur, iron and manganese speciation in the sediments from the shore, littoral and sublittoral zones with and without vegetation. Our results show that at ≥ 12 m water depth, the upper 10 cm of the sediments are affected by the active sulfur cycling with concentrations of hydrogen sulfide > 70 μM near the sediment–water interface. Speciation of sulfur, iron, and manganese in the upper 10 cm of littoral sediments, which are covered by < 20 cm of water, are affected by their permeability and, to a lesser extent, by roots penetration. In the case when sediments are not covered by water, oxygen penetration to the sediments by desiccation is an additional important control of the redox zonation in the surface sediments. In the shore sediments, despite relatively high concentrations of sulfate in the pore-waters, sulfur cycling may be described as “cryptic” as expressed by very low concentrations of hydrogen sulfide in the pore-waters. This is most likely a result of its fast reoxidation by the abundant highly reactive Fe(III) and Mn(IV) phases. [ABSTRACT FROM AUTHOR]

In the long-term after atmospheric deposit onto a forest ecosystem, Cs-137 becomes incorporated into the biogeochemical cycle of stable elements and progressively reaches a quasi-equilibrium state. This study aimed at determining to what extent Cs-137 activity distribution in tree vegetation could be predicted from that of stable caesium (Cs-133) and potassium (K), which are known to be stable chemical analogues and competitors for Cs-137 intake in tree organs. Field campaigns that focused on beech trees (Fagus sylvatica L.) were conducted in 2021 in three French forest stands with contrasted characteristics regarding either the contribution of global vs. Chornobyl fallouts, soil or climatic conditions. Decades after Cs-137 fallouts, it was found that more than 80% of the total radioactive inventory in the system remained confined in the top 20 cm mineral layers, while organic layers and beech vegetation (including roots) contributed each to less than 1.5%. The enhanced downward migration of Cs-137 in cambisol than podzol forest sites was presumably due to migration of clay particles and bioturbation. The distribution of Cs-137 and Cs-133 inventories in beech trees was very similar among sites but differed from that of K due a higher accumulation of Cs isotopes in roots (40–50% vs. < 25% for K). The aggregated transfer factor (Tag) of Cs-137 calculated for aerial beech organs were all lower than those reported in literature more than 20 years ago, this suggesting a decrease of bioavailability in soil due to ageing processes. Regarding their variability, Tag s were generally lower by a factor 5 at the cambisol site, which was fairly well explained by a much higher value of RIP (radiocesium immobilisation potential). Cs-137 concentrations in trees organs normalized by the soil exchangeable fractions were linearly correlated to those of Cs-133 and the best fit was found for the linear regression model without intercept indicating that no more contribution of the foliar uptake could be observed on long term. Provided that the vertical distribution of caesium concentrations and fine root density are properly measured or estimated, Cs-133 was shown to be a much better proxy than K to estimate the root transfer of Cs-137. • Beech trees contributed to less than 1.5% of the total Cs-137 inventory. • The signature of Cs-137 foliar uptake could not be observed anymore in the long term. • Root uptake of Cs-137 was much higher at podzol than cambisol sites. • Partitioning of both Cs inventories among tree organs differed from that of K. • Cs-133 was shown a better proxy than K to assess root uptake of Cs-137. [ABSTRACT FROM AUTHOR]

• GC-GC-MS and GC-O-MS were combined to determine key aroma compounds of CHCP. • Sensomics approach revealed the effect of indigenous strains on low-salt CHCP. • Quantitative analysis combined with OAV determined 20 key aroma-active compounds. • T. halophilus and C. versatilis could alleviate acidic and irritating flavor. • Bioturbation contributed to a richer aromatic profile of low-salt CHCP. To achieve salt reduction while ensuring flavor quality of Chinese horse bean-chili-paste (CHCP), we comprehensively explored the effect of indigenous strains Tetragenococcus halophilus and Candida versatilis on the aroma profiles of low-salt CHCP by metabolomics and sensomics analysis. A total of 129 volatiles and 34 aroma compounds were identified by GC × GC-MS and GC-O-MS, among which 29 and 20 volatiles were identified as significant difference compounds and aroma-active compounds, respectively. Inoculation with the two indigenous strains could effectively relieve the undesired acidic and irritative flavor brought by acetic acid and some aldehydes in salt-reduction samples. Meanwhile, inoculated fermentation provided more complex and richer volatiles in low-salt batches, especially for the accumulation of 3-methylbutanol, 1-octen-3-ol, benzeneacetaldehyde, phenylethyl alcohol, and 4-ethyl-phenol etc., which were confirmed as essential aroma compounds of CHCP by recombination and omission tests. The research elucidated the feasibility of bioturbation strategy to achieve salt-reducing fermentation of fermented foods. [ABSTRACT FROM AUTHOR]

Mangrove ecosystems are pivotal in blue carbon capture, yet they can also release varying levels of methane (CH 4). Fiddler crabs are known players in carbon (C) cycling within mangrove ecosystems, but their precise contributions to CH 4 emissions and microbially-driven processes are not yet well understood. We compared CH 4 emissions, soil physicochemical properties, and methanogenic and methanotrophic communities in non-bioturbated and bioturbated soils within two mangrove communities: Sonneratia apetala (SA) and Pongamia pinnata (PP). The presence of fiddler crabs led to an increase in CH 4 emission rates in the bioturbated soil, ranging from 86% to 430% compared to un-bioturbated soil. The bioturbated soil also exhibited higher levels of ammonium, pH, and dissolved organic carbon (DOC) but with lower concentrations of nitrate, sulfate, salinity, and total nitrogen. Moreover, an increase was observed in the abundance methanogenic communities, but the abundance and diversity of methanotrophic communities was reduced in the bioturbated soil. The increased abundance of Methanosarcina and reduced abundance of type II methanotrophs in the bioturbated soil could result in an overall increase in CH 4 emissions. This study result highlights that bioturbation can greatly influence CH 4 emissions in mangroves and emphasizes the importance of considering the ecological role of fiddler crabs in the evaluation of coastal blue carbon sequestration. [Display omitted] • Fiddler crabs greatly accelerated CH 4 emissions in mangrove soils. • Crab bioturbation changed soil properties. • Crab bioturbation altered CH 4 -cycling communities. • CH 4 -cycling communities were associated with sulfate and salinity. • Fiddler crabs should be considered in mangrove carbon-cycling processes. [ABSTRACT FROM AUTHOR]