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Leaf litter that enters to rivers and streams generates leaf packs of diverse mass, but it is not clear if increasing litter mass of these accumulations modifies their decomposition rates and invertebrate assemblages associated. We tested whether greater initial leaf litter masses (3, 5, or 7 g) modified the breakdown rates and colonization of alder litterbags by invertebrates in two Iberian mountain streams. Similar to most previous experimental studies that compared leaf litter masses of 5 g or less in streams, higher initial masses reduced the percentage of lost leaf litter, but only when compared with litterbags that had the lowest mass (3 g). We found that greater initial mass did not hinder large invertebrates accessing the leaf litter, and it did not increase the ability of litterbags to provide refuges from predators. Higher initial mass was positively related to invertebrate diversity and total invertebrate abundance (animals/litterbag), but negatively related to invertebrate density (animals/g of litter remaining), possibly due to the geometry of leaf litter packs because a greater leaf mass (i.e., greater volume) reduces the surface area:volume ratio in a non-uniform manner, as well as decreasing the fraction of the leaf litter that is exposed directly to water flow. [ABSTRACT FROM AUTHOR]

We describe RAPID: a Real-time Automated Plankton Identification Dashboard, deployed on the Plankton Imager, a high-speed line-scan camera that is connected to a ship water supply and captures images of particles in a flow-through system. This end-to-end pipeline for zooplankton data uses Edge AI equipped with a classification (ResNet) model that separates the images into three broad classes: Copepods, Non-Copepods zooplankton and Detritus. The results are transmitted and visualised on a terrestrial system in near real time. Over a 7-days survey, the Plankton Imager successfully imaged and saved 128 million particles of the mesozooplankton size range, 17 million of which were successfully processed in real-time via Edge AI. Data loss occurred along the real-time pipeline, mostly due to the processing limitation of the Edge AI system. Nevertheless, we found similar variability in the counts of the three classes in the output of the dashboard (after data loss) with that of the post-survey processing of the entire dataset. This concept offers a rapid and cost-effective method for the monitoring of trends and events at fine temporal and spatial scales, thus making the most of the continuous data collection in real time and allowing for adaptive sampling to be deployed. Given the rapid pace of improvement in AI tools, it is anticipated that it will soon be possible to deploy expanded classifiers on more performant computer processors. The use of imaging and AI tools is still in its infancy, with industrial and scientific applications of the concept presented therein being open-ended. Early results suggest that technological advances in this field have the potential to revolutionise how we monitor our seas. [ABSTRACT FROM AUTHOR]

Captive breeding of freshwater mussels is essential for conservation strategies to maintain populations of endangered bivalve mollusks. In the Czech Republic, breeders use detritus from natural sources, preferably from nearby streams and spring areas, to prepare pearl mussels for release into the target localities to reestablish sustainable populations in their native habitats. This strategy is subject to sudden changes, and breeders must consider different detritus qualities between seasons and the unpredictability of weather conditions. Therefore, harvesting natural detritus on a regular basis is challenging and time-consuming, and more samples require more testing, which increases the cost of captive breeding. We proved that juvenile freshwater pearl mussels grew faster when fed detritus stored frozen in a freezer than when fed the same chilled detritus. Therefore, detritus can be harvested under optimal conditions and stored in a freezer for the remaining season, thereby simplifying and reducing mussel conservation costs. Moreover, this approach offers a sustainable, environmentally friendly method that does not require the industrial production of artificial feeds. [ABSTRACT FROM AUTHOR]

The goal of this work is to analyze the dynamics of soil organic matter (SOM) in arable soils of Yamal using computational experiments with the ROMUL model. Soil temperature and moisture dynamics were simulated using the SCLISS model. The Yamal experimental station was organized in 1932. The soil is Plaggic Podzol. The thickness of humus horizon (PY) is 30 cm. Pools, kg/m2: SOM – 9.32 and 13.75; N – 0.46 and 0.66 for 0–20 and 0–30 cm respectively. Background: soddy-green-moss tundra near Salekhard. Soil: Folic Podzol: litter (O, 2 cm) and humus-accumulative (AY, 4 cm) and illuvial ferruginous (BF, 6 cm) horizons. Pools, kg/m2: SOM – 1.38 and 2.69, N – 0.03 and 0.18 for 0–2 and 2–6 cm respectively. The quantity and quality of background fall was estimated according to literature data. Clarification of the amount of fall was carried out by the method of inverse problem solving (spin-up). Peat application was simulated: starting application in the dose of 12 kg/m2 and maintenance (every 6 years) in doses 4, 8 and 12 kg/m2, N 1%. Application of mineral fertilizers, 2 variants: a) N 4 g/m2 (40 kg/ha) in peatting years and b) application of the same dose of nitrogen every year. The duration of computational experiments is 30 and 90 years. Computational experiments showed that after the starting peatting of Folic Podzol at the rate of 12 kg/m2 after 30 years, only 15% of the applied detritus remained. Maintenance peatting of 8–12 kg/m2 leads to an increase in SOM pool to 20–30 kg/m2 and excessive accumulation of detritus. Application of 4 kg/m2 of peat once every 6 years for 90 years shows the dynamics of SOM pools from Folic Podzol to Plaggic Podzol which is confirmed by field survey data. Application of mineral nitrogen (4 g/m2) once every 6 years does not affect SOM pools. Annual application of mineral N (4 g/m2) increases SOM pools due to intensified humification. This fact requires experimental verification.

The size and sex structure, the dependence of the state of the gonads of females on the size of the individual, and the composition of the food of the shrimp Sabinea septemcarinata (Sabine 1824) (Crustacea, Crangonidae) from the Laptev Sea, from Khatanga Bay in the Laptev Sea, and from the Kara Sea are described (598 individuals: 230 of them had empty stomachs, 368 contained food in their stomachs, and 34 were full). The shrimp were collected in August–September 2016. The total body length of the shrimp examined varied from 31 to 103 mm: 32–103 mm in females and 31–74 mm in males. The lifespan seems to last 3–4 years in females and 2–3 years in males. Based on the condition of the gonads of the females, the time of material collection coincided with spawning. Among the females there are individuals at all stages of the reproductive cycle: feeding, spawning, and preparing for the next spawning. This indicates extended population spawning. Sabinea septemcarinata belongs to the life form of burrowing shrimp. According to the frequency of occurrence in the stomachs, detritus occupies first place (92.2%). The second and third places are taken up by cumaceans and sedentary polychaetes, which occur in almost every second and third stomach (frequency of occurrence 37.7 and 23.9%, respectively). Sand shows a frequency of occurrence of 50.3%. In the virtual food lump, a little more than a third of its volume is taken up by detritus (39.7%), followed by cumaceans and polychaetes that take second and third places (23.6 and 22.6%, respectively). Consequently, S. septemcarinata feed on infauna. Thus, S. septemcarinata are characterized by elements of an attacking predator and a detritophage. [ABSTRACT FROM AUTHOR]

The understanding of the role of fishes in the trophic functioning of estuaries has increased in stages over many decades. It began with qualitative and quantitative dietary studies, mainly from the 1970s onwards, and progressed to more sophisticated stable isotope work towards the end of the 20th Century and into the present. Building on an initial wide array of predominantly single species rather than community dietary studies, our global knowledge of the food and feeding ecology of fishes in estuaries has now progressed to a stage where we can begin to discern patterns and make generalised statements on the nature and role of fish assemblages in the trophic functioning of these systems. In this review we summarize the dominant aspects relating to the trophic ecology of fishes in estuaries, including ontogenetic changes in fish diet and food provision for the nursery function of estuaries, detritus as a direct and indirect driver of the food web, the influence of latitude and habitat type on trophic structuring, predator prey relationships with an emphasis on the importance of invertebrates in fish food chains, the role of stable isotopes in combination with dietary analyses in understanding trophic functioning, and the effects of environmental change and fishing and other human activities on fish food webs in estuaries. Apart from providing an overview of information on the current status of our knowledge on fish trophic ecology in estuaries, this review also identifies important research gaps that need to be filled. [ABSTRACT FROM AUTHOR]

Ecosystem size and spatial resource flows are key factors driving species diversity and ecosystem function. However, the question of whether and how these drivers interact has been largely overlooked. Here, we investigated how ecosystem size asymmetry affects species diversity and function of two‐patch meta‐ecosystems connected through flows of nonliving resources. We conducted a microcosm experiment, mimicking resource flows between ecosystems of different sizes yet otherwise identical properties or between ecosystems of the same size. Meta‐ecosystems with asymmetric ecosystem sizes displayed higher α‐diversity but lower β‐diversity and ecosystem function (total biomass) than their unconnected counterparts. At the same time, such an effect was not found for meta‐ecosystems of identical patch sizes. Our work demonstrates how the size of ecosystems, interconnected via resource flows, can modulate cross‐ecosystem dynamics, having implications for species diversity and function across scales. [ABSTRACT FROM AUTHOR]

Stream bryophytes (mosses and liverworts) are widely recognized as important macroinvertebrate habitats, but their overall role in the stream ecosystem, particularly in nutrient cycling, remains understudied. Hubbard Brook Experimental Forest in New Hampshire, USA, contains some of the most extensively researched streams in the world, yet few studies mention their bryophytes. Perhaps this is because early estimates place bryophyte coverage in these streams at an insignificant 2%. However, data from 2019 show that contemporary coverage ranges from 4 to 40% among streams. To investigate how stream bryophyte cover may be changing over time and influencing stream nutrient stocks, we conducted field surveys, measured the mass of organic and inorganic bryophyte contents, and quantified nutrient uptake with bottle incubations of bryophyte mats. This study marks a novel attempt to map stream bryophyte coverage with estimates of C, P, and N stocks and fluxes. From our 2022 field surveys, we found that median bryophyte coverage varied across streams in the same catchment (0–41.4%) and shifted from just 3 y prior. We estimate that these bryophyte mats stored between 14 and 414 g of organic matter per m2 of stream in the form of live biomass and captured particulates. Within 12 h of light incubation, 35 out of 36 bryophyte clump samples sorbed peak historical water-column concentrations of PO43–, as measured in the Hubbard Brook stream chemistry record. In Bear Brook, our scaled estimate of bryophyte mat NO3– uptake (2.3 g N/y) constitutes a substantial portion of previously estimated whole-stream NO3– uptake (12 g N/y). Cumulatively, our data demonstrate that bryophytes and their associated mineral substrates and biota—known as the bryosphere—are crucial in facilitating headwater stream nutrient cycling. These bryospheres may contribute significantly to interannual variability in stream nutrient concentrations within nutrient-poor streams, especially in climate-sensitive regions. [ABSTRACT FROM AUTHOR]

Plastic pollution and ocean warming threaten crucial ecosystem processes, including detrital decomposition. We carried out a manipulative experiment using 20 outdoor raceways to test hypotheses about the influence of macroplastics (polyvinyl chloride (PVC), polyethylene terephthalate (PET), high-density polyethylene (HDPE), low-density polyethylene (LDPE), and biodegradable (BIO)) and ocean warming (as 3 °C above ambient sea surface temperatures) on the decomposition of Sargassum vestitum. All types of plastic significantly decreased rates of S. vestitum decomposition compared to controls. LDPE was associated with the greatest decrease in detrital decomposition (41%), followed closely by BIO (28%), whilst HDPE had the least influence (12%) during our 40-day experiment. Treatments with LDPE and PET retained more carbon (%) in S. vestitum than the control treatment. However, plastics neither affected nitrogen (%), nor C/N ratio of the decomposing detritus. Ocean warming significantly increased the decomposition of S. vestitum, but did not affect relative carbon or nitrogen, nor C/N of the remaining detritus, nor did temperature interact with plastic treatments. As detrital decomposition significantly contributes to marine biogeochemical cycling, food-web connectivity, and secondary production, our multiple stressor experiment demonstrates the value of management strategies that simultaneously address the impacts of ocean warming and plastic pollution in nearshore environments. [ABSTRACT FROM AUTHOR]

The Early–Middle Jurassic Nazas continental rift province in Mexico has been debated as either an extensional continental arc due to eastward subduction beneath North America or an intracontinental rift linked to Pangea break-up. New petrographic and U-Pb geochronological data from the La Boca Formation near Ciudad Victoria – a key locality within this province – reveal diverse clastic sources, forming three provenance groups. Group 1 (Juan Capitán Member) crops out in the Huizachal Valley and consists of volcaniclastic fluvial deposits derived from a local volcanic centre. Group 2 (Agua de Las Minas Member), also found in the Huizachal Valley, overlies Group 1 and has mixed provenance from local volcanic and surrounding basement uplift sources. Both groups transition laterally to deposits of Group 3 (San Pedro Member) to the north, which consists of metamorphiclastic fluvial deposits from the eastern basement uplift and is not influenced by the volcanic centre. The rapid dilution of volcanic detritus within ~35 km highlights the limited extent of the volcanic centre as a source of sediment. Our results suggest that the Nazas province was more likely formed in a continental rift basin with sparse volcanic activity linked to Pangea break-up rather than as an extensive volcanic arc. [ABSTRACT FROM AUTHOR]

Community structure and ecosystem function may be driven by the size or the energy within a given habitat, but these metrics (space and energy) are difficult to separate, especially in systems where the habitat itself is also food, such as detritus. Only a handful of studies have attempted to isolate potential mechanisms experimentally, which has left a notable knowledge gap in understanding the drivers of community structure and function. Here, we tested whether fine woody debris (FWD) affects leaf litter communities primarily as a source of space or energy. We used a crossed factor design to isolate the effects of FWD as space and energy, with four treatments: (1) no FWD, (2) only energy‐providing FWD (sawdust), (3) only space‐providing synthetic wood debris, and (4) a combination of both space and energy. We hypothesized that the highest levels of diversity, carnivore:detritivore ratio, and decomposition rate would occur on plots supplied with sawdust (representing energy), synthetic woody debris (representing space), or a combination of both, depending on the relative significance of FWD as a source of either energy or space. After 7 months, FWD as a source of energy but not space led to decreased decomposer abundance and richness. Conversely, increased proportion of carnivores and labile substrate decomposition was primarily driven by FWD as a source of space. However, the fastest decomposition of more recalcitrant substrates required both space and energy (additive), and the synergy of space and energy supported the greatest proportion of carnivores. These results suggest that the presence of FWD in forest ecosystems supports increased diversity and decomposition through a synergistic interaction of space and energy and the maintenance of deadwood like FWD in forest ecosystems can thus significantly contribute to forest ecosystem function. [ABSTRACT FROM AUTHOR]

The degradation of vegetation in the watershed and associated release of dissolved organic matter (DOM) and particulate organic matter (POM) can influence the water quality of new reservoirs. This study aimed to evaluate whether water velocity influences the degradation of twigs of different diameters that remain in the watershed of new reservoirs. The results of twigs degradation under flowing and stagnant water over time were fitted to a double exponential decay kinetic model, which presents the detritus as labile/soluble and refractory compounds. The model parameterization showed that labile fractions presented higher decomposition rates (KT) in flowing than, but there was not a clear trend in the comparison between the diameters in each water condition. On the contrary, the refractory fraction decomposition rates (kR) showed a clear pattern in all comparisons, showing higher values in flowing water and for thin twigs. These results showed that thinner twigs decompose more rapidly, due to the greater A:V ratio, and that the abrasive effect of water velocity promotes faster decomposition. In general, we observed that there was a pattern of increasing decomposition rates as the twigs decrease in diameter (9–10 mm < 5–6 mm < 2–3 mm) and from stagnant water to flowing water. [ABSTRACT FROM AUTHOR]

U–Pb ages and Hf isotopic data from detrital zircon of the Silasia Formation in the Midyan Terrane record evidence for the provenance and tectonic evolution of the northern Arabian Shield. Given that the youngest acknowledged age of these detritus sediments is 735 ± 13 Ma, it is likely that the Silasia Formation was deposited during the closure of the Mozambique Ocean. The U–Pb ages define a major Mesoproterozoic peak, with two minor peaks of Neoproterozoic and Archean age. Combined with zircon Hf isotopic compositions, the sedimentary detritus of the Silasia Formation was mainly derived from source rocks formed during the Grenville Orogeny during the assembly of Rodinia, with a minor contribution from Archean and Paleoproterozoic crustal material, in addition to a limited arc‐basement supply related to the early Mozambique Ocean. The youngest Concordia age of 735 ± 13 Ma with highly variable εHf(t) values (11 to −35) indicates a complex mixture of sources from juvenile to extremely ancient. The Concordia ages at 1113 ± 11 and 1046 ± 10 Ma have positive hafnium isotope signatures (up to +10.45) that are consistent with juvenile source rocks formed during the Grenville Orogeny. Several detrital zircons with ages of 2622 ± 22 Ma and 2690 ± 7 Ma are similar to those reported in Yemen, whereas 1818 ± 19 Ma, 2071 ± 8 Ma and 2001 ± 19 Ma Paleoproterozoic ages are similar to dated outcrops in the Khida terrane in the eastern Arabian Shield. [ABSTRACT FROM AUTHOR]

The forest floor is an integral component of forest soils, which constitutes a significant yet underaccounted terrestrial carbon pool. Comprehensive studies were conducted at a test site in the Kivach State Nature Reserve, which represents little disturbed middle-taiga ecosystems of Eastern Fennoscandia. Forest floor properties were studied following the methods guidelines of the project "National system for monitoring the dynamics of climate-active substances in terrestrial ecosystems of the Russian Federation". Organic carbon content (Сorg) was determined using Perkin Elmer 2400 Series II CHNS/O Analyzer (USA). The forest floor is a heterogeneous formation with quite variable composition and state. There predominantly (80% of all sampling points) forms a fermentation-type raw-humus forest floor with average thickness of 5.9 ± 0.2 cm and a stock of 49.8±1.9 t/ha in the study area. Organic matter is lost gradually in the course of dead plant biomass degradation, so Сorg content in the dwarf shrub–true moss habitats predominating at the test site was the highest in the top layer of the forest floor, OL, reaching 52.8 ± 0.6%. Carbon content in the lower floor subhorizons declined to 40.8 ± 2.0%. Where the proportion of forb species increased, average Сorg content significantly decreased, to 19%. Average estimated forest-floor Сorg stock in the studied ecosystems is 20.9 ± 0.9 t/ha. It exhibited high spatial variation of 1.5 to 45 t/ha. The predictors of forest-floor Сorg variation in the study area include land cover characteristics, dominant tree species, and location relative to the tree. Thorough estimation of the contribution of forest-floor carbon is necessary for accurate quantification of the stock of this pool within the new national system for monitoring carbon pools and greenhouse gas fluxes. [ABSTRACT FROM AUTHOR]

Coralligenous bioconstructions are biogenic calcareous formations developing at low irradiance on littoral rocky cliffs or on the deeper sub-horizontal bottom in the Mediterranean Sea. Unusually shallow coralligenous banks on the sandy coast of Sinuessa (Mondragone City, Gulf of Gaeta, SW Italy) were investigated. Their communities and the surrounding biogenic detritus were characterized. Geophysical and acoustic data revealed the presence of coralligenous banks between 7.5 and 15 m depth, showing constant thickness and sub-horizontal geometry, incised by sub-perpendicular channels. Sediment deposits ranging from silty sands to bioclastic gravel occur in the area. The biogenic detritus of the soft bottom sampled around the coralligenous banks is highly heterogeneous. Through the thanatocoenosis analysis of macrozoobenthos, different biocenoses were detected, among which the coralligenous and photophilic habitats are mainly represented, followed by the well-calibrated fine sands and the relit sands. A total of 16 different species and 10 epimegabenthic morphological groups (MGs) were detected on the coralligenous banks, of which 4 are included in European regulation for threatened species. The density of epimegabenthic organisms has an average of 10.34 ± 5.46 individuals or colonies/100 m2. Cladocora caespitosa is the dominant species, with a height of 17 ± 5 cm. This and other structuring species (SS) were larger in size in the sampled sites than in the literature data. Overall, coralligenous had a "medium" health status, with 52% of the individuals or colonies in healthy conditions, compared to 47% with epibiosis phenomena and 1% with entanglement. Longlines were the most common anthropogenic litter, with a density of 2/100 m2. Ad hoc monitoring programs and conservation measures would be desirable to protect and guarantee the well-being of these sensitive and rare shallow bioconstructions. [ABSTRACT FROM AUTHOR]

During the Second World War, the British painter Prunella Clough composed a set of poems now preserved in her archive at Tate Britain, of which only two were published. This article prefaces the sixteen poems, situating them in relation to Clough’s avowed models in poetry of the period, and comparing them to poems by two women writing on the Second World War home front, Sylvia Townsend Warner and Lynette Roberts. Clough’s developing practice as a painter is considered in the light of her poems, which preceded her post-war commitment to painting as primary vocation. Clough’s paintings are analysed in their equivocal relation to abstraction, both American and British. Her later paintings’ singular focus on detritus staged before an undifferentiated background, is interpreted as consistent with her poems’ startling domination by the death drive, inviting the destruction of the Blitz. Clough’s peculiar sublime, whereby the act of seeing becomes death-dealing, is shown to be announced in her poems, and contrasted with the high capitalist abstract sublime exemplified in Peter de Bolla’s encounter with Barnett Newman. The article ends by associating Clough’s objectifying vision with the photography of Robert Mapplethorpe, using terms that draw on the writing of Roland Barthes. [ABSTRACT FROM AUTHOR]

Water‐choice experiments were conducted using glass eels of Anguilla japonica and A. marmorata, which coexist in subtropical East Asian rivers. The results of the present study, together with those of previous water‐choice experiments, suggest that salinity enhances the odor preferences of glass eels. Compared to A. marmorata glass eels, A. japonica glass eels were more strongly attracted to water collected from a leaf detritus‐accumulating backwater area than to normal river water under the same salinity conditions. These results suggest that interspecific differences in odor preferences may facilitate their habitat segregation. [ABSTRACT FROM AUTHOR]

From soil to freshwater ecosystems, decomposition can be conceived as the result of interactions between organic matter and a diversity of organisms. This function is driven in part by detritivores, invertebrates that feed on detritus or graze on its associated microbes and that have a significant but extremely variable contribution to decomposition.In order to better understand and predict detritivore–detritus pairwise interactions, we propose a conceptual framework, called Detri2match, to study the consumption of detritus by detritivores, using a trait‐matching approach at the individual detritivore level. Here, we focus on the interaction between saprophagous detritivores that fragment plant detritus.We propose a novel definition of a saprophagous detritivore as an animal that consumes plant detritus when its traits match sufficiently the traits of its resource, passing through five interaction facets of consumption. These include (1) a spatial match rule regarding the encounter, (2) a biomechanical match rule regarding ingestion, (3) a digestive match rule regarding assimilation, (4) an energetic match rule regarding the fulfilment of metabolic needs and (5) a nutritional match rule regarding the fulfilment of chemical element needs in adapted proportions.The main goal of this framework is to guide future research to establish generic rules of misunderstood detritus–detritivore pairwise interactions by identifying relevant interaction facets and their key associated traits for both detritivores and detritus. This investigation should be conducted over the temporal variability of trait‐matching constraints throughout the whole decomposition process. Coupled with adequate accumulation of trait information, the Detri2match framework could also facilitate predictions by inference of non‐tested pairwise detritivore–litter interactions.We also outline conceptual, methodological and analytical challenges of this framework. The main challenge would be to scale up these pairwise rules at the detrital network level and to test their genericity, which would contribute to a better understanding of the functioning of the detrital network and its contribution to decomposition. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Because of the high growth rates often achieved by invasive alien macrophytes, their establishment in recipient ecosystems may alter the abundance and composition of litter entering detrital pathways, representing a significant—but often overlooked—ecological effect of these invasions. Crassula helmsii (Kirk) Cockayne (New Zealand pygmyweed) is an invasive alien macrophyte, notorious for its profuse growth in invaded waterbodies. C. helmsii is perennial and often forms dense stands, producing abundant detritus. To investigate whether some of C. helmsii's impacts are mediated by this detritus, we conducted an 85-day litterbag experiment comparing decomposition of C. helmsii with that of Callitriche stagnalis Scop. (water-starwort), a commonly co-occurring native macrophyte. Macroinvertebrate assemblage composition was comparable between macrophyte species throughout the experiment, but shifted as plants decayed. Litterbags were initially dominated by the invasive shredder Crangonyx pseudogracilis Bousfield, 1958 and later by Euglesa casertana (Poli, 1791), an interstitial suspension feeder. C. helmsii litter decomposed more slowly, with proportionally less invertebrate-mediated breakdown, but was ultimately colonised by more abundant macroinvertebrates, including more C. pseudogracilis. Decomposition may be slowed by C. helmsii's high carbon: nitrogen ratio. These results suggest that C. helmsii invasion may impact macroinvertebrate assemblages via the production of long-lasting and relatively unpalatable detritus. [ABSTRACT FROM AUTHOR]

Increased temperatures are altering rates of organic matter (OM) breakdown in stream ecosystems with implications for carbon (C) cycling in the face of global change. The metabolic theory of ecology (MTE) provides a framework for predicting temperature effects on OM breakdown, but differences in the temperature dependence of breakdown driven by different organismal groups (i.e., microorganisms vs. invertebrate detritivores) and litter species remain unresolved. Over two years, we conducted 12 60‐day leaf litterbag incubations in 20 headwater streams in the southern Appalachian Mountains (USA). We compared temperature dependence (as activation energy, Ea) between microbial and detritivore‐mediated breakdown, and between a highly recalcitrant (Rhododendron maximum) and a relatively labile (Acer rubrum) leaf species. Detritivore‐mediated breakdown had a higher Ea than microbial breakdown for both leaf species (Rhododendron: 1.48 > 0.56 eV; Acer: 0.97 > 0.29 eV), and Rhododendron breakdown had a higher Ea than Acer breakdown for both organismal groups. Similarly, the Ea of total (coarse‐mesh) Rhododendron breakdown was higher than the Ea of total Acer breakdown (0.89 > 0.52 eV). These effects for total breakdown were large, implying that the number of days to 95% mass loss would decline by 40% for Rhododendron and 26% for Acer between 12°C (our mean temperature value) and 16°C (+4°C, reflecting projected increases in global surface temperature due to climate change). Despite patterns in Ea, overall breakdown rates were higher for microbes than detritivores, and for Acer than Rhododendron over most of our temperature gradient. Additionally, the Ea for a subset of the microbial breakdown data declined from 0.40 to 0.22 eV when fungal biomass was included as a model predictor, highlighting the key role of fungi in determining the temperature dependence of litter breakdown. Our results imply that, as streams warm, routing of leaf litter C to detritivore‐mediated fates will increase faster than predicted by previous studies and MTE, especially for labile litter. As temperatures rise, earlier depletion of autumn‐shed, labile leaf litter combined with rapid breakdown rates of recalcitrant litter could exacerbate seasonal resource limitation and alter carbon storage and transport dynamics in temperate headwater stream networks. [ABSTRACT FROM AUTHOR]

This article examines some work by the Oaxaca-based Mexican experimental filmmaker and video artist Bruno Varela in order to explore the sense of Gilles Deleuze's view that modern political cinema is characterized by a "missing" people, to which the adequate response is the people-sustaining or people-generating trance. I argue that the element missing from Deleuze's discussion is how the typical way for a people to go "missing" under capitalism involves the obfuscation of their labor, an idea that sustains the materially grounded trance in Varela's Papeles Secundarios (2004) and Cuerpos Complementarios (2022), drawn from the filmmaker's experience as casting director of Iranian artist Shirin Neshat's production of her video installation Tooba (2002) in Oaxaca. The article discusses the "baroque critique" involved in Varela's elliptically representing the workday of the non-professional Oaxacan actors employed in Neshat's production, understood here as a critique articulated using the detritus of that production. The result is a paradigm of trans-temporal playfulness on film that also challenges the claims to trans-temporal experience sought in Neshat's work. Thus, the article also locates these arguments within debates about whether films can "do philosophy", including a hypothesis about the obfuscations of labor lying behind why making-of documentaries—and their capacities to critique the philosophical pretensions of their original subjects—have not figured more centrally in those debates. [ABSTRACT FROM AUTHOR]

Abstract: The San Francisco Estuary, in central California, has several long-running monitoring programs that have been used to reveal human-induced changes throughout the estuary in the last century. Here, we pair synoptic records of particulate organic matter (POM) composition from 1990–1996 and 2007–2016 with more robust long-term monitoring program records of total suspended sediment (TSS) concentrations generally starting in the mid-1970s to better understand how POM and TSS sources and transport have shifted. Specifically, POM C:N ratios and stable isotope values were used as indicators of POM source and to separate the bulk POC pool into detrital and phytoplankton components. We found that TSS and POC sources have shifted significantly across the estuary in time and space from declines in terrestrial inputs. Landward freshwater and brackish water sites, in the Delta and near Suisun Bay, witnessed long-term declines in TSS (32 to 52%), while seaward sites, near San Pablo Bay, recorded recent increases in TSS (16 to 121%) that began to trend downwards at the end of the record considered. Bulk POM C:N ratios shifted coeval with the TSS concentration changes at nearly all sites, with mean declines of 12 to 27% between 1990–1996 and 2007–2016. The widespread declines in bulk POM C:N ratios and inferred changes in POC concentrations from TSS trends, along with the substantial declines in upstream TSS supply through time (56%), suggest measurable reductions in terrestrial inputs to the system. Changes in terrestrial TSS and POM inputs have implications for biotic (e.g., food web dynamics) and abiotic organic matter cycling (e.g., burial, export) along the estuarine continuum. This work demonstrates how human-generated environmental changes can propagate spatially and temporally through a large river-estuary system. More broadly, we show how underutilized monitoring program datasets can be paired with existing (and often imperfect) synoptic records to generate new system insight in lieu of new data collection.

The provenance of Precambrian detritus in the Junggar and Altai terranes provides crucial constraints on the peri-Siberian accretionary tectonic evolution in the middle Paleozoic. The Precambrian detrital zircons have no coeval magmatic equivalents in the Junggar terrane but show U–Pb age spectra and εHf(t) values comparable to those in the Altai terrane. The correlations suggest that the old detrital materials in the Junggar and Altai terranes were most likely derived from the Siberia craton and adjacent Tuva-Mongolian microcontinent. Paleozoic zircons in the Junggar terrane display a εHf(t) pattern from large spread to dominantly positive values at ca. 420–410 Ma. Such an abrupt change points to an accretionary tectonic transition from an advancing to retreating mode during mid-Paleozoic time, synchronous with similar tectonic switch occurring in the Altai terrane. Taking into account the temporal and spatial relations in sedimentation, tectonism and arc magmatism, we propose that the Junggar terrane had once collided onto the peri-Siberian Altai terrane to receive abundant old detritus from the Siberian continent in the Silurian–early Devonian. They were subsequently separated at ca. 420–410 Ma, possibly due to the slab rollback of the subducting Paleo-Asian Ocean (PAO) plate. These results constrain an Early Paleozoic tectono-paleogeographic boundary of the CAOB along the North Tianshan–Solonker suture zone, and also imply a long-lived PAO subduction was responsible for the Neoproterozoic to Paleozoic accretionary orogenesis at the margins of southern Siberia, eastern Kazakhstan, and northern Gondwana. [ABSTRACT FROM AUTHOR]

Essential Climate Variables (ECVs) like ocean colour provide crucial information on the Optically Active Constituents (OACs) of seawater, such as phytoplankton, non-algal particles, and coloured dissolved organic matter (CDOM). The challenge in estimating these constituents through remote sensing is in accurately distinguishing and quantifying optical and biogeochemical properties, e.g., absorption coefficients and the concentration of chlorophyll a (Chla), especially in complex waters. This study evaluated the temporal and spatial variability of bio-optical properties in the coastal waters of the Western Iberian Coast (WIC), contributing to the assessment of satellite retrievals. In situ data from three oceanographic cruises conducted in 2019–2020 across different seasons were analyzed. Field-measured biogenic light absorption coefficients were compared to satellite estimates from Ocean-Colour Climate Change Initiative (OC-CCI) reflectance data using semi-analytical approaches (QAA, GSM, GIOP). Key findings indicate substantial variability in bio-optical properties across different seasons and regions. New bio-optical coefficients improved satellite data retrieval, reducing uncertainties and providing more reliable phytoplankton absorption estimates. These results highlight the need for region-specific algorithms to accurately capture the unique optical characteristics of coastal waters. Improved comprehension of bio-optical variability and retrieval techniques offers valuable insights for future research and coastal environment monitoring using satellite ocean colour data. [ABSTRACT FROM AUTHOR]

Sedimentological and geochronological data from late Paleozoic strata located between the East Junggar and Chinese Altai regions in NW China were examined, aiming to decipher the tectono-sedimentary evolution of this important tectonic boundary. Carboniferous sediments on the East Junggar side show arc-proximal depositional characteristics of the proximal Heishantou and Nanmingshui Formations and distal Beitashan and Yundukala Formations, while the Erqis complex on the Chinese Altai side is characterized by continental margin affinity. Lithological analysis revealed the dominant input of arc-related detritus for all these sequences and a uniform transition from volcaniclastic to siliciclastic components in their respective upper sections. The investigated East Junggar strata are dominated by Carboniferous zircons with positive εHf(t) values, sourced exclusively from the southerly Yemaquan-Jiangjunmiao arc domain, whereas the Erqis complex received detritus from the same arc domain but also evolved components from the northerly Chinese Altai. Combined with regional data, the examined strata are interpreted to have developed in a back-arc basin with regard to an arc that developed above the north-dipping Kalamaili subduction system. In contrast, the unmetamorphosed Lower Permian Tesibahan Formation, unconformably overlying the Erqis complex, received detritus mainly from the Chinese Altai. These sediments were deposited in an intracontinental piggyback or synformal basin following closure of the back-arc basin. The late Paleozoic sedimentation records support the interpretation that the Chinese Altai and East Junggar domains evolved from the same suprasubduction system prior to the Carboniferous rather than as independent terranes mutually juxtaposed during Permian lateral translation, as previously proposed. [ABSTRACT FROM AUTHOR]

Obsolescence presents an opportunity to reflect on the impermanence of human presence. The ontological unpredictability of the obsolete means that objects relegated to social peripheries can unexpectedly solicit attention. Building off of a personal encounter with a discarded shoe sole jutting out of sand on the beach, this _Perspective examines how the obsolete objects that appear in Mike Nelson's installation artworks are changed by their reappearance in his 2023 survey at the Hayward Gallery, a brutalist art gallery at the Southbank Centre in Central London. Nelson is a contemporary British installation artist who constructs large-scale dreamlike environments out of the very real detritus of post-industrial ruins. By forcing an encounter between trashed objects and spectators passing through gallery space, Nelson troubles the ocular habit that keeps waste out of sight (and out of institutional site). This _Perspective traces Nelson's practice of forming and later reforming trash into sculptural installations, and considers how the obsolescence of his chosen materials can frustrate fixed categorizations of site, spectator, and sculpture. [ABSTRACT FROM AUTHOR]

Species of Plesionika Spence Bate, 1888 holds significant importance in the commercial harvesting of deep-sea shrimps along the southern coasts of India. Despite Plesionika quasigrandis Chace, 1985 being a crucial resource on the southwest coast of India, there is a need for comprehensive information on its food and feeding habits. We investigated the diet of P. quasigrandis in relation to sex, size, and season. The species exhibited a diet primarily consisting of crustaceans, foraminiferans, and detritus. Both males and females showed a noteworthy reliance on detritus, as indicated by an index of preponderance values exceeding 45.8. The species displayed active scavenging behaviour alongside predatory dietary habits. We observed a decrease in feeding intensity from pre-monsoon to post-monsoon in both males and females. Permutational multivariate analysis of variance (PERMANOVA) revealed significant differences in the diets of P. quasigrandis , considering the combined effects of size and sex (P < 0.01). No significant distinctions were noted in the diet composition between males and females in relation to season. [ABSTRACT FROM AUTHOR]

Phytoplankton is a diverse group of photosynthetic organisms and accounts for almost half of global primary production. However, most existing marine ecosystem models incorporate limited phytoplankton diversity, overlook phytoplankton evolution, and treat phytoplankton as concentrations instead of particles. Here we present an individual-based phytoplankton model that captures three dimensions of phytoplankton traits (size, temperature, and light affinities) and allows phytoplankton cells to mutate in a one-dimensional (1D) water column. Other components of this ecosystem include dissolved inorganic nitrogen, twenty size classes of zooplankton, and detritus, all modelled as Eulerian fields. This hybrid plankton model can reproduce the general seasonal patterns of nutrients, chlorophyll, and primary production in the subtropical ocean. We expect that this model will be a useful tool for studying phytoplankton physiology, diversity and evolution in the ocean. [ABSTRACT FROM AUTHOR]

This study advances our understanding of the Jiangnan Orogenic Belt by integrating high-precision geochronological data with interpretations of sedimentary and tectonic environments. Specifically, it addresses the controversy over the geological significance, origins, and tectonic significance of the Shengong Unconfomity: at the base of the Luojiamen Formation. This paper shows that the formation developed over four stages with the primary source of detritus lying in a volcanic arc to the south. The study also reassesses the "unconformity" between the Luojiamen Formation of the Heshangzhen Group and the Zhangcun Formation of the Shuangxiwu Group, concluding that it does not demarcate the end of the orogenic collision between the Cathaysia and Yangtze blocks. [ABSTRACT FROM AUTHOR]

Herbivorous invaders promote changes in community structure and ecosystem functioning. The apple snail, Pomacea canaliculata, is an invader with strong impacts on wetland vegetation and aquatic crops. While able to feed on diverse trophic resources using different feeding mechanisms it is usually regarded as a macrophytophage. However, studies showing direct evidence of what they actually eat in natural waterbodies are few and their results do not fully support such a feeding habit. We analyzed the digestive contents of P. canaliculata using a micrographic technique to describe the spatiotemporal variation of its natural diet within its native range. Stomach and intestine contents were similar but the intestines were never empty and their volume and diversity were generally higher. Detritus was the dominant food item (84.1% of total abundance) and was consumed by all the snails whereas macrophytes were eaten by only half of the snails and represented only an 8.6% of total abundance; filamentous algae, animal remains and grasses showed lower than 5% of total abundance. The spatiotemporal variation in these feeding patterns was minor, despite the among site variation in macrophyte coverage and richness. In the Encadenadas del Oeste basin, P. canaliculata behaves as a specialist on detritus, with some individuals occasionally consuming other resources and can thus be described as an opportunistic generalist omnivore. The impacts of apple snail invasions on both detritus and on other detritivores have seldom been studied although they may have important negative and positive effects, respectively, on dead vegetal matter decomposition. [ABSTRACT FROM AUTHOR]

A systematic study of the interaction of hydrobiological, hydrochemical, hydrological, and hydrophysical processes that occur in the ecosystem of the Vistula Lagoon (VL) of the Baltic Sea has been carried out using mathematical modeling and taking into account the processes in the active layer of bottom sediments (BSs). The features of the dynamics of nitrogen and phosphorus compounds, the turnover time, and the components of the balance of compounds of biogenic elements in the VL ecosystem, as well as the degree of their temporal variability, have been analyzed. It is shown that the variability of nitrogen and phosphorus compounds in the aquatic environment increases in spring and autumn periods. This is due to an increase in river flow into the lagoon and an increase in the level of external biogenic load on the water area of the VL. Model calculations of matter fluxes allow us to state that the inputs of dissolved organic and suspended matter into the lagoon from external sources and the removal to the Baltic Sea are important processes that significantly affect their content in the VL ecosystem. It has been established that under strong winds the process of sedimentation of suspensions can be largely blocked, and the intensity of BS resuspension can increase significantly. An analysis of the main qualitative and quantitative features of the nature of the temporal dynamics of the DON and DOP turnover times, as well as the mineral compounds of nitrogen and phosphorus, indicates a close conjugation of the processes of transformation of dissolved organic and inorganic substances in the water of the VL. A quantitative assessment of the processes of consumption and excretion of compounds of biogenic elements by different groups of aquatic organisms has been performed, and the important role of heterotrophic bacterioplankton and protozoa in the processes of transformation of compounds of nutrients in the VL ecosystem has been shown. The model can be used for scenario modeling and analyzing possible changes in the VL ecosystem under changing climatic and anthropogenic conditions. [ABSTRACT FROM AUTHOR]

The present work aims to evaluate the macroinvertebrate community associated with macroalgae in earthen pond systems to better understand their potential in detritus recycling and as an accessory production. Sampling took place on the settling pond of an aquaculture research station, where macroalgae permanently occurred at high densities. The results suggest differentiation between seasons but not between sites within the settling pond. Seasonal variation was observable in terms of macroinvertebrate density, biomass, and diversity. Two non-indigenous species of invertebrates were found, the crustaceans Grandidierella japonica and Paracerceis sculpta Amphipods were the most abundant group, and their high nutritional value can be exploited. Detritus and the epiphyte layer are the main food items for the invertebrates, reinforcing the advantages of these organisms being present to enhance the recycling of excess detritus and to transfer organic matter to upper trophic levels. These species, naturally present in aquaculture facilities, can improve the water quality and increase the variability of food nutrients for reared species. [ABSTRACT FROM AUTHOR]

Drylands are characterized by high spatial variability in resource availability due to sporadic rainfall, topography of the landscape and important effects of animals. Resource availability gradients may trigger patterns in decomposer population abundances and activity, which could affect ecosystem functions such as decomposition. Here, we examined the influence of resource availability gradients on the importance of termites in the decomposition of wood and grass litter. We placed wood blocks and grass litter baits in bags accessible and inaccessible to termites across wood and grass resource gradients as determined by the presence or absence of a top mammalian predator and across topographic gradients during a 9‐month period in arid Australia. We hypothesized that grass‐eating termite activity would track grass abundance and wood‐eating termite activity would track wood abundance. Termites were the predominant decomposition agent at these sites. Termites contributed to 99.5% of wood decomposition and 83.9% of grass decomposition during our study period. For wood, the termite effect was spatially variable and increased with habitat wood availability, which was greatest on dunes and where top predators were absent. However, the contribution of termites to grass litter decomposition did not track grass availability or termite abundance. The highest effects of termites on grass decomposition rates were found in habitats where the absence of top predators led to low grass availability. Our findings highlight how spatial variability in resources in addition to other factors that we do not document but are known to be influenced by the presence of top predators, such as insectivore predation rates, across the landscape could affect ecosystem functions such as decomposition. [ABSTRACT FROM AUTHOR]

Vorticella convallaria are microscopic sessile suspension feeders that live attached to substrates in aquatic environments. They feed using a self‐generated current and help maintain the health of aquatic ecosystems and wastewater treatment facilities by consuming bacteria and detritus. Their environmental impact is mediated by their feeding rate. In ambient flow, feeding rates are highly dependent on an individual's orientation relative to the substrate and the flow. Here, we investigate how this orientation is impacted by flow speed. Furthermore, we examined whether individuals actively avoid orientations unfavorable for feeding. We exposed individuals to unidirectional laminar flow at shear rates of 0, 0.5, 1.0, and 1.5 s−1, and recorded their 3D orientation using a custom biplanar microscope. We determined that V. convallaria orientation became progressively tilted downstream as the shear rate increased, but individuals were still able to actively reorient. Additionally, at higher shear rates, individuals spent a larger fraction of their time in orientations with reduced feeding rates. Our shear rates correspond to freestream flows on the scale of mm s−1 to cm s−1 in natural environments. [ABSTRACT FROM AUTHOR]

This article provides information about Obersee, a lake in Kißlegg, Germany. It describes the size and depth of the lake, as well as the surrounding landscape. The article also discusses the sediment core of the lake, which contains ancient sediments dating back to 6500 BC. The document includes a pollen record based on samples from the Obersee region, showing changes in vegetation and human impact over time. The authors acknowledge the assistance of individuals who helped with the research. No conflicts of interest were reported. [Extracted from the article]

Conversion of wetlands in the Sacramento–San Joaquin Delta beginning in the mid-1800s resulted in a pronounced shift from a wetland-dominated food web to one driven by open-water primary producers. Submersed and floating aquatic vegetation (SAV and FAV) now rank highest in potential net primary production (NPP) among producer groups, and provide a comparable amount of carbon to the detrital food web as marshes. However, important details of this contribution that relate to shifts in species composition and habitat extent were not understood. Here, we review how changes in aquatic vegetation influence NPP and trophic support from the historical to modern periods, within the modern period (the last 2 decades), and under future management and climate scenarios. We estimate that NPP of SAV and FAV during the historical period was approximately half that of today, before increases in open water and introduction of the highly productive water primrose. During the modern period (the last 20 years), high interannual variability in the extent and relative composition of aquatic vegetation species has driven significant variation in total NPP. This recent temporal variation is 6 to 13 times larger than projected changes in production from the potential future scenarios we modeled, including a reduction in FAV by 20% through control measures, substantial wetland restoration (and thus increased channel area that could support SAV and FAV), and increased salinity intrusion in the western Delta with climate warming, which favors native species with greater salinity tolerance. Large temporal swings in NPP of SAV and FAV cascade to influence the degree of carbon that flows to consumers through detrital pathways and herbivory. This volatility and interannual inconsistency in aquatic vegetation support of food webs make achieving wetland restoration goals for the Delta—which could lead to recovery of a portion of the NPP lost since historical times—even more imperative.

The Neoproterozoic (>1160 to ~540 Ma) sedimentary record of the Tandilia System is reorganized into eight depositional sequences based on a detailed review of published sources and new lithological observations. The main compositional attributes compiled from the studied units were used to indicate changes in lithology regarding their origin. Epiclastic sections reveal supply and sources changes through the succession. Basement detritus was dominant during the deposition of the basal sequences turning drastically to a volcanic affinity dominance. The carbonate sections, dominated by intra-basinal components, were deposited in periods of rare or restricted detrital input. The older, described as a cap-dolostone, was related to bio-induced dolomite precipitation under a deglacial to interglacial context. The younger, a carbonate ramp, reveals to have been built by microbial activity adding high levels of oxygen to seawater correlated to a global oxygenation event. Compositional changes recorded in the shallow marine deposits of Tandilia could have been intricately linked to periods of tectonic and paleo-relief configurations, favoring the detrital supply into the basin, followed by relevant episodic biogeochemical changes. This study shows that the basinal-components progression was controlled by paleoclimate and paleoenvironments associated to the extensive interval between the rupture of the Rodinia to Gondwana paleogeographical framework. [ABSTRACT FROM AUTHOR]

Species in one ecosystem can indirectly affect multiple biodiversity components and ecosystem functions of adjacent ecosystems. The magnitude of these cross‐ecosystem effects depends on the attributes of the organisms involved in the interactions, including traits of the predator, prey and basal resource. However, it is unclear how predators with cross‐ecosystem habitat interact with predators with single‐ecosystem habitat to affect their shared ecosystem. Also, unknown is how such complex top‐down effects may be mediated by the anti‐predatory traits of prey and quality of the basal resource.We used the aquatic invertebrate food webs in tank bromeliads as a model system to investigate these questions. We manipulated the presence of a strictly aquatic predator (damselfly larvae) and a predator with both terrestrial and aquatic habitats (spider), and examined effects on survival of prey (detritivores grouped by anti‐predator defence), detrital decomposition (of two plant species differing in litter quality), nitrogen flux and host plant growth. To evaluate the direct and indirect effects each predator type on multiple detritivore groups and ultimately on multiple ecosystem processes, we used piecewise structural equation models. For each response variable, we isolated the contribution of different detritivore groups to overall effects by comparing alternate model formulations.Alone, damselfly larvae and spiders each directly decreased survival of detritivores and caused multiple indirect negative effects on detritus decomposition, nutrient cycling and host plant growth. However, when predators co‐occurred, the spider caused a negative non‐consumptive effect on the damselfly larva, diminishing the net direct and indirect top‐down effects on the aquatic detritivore community and ecosystem functioning. Both detritivore traits and detritus quality modulated the strength and mechanism of these trophic cascades. Predator interference was mediated by undefended or partially defended detritivores as detritivores with anti‐predatory defences evaded consumption by damselfly larvae but not spiders. Predators and detritivores affected ecosystem decomposition and nutrient cycling only in the presence of high‐quality detritus, as the low‐quality detritus was consumed more by microbes than invertebrates.The complex responses of this system to predators from both recipient and adjacent ecosystems highlight the critical role of maintaining biodiversity components across multiple ecosystems. [ABSTRACT FROM AUTHOR]

Global environmental change has redistributed earth's biomass and the inputs and dynamics of basal detrital resources in ecosystems, contributing to the decline of biodiversity. Yet efforts to manage detrital necromass for biodiversity conservation are often overlooked or consider only singular resource types for focal species groups. We argue there is a significant opportunity to broaden our perspective of the spatiotemporal complexity among multiple necromass types for innovative biodiversity conservation. Here, we introduce an ecosystem-scale perspective to disentangling the spatial and temporal characteristics of multiple and distinct forms of necromass and their associated biota. We show that terrestrial and aquatic ecosystems contain a diversity of necromass types, each with contrasting temporal frequencies and magnitudes, and spatial density and configurations. By conceptualising an ecosystem in this way, we demonstrate that specific necromass dynamics can be identified and targeted for management that benefits the unique spatiotemporal requirements of dependent decomposer organisms and their critical role in ecosystem biomass conversion and nutrient recycling. We encourage conservation practitioners to think about necromass quantity, timing of inputs, spatial dynamics, and to engage with researchers to deepen our knowledge of how necromass might be manipulated to exploit the distinct attributes of different necromass types to help meet biodiversity conservation goals. [ABSTRACT FROM AUTHOR]

Sedimentary basins adjacent to subduction‐related continental arcs provide important archives for deciphering the intricate history of convergent plate margins. The east‐west trending Gangdese magmatic arc was one of the most predominant topographic features located at the southern margin of Tibet before the arrival of the Indian plate. However, the detailed Cretaceous growth and evolution across the arc system remains ambiguous. Stratigraphy of the adjacent Xigaze forearc basin provides a well‐preserved and well‐exposed record of the tectonic and magmatic evolution of the arc throughout the Cretaceous period. We report new stratigraphic, sedimentological, geochronological, and provenance analyses of the Quarry Ridge sandstone in the Xigaze forearc basin along with compiled zircon U‐Pb ages (n = 9674) and Lu‐Hf isotopic signatures (n = 3389) from the Gangdese arc, the Xigaze forearc basin, and the Linzhou retroarc foreland basin to reconstruct the Early to middle Cretaceous magmatism and uplift of the Gangdese arc and concurrent sedimentary responses within both basins. Exhumation of the arc initiates at around 113 Ma suggested by arc detritus first arriving in both basins. Another episode of inferred uplift occurs at around 108 Ma, which resulted in coarse‐grained sedimentation in adjacent basins, preventing Central Lhasa detritus from reaching the Xigaze forearc basin further south and a facies and provenance change within the Linzhou basin. Finally, a third episode at around 101 Ma is reflected by deposition of the progradational Quarry Ridge clastic succession and marks the initiation of a substantial coarse‐grained depositional stage in the Xigaze forearc basin. Our study emphasizes the connection between coarse‐grained deposition in the forearc basin and arc magmatism and uplift. This study also provides an orogen‐scale assessment of the history of arc magmatism, uplift, and sedimentation across the Gangdese magmatic arc system, which supports interpretations that Tibet was already characterized by complex and substantial topographic relief during the Cretaceous before the collision between the Indian and Eurasian plates. [ABSTRACT FROM AUTHOR]

Detrital zircon provenance analysis plays a key role in reconstructions of past tectonic and sedimentary environments. However, non-unique (or even erroneous) interpretations can be introduced due to the inherent limitations of both zircon provenance analysis (fertility bias, recycling) and those of single-proxy provenance systems in general. Apatite crystallizes in a wider range of lithologies than zircon, and can thus facilitate more detailed source reconstructions. In this study, detrital apatite analysis of Cryogenian to Ordovician sandstones in the Cathaysia Block was carried out in comparison with detrital zircon data for a better understanding of the source-sink process on the northern margin of Gondwana. In contrast to the abundant Grenvillian (1300-900 Ma) detrital zircons of igneous origin, detrital apatites show major Pan-African (650-500 Ma) age peaks that are mostly derived from metamorphic rocks (52%-72%). The apatite data show that the Cathaysia Block mainly received detritus from western Australia and India during the late Neoproterozoic to early Paleozoic, with much lower affinities to East Antarctica and the terranes of Iran-Turkey. Provenance variations include a shift with time in the major age populations from ca. 900 Ma to 600 Ma with a decrease in metamorphic apatite (from 72% to 52% of all grains) in the late Cryogenian, an increase in high-grade metamorphic apatite (from 27% to 56%) in the late Ediacaran-Cambrian, and an increase in igneous apatite (from 33% to 45% of all grains) in the Early Ordovician. In contrast, detrital zircon data could only reveal the source change in the late Ediacaran. These provenance switches were likely caused by the unroofing of Pan-African orogens (640-490 Ma) and subsequent erosion of their exposed cores, due to the rapid uplift of source rocks formed in the Pan-African orogens during the Gondwana assembly. [ABSTRACT FROM AUTHOR]

Here a nonlinear mathematical model for an aquatic ecosystem containing both non-toxic and toxin-producing algal blooms is formulated and analyzed. The presence of harmful algae impacts the aquatic population, subsequently affecting the human population that relies on zooplankton (fish, crabs, etc.). It also deteriorates the water quality, and it is advisable not to use water from lakes containing harmful algae. Here, our focus is to understand the dynamics of aquatic ecosystems when we have both types of algae, one that is non-toxic and acts as food to zooplankton, and another that is toxin-producing algae that causes death to zooplankton. The predation of zooplankton on algae influences the growth of the algae population. First, we consider a deterministic model, and later, this model is extended to stochastic model to check whether it has any impact on the dynamics of the populations under consideration. Various equilibria of the proposed model are derived, and the local stability of these equilibria is thoroughly examined. The existence of Hopf-bifurcation is also demonstrated for a suitable set of parameters. The results of deterministic and stochastic models are compared using numerical simulation. Upon examining our results and simulation data, it is evident that modifying specific key parameters, such as the growth rate of non-toxic algae due to nutrient intake and the parameter associated with the predation of non-toxic algae by zooplankton, has a substantial impact on algal bloom dynamics. Minor adjustments to these parameters can result in an augmented presence of non-toxic algae and a simultaneous decrease in toxin-producing algae, aligning with the primary objectives set by policymakers. [ABSTRACT FROM AUTHOR]

The Late Cretaceous Simsima Formation is a post-obduction mixed carbonate–sliciclastic sequence exposed in isolated outcrops in the Oman Mountains. This study utilizes an integrated facies analysis to interpret the depositional environment of the Simsima Formation in the Jabel Al-Rawdah section, Oman. The Simsima Formation in the study area is 75 m thick and unconformably overlies the Semail ophiolite complex. The formation consists of six lithofacies, including (i) paraconglomerate, (ii) laminated mudstone, (iii) arenaeous bioclastic grainstone, (iv) bioclastic grainstone, (v) greyish massive pack to rudstone, and (vi) rudist grainstone. The Simsima Formation is highly fossiliferous, containing corals, crinoids, rudists, Larger Benthic Foraminifera (Omphalocyclus macroporus, Siderolites calcitrapoide, and Orbitoides sp.), gastropods, and bivalves. According to petrographic analysis, the fabric texture of limestone is mainly grainstone (lower part), a few packstone intervals (middle part), and boundstone in the upper part of the formation. The most common non-skeletal grains are peloids, a few intraclasts, and coated grains. Terrigenous detritus grains are also present. The lithologic properties, fossil content, and sedimentary structures and textures of the six lithofacies that constitute the formation allow to decipher the deposition of the formation in a well-agitated shallow marine environment. The vertical arrangement of the various lithofacies of the Al-Rawdah section indicates an overall deepening-upward succession. The deposition of the formation was influenced by both tectonic and climatic factors. [ABSTRACT FROM AUTHOR]

The provenance and tectonic setting of the Stenian (<1200 to 1015 Ma) metasedimentary sequences of the South Delhi Supergroup, NW India, are least understood and thus debatable. The results of this study show that the protoliths of the metasedimentary rocks received detritus dominantly from felsic sources, particularly from Mesoproterozoic granitoids exposed in northern and eastern India. The weathering indices suggest low to moderate weathering in the source areas and that the sediment compositions reflect mixing of provenance components having different compositions. Overall, the REE patterns of the South Delhi rocks are similar with variable negative Eu anomalies and absolute ∑REE contents. The low REE abundances in the quartzites are the consequence of quartz dilution during hydraulic sorting. The tectonic multidimensional discrimination diagrams suggest a passive margin setting for the South Delhi metasedimentary rocks, which is in consonance with the detrital zircon age spectra and regional geology of the western margin of Aravalli orogen, NW India. [ABSTRACT FROM AUTHOR]

The follicular fluid's composition changes physiologically to meet the demands of specific local phenomena during oogenesis and folliculogenesis. Here, we investigated whether follicular fluid from polycystic ovarian syndrome (PCOS) patients influence the systemic functioning of body compared to the follicular fluid from non-PCOS patients. Follicular fluid was pooled separately from both healthy and PCOS subjects. Tissues and other detritus were separated from the collected fluid by centrifugation. Female Swiss albino mice received 1 and 2 mL/kg of the fluid intraperitoneally, and were observed for 21 days for physiological changes. Variation in body weight was tracked intermittently. Serum was obtained for estimation of oestrogen, progesterone, testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), insulin and glucose on the day the animals were euthanized. Liver, kidney, heart, lung, pancreas, spleen and ovary were examined histologically. Haemoglobin and haematocrit levels were found significantly lowered in animals administered with follicular fluid from PCOS patients. Beginning at day 14, there was a significant increase in total body weight. Blood glucose level increased consistently and almost doubled on day 21 from 101.2±0.86 to 201.0±5.34 mg/dL. Serum concentrations of oestrogen and progesterone reduced significantly and testosterone level got increased in PCOS follicular fluid treated animals compared to non-PCOS follicular fluid. Both the LH/FSH ratio and insulin level rose significantly (P <0.001) increased in PCOS follicular fluid treated animals. The HOMA-IR was likewise statistically significantly increased (P <0.001). However, both the HOMA-Beta and QUICKI scores dropped significantly (P <0.001). A PCOS follicular fluid treatment group of female mice showed clear signs of myocarditis, cardiac atrophy and numerous ovarian cysts. The follicular fluid of PCOS patients showed a localised effect, and the components, through the systemic circulation, posed detrimental consequences systemically suggesting involvement in the pathogenesis of PCOS. Follicular fluid from PCOS patients should be further studied for proteomics and its potential in therapeutic, diagnosis and prognosis. [ABSTRACT FROM AUTHOR]

Predicting how increasing temperatures interact with other global change drivers to influence the structure and dynamics of Earth's ecosystems is a primary challenge in ecology. Our study made use of multiple simultaneous "natural experiments" to examine how rapid warming, declining nutrients, invasive consumers, and riparian invasive species management interact to influence leaf decomposition in a large and regulated river. Specifically, we compared the breakdown of cottonwood (Populus fremontii), willow (Salix exigua), and saltcedar (Tamarix sp.) leaf litter in 2022 to a previous experiment from 1998 that occurred under much cooler water temperatures, and had higher water phosphorus concentrations, low numbers of invasive New Zealand mudsnails (Potamopyrgus antipodarum), and unaltered litter chemistry from the herbivory of saltcedar leaf beetles (Diorhabda carinulata). We found that the effects of up to 10°C warmer temperatures on leaf decomposition were mediated by the establishment and management of invasive species and declining water nutrient concentrations arising from upstream reservoir lowering. Such interactions led to accelerated breakdown of saltcedar, but relatively minor effects of warming on the rate of cottonwood and willow decomposition. Additionally, our results demonstrate the potential for favorable invasive species management outcomes in the terrestrial environment to produce unintended responses in adjacent freshwater ecosystems. As temperatures continue to rise, it is critical that future studies consider how warming interacts with multiple stressors and environmental factors to influence processes such as decomposition in freshwater ecosystems. [ABSTRACT FROM AUTHOR]

Pelagic tunicates (salps, pyrosomes) and fishes generate jelly falls and/or fecal pellets that sink roughly 10 times faster than bulk oceanic detritus, but their impacts on biogeochemical cycles in the ocean interior are poorly understood. Using a coupled physical‐biogeochemical model, we find that fast‐sinking detritus decreased global net primary production and surface export, but increased deep sequestration and transfer efficiency in much of the extratropics and upwelling zones. Fast‐sinking detritus generally decreased total suboxic and hypoxic volumes, reducing a "large oxygen minimum zone (OMZ)" bias common in global biogeochemical models. Newly aerobic regions at OMZ edges exhibited reduced transfer efficiencies in contrast with global tendencies. Reductions in water column denitrification resulting from improved OMZs improved simulated nitrate deficits relative to phosphate. The carbon flux to the benthos increased by 11% with fast‐sinking detritus from fishes and pelagic tunicates, yet simulated benthic fluxes remained on the lower end of observation‐based estimates. Plain Language Summary: Marine ecosystems play a critical role in the global carbon cycle through the food web regulation of air‐sea carbon fluxes and the transfer of particulate matter from the upper oceans to depth. Recent evidence has suggested that the detritus from fishes and gelatinous zooplankton (GZ), specifically the pelagic tunicates such as salps and pyrosomes, may have a disproportionate impact on the ocean's biological pump due to them sinking approximately 10 times faster than bulk detritus. These fluxes result in increased sequestration of particulate carbon and nutrients into the deep oceans, but their impact on biogeochemical cycles at depth is poorly understood. Here, we investigated the sensitivity of deep ocean carbon, oxygen, and nutrient cycles to fast‐sinking detritus from tunicates and fishes. We found that the fast‐sinking detritus decreased surface productivity and export, as well as the size of ocean oxygen minimum zones (OMZs). Also, we examined whether observational evidence of seafloor oxygen consumption could support the increased detrital fluxes (and respiration) at depth, and found that even with the increased oxygen consumption, the modeled values were still below the observations. This suggests that these processes could be realistically incorporated into future generations of Earth System Models. Key Points: We incorporated fast‐sinking detritus from pelagic tunicates and fishes into a modified version of the ocean biogeochemical model COBALTThe fast‐sinking detritus increased carbon sequestration and transfer efficiency to depth, but decreased surface productivity and exportFast‐sinking detritus decreased the size of oxygen minimum zones (OMZs) and water column denitrification, a common model bias [ABSTRACT FROM AUTHOR]