Litter decomposition is a key process in carbon (C) and nutrient cycling, but how nitrogen (N) addition affects decomposition via soil properties versus altered litter quality remains unclear. We conducted a 30-day laboratory incubation using litter from three grassland species (Poa annua, Lolium perenne, Dactylis glomerata) and soils from a four-year N addition field experiment (0, 1.49, 2.99, 5.99 g N·m-2·yr-1) in a subtropical grassland of Southwest China. Because all litter was collected from unfertilized areas, our experiment specifically tested the soil legacy effects of N addition on decomposition of standardized litter, not the direct effects on litter quality. Decomposition rates (decay constant k) ranged from 0.017 day-1 (P. annua, no N) to 0.068 day-1 (L. perenne, high N). N addition significantly increased decomposition for all species, with the strongest stimulation for low-quality litter (P. annua). First-order kinetic models fitted the 30-day data well (R² > 0.98), but extrapolation beyond the incubation period is not justified. Initial C:N ratio was negatively correlated with both k (r = -0.625, P < 0.01) and cumulative CO2 efflux significantly influenced by both species identity and N addition. Our design does not allow attribution of the stimulation to N-induced changes in litter quality. Instead, long-term N addition altered soil properties (increased inorganic N, reduced pH), which in turn modulated decomposition of subsequently added litter. We conclude that soil legacy effects of N addition accelerate litter decomposition and CO2 efflux, with effects modulated by litter quality. These findings provide empirical evidence for predicting ecosystem C dynamics under future N deposition but highlight the need for longer-term experiments that directly manipulate both soil properties and litter chemistry.
Anthropogenic marine litter has emerged as one of the most pervasive environmental problems worldwide, exerting multifaceted ecological, economic, and social impacts. This study assessed the seasonal dynamics and composition of beached litter on urbanized tropical beaches located within a semi-enclosed estuarine bay system along the west coast of India. A total of 5695 litter items were recorded, with the highest abundance observed during the monsoon season (N = 3571; 14.28 ± 0.54 items. m-2), followed by post-monsoon (N = 1080; 4.32 ± 0.80 items m-2) and pre-monsoon (N = 1044; 4.17 ± 0.79 items m-2). Across all seasons, plastics consistently dominated the litter composition, representing more than 90% of the total litter items. Seasonal differences in litter density were statistically significant, with litter densities during the monsoon season being markedly higher than those recorded during the pre- and post-monsoon periods, indicating the important role of enhanced river discharge, surface runoff, and hydrodynamic transport processes in driving litter accumulation along estuarine beaches. Beach environmental quality was evaluated using multiple environmental indices, including the Clean Coast Index (CCI), Clean Environment Index (CEI), Plastic Abundance Index (PAI), Hazardous Item Index (HII), Pollution Load Index (PLI), and Environmental Status Index (ESI), which consistently revealed the poor environmental quality and elevated pollution risk, particularly during the monsoon. The Delft3D FM modeling framework demonstrated that local hydrodynamic processes govern the advection, retention, and redistribution of anthropogenic litter. Source apportionment analysis revealed that land-based activities contributed more than 75% of total litter across all seasons, driven by urban runoff, tourism, and inadequate waste management. The study underscores the urgent need for comprehensive waste management strategies and seasonal intervention measures to mitigate litter impacts on tropical coastal systems.
Litter decomposition is a core process regulating the formation and stability of soil organic carbon. Under the background of climate warming, the intrinsic mechanisms by which the expansion of alpine shrubs affects carbon balance of alpine ecosystems by altering litter input characteristics (decomposition rate and chemical composition) remains unclear. We explored the effects of warming on the decomposition dynamics, carbon fraction changes of litters with different qualities and the stability of soil organic carbon, taking the leaf litters of Sorbus rufopilosa (high-quality, low C/N ratio and low lignin content) and Rhododendron lapponicum (low-quality, high C/N ratio and high lignin content) in the alpine regions of western Sichuan as the research objects. We conducted a 180-day laboratory controlled-temperature incubation experiment, with two temperature treatments: ambient temperature (10 ℃ in the daytime / 5 ℃ at night) and warming (20 ℃ in the daytime / 15 ℃ at night). The results showed that warming significantly accelerated the decomposition of the litters of two shrub species, with the decomposition rates of S. rufopilosa and R. lapponicum being increased by 47.9% and 21.0%, respectively. There was an average decrease of 9.7% and 14.7% in the non-polar extractives and acid-hydrolyzable carbohydrates and an average increase of 16.9% in the acid-unhydrolyzable residue. Warming significantly increased the content of soil dissolved organic carbon and decreased the content of soil recalcitrant organic carbon, but did not affect the content of soil total organic carbon. Under warming conditions, soil carbon stock index and carbon stock activity increased by 2.5% and 53.4% compared to normal temperature under S. rubra litters input, and increased by 3.2% and 79.5% for R. alpinum litters input, while the soil carbon stock management index decreased by 13.6% and 7.3%, respectively. In conclusion, warming accelerated the decomposition of alpine shrub litters and reduced the stability of soil organic carbon, while the input of low-quality litter could better maintain the stability of soil organic carbon in alpine meadows compared with high-quality litter. 凋落叶分解是调控土壤有机碳形成与稳定性的核心过程,而气候变暖背景下,高山灌丛扩张通过改变凋落叶输入特征(分解速率、化学组成)影响高寒生态系统碳平衡的内在机制尚未明确。本研究以红毛花楸(高质量,低C/N、低木质素含量)和高山杜鹃(低质量,高C/N、高木质素含量)凋落叶为研究对象,设置常温(白天10 ℃/夜间5 ℃)和增温(白天20 ℃/夜间15 ℃)两种温度处理,开展为期180 d的室内控温培养试验,探究增温对不同凋落叶分解动态、碳组分变化及土壤有机碳稳定性的影响。结果表明:增温加速两种灌木凋落叶分解,红毛花楸和高山杜鹃分解速率较常温分别提升47.9%和21.0%;有机溶性组分、酸溶组分分别平均降低9.7%和14.7%,酸不溶组分平均增加16.9%。增温显著提高土壤溶解性有机碳含量,显著降低惰性有机碳含量,对土壤总有机碳含量无影响。增温条件下,红毛花楸凋落叶输入下土壤碳库指数和碳库活度较常温提升2.5%和53.4%,高山杜鹃凋落叶输入下提升3.2%和79.5%,两者土壤碳库管理指数较常温分别降低13.6%和7.3%。综上,增温加速了高山灌木凋落叶分解并且降低了土壤有机碳稳定性,而低质量的凋落叶输入比高质量的凋落叶能更好地维持高寒土壤有机碳的稳定性。.
Marine litter has been quantified in several deep-sea environments, including complex habitats such as submarine canyons that host Vulnerable Marine Ecosystems. However, a standardized method for its characterization and quantification is still lacking. Here, we propose a simple and replicable method based on repeated 100 m transects conducted using Remotely Operated Vehicle video surveys. The method was tested at two sites off the French coasts, in the Western Mediterranean Sea in 2023 and the North-East Atlantic in 2025. Mean litter densities reached 30,101 items km-2 in the Lacaze-Duthiers Canyon, Gulf of Lion, and 18,333 items km-2 in the Lampaul Canyon, Bay of Biscay. The type of litter differed according to the canyons and/or bathymetry. Fishing gear largely dominated the litter at the head of the Lacaze-Duthiers Canyon, whereas plastic bags and packaging constituted most of the litter in the Lampaul Canyon. Litter densities were particularly high in coral reefs that inhabit these canyons, lines and bags being entangled in coral branches. Our results demonstrate the efficiency, robustness, and reproducibility of this approach, as it generated comparable results across two distinct canyons. The method represents a practical and reliable tool for supporting the assessment of criterion D10C1 (seafloor litter) of Descriptor 10 (Marine Litter) of the Marine Strategy Framework Directive (MSFD). It contributes to improved monitoring of marine debris, beyond seafloor litter derived from trawling data, as well as its potential impacts on deep-sea habitats, and will support the implementation of appropriate management plans for the conservation of these vulnerable ecosystems.
Reproduction traits constitute the primary objective of porcine genetic improvement programs, with litter size being the principal determinant of herd reproduction output. Relative to the intensively selected Large White line, as a breed derived from Large White (LW) and Beijing Black (BJB) pigs, Jishen Black (JSB) pigs exhibit markedly lower litter size, indicating substantial potential for genetic improvement. Whole-genome resequencing data were obtained from 110 individuals of six pig populations differed in litter size: a Large White line with high litter size (> 16, LWH), cryopreserved Large White samples from 1977 (LW1977), dam-selected (LWD) and sire-selected (LWS) lines derived from LW1977, Berkshire (BKS), and Jishen Black pigs (JSB). Principal component analysis (PCA) captured clear population genetic structure along PC2, with the observed distribution pattern descriptively coinciding with litter size variation across populations, though such an association was not statistically verified. A composite selection-signature scan that integrated Fst, π-ratio, and XP-EHH was performed between multiple population groups. Candidate signals were filtered by excluding those also detected in a control comparison (Jishen Black vs. Berkshire) that showed minimal litter‑size difference, to screen selection signatures with potential relevance to reproductive trait differentiation at the population level. Twelve genes were identified as putative candidate genes for litter size, including PEX14, CDK15, KCNQ1, SPAG17, TTF2, CD101, CASQ2, VANGL1, ARID5B, KLHL32, EML1, and NAV1. Functional enrichment analysis indicated that these genes significantly over-represented in microtubule-related biological processes. Among them, KCNQ1 was consistently detected by all methods and comparison groups. Further analysis of KCNQ1 revealed multiple SNPs with significant allele-frequency differentiation among populations; notably, two intronic variants (chr2:A1,861,604G and chr2:A1,867,076G) showed population-specific allele frequency patterns that descriptively aligned with the stratification of litter size performance. By comprehensively dissecting population genomic differentiation among multi-breed populations divergent in litter-size performance, this study implemented established a feasible framework for screening candidate loci associated with porcine prolificacy at the population level, expanded the gene list with suggestive selection signatures, and provided potential molecular markers requiring further independent cohort validation and functional verification to support future genetic improvement in swine reproduction efficiency.
Mosquito larvae feed on microbes growing on decomposing organic matter, which in cities is often limited to a finite amount of allochthonous leaf litter in artificial container habitats. Curiously, field surveys in US cities consistently document a mismatch between blocks with the greatest mosquito infestations and blocks where their plant resources are most plentiful, with variation shaped by socioeconomic factors. We gathered leaves characteristic of socioeconomically diverse blocks in Baltimore, Maryland, and Washington, DC, to create lab mesocosms for two common mosquito species, Aedes albopictus (Skuse) and Culex pipiens (Linnaeus). We reared mosquitoes at varying densities to assess the effects of leaf litter composition on survival, development time, and body size, from which we calculated population performance and effects on competition. We also investigated traits of the leaf litter and aquatic environment. Leaf litter containing at least one non-native species, including the mix common on low-income blocks (nonnative trees Ailanthus altissima and Paulownia tomentosa) and the mix common across the region (native tree Juglans nigra and nonnative tree Morus alba) improved mosquito outcomes compared to the native leaf litter common on high-income blocks (native trees Acer rubrum and Ulmus americana) and also alleviated competitive effects on development time, perhaps making coexistence more likely. The three litter types showed significant differences in C:N ratio, decay rate, and tannin/lignin concentration but not in microbial abundance. These results offer a mechanistic explanation for previously observed socioeconomic patterns in urban mosquito populations and point toward novel strategies for mosquito control through vegetation management.
Oceanographic models predict relatively high rates of floating litter arrivals on shores influenced by onshore currents compared to regions with extensive offshore transport, such as Eastern Boundary Upwelling Systems. However, the lack of large-scale observations along continental coasts has prevented tests of this prediction. Volunteer participants (here, schoolchildren) sampled marine litter on continental beaches along 12,000 km of the East Pacific coast from 30°N to 45°S to assess the presence of biofouling organisms on objects with positive buoyancy. The presence of sessile biota indicates that litter items spent sufficient time in the water for these organisms to colonize, while positive buoyancy is necessary for litter to be transported by marine currents. In agreement with the predictions from Lagrangian particle simulations, higher proportions of floating litter with biofouling arrived along Central American beaches influenced by the Equatorial Current System than on the shores within Eastern Boundary Upwelling Systems. Our study highlights the considerable potential of participatory science to generate extensive, long-term, and reliable measures of floating litter and associated biota along coasts.
A key knowledge gap exists in understanding how the decomposition of litter from different halophyte species influences microbial community dynamics in soils. This study addressed this gap through a 180-day laboratory microcosm experiment investigating the effects of leaf litter decomposition from three halophytes (Kalidium cuspidatum, Nitraria tangutorum, and Reaumuria songarica) on soil biogeochemical properties, microbial dynamics, and community compositional constancy. The main research results indicate that at 180 days, the leaf mass loss (Mm) of the three halophytes reached 40.09%-42.89%, and the decomposition constants (k) were all < 0.2. Leaf total nitrogen, lignin, and carbon/nitrogen ratio directly regulated the decomposition process. Decomposition significantly increased soil nutrient pools, including total organic carbon (57.64%-100.12%), total nitrogen (51.92%-129.80%), dissolved organic carbon (44.35%-224.40%), and dissolved organic nitrogen (24.15%-238.58%), relative to bulk soil. Microbial carbon limitation increased by 21.81%-37.99%, while nitrogen limitation was alleviated, as evidenced by a 67.86%-92.28% increase in the vector angle of enzyme stoichiometry. These changes were driven by soil chemistry (explaining 45.47% of the variance) and microbial traits (42.31%-65.77%). Plant litter decomposition reshaped the structure of bacterial and fungal communities while reshaped the structure, which was linked to microbial biomass carbon, β-glucosidase, and alkaline phosphatase (p < 0.05). Furthermore, partial least squares path modeling revealed that plant litter decomposition increased soil organic resources, thereby exacerbating microbial carbon limitation; yet, along with microbial biomass, it also influenced microbial community composition. These results underscore species-specific litter effects on soil-microbe feedbacks in a controlled microcosm, emphasizing the role of resource stoichiometry and enzymatic activity in shaping microbial community in saline ecosystems.
Total born number (TBN) and number born alive (NBA) are primary selection targets for improving reproduction performance in pigs; however, genetic progress is constrained by the low heritability of single-parity records. To better capture the genetic potential underlying litter size, we evaluated maximum (maxTBN and maxNBA) and mean (meanTBN and meanNBA) litter size traits derived from multiple parities as alternative selection criteria. Using data from a Dongliao Black (DL) pig population, heritability estimates for maxTBN (h2 = 0.19), meanTBN (h2 = 0.16), maxNBA (h2 = 0.24) and meanNBA (h2 = 0.17) were substantially higher than those for single-parity TBN (h2 = 0.06) and NBA (h2 = 0.07). Genome-wide association analyses (GWAS) based on estimated breeding values of maximum and mean traits identified 158 significant single-nucleotide polymorphisms, implicating several candidate genes, including BPI, KCNC2, ELMO1, CHD6, OPCML, and MND1. Validation in an independent Large White population with high litter size (TBN > 16) showed that favorable alleles at representative loci were close to fixation, supporting their effects on reproduction performance. Furthermore, genomic prediction models based on maxTBN and maxNBA exhibited higher cross-validation variance than those using conventional litter size traits, reflecting greater prediction instability. Collectively, these results demonstrate that mean litter size traits constitute robust phenotypes for genetic evaluation of sow fertility, while maximum traits may serve as supplementary indicators for identifying elite individuals, and provide functionally relevant markers that can be exploited to inform balanced selection strategies for reproduction in pig breeding programs.
Poultry litter is widely applied as an organic fertilizer, yet concerns remain regarding the cumulative input and potential accumulation of potentially toxic elements (PTEs) in agricultural soils. This study evaluated the medium-term effects of repeated poultry litter application on pseudo-total concentrations and cumulative inputs of arsenic (As), cadmium (Cs), chromium (Cr), copper (Cu), nickel (Ni), and zinc (Zn) in an acidic dystrophic Red Latosol under subtropical conditions in southern Brazil. An eight-year field experiment (2011-2018) evaluated four annual poultry litter rates (0, 4, 8, and 12 t ha⁻1) combined with dolomitic limestone application under a randomized complete block split-plot design. Baseline soil characterization, cumulative PTE mass balance, and linear mixed-effects models were integrated to assess treatment responses and environmental relevance. Despite continuous inputs, no significant accumulation of As, Cd, Cr, Cu, or Ni was detected within the evaluated 0-20 cm soil layer, likely reflecting low cumulative additions relative to initial soil stocks and soil retention processes. In contrast, Zn showed significant dose-dependent accumulation in the surface layer (0-10 cm), consistent with its higher cumulative input from poultry litter. Dolomitic limestone application had no detectable effect on PTE dynamics during the evaluated period, probably due to the limited increase in soil pH. Although all PTE concentrations remained below Brazilian regulatory thresholds, cumulative Zn inputs represented the largest proportional increase relative to the initial soil pool, highlighting Zn as a sensitive indicator for monitoring repeated organic amendment applications. These findings emphasize the importance of combining baseline characterization, mass balance approaches, and continued monitoring to improve environmental risk assessments of organic waste reuse in subtropical agroecosystems.
Seafloor litter has become a growing environmental concern to marine ecosystems and coastal economies. To better understand the environmental behavior of seafloor litter, it is important to characterize its spatial patchiness at local scales. However, the local-scale patch size of seafloor litter has rarely been quantified. Thus, a patch size spectrum method was developed to estimate local-scale patch size from bottom-trawling survey data. The method utilized geostatistical simulations to relate observed area-normalized catches with simulated area-normalized catches under varying potential patch sizes. Cross-validation demonstrated predictive accuracy with a typical relative error of ∼20% and 31% in worst-performing cases. Application to experimental bottom-tow data collected from Tokyo Bay showed the local-scale patch size of 134 m, substantially smaller than the trawling transect length (∼2.8 km). Moreover, the local-scale patch size remained temporally stable between two survey periods. This method provides a novel framework for quantifying local-scale heterogeneity in seafloor litter distribution, and it is broadly applicable to other forms of integrated line transect sampling, such as benthic organism surveys and environmental monitoring where within-transect spatial resolution is limited.
Poultry farming is a rapidly expanding sector that faces numerous challenges related to biosecurity and production efficiency.One major concern is the prevalence of pathogens, such as Escherichia coli, in broiler farm litter, which can lead to increased morbidity and mortality in flocks, ultimately affecting farm productivity. This study aimed to evaluate the efficacy of a farmer's homemade biodisinfectant solution containing Lactobacillus casei, Lactobacillus paracasei, Saccharomyces cerevisiae, and Eco Enzyme applied to broiler farm litter for reducing Escherichia coli (E. coli) populations and their subsequent effects on broiler production performance. A biodesinfectant was applied to the litter of a commercial broiler farm over a period of 30 days.  One-day-old Ross broilers (900 samples) were fed pre-starter, starter, and finisher diets as controls. The farm consisted of 3 broiler grow-out pens that were used for 3 treatment groups. As the maximum stocking density was restricted to 18 kg/m², the house space is 600 m². The biodisinfectant was applied at two concentrations in the treatment groups: TA (1 ml/100 ml) and TB (1 ml/250 ml) at 2-day intervals. Performance metrics, including FCR, slaughter body weight (BW), mortality rate, and overall health, were monitored. The control group (CON) had the lowest BW (p < 0.05) and the highest mortality rate (p < 0.05) compared with the other treatments. Significant E. coli reduction at both treatments (p < 0.05) compared with the control, with no significant adverse effects on broiler performance metrics in every treatment group. These findings suggest that biodisinfectants offer a promising, eco-friendly alternative for enhancing both biosecurity and production performance efficiency in broiler poultry farms.
AMH plays a critical role in ovarian follicular development and may influence reproductive performance. However, its genetic variation and association with litter size in goats remain unclear. In this study, three single-nucleotide polymorphisms (SNPs) in the AMH gene (g.89169447C>A, g.89169684G>A, and g.89170008T>C) were identified in Dazu Black goats. Association analysis showed that the g.89169447C>A locus was significantly associated with litter size at first parity (p < 0.05), while the g.89169684G>A locus was significantly associated with the average litter size across the first three parities (p < 0.05). Functional assays in granulosa cells indicated that the g.89169684G>A variant altered the expression of proliferation and apoptosis-related genes. These results suggest that the g.89169684G>A variant may serve as a potential molecular marker for improving reproductive performance in goats.
Identifying sperm biomarkers that predict fertility in swine is important for improving animal selection and production. In this context, however, sperm chromatin in swine remains understudied, and whether it varies by breed and season remains unresolved. Additionally, the impact of sperm chromatin protamination, condensation, and DNA integrity on reproductive outcomes (farrowing rate and litter size) is unclear in swine. This study aimed to improve the understanding of sperm chromatin features by evaluating breed- and month-related differences and determining their influence on fertility outcomes. To this end, we evaluated sperm chromatin protamination and condensation, as well as global and double-strand DNA damage, in 91 ejaculates from 41 boars (25 Landrace and 16 Large White) using chromomycin A3, dibromobimane, and alkaline and neutral Comet assays, respectively. Single sperm analysis revealed six clusters associated with chromatin protamination, four clusters related to chromatin condensation, and two clusters corresponding to global DNA damage. Differences between the Landrace and Large White breeds were observed in the percentage of sperm with global DNA damage (P = 0.015), and in chromatin protamination (P = 0.012) and condensation (P < 0.001). Overall, sperm chromatin integrity was better in Large White than in Landrace boars. Monthly analysis revealed that sperm chromatin quality worsened in September due to an increase in global DNA damage (P < 0.01), affecting condensation in one cluster and sperm protamination in two clusters (P < 0.05). Finally, multivariate analysis showed that the percentage of sperm with double-strand DNA breaks was associated with litter size in both breeds. This study identified sperm subpopulations based on chromatin features in swine. Differences were observed between Large White and Landrace breeds, with the sperm from Large White boars having healthier chromatin quality in terms of DNA damage, protamination, and condensation. Monthly variations were also seen, primarily in relation to global DNA damage. Finally, our study showed an association between the incidence of sperm with double-strand DNA breaks and litter size in both breeds.
This study investigated the effects of different flooring designs on the welfare and behavioral traits in fast-growing broilers. A total of 600 day-old Ross-308 chickens were randomly allocated to five treatment groups: fully littered (FL), fully slatted (FS), and combined systems with varying slatted floor ratios (1/3SF, 1/2SF, and 2/3SF). Welfare parameters, including body defects, gait score, and tonic immobility (TI), along with behavioral activities, were assessed. Results indicated that hock burn and breast skin burn scores were significantly higher in male birds and increased with the proportion of slatted flooring (p < 0.001). Conversely, the FS and high-ratio slatted groups exhibited significantly better body cleanliness and breast feathering scores compared to the FL group. While gait scores were generally poorer in males, the floor design significantly influenced walking ability (p = 0.05), with higher impairment observed in FS males. TI duration did not differ significantly among treatments. Behavioral observations revealed that the FL system promoted active behaviors, particularly foraging and locomotion (p < 0.001). In contrast, the FS system inhibited natural behaviors such as dust bathing and foraging, leading to increased preening and passive behaviors. In conclusion, while slatted floor systems offers advantages in hygiene and cleanliness, it negatively impacts leg health and restricts the expression of natural behaviors. Partially slatted floor systems presented intermediate results but did not fully mitigate the welfare trade-offs associated with slatted systems.
Selection for uniformity in livestock species is desirable because it is associated with welfare and robustness. To address variability, it is essential to have more than one record per animal; therefore, the number of records per individual is crucial. The guinea pig, characterised by its low litter size, is a species of notable economic and nutritional importance, especially in the Andean region of South America. The objective of this study was to evaluate, through simulation, the impact of low record numbers on the performance of heteroscedastic models used in selection for uniformity, using guinea pig birth weight as an example. Different data structures that modulated litter size (LS), number of litters (NL), number of breeding animals (BAs), and number of generations of records were evaluated. The analysis of simulated data was performed under Frequentist and Bayesian statistical approaches. In general, the model was able to adequately estimate the variance components and predict genetic values, although its performance depended on the data structure. Under the Frequentist approach, the litter variance affecting the residual variance was biased downward in LS = 2 and LS = 3 (between -69 and -96%), although the bias decreased in LS = 5 and LS = 7 (between -10 and -44%). The BAs did not influence the bias. At NL = 2, the bias ranged from -68 to -76%, and at NL = 6, from -35 to -69%. The Bayesian method failed to converge in the scenario with two generations and NL = 2. The accuracy of the genetic values for both the trait and the residual variance was identical regardless of the statistical approach used. An increase in BAs did not lead to favourable changes in accuracy, but higher LS and NL tended to improve the accuracy of the genetic values of the trait and the residual variance. We conclude that selection for uniformity under a low number of repeated records, such as the limited number of within-litter birth weight data in guinea pigs, is feasible. However, it is recommended to carefully monitor the data structure to predict the expected response and, if possible, to use populations with the highest possible litter sizes.
Understanding shark reproductive modes is crucial for conservation, as these K-strategist species are vulnerable to overexploitation. The spiny dogfish (Squalus acanthias), a small shark listed as 'vulnerable' by the IUCN, has a 22-month gestation period and a reproductive output ranging from 1 to 21 pups per litter. This study aimed to investigate multiple paternity in S. acanthias using Single Nucleotide Polymorphism (SNP) markers. Samples from six litters, comprising 40 individuals collected in Argentina, were analyzed using a ddRADseq library. SNP markers were screened with the STACKS pipeline, and kinship and paternity were analyzed using COANCESTRY and COLONY software. Results revealed 1,021 to 1,620 SNPs per litter, with multiple paternity detected in all litters. The number of sires per litter ranged from 2 to 4. No correlation was found between litter size and multiple paternity, suggesting this behavior may enhance genetic diversity. The species' size and sex segregation, coupled with females in shallower waters, increase their vulnerability to fishing pressure. Overfishing and bycatch exacerbate the reduction in sexually mature individuals, threatening population recovery. This study highlights the need for management policies that incorporate reproductive strategies, especially for species like S. acanthias with complex life histories and low recovery rates.
Syringe services programs (SSPs) decrease HIV and overdose incidence among people who use drugs (PWUD). In May 2024, Pueblo, Colorado, banned syringe distribution, citing public complaints about syringe litter. The ban was overturned in June 2024. The two SSPs in Pueblo halted syringe distribution during the three-week ban but continued other services. The effect of short-term syringe bans on harm reduction services is unknown. We analyzed program data from one SSP in Pueblo, Colorado, and syringe litter pickup data from the Pueblo Department of Parks and Recreation from January to September 2024. We used Interrupted Time Series analysis to evaluate the association between the syringe distribution ban and four weekly outcomes: SSP visits, naloxone kits distributed, syringes distributed, and syringe litter collected. The ban was associated, on average, with 31 fewer visits (95% CI: -48, -15), 23 fewer naloxone kits distributed (95% CI: -34, -12), and 2406 fewer syringes distributed (95% CI: -3308, -1504) every week. There was an immediate decrease of 120 syringe litter units collected (95% CI: -285, 46) weekly. After the ban was overturned, there was an immediate increase and increasing trend in visits, naloxone kits, and syringes distributed, and no changes in syringe litter. Naloxone distribution did not return to expected levels in the 16 weeks following the ban being overturned. Banning syringe distribution in Pueblo, Colorado was associated with sustained decreases in SSP usage and naloxone distribution. Eliminating funding for certain SSP activities could inadvertently decrease access to naloxone.
Climate change is increasing the frequency of drought-rewetting cycles in temperate forests, yet the short-term responses of soil fungal communities to these events remain poorly resolved. We investigated whether an intense summer drought followed by heavy rainfall alters fungal community composition and oxidative enzyme activity in managed temperate beech forests of Central Slovakia. Soil samples from litter and mineral horizons were collected before and seven days after a rainfall event that followed an 18-day dry period. Fungal communities were characterized using ITS2 metabarcoding, and manganese peroxidase (MnPox) activity was measured as an indicator of oxidative decomposition potential. Fungal communities differed strongly between litter and mineral soil horizons across taxonomic and trophic classifications. Ectomycorrhizal fungi and soil saprotrophs dominated the mineral soil, whereas plant pathogens, litter saprotrophs, and wood-decomposing fungi were more abundant in the litter layer. In contrast, short-term rewetting did not produce detectable changes in fungal community composition or alpha diversity within either horizon. MnPox activity showed substantial spatial variability among plots but no consistent response to the rainfall event. Together, these results indicate that vertical stratification exerts a stronger influence on fungal community structure than short-term moisture fluctuations in these beech forest soils. The absence of rapid compositional change suggests that fungal communities in mature temperate forests may exhibit short-term resistance to drought-rewetting pulses, highlighting the importance of soil structure and litter layers in buffering microbial communities against transient climatic extremes.
Dairy goats exhibit distinct physiological adaptations during pregnancy and lactation, necessitating breed-specific biochemical reference values for accurate health assessment. The Thuringian Forest goat, an important regional dairy breed managed under organic systems, remains insufficiently characterized in this regard. This longitudinal study aimed to evaluate clinical-chemical profiles and metabolic dynamics across reproductive stages and to determine the influence of lactation number, milk yield, and litter size on biochemical parameters. A total of 25 clinically healthy Thuringian Forest dairy goats were monitored over one production cycle under standardized organic farming conditions. Blood samples were collected monthly from late gestation (-3 to -1 months) through 12 months of lactation, yielding 300 serum samples. Analyses included enzyme activities (alkaline phosphatase, gamma-glutamyl transferase, aspartate aminotransferase, glutamate dehydrogenase, and creatine kinase), electrolytes (sodium, potassium, calcium, phosphate, and magnesium), and metabolic indicators (glucose, cholesterol, β-hydroxybutyrate, urea, creatinine, total protein, triglycerides, and free fatty acids). Repeated measures analysis of covariance was used to assess the effects of time, lactation number, milk yield, and litter size. Marked physiological variations were observed across reproductive stages. Sodium and potassium decreased slightly prepartum and fluctuated significantly during lactation, while calcium, phosphate, and magnesium showed stage-dependent changes. Enzyme activities exhibited clear lactation-related patterns, with alkaline phosphatase increasing progressively, gamma-glutamyl transferase peaking in early lactation, and aspartate aminotransferase declining over time. Metabolic parameters demonstrated adaptive responses, including increased glucose, total protein, and cholesterol during lactation, and elevated β-hydroxybutyrate in early lactation without exceeding clinical thresholds. Milk yield significantly influenced several biochemical markers, including sodium, creatine kinase, triglycerides, and β-hydroxybutyrate, whereas litter size had minor effects, primarily on sodium and urea concentrations. No evidence of pathological alterations was detected. The study provides comprehensive longitudinal data on biochemical and metabolic adaptations in Thuringian Forest dairy goats under organic management. Lactation stage and milk yield are the primary determinants of biochemical variation, while litter size plays a limited role. These findings support the development of breed-specific reference intervals and highlight the importance of considering physiological and production factors for accurate clinical interpretation and improved herd management.