{"title":"Sedimentary organic matter load influences the ecological effects of submerged macrophyte restoration through rhizosphere metabolites and microbial communities.","authors":"Chuan Wang, Jianglong Zhu, Huihui Wang, Liping Zhang, Yahua Li, Yi Zhang, Zhenbin Wu, Qiaohong Zhou","doi":"10.1016/j.scitotenv.2024.175419","DOIUrl":"10.1016/j.scitotenv.2024.175419","url":null,"abstract":"<p><p>Organic matter (OM) accumulation in lake sediments has doubled owing to human activities over the past 100 years, which has negatively affected the restoration of submerged vegetation and ecological security. Changes in the pollution structure of sediments caused by plant recovery and rhizosphere chemical processes under different sediment OM levels are the theoretical basis for the rational application of plant rehabilitation technology in lake management. This study explored how Vallisneria natans mediates changes in sediment N and P through rhizospheric metabolites and microbial community and function under low (4.94 %) and high (17.35 %) sediment OM levels. V. natans promoted the accumulation of NH<sub>4</sub>-N in the high-OM sediment and the transformation of Fe/Al-P to Ca-P in the low-OM sediment. By analyzing 63 rhizospheric metabolites and the sediment microbial metagenome, the metabolites lactic acid and 3-hydroxybutyric acid and the genus Anammoximicrobium were found to mediate NH<sub>4</sub>-N accumulation in the high-OM sediment. Additionally, 3-hydroxy-decanoic acid, adipic acid, and the genus Bdellovibrionaceae mediated the transformation of Fe/Al-P to Ca-P in the low-OM sediment. The growth of V. natans enriched the abundance of functional genes mediating each step from nitrate to ammonia and the genes encoding urease in the high-OM sediment, and it up-regulated three genes related to microbial phosphorus uptake in the low-OM sediment. This study revealed the necessity of controlling endogenous pollution by recovering submerged macrophytes under high- and low-OM conditions from the perspective of the transformation of inorganic nitrogen and phosphorus.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141915793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Unsustainable production patterns and disease emergence: The paradigmatic case of Highly Pathogenic Avian Influenza H5N1.","authors":"Pablo I Plaza, Sergio A Lambertucci","doi":"10.1016/j.scitotenv.2024.175389","DOIUrl":"10.1016/j.scitotenv.2024.175389","url":null,"abstract":"<p><p>Current food production systems are causing severe environmental damage, including the emergence of dangerous pathogens that put humans and wildlife at risk. Several dangerous pathogens (e.g., the 2009 A(H1N1) Influenza Virus, Nipah virus) have emerged associated with the dominant intensive food production systems. In this article, we use the case of the emergence and spillover of the Highly Pathogenic Avian Influenza virus H5N1 (hereafter, H5N1) to illustrate how intensive food production methods provide a breeding ground for dangerous pathogens. We also discuss how emerging pathogens, such as H5N1, may affect not only ecosystem health but also human well-being and the economy. The current H5N1 panzootic (2020-2024) is producing a catastrophic impact: the millions of domestic birds affected by this virus have led to significant economic losses globally, and wild birds and mammals have suffered alarming mortalities, with the associated loss of their material and non-material ecosystem services. Transformative actions are required to reduce the emergence and impact of pathogens such as H5N1; we particularly need to reconsider the ways we are producing food. Governments should redirect funds to the promotion of alternative production systems that reduce the risk of new emerging pathogens and produce environmentally healthy food. These systems need to have a positive relationship with nature rather than being systems based on business as usual to the detriment of the environment. Sustainable food production systems may save many lives, economies, and biodiversity, together with the ecosystem services species provide.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141970322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Annika Dose, Winn Jason Kennington, Jonathan Paul Evans
{"title":"Heat stress mediates toxicity of rutile titanium dioxide nanoparticles on fertilisation capacity in the broadcast spawning mussel Mytilus galloprovincialis.","authors":"Annika Dose, Winn Jason Kennington, Jonathan Paul Evans","doi":"10.1016/j.scitotenv.2024.175567","DOIUrl":"10.1016/j.scitotenv.2024.175567","url":null,"abstract":"<p><p>Titanium dioxide nanoparticle (nTiO<sub>2</sub>) pollution of marine environments is rapidly increasing with potentially deleterious effects on wildlife. Yet, the impacts of nTiO<sub>2</sub> on reproduction remain poorly understood. This is especially the case for broadcast spawners, who are likely to be more severely impacted by environmental disturbances because their gametes are directly exposed to the environment during fertilisation. In addition, it is unclear whether rising water temperatures will further exacerbate the impact of nTiO<sub>2</sub> toxicity. Here, in a series of fertilisation trials, we systematically examine the main and interactive effects of nTiO<sub>2</sub> exposure and seawater temperature on fertilisation success in the Mediterranean mussel Mytilus galloprovincialis. Specifically, our fertilisation trials explored whether nTiO<sub>2</sub> exposure influences fertilisation rates when (i) eggs alone are exposed, (ii) both sperm and eggs are exposed simultaneously, and (iii) whether increases in seawater temperature interact with nTiO<sub>2</sub> exposure to influence fertilisation rates. We also ask whether changes in nTiO<sub>2</sub> concentrations influence key sperm motility traits using computer-assisted sperm analysis (CASA). In fertilisation trials for treatment groups (i) and (ii), we found no main effects of nTiO<sub>2</sub> at environmentally relevant concentrations of 5, 10 and 50 μg L<sup>-1</sup> on fertilisation capacity relative to the control. Consistent with these findings, we found no effect of nTiO<sub>2</sub> exposure on sperm motility. However, in treatment group (iii), when fertilisation trials were conducted at higher temperatures (+6 °C), exposure of gametes from both sexes to 10 μg L<sup>-1</sup> nTiO<sub>2</sub> led to a reduction in fertilisation rates that was significantly greater than when gametes were exposed to elevated temperature alone. These interacting effects of nTiO<sub>2</sub> exposure and seawater temperature demonstrate the toxic potential of nTiO<sub>2</sub> for fertilisation processes in a system that is likely to be impacted heavily by predicted future increases in sea surface temperatures.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141994996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Antibiotic resistome dynamics in agricultural river systems: Elucidating transmission mechanisms and associated risk to water security.","authors":"Tong Chen, Ziwei Wang, Xiaohong Ruan","doi":"10.1016/j.scitotenv.2024.175580","DOIUrl":"10.1016/j.scitotenv.2024.175580","url":null,"abstract":"<p><p>Usage of antibiotics in agriculture has increased dramatically recently, significantly raising the influx of antibiotic resistance genes (ARGs) into river systems through organic manure runoff, seriously threatening water security. However, the dynamics, transmission mechanisms, and potential water security risk of ARGs, as well as their response to land use spatial scale and seasonal variations in agricultural river systems remain unclear. To address these challenges, this work employed metagenomic technique to systematically evaluate the pollution and dissemination of ARGs in overlying water and sediment within a typical agricultural catchment in China. The results demonstrated significant differences between overlying water and sediment ARGs. Overlying water dominated by multidrug ARGs exhibited higher diversity, whereas sediment predominantly containing sulfonamide ARGs had higher abundance. The dynamics of ARGs in overlying water were more responsive to seasonal variations compared to sediment due to greater changes in hydrodynamics and nutrient conditions. The profiles of ARGs in overlying water were largely regulated by microbiota, whereas mobile genetic elements (MGEs) were the main forces driving the dissemination of ARGs in sediment. The variation in dissemination mechanisms led to different resistance risks, with sediment presenting a higher resistance risk than overlying water. Furthermore, Mantel test was applied to discover the impact of land use spatial scale and composition on the transmission of ARGs in river systems. The findings showed that cultivated land within 5 km of the riverbank was the key influencing factor. Cultivated land exacerbated ARGs spread by increasing MGEs abundance and nutrient concentrations, resulting in the abundance of ARGs in high-cultivated sites being twice that in low-cultivated sites, and raising the regional water security risk, with a more pronounced effect in sediment. These findings contribute to a better understanding of ARGs dissemination in agricultural watersheds, providing a basis for implementing effective resistance control measures and ensuring water security.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141995012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jingye Tan, Jun Wang, Haikun Wang, Zhu Liu, Ning Zeng, Ran Yan, Xinyu Dou, Xunmei Wang, Meirong Wang, Fei Jiang, Hengmao Wang, Weimin Ju, Jing M Chen
{"title":"Influence of extreme 2022 heatwave on megacities' anthropogenic CO<sub>2</sub> emissions in lower-middle reaches of the Yangtze River.","authors":"Jingye Tan, Jun Wang, Haikun Wang, Zhu Liu, Ning Zeng, Ran Yan, Xinyu Dou, Xunmei Wang, Meirong Wang, Fei Jiang, Hengmao Wang, Weimin Ju, Jing M Chen","doi":"10.1016/j.scitotenv.2024.175605","DOIUrl":"10.1016/j.scitotenv.2024.175605","url":null,"abstract":"<p><p>An unprecedented heatwave hit the Yangtze River Basin (YRB) in August 2022. We analyzed changes of anthropogenic CO<sub>2</sub> emissions in 8 megacities over lower-middle reaches of the YRB, using a near-real-time gridded daily CO<sub>2</sub> emissions dataset. We suggest that the predominant sources of CO<sub>2</sub> emissions in these 8 megacities are from the power and industrial sectors. In comparison to the average emissions for August in 2020 and 2021, the heatwave event led to a total increase in power sector emissions of approximately 2.70 Mt CO<sub>2</sub>, potentially due to the increase in urban cooling demand. Suzhou experienced the largest increase, with a rise of 1.12 Mt CO<sub>2</sub> (12.88 %). Importantly, we observed that changes in daily power emissions exhibited strong linear relationships with temperatures during the heatwave, albeit varying sensitivities across different megacities (with an average of 0.0076 ± 0.0075 Mt d<sup>-1</sup> °C<sup>-1</sup>). Conversely, we find that industrial emissions decreased by a total of 8.45 Mt CO<sub>2</sub>, with Shanghai seeing the largest decrease of 4.71 Mt CO<sub>2</sub>, while Hangzhou experienced the largest relative decrease (-21.22 %). It is noteworthy that the majority of megacities rebounded in industrial emissions following the conclusion of the heatwave. We convincingly suggest a tight linkage between the reductions in industrial emissions and China's policy to ensure household power supply. Overall, the reduction in industrial emissions offset the increase in power sector emissions, resulting in weaker emissions for majority of megacities during the heatwave. Despite remaining uncertainties in the emissions data, our study may offer valuable insights into the complexities of anthropogenic CO<sub>2</sub> emissions in megacities amidst frequent summer heatwaves intensified by greenhouse warming.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141999157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cyclic methylsiloxanes in wastewater treatment plants: Occurrence, emissions, environmental distributions, and occupational exposure.","authors":"Kaixin Dong, Ying Zhou, Junyu Guo, Yao Jiang, Boya Zhang, Yifei Wang, Yuan Chen","doi":"10.1016/j.scitotenv.2024.175524","DOIUrl":"10.1016/j.scitotenv.2024.175524","url":null,"abstract":"<p><p>Cyclic methylsiloxanes (CMSs), widely found in wastewater treatment plants (WWTPs), are potentially hazardous to the environment and human health. In this study, the environmental behavior and human exposure risks of three CMSs (D4-D6) were evaluated in WWTPs located in Beijing and Kunming, Yunnan province. D5 had the highest concentrations in air, water, and sludge, with seasonal variation that consisted of a high concentration in summer and low concentration in winter. The CMS concentrations in air were 3-4-fold higher in the A<sup>2</sup>/O (Anaerobic-Anoxic-Oxic) treatment units than in the other units. CMS emissions to air, soil, and water from the Beijing WWTP were in the ranges of 3.4 × 10<sup>4</sup>-5.0 × 10<sup>4</sup> kg·a<sup>-1</sup>, 4.5 × 10<sup>2</sup>-7.5 × 10<sup>2</sup> kg·a<sup>-1</sup>, and 2.5 × 10<sup>2</sup>-2.9 × 10<sup>2</sup> kg·a<sup>-1</sup>, constituting 98 %, 1.3 %, and 0.7 % of the total emissions, respectively. Total daily inhalation exposure doses of CMSs (ADD<sub>inh,CMSs</sub>) associated with four different jobs in WWTPs showed that wastewater treatment technicians had the highest ADD<sub>inh,CMSs</sub> (51 μg/kg/day), indicating that these people had the highest occupational exposure risk in WWTPs. Therefore, this study identified that atmospheric emission was the main environmental fate of CMSs in WWTPs, and provide a basis for the improvement of WWTP process and risk management decisions. ENVIRONMENTAL IMPLICATION: Assessing the environmental fate and occupational exposure risk of cyclic methylsiloxanes (CMSs) found in wastewater treatment plants (WWTPs) is crucial. This is the first study to identify that atmospheric emission was the main environmental fate of CMSs in WWTPs, especially D5; the inhalation exposure doses of CMSs were all significantly higher in the occupational population working in WWTPs. The results described in our study will help enhance the understanding of current knowledge base of environmental fate and exposure risk of CMSs in WWTPs, and provide a basis for the improvement of WWTP process and risk management decisions.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141999182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C F Rutkoski, I Vergara-Luis, E Urionabarrenetxea, N García-Velasco, B Zaldibar, M Anza, M Olivares, A Prieto, L Epelde, C Garbisu, E A Almeida, M Soto
{"title":"Effects of sulfamethazine and tetracycline at molecular, cellular and tissue levels in Eisenia fetida earthworms.","authors":"C F Rutkoski, I Vergara-Luis, E Urionabarrenetxea, N García-Velasco, B Zaldibar, M Anza, M Olivares, A Prieto, L Epelde, C Garbisu, E A Almeida, M Soto","doi":"10.1016/j.scitotenv.2024.175579","DOIUrl":"10.1016/j.scitotenv.2024.175579","url":null,"abstract":"<p><p>Soil contamination by antibiotics is a global issue of great concern that contributes to the rise of bacterial antibiotic resistance and can have toxic effects on non-target organisms. This study evaluated the variations of molecular, cellular, and histological parameters in Eisenia fetida earthworms exposed to sulfamethazine (SMZ) and tetracycline (TC), two antibiotics commonly found in agricultural soils. The earthworms were exposed for 14 days to a series of concentrations (0, 10, 100, and 1000 mg/kg) of both antibiotics. SMZ and TC did not affect the survival of E. fetida, however, other effects at different levels of biological complexity were detected. The two highest concentrations of SMZ reduced the viability of coelomocytes. At the highest TC concentration, there was a noticeable decline in cell viability, acetylcholinesterase activity (neurotoxicity), and the relative presence of mucopolysaccharides in the epidermis (mucous production). Glutathione S-transferase activity decreased in all TC treatments and at the highest SMZ concentration. However, levels of malondialdehyde and protein carbonyls did not change, suggesting an absence of oxidative stress. Tetracycline was neurotoxic to E. fetida and changed the integrity of the epidermis. Both antibiotics altered the intestinal microbiota of E. fetida, leading to a reduction in the relative abundance of bacteria from the phyla Proteobacteria and Bacteroidetes, while causing an increase in the phylum Actinobacteroidota. All observed changes indicate that both SMZ and TC can disrupt the earthworms' immune system and gut microbiome, while fostering the growth of bacteria that harbour antibiotic resistance genes. Finally, both antibiotics exerted additional metabolic and physiological effects that increased the vulnerability of E. fetida to pathogens.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141999184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Woo-Jin Shin, Dong-Chan Koh, Bernhard Mayer, Hong-Il Kwon, Ji-Hoon Kim, Kwang-Sik Lee
{"title":"Effect of intensive seasonal pumping and recharge on sulfur biogeochemistry in groundwater of agricultural riparian zones.","authors":"Woo-Jin Shin, Dong-Chan Koh, Bernhard Mayer, Hong-Il Kwon, Ji-Hoon Kim, Kwang-Sik Lee","doi":"10.1016/j.scitotenv.2024.175618","DOIUrl":"10.1016/j.scitotenv.2024.175618","url":null,"abstract":"<p><p>Physico-chemical characteristics of groundwater are often impacted by agricultural practices such as land use, fertilizer types, and groundwater pumping. This study aimed to identify contaminant sources and redox processes controlling the hydrogeochemistry of groundwater in riparian zones influenced by intensive agricultural activities, focusing on sulfur species. Groundwater samples were collected bimonthly from March 2014 to March 2015 from groundwater wells in two zones in South Korea with different agricultural systems. The water isotopic compositions of the groundwater indicated that all groundwater originated from the same meteoric water. Groundwater samples affected by periodic groundwater pumping exhibited wide variations in Mn<sup>2+</sup> (47.8 ± 18.2 μM) and Fe<sup>2+</sup> (123 ± 61.0 μM) and elevated SO<sub>4</sub><sup>2-</sup>, while NO<sub>3</sub><sup>-</sup> was below the detection limit. Groundwater chemistry was affected by fertilizer and manure, and denitrification. The oxidation of reduced sulfur compounds by oxygen and nitrate did not fully account for the elevated SO<sub>4</sub><sup>2-</sup> concentrations and isotopic composition of sulfate (δ<sup>34</sup>S and δ<sup>18</sup>O) in the investigated aquifers. Therefore, we postulate that water level change due to periodic groundwater pumping and recharge enabled oxidants (MnO<sub>2</sub> and Fe<sup>3+</sup>) to also contribute to oxidation of reduced sulfur. Additionally, fertilizers with distinct δ<sup>34</sup>S values and bacterial sulfate reduction (BSR) affected groundwater chemistry and its sulfur species, including δ<sup>34</sup>S<sub>SO4</sub> and δ<sup>18</sup>O<sub>SO4</sub>. Removal of sulfate from the aquifer during pumping limited BSR. Consequently, the agricultural practices may further increase sulfate concentrations in the groundwater. This environmental impact should be thoroughly managed because high sulfate concentrations in drinking water cause ingestion problems in humans.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142003253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shimin Yang, Yuanting Ma, Jie Gao, Xiajie Wang, Futian Weng, Yan Zhang, Yan Xu
{"title":"Exploring the response and prediction of phytoplankton to environmental factors in eutrophic marine areas using interpretable machine learning methods.","authors":"Shimin Yang, Yuanting Ma, Jie Gao, Xiajie Wang, Futian Weng, Yan Zhang, Yan Xu","doi":"10.1016/j.scitotenv.2024.175600","DOIUrl":"10.1016/j.scitotenv.2024.175600","url":null,"abstract":"<p><p>Coastal marine areas are frequently affected by human activities and face ecological and environmental threats, such as algal blooms and climate change. The community structure of phytoplankton-primary producers in marine ecosystems-is highly sensitive to environmental factors, such as temperature, salinity, and nutrients. However, traditional methods for exploring the relationship between phytoplankton communities and environmental factors in eutrophic marine areas are limited by various factors. Therefore, this study employed interpretable machine learning models, integrating high-dimensional data analysis and complex system modeling, to quantitatively and thoroughly analyze the dynamic relationship between phytoplankton communities and environmental variables in high-frequency samples collected over 53 weeks from eutrophic marine areas. The cell abundance of phytoplankton exhibited a distinct \"two-peak pattern\" variation. Interpretable machine learning model analysis revealed the dynamic contributions of different environmental factors during changes in the phytoplankton community structure. The results showed that temperature was a key environmental factor that affected phytoplankton growth during peak periods. In addition, the contribution of salinity increased during the second peak in phytoplankton abundance, highlighting its central role in the ecological dynamics of this phase. During green tide outbreaks, particularly in Area 01, the contributions of factors such as temperature and salinity increased, whereas those of phosphates and silicates decreased, indicating that green tide outbreaks substantially altered the nutritional dynamics of the ecosystem. Furthermore, different phytoplankton species, such as Skeletonema costatum, Thalassiosira spp., and Nitzschia spp., exhibit varying responses to environmental factors. Hence, the predictions made using random forest and generalized additive models for phytoplankton cell abundance in two marine areas revealed complex nonlinear relationships between environmental factors, such as temperature, salinity, and phytoplankton abundance.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142003255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christina L Marley, Rhun Fychan, John W Davies, Mark Scott, Felicity V Crotty, Ruth Sanderson, John Scullion
{"title":"Grasslands and flood mitigation - Contrasting forages improve surface water infiltration rates.","authors":"Christina L Marley, Rhun Fychan, John W Davies, Mark Scott, Felicity V Crotty, Ruth Sanderson, John Scullion","doi":"10.1016/j.scitotenv.2024.175598","DOIUrl":"10.1016/j.scitotenv.2024.175598","url":null,"abstract":"<p><p>Grasslands globally deliver many ecosystem services, including water management to alleviate flood risk reduction. Two replicated field experiments were conducted to study how agricultural forage species with diverse rooting systems, sown as single species, affected rooting, soil structure and earthworm populations, and consequently water infiltration to understand how they each might influence flood risk from grasslands. Experiment One showed soils under red clover (Trifolium pratense), white clover (Trifolium repens) and chicory (Cichorium intybus) had higher infiltration rates three years after establishment, compared to perennial ryegrass (Lolium perenne). Higher red clover and chicory root biomass or increased earthworm abundance under white clover may have caused these effects. Experiment Two monitored infiltration at intervals over several years post establishment to understand the timeframe for changes in rates; plantain (Plantago lanceolata) was sown as an additional forage. Infiltration declined post establishment, the timing and extent of decline varying with forages; forage effects were significant after 27 months (P < 0.05). Infiltration rates were higher under red and white clover compared to ryegrass, with chicory and plantain intermediate (P < 0.05). Forages again differed in likely mechanisms delivering higher water infiltration, notably between the two clover species. White clover had higher earthworm biomass (P < 0.05), whereas red clover had a higher average root diameter compared to the other forages (P < 0.05). Drivers of intermediate benefits of chicory and plantain also differed: chicory had higher earthworm abundance (month 38) compared to plantain, which had higher average root diameter compared to ryegrass (month 41); 30 months post-establishment soil bulk density was lower under both forages compared to ryegrass and red clover, with white clover intermediate (P < 0.05); bulk density and penetration resistance did not relate to infiltration. Findings demonstrate that a shift from perennial ryegrass-dominated pastures to swards with more contrasting forages provides an ecohydrological approach to mitigating flood risk and climate adaptation.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142003256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}