Interspecific root interaction enhances cadmium accumulation in Oryza sativa when intercropping with cadmium accumulator Artemisia argyi.

The contamination of arable land with heavy metals, such as Cd, is a serious concern worldwide. Intercropping with Cd accumulators can be used for efficient safe crop production and phytoremediation of Cd-contaminated soil. However, the effect of intercropping on Cd uptake by main crops and accumulators varies among plant combinations. Rhizosphere interaction may mediate Cd uptake by intercropped plants, but the mechanism is unclear. Thus, in the present study, we aimed to examine the effect of rhizosphere interaction on Cd uptake by intercropping rice (Oryza sativa L.) with mugwort (Artemisia argyi Levl. et Vant.) in Cd-contaminated paddy soil. We grew O. sativa and A. argyi in pots designed to allow different levels of interaction: complete root interaction (no barrier), partial root interaction (nylon mesh barrier), and no root interaction (plastic film barrier). Our results indicated that both complete and partial root interaction increased the shoot and root mass of A. argyi, but did not decrease the shoot, root, and grain mass of O. sativa. Interspecific root interaction significantly increased the Cd content in the shoots, roots, and grains of O. sativa and the shoots of A. argyi. Increased content of total organic acids in the rhizosphere, which increased the content of available Cd, was a possible mechanism of increased Cd uptake in both plants under interspecific root interaction. Our findings demonstrate that an intercropping system can extract more Cd from contaminated soil than a monocropping system of either A. argyi or O. sativa. However, the intercropping system did not facilitate safe crop production because it substantially increased grain Cd content in O. sativa.

Differential responses of ecosystem stability to climatic and anthropogenic factors in connected and isolated lake basins on the Yangtze River.

Maintaining optimal ecological security in the Yangtze River-connected and isolated lake basins is of great significance to national projects involving Yangtze River protection. Ecosystem stability and associated factors are important components of ecological security in these basins. However, few studies have focused on ecosystem stability and its driving factors over long periods in the Yangtze River Basin. In this study, a remote sensing index was used to analyze the spatiotemporal variation in the ecosystem stability of the Dongting Lake Basin (DTL), Poyang Lake Basin (PYL), and the isolated Chaohu Lake Basin (CHL) and Taihu Lake Basin (THL) in the Yangtze River over the period 2000-2022 to determine the potential affecting factors. The results showed fluctuations in the ecosystem stability of the DTL and PYL, while a V-shape was observed for the CHL and THL during the same period; the closer to the lake, the weaker the stability of the ecosystem, especially in the DTL and PYL. Moreover, the ecosystem stability was greater in the DTL and PYL than in the CHL and THL. The spillover effect of anthropogenic activities on the ecosystem stability of the four basins and the direct effect of temperature have the greatest effect on the ecosystem stability. Specifically, the ecosystem stability index for the area around the DTL and PYL decreased with increasing human interference, whereas the opposite was observed in the CHL and THL. The effect of temperature was negative for the ecosystem stability of DTL and PYL and significantly positive for CHL and THL, at a level of 0.01 %. The findings of this study provide significant information for targeted ecological restoration of the Yangtze River Basin.

The expression characteristics of cytochrome C oxidase subunit I in mitochondrial of MRL/lpr lupus mice.

OBJECTIVES: We sought to analyse the expression characteristics of cytochrome C oxidase subunit I in mitochondrial of MRL/lpr lupus mice. METHODS: The whole blood of MRL/lpr lupus mice was detected for whole mitochondrial genome sequencing performed by Illumina HiSeq PE150 instrument, compared with house mouse (NC_005089.1) and screened for the maximum difference gene, MT-CO1. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were used to detect the mRNA and protein expression of MT-CO1 in lupus mice and control mice. The total antioxidant capacities of lupus mice and control mice were measured using the rapid 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) method. RESULTS: The mitochondrial genome sequencing showed that five mitochondrial genes had base differences and MT-CO1 was the maximum difference gene, 31 in total. Among the 31 base difference sites, 2 were missense mutations and 29 were synonymous_variant. qRT-PCR test results showed that the MT-CO1 expression in lupus mouse blood was statistically lower than that in control mice blood (t=4.333; p=0.0003). Western blot test results revealed that the expression of MT-CO1 was lower in the lupus mice compared with the control mice at the protein level. Serum total antioxidant capacity testing showed that: the serum total antioxidant capacity of lupus mice was statistically lower than that of the control mice (t=9.957; p<0.0001). CONCLUSIONS: High mutation rate and decreased expression of MT-CO1 in MRL/lpr lupus mice accompanied the decrease of antioxidant capacity, which indicated that abnormal MT-CO1 might be involved in the pathogenesis of SLE and the production of anti-dsDNA antibodies.

Talaromyces marneffei infection in non-HIV-infected patients in mainland China.

BACKGROUND: Talaromyces marneffei, formerly known as Penicillium marneffei, is a significant emerging pathogenic fungus in Southeast Asia which can generate life-threatening systemic infections. Human immunodeficiency virus (HIV) infection is considered as the most underlying disease among systemic infections. However, infections due to T. marneffei without HIV are increasing in recent years. OBJECTIVES: Research the characteristics of T. marneffei infection in non-HIV individuals in mainland China. METHODS: In this study, we searched Pubmed, China National Knowledge Infrastructure (CNKI) and WanFang from inception to 31 December 2019 for studies reporting T. marneffei infection. Our research concentrates on non-HIV-infected cases and their epidemiology, clinical manifestations, laboratory findings, treatment methods and prognosis. RESULTS: T. marneffei infections in non-HIV individuals are increasing. Due to frequent present with atypical symptoms, these non-HIV-infected cases were usually misdiagnosed as other diseases, containing tuberculosis (80.7%), bacterial pneumonia (20.5%), lung cancer (5.1%) or other diseases (5.1%). CONCLUSIONS: T. marneffei infection in non-HIV individuals should be taken seriously. Their symptoms and signs are not typical. Accurate diagnosis and timely antifungal agent treatment is the key to the treatment for the disease.

Design, synthesis, and evaluation of a novel macrocyclic anti-EV71 agent.

We describe here the design, synthesis, and evaluation of a macrocyclic peptidomimetic as a potent agent targeting enterovirus A71 (EV71). The compound has a 15-membered macrocyclic ring in a defined conformation. Yamaguchi esterification reaction was used to close the 15-membered macrocycle instead of the typical Ru-catalyzed ring-closing olefin metathesis reaction. The crystallographic characterization of the complex between this compound and its target, 3C protease from EV71, validated the design and paved the way for the generation of a new series of anti-EV71 agents.

A prospective study of salvational intervention with ICS/LABA for reducing chronic obstructive pulmonary disease exacerbation under severe air pollution (SIRCAP) in Beijing: protocol of a multi-center randomized controlled trial.

BACKGROUND: Chronic Obstructive Pulmonary Disease (COPD) is a major cause of morbidity and mortality all over the world. Acute exacerbation of COPD (AECOPD) not only accelerates the progression of disease, but also causes hospital administration and death events. Epidemiologic studies have shown air pollution is a high risk factor of AECOPD. However, there are rare technics or treatment strategies recommended to reduce severe air pollution related AECOPD. METHODS: This is a multi-center, prospective, randomized and standard treatment parallel control clinical trial. Seven hundred sixty-four stable COPD patients in group B, C and D according to GOLD 2017 will be recruited and equally divided into two parallel groups, salvational intervention (SI group) and control group (CT group). Original treatments for participants include tiotropium (18µg once q.d), budesonide/formoterol (160µg/4.5µg once or twice b.i.d) or budesonide/formoterol (160µg/4.5µg once or twice b.i.d) with tiotropium (18µg once q.d). The savational intervention for SI group is routine treatment plus budesonide/formoterol (160µg/4.5µg once b.i.d) from the first day after severe air pollution (air quality index, AQI ≥200) to the third day after AQI < 200. CT group will maintain the original treatment. The intervention will last for 2 years. Primary outcome is the frequency of AECOPD per year and the secondary outcomes include the incidence of unplanned outpatient visits, emergency visits, hospitalization, medical cost and mortality associated with AECOPD per year. DISCUSSION: The salvational intervention is a novel strategy for COPD management under severe air pollution. Results of the present study will provide reference information to guide clinical practice in reducing the air pollution related exacerbation of COPD. TRIAL REGISTRATION: This study has been registered at www.ClinicalTrials.gov (registration identifier: NCT03083067 ) in 17 March, 2017.

Endoscopic therapy and curative effect in pituitary adenoma patients complicated by acromegalic cardiomyopathy.

The study aimed to retrospectively analyze the clinical characteristics of patients with pituitary adenomas complicated by acromegalic cardiomyopathy and to evaluate the effect of endoscopic surgery. Eighty-six pituitary adenoma patients complicated by acromegalic cardiomyopathy who were treated with endoscopic surgery in the First Affiliated Hospital of Soochow University from January 2010 to December 2016 were enrolled. We noted patient clinical characteristics and explored the relationships with surgical treatment. Before and after surgery, all patients underwent an examination of pituitary endocrinology, brain magnetic resonance (MR), and echocardiography. The serum levels of growth hormone (GH), left ventricular end-diastolic diameter (LVIDd), interventricular septal thickness (IVST), left ventricular posterior wall thickness (LVPWT), left ventricular ejection fraction (EF), and mitral valve (E/A ratio) were examined with non-invasive methods, and the results were compared. Of the 86 patients, there were 23 with microadenomas, 27 with large adenomas, and 36 with giant adenomas. There were 28 patients with invasive adenomas and 58 with non-invasive adenomas. The pre-operative mean GH level was 71.23 ± 3.29 µg/L, which was positively correlated with tumor volume (r = 0.751, P < 0.01). Via trans-sphenoidal endoscopic pituitary adenoma resection, 51 patients underwent total tumor resections, 25 underwent subtotal resections, 8 underwent major part resections, and 2 underwent partial resections. After surgery, the GH mean level was 3.81 ± 1.03 µg/L, which was significantly different (t = 3.72, P < 0.01) from the pre-operative level. Cardiac function indices, including LVIDd, IVST, LVPWT, E/A, and EF, were significantly improved. The long-term curative rate was 39.17% and the remission rate was 77.29%. For pituitary adenoma patients complicated by acromegalic cardiomyopathy, endoscopic surgery resulted in a good curative effect and the growth hormone levels were maintained, which can significantly improve cardiac structure and function.

Fragment-wise design of inhibitors to 3C proteinase from enterovirus 71.

BACKGROUND: Enterovirus 71 (EV71) is a causative agent of hand, foot and mouth disease (HFMD), which can spread its infection to central nervous and other systems with severe consequence. A key factor in the replication of EV71 is its 3C proteinase (3C(pro)), a significant drug target. Peptidomimetics were employed as inhibitors of this enzyme for developing antivirals. However, the peptide bonds in these peptidomimetics are a source of low bioavailability due to their susceptibility to protease digestion. To produce non-peptidomimetic inhibitors by replacing these peptide bonds, it would be important to gain better understanding on the contribution of each component to the interaction and potency. METHODS: A series of compounds of different lengths targeting 3C(pro) and having an α,ß-unsaturated ester as the warhead were synthesized and their interactions with the enzyme were evaluated by complex structure analyses and potency assays for a better understanding on the relationship between potency and evolution of interaction. RESULTS: The P2 moiety of the compound would need to be oriented to interact in the S2 site in the substrate binding cleft and the P3-P4 moieties were required to generate sufficient potency. A hydrophobic terminal group will benefit the cellular uptake and improve the activity in vivo. CONCLUSIONS AND GENERAL SIGNIFICANCE: The data presented here provide a basis for designing a new generation of non-peptidomimetics to target EV71 3C(pro).

Design, synthesis, and biological evaluation of anti-EV71 agents.

Enterovirus 71 (EV71) is a major causative agent of hand, foot and mouth disease (HFMD), which can spread its infections to the central nervous and other systems with severe consequences. In this article, design, chemical synthesis, and biological evaluation of various anti-EV71 agents which incorporate Michael acceptors are described. Further SAR study demonstrated that lactone type of Michael acceptor provided a new lead of anti-EV71 drug candidates with high anti-EV71 activity in cell-based assay and enhanced mouse plasma stability. One of the most potent compounds (2K, cell-based anti-EV71 EC50=0.028µM), showed acceptable stability profile towards mouse plasma, which resulted into promising pharmacokinetics in mouse via IP administration.

A mutation interfering with 5-lipoxygenase domain interaction leads to increased enzyme activity.

5-Lipoxygenase (5-LOX) catalyzes two steps in conversion of arachidonic acid to proinflammatory leukotrienes. Lipoxygenases, including human 5-LOX, consist of an N-terminal C2-like ß-sandwich and a catalytic domain. We expressed the 5-LOX domains separately, these were found to interact in the yeast two-hybrid system. The 5-LOX structure suggested association between Arg(101) in the ß-sandwich and Asp(166) in the catalytic domain, due to electrostatic interaction as well as hydrogen bonds. Indeed, mutagenic replacements of these residues led to loss of two-hybrid interaction. Interestingly, when Arg(101) was mutated to Asp in intact 5-LOX, enzyme activity was increased. Thus, higher initial velocity of the reaction (vinit) and increased final amount of products were monitored for 5-LOX-R101D, at several different assay conditions. In the 5-LOX crystal structure, helix α2 and adjacent loops (including Asp(166)) of the 5-LOX catalytic domain has been proposed to form a flexible lid controlling access to the active site, and lid movement would be determined by bonding of lid residues to the C2-like ß-sandwich. The more efficient catalysis following disruption of the R101-D166 ionic association supports the concept of such a flexible lid in human 5-LOX.

Inulin Reduces Kidney Damage in Type 2 Diabetic Mice by Decreasing Inflammation and Serum Metabolomics.

This study is aimed at assessing the impact of soluble dietary fiber inulin on the treatment of diabetes-related chronic inflammation and kidney injury in mice with type 2 diabetes (T2DM). The T2DM model was created by feeding the Institute of Cancer Research (ICR) mice a high-fat diet and intraperitoneally injecting them with streptozotocin (50 mg/kg for 5 consecutive days). The thirty-six ICR mice were divided into three dietary groups: the normal control (NC) group, the T2DM (DM) group, and the DM + inulin diet (INU) group. The INU group mice were given inulin at the dose of 500 mg/kg gavage daily until the end of the 12th week. After 12 weeks, the administration of inulin resulted in decreased serum levels of fasting blood glucose (FBG), low-density lipoprotein cholesterol (LDL-C), blood urea nitrogen (BUN), and creatinine (CRE). The administration of inulin not only ameliorated renal injury but also resulted in a reduction in the mRNA expressions of inflammatory factors in the spleen and serum oxidative stress levels, when compared to the DM group. Additionally, inulin treatment in mice with a T2DM model led to a significant increase in the concentrations of three primary short-chain fatty acids (SCFAs) (acetic acid, propionic acid, and butyric acid), while the concentration of advanced glycation end products (AGEs), a prominent inflammatory factor in diabetes, exhibited a significant decrease. The results of untargeted metabolomics indicate that inulin has the potential to alleviate inflammatory response and kidney damage in diabetic mice. This beneficial effect is attributed to its impact on various metabolic pathways, including glycerophospholipid metabolism, taurine and hypotaurine metabolism, arginine biosynthesis, and tryptophan metabolism. Consequently, oral inulin emerges as a promising treatment option for diabetes and kidney injury.

Structures of Enterovirus 71 3C proteinase (strain E2004104-TW-CDC) and its complex with rupintrivir.

The crystal structure of 3C proteinase (3C(pro)) from Enterovirus 71 (EV71) was determined in space group C2221 to 2.2 Šresolution. The fold was similar to that of 3C(pro) from other picornaviruses, but the difference in the ß-ribbon reported in a previous structure was not observed. This ß-ribbon was folded over the substrate-binding cleft and constituted part of the essential binding sites for interaction with the substrate. The structure of its complex with rupintrivir (AG7088), a peptidomimetic inhibitor, was also characterized in space group P212121 to 1.96 Šresolution. The inhibitor was accommodated without any spatial hindrance despite the more constricted binding site; this was confirmed by functional assays, in which the inhibitor showed comparable potency towards EV71 3C(pro) and human rhinovirus 3C(pro), which is the target that rupintrivir was designed against.

Genetic model of selective COX2 inhibition reveals novel heterodimer signaling.

Selective inhibitors of cyclooxygenase-2 (COX2) have attracted widespread media attention because of evidence of an elevated risk of cardiovascular complications in placebo-controlled trials, resulting in the market withdrawal of some members of this class. These drugs block the cyclooxygenase activity of prostaglandin H synthase-2 (PGHS2), but do not affect the associated peroxidase function. They were developed with the rationale of conserving the anti-inflammatory and analgesic actions of traditional nonsteroidal anti-inflammatory drugs (tNSAIDs) while sparing the ability of PGHS1-derived prostaglandins to afford gastric cytoprotection. PGHS1 and PGHS2 coexist in the vasculature and in macrophages, and are upregulated together in inflammatory tissues such as rheumatoid synovia and atherosclerotic plaque. They are each believed to function as homodimers. Here, we developed a new genetic mouse model of selective COX2 inhibition using a gene-targeted point mutation, resulting in a Y385F substitution. Structural modeling and biochemical assays showed the ability of PGHS1 and PGHS2 to heterodimerize and form prostaglandins. The heterodimerization of PGHS1-PGHS2 may explain how the ductus arteriosus closes normally at birth in mice expressing PGHS2 Y385F, but not in PGHS2-null mice.

Potential risk of eutrophication in the deepest lake of Southwest China: Insights from phosphorus enrichment in bottom water.

Large deep lakes in plateau regions provide crucial ecosystem services but are susceptible to eutrophication due to their long water residence time. To date, the water quality of deep lakes has not received as much attention as that of shallow lakes owing to logistical challenges. This study investigated the seasonal variation and vertical distribution of phosphorus and related environmental variables in a large deep lake in the Yunnan Plateau, China (Fuxian Lake). Generally, the concentrations of total phosphorus (TP, R2 = 0.862), total dissolved phosphorus (TDP, R2 = 0.922), and dissolved inorganic phosphorus (DIP, R2 = 0.889) exhibited a linear increase with the greater water depth, whereas the pH and dissolved oxygen (DO) showed decreasing trends. The TP, TDP, and DIP values were 0.012, 0.006, and 0.004 mg/L, respectively, in surface waters (0.5 m depth), and increased to 0.074, 0.065, and 0.062 mg/L, respectively, at 140.0 m depth. The averaged over ordering method demonstrated that DO and air temperature accounted for a higher proportion of the explained variance of TP, TDP, and DIP in the shallow water layer (0.5-20.0 m). In contrast, DO and pH accounted for a higher proportion of the explained variance of TP, TDP, and DIP in deeper water layers (40.0-150.0 m). As a warm monomictic lake, the higher observed phosphorus concentrations in deeper water and sediment potentially pose a risk of future eutrophication in the Fuxian Lake. Our findings demonstrate that more efficient technical and management measures should be taken to reduce the external phosphorus load to Fuxian Lake, so that the load to and from the sediment will decrease eventually.

Concurrent effects of flooding regimes and floodwater quality on sediment properties in a Yangtze River-connected floodplain wetland: Insights from field investigations during 2011-2020.

Changes in flood regimes, floodwater quality, and macrophyte types may affect sediment characteristics post-flooding. However, few studies have attempted to unravel their complex influences in floodplain wetlands. From 2011 to 2020, the physical and chemical properties of surface layer sediment pre- and post-flooding was investigated through field surveys in the Dongting Lake wetland. Results indicated that the pre-flooding soil total phosphorus (TP) and total nitrogen (TN) exhibited an increasing trend during 2011-2020. Soil TP increased post-flooding relative to that pre-flooding. The changes in TN, sediment organic matter (SOM), sediment moisture content (SMC), and sediment bulk density (SBD) fluctuated over the years. The best-fitting multi-regression model demonstrated that the changes in sediment variables post-flooding showed a parabolic trajectory along the inundation duration (ID), except for SMC. Changes in soil properties post-flooding were negatively correlated with ID for sediment with a low IDs (<148 days). Meanwhile, changes in soil properties post flooding were positively correlated with ID for sediment with a high IDs (>193 days). Changes in SBD and SOM post-flooding were positively influenced by the TP content in the floodwater. These findings indicate that changes in the flooding regime, and water quality generated by anthropogenic disturbances such as the Three Gorges Dam significantly affect sediment properties, and subsequently influence the ecological functions of the Dongting Lake wetland.

Corrigendum: Wildlife is a potential source of human infections of Enterocytozoon bieneusi and Giardia duodenalis in southeastern China.

[This corrects the article DOI: 10.3389/fmicb.2021.692837.].

Inter-annual and intra-annual variations in water quality and its response to water-level fluctuations in a river-connected lake, Dongting Lake, China.

The hydrological conditions of river-connected lakes are complex primarily owing to their considerable water-level fluctuations (WLFs). Water quality in such lakes varies with hydrodynamic variations; however, their relationship is not clear. To identify the unique relationship between water level and water quality in river-connected lakes, we used the comprehensive pollution index (CPI) and regression analysis to analyze the spatiotemporal variation in water quality in Dongting Lake from 2015 to 2018 and the effects of water level on water quality. Four water quality parameters were selected: total nitrogen (TN), total phosphorus (TP), permanganate index (CODMn), and chlorophyll a (Chl-a). The results showed significant spatial variation in the lake water quality, with relatively high concentrations of TN, TP, CODMn, and Chl-a in East Dongting Lake. TN and TP decreased by 12.15% and 37.61%, respectively, from 2015 to 2018, whereas CODMn increased from 1.781 to 2.009 mg/L. Seasonally, TN and TP concentrations were low in the summer and autumn, with high concentrations in the winter and spring. In contrast, CODMn and Chl-a concentrations exhibited opposite trends. The pollution level in Dongting Lake ranged between slightly and moderately polluted, with a CPI ranging from 0.76 to 1.32 across all sampling sites during 2015-2018. The water level in Dongting Lake initially increased and, then, decreased in a year, with marked WLFs owing to seasonal shifts in precipitation and human activities. The water level had significant negative relationships with TN and TP concentrations and a significant positive relationship with CODMn concentration (p < 0.05). Based on the results, strict control of excessive external nutrient loading should be actively implemented in Dongting Lake, in addition to hydrological regulation for effective lake water quality management.

Belowground seed and bud banks play complementary roles in the potential recruitment of dominant macrophyte communities in a Yangtze River-connected floodplain wetland.

Both seed and bud banks play important roles in the recruitment and maintenance of macrophyte communities; however, few studies have investigated them simultaneously. We investigated the abundance, species composition, and seasonal patterns of seed and bud banks in two dominant macrophyte communities, Carex and Miscanthus, in the Dongting Lake wetlands. The seed densities of both communities were lower from November (after flooding) to March and increased dramatically before flooding (in May). The bud densities of the two dominant communities peaked in the coldest month of the year (January), decreased markedly in March, and were the lowest before flooding. The seed banks of the two macrophyte communities were mainly composed of annual species and a few perennial species, whereas the bud banks were composed of only dominant perennials. Furthermore, the perennial species present in bud banks did not occur in seed banks. Among the soil variables, the bud densities of both plant communities were negatively associated with soil bulk density, whereas the seed density of the Miscanthus community was positively associated with soil bulk density. Our results suggest that seed and bud banks are complementary in the potential recruitment of macrophyte communities; that is, bud banks regulate the demography of dominant perennials, and seed banks contribute to the recruitment and dispersal of annual species. Given the high abundance of annuals and near absence of the most dominant perennials in the seed bank, the bud banks of dominant perennial species should be more widely used in wetland restoration and management.

Exploring the relative contribution of flood regimes and climatic factors to Carex phenology in a Yangtze River-connected floodplain wetland.

Hydrological regimes can combine with climatic factors to affect plant phenology; however, few studies have attempted to quantify their complex influences on plant phenology in floodplain wetlands. We obtained phenological information on Carex vegetation through MODIS normalized difference vegetation index (NDVI) data during 2001-2020, and monthly field investigation during 2011-2020. We then explored how these data were correlated with climatic factors and flood regimes in a Yangtze River-connected floodplain wetland (Dongting Lake, China). Our results showed that warmer temperature tended to advance the start of the pre-flooding growing season (SOS1), with a relative contribution of 76.1 %. Flood rising time strongly contributed to controlling the end of the pre-flooding growing season. Flood recession time and inundation duration were dominant factors determining the start of the post-flooding growing season (SOS2). Earlier flood recession time and shortened inundation duration tended to advance the SOS2. Shortened inundation duration, earlier flood recession time, and lower solar radiation tended to advance the end of the post-flooding growing season. The phenology of Carex distributed at high-elevation areas was more affected by hydrology than that of Carex distributed at low-elevation areas. Thus, climatic factors strongly affect the phenology of Carex during the pre-flooding growing season, whereas flood regimes play a dominant role in determining the phenology in the post-flooding growing season. The different responses of Carex phenology to climatic and flooding factors may provide insights for the conservation and management of floodplain wetlands in Yangtze River because Carex are primary food source and habitat for herbivorous waterfowls.

Dyke demolition led to a sharp decline in waterbird diversity due to habitat quality reduction: A case study of Dongting Lake, China.

Dongting Lake, an important wintering habitat for migratory waterbirds in the East Asian-Australasian Flyway, has suffered serious degradation in recent decades. To restore habitats for biodiversity conservation and flood control, 459 dykes were demolished and 14 were preserved in 2017. However, the direct impact of dyke demolition on wintering waterbirds was not comprehensively assessed. In this study, based on annual waterbird census and habitat data (2013/14-2020/21), we compared the differences in habitat areas and species composition of waterbirds in the dyke-demolished and preserved areas, and explored whether habitat changes caused by the dyke demolition were responsible for the changes in the number of species and percentages of waterbird individuals. The results indicate that the areas of water (including shallow water) and mudflat habitats significantly decreased, but the vegetation area significantly increased in the dyke-demolished areas. The species numbers and percentages of waterbird individuals at the community and foraging guilds levels, and the percentages of nine species, were higher in the dyke-preserved areas than those in the dyke-demolished areas. Changes in the numbers of species and percentages of individuals of fish eaters, insectivores, and omnivores positively correlated with drastic changes in the percentages of water habitats (including shallow water) after dyke demolition. Effective measures should be carried out to restore hydrological regimes, providing waterbirds sufficient suitable habitats with different water depths. These findings improve our understanding of the influence of dyke demolition on waterbirds and provide insights for wetland management and waterbird conservation.