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1.
Front Microbiol ; 15: 1347016, 2024.
Article in English | MEDLINE | ID: mdl-38650869

ABSTRACT

Global warming has contributed to shifts in precipitation patterns and increased plant productivity, resulting in a significant increase in litter input into the soils. The enhanced litter input, combined with higher levels of precipitation, may potentially affect soil microbial communities. This study aims to investigate the effects of litter input and increased precipitation on soil microbial biomass, community structure, and diversity in a temperate meadow steppe in northeastern China. Different levels of litter input (0%, +30%, +60%) and increased precipitation (0%, +15%, +30%) were applied over a three-year period (2015-2017). The results showed that litter input significantly increased the biomass of bacteria and fungi without altering their diversity, as well as the ratio of bacterial to fungal biomass. Increased precipitation did not have a notable effect on the biomass and diversity of bacteria and fungi, but it did increase the fungal-to-bacterial biomass ratio. However, when litter input and increased precipitation interacted, bacterial diversity significantly increased while the fungal-to-bacterial biomass ratio remained unchanged. These findings indicate that the projected increases in litter and precipitation would have a substantial impact on soil microbial communities. In energy-and water-limited temperate grasslands, the additional litter inputs and increased precipitation contribute to enhanced nutrient and water availability, which in turn promotes microbial growth and leads to shifts in community structure and diversity.

2.
Plants (Basel) ; 13(5)2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38475512

ABSTRACT

Grassland management affects soil respiration (Rs, consists of heterotrophic respiration and autotrophic respiration) through soil micro-ecological processes, such as hydrothermal, plant root, organic carbon decomposition and microbial activity. Flooding, an irregular phenomenon in grasslands, may strongly regulate the response of soil respiration and its components to grassland management, but the regulatory mechanism remains unclear. We conducted a 3-year experiment by grassland management (fencing and grazing) and flooding conditions (no flooding (NF), short-term flooding (STF) and long-term flooding (LTF)) to study their effects on Rs and its components in a meadow steppe in the Hui River basin of Hulunbuir. We found differences in the patterns of Rs and its components under grassland management and flooding conditions. In 2021-2023, the temporal trends of Rs, heterotrophic respiration (Rh) and autotrophic respiration (Ra) were generally consistent, with peaks occurring on days 190-220, and the peaks of grazing were higher than that of fencing. In NF, Rs of grazed grassland was significantly higher than that of fenced grassland in 2021-2022 (p < 0.05). In STF and LTF, there was no significant difference in Rs between fenced and grazed grassland (p > 0.05). The dependence of Rs on soil temperature (ST) decreased with increasing flooding duration, and the dependence of Rs on ST of grazed grassland was higher than fenced grassland under NF and STF, but there was no difference between fenced grassland and grazed grassland under LTF. In addition, Rh was more sensitive to ST than Ra. This may be due to the different pathways of ST effects on Rs under grazing in different flooding conditions. Our study indicates that the effect of flooding on Rs is the key to the rational use of grassland under future climate change. To reduce regional carbon emissions, we recommend grazing on flooding grassland and fencing on no-flooding grassland.

3.
J Orthop Surg Res ; 18(1): 212, 2023 Mar 17.
Article in English | MEDLINE | ID: mdl-36932447

ABSTRACT

BACKGROUND: Low back pain (LBP) from hip and spinal disorders has been one of the main reasons for visiting physicians in patients with developmental dysplasia of the hip (DDH). It is essential to identify the LBP improvement among all grades of DDH patients treated with total hip arthroplasty (THA) at 5-year follow-up. METHODS: The study included 407 hips of 306 patients (38 males, 268 females) who underwent THA between July 2007 and December 2016. There were 65 hips in Crowe I, 61 hips in Crowe II, 69 hips in Crowe III, and 212 hips in Crowe IV. One hundred and fourteen hips received subtrochanteric shortening. Patients included 101 bilateral THA (BTHA) and 205 unilateral THA (UTHA). The evaluation was performed through Back Pain Function Scale (BPFS), Harris hip score, Visual Analogue Scale (VAS), operative data and radiographic examinations. RESULTS: The BPFS in patients of unilateral Crowe III and IV relieved significantly more (p < 0.05). However, the BPFS in patients with bilateral symmetry DDH hips relieved significantly less than other groups of DDH hips (p < 0.05). Harris in hips of Crowe II improved significantly more (p < 0.05). The VAS in hips of Crowe II and III improved significantly more (p < 0.05). The unilateral THA surgical time, blood loss, blood transfusion, and osteotomy number and length in Crowe IV were significantly more (p < 0.05). CONCLUSION: THA is reliable to relieve LBP in DDH patients of unilateral Crowe III and IV; however, in patients with unilateral Crowe I, Crowe II, and bilateral DDH hips, the LBP improvements were limited. This should assist shared decision-making between orthopedic surgeons and patients. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.


Subject(s)
Arthroplasty, Replacement, Hip , Developmental Dysplasia of the Hip , Hip Dislocation, Congenital , Low Back Pain , Male , Female , Humans , Arthroplasty, Replacement, Hip/adverse effects , Developmental Dysplasia of the Hip/diagnostic imaging , Developmental Dysplasia of the Hip/surgery , Developmental Dysplasia of the Hip/etiology , Low Back Pain/etiology , Low Back Pain/surgery , Hip Dislocation, Congenital/complications , Hip Dislocation, Congenital/diagnostic imaging , Hip Dislocation, Congenital/surgery , Retrospective Studies , Follow-Up Studies
4.
Orthop Surg ; 15(1): 111-117, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36394084

ABSTRACT

OBJECTIVE: Previous studies on osteoporotic vertebral fractures are usually based on the neutral posture of spine; however, the fractures are usually associated with the flexion posture of spine. Therefore, we aimed to ascertain the relationship between vertebral compression fractures and thoracolumbar hyperflexion Cobb angles (TLHCobb) and determine the clinical cut-off of the TLHCobb angle. METHODS: In this retrospective case-control study, TLHCobbs were collected from 154 postmenopausal women (67.45 ± 6.68 years) with vertebral compression fractures (study group) and 310 postmenopausal women (66.57 ± 8.22 years) without vertebral compression fractures (control group) from June 2017 to July 2019. Demographic data, clinical data, and quantitative computed tomography (QCT) findings were compared between the groups. Chi-squared tests, unpaired t-tests, and Mann Whitney U were used to assess the group characteristics and proportions. Logistic regression was used to examine the association between vertebral compression fractures and TLHCobb. The cut-off of the TLHCobb was determined by ROC curve and Youden's index. RESULTS: Fracture prevalence was higher in the higher TLHCobb study group than that in the control group [OR = 2.81 (2.15-3.67)] after adjusting for age, BMI, and QCT findings. TLHCobbs at and >20.05° were associated with an increased fracture prevalence and ORs of 2.79 (1.82-4.27) and 4.83 (3.24-7.20), respectively. TLHCobb, disk height (semiquantitative grading score) and QCT values differed between the study and control groups (p < 0.001 for all three). There were no significant differences in body mass index (BMI), or coronal TLCobb between the two groups. CONCLUSION: There was an association between the prevalence of vertebral compression fractures and TLHCobbs in postmenopausal women, and a TLHCobb > 20.05° can be an indicator of vertebral fracture.


Subject(s)
Bone Diseases, Metabolic , Fractures, Compression , Osteoporotic Fractures , Spinal Fractures , Female , Humans , Spinal Fractures/diagnostic imaging , Spinal Fractures/etiology , Fractures, Compression/diagnostic imaging , Fractures, Compression/etiology , Retrospective Studies , Postmenopause , Case-Control Studies , Bone Density , Lumbar Vertebrae/diagnostic imaging , Lumbar Vertebrae/injuries , Osteoporotic Fractures/epidemiology , Osteoporotic Fractures/etiology
5.
Environ Technol ; 44(21): 3263-3280, 2023 Sep.
Article in English | MEDLINE | ID: mdl-35306978

ABSTRACT

A new porous solid base catalyst was prepared using dewatered paper sludge and successfully employed to produce biodiesel from soybean oil. The as-prepared catalyst was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transforms infrared spectroscopy, X-ray photoelectron spectroscopy, thermal gravity/differential thermal gravity analysis, Brunauer-Emmet-Teller analysis, and CO2-temperature programmed analysis. The results showed that the formation of CaO and uniformly distributed porous structure should account for the high catalytic activity of the as-prepared catalyst. The optimum reaction conditions were observed at 180 ℃, 8 wt.% catalyst/oil weight ratio, 16:1 methanol/oil molar ratio, and 300 min reaction time with 91.6% biodiesel yield. After being used several times and recycled, the regenerated catalyst still exhibited effective catalytic activity without apparent deactivation. The kinetic study confirmed that the experimental data satisfied with Pseudo-first-order kinetic model controlled by reaction temperature and catalyst/oil weight ratio. The reaction activation energy was 24.98 kJ/mol. The change of enthalpy ΔH (14.98 kJ/mol), entropy ΔS (-208.57 J/mol/K), and Gibbs free energy ΔG (109.46 kJ/mol) indicated that the transesterification reaction catalyzed by the dewatered paper sludge-derived catalyst is endothermic, endergonic, and non-spontaneous. Our research finding indicated that the CaO-based catalyst derived from dewatered paper sludge was an economically promising and eco-friendly solid base catalyst for biodiesel production.


Subject(s)
Biofuels , Sewage , Biofuels/analysis , Kinetics , Porosity , Thermodynamics , Catalysis , Esterification , Plant Oils/chemistry
6.
Pain Physician ; 25(5): 401-408, 2022 08.
Article in English | MEDLINE | ID: mdl-35901481

ABSTRACT

BACKGROUND: The 39-item ROwan Foot Pain Assessment Questionnaire (ROFPAQ) has affective, cognitive, and sensory dimensions to evaluate chronic foot pain. However, to date, the ROFPAQ has only been validated in English and Spanish versions. A simplified Chinese version of ROFPAQ is still not available, even though China has a large population of patients with foot pain. OBJECTIVE: This study's aim was to translate the ROFPAQ into a Chinese version and assess its reliability and validity in Chinese patients with chronic foot pain. STUDY DESIGN: A cross-sectional, multicenter descriptive study. SETTING: This study took place at the Chinese PLA General Hospital, PLA Strategic Support Force Characteristic Medical Center and Wenzhou integrated traditional Chinese and Western Medicine Hospital Affiliated to Zhejiang traditional Chinese Medicine University. METHODS: The ROFPAQ-C (Chinese) was developed by a forward/backward translation protocol and cross-cultural adaptation from the United Kingdom to China, and from English to Chinese Putonghua. A total of 194 patients from 3 centers with chronic foot pain were recruited for test-retest measures from July 2020 though September 2021. RESULTS: Adequate internal consistencies (Cronbach's Alpha) in 3 domains ranged from 0.875 to 0.799 for the cognitive, from 0.795 to 0.629 for the affective, and from 0.801 to 0.811 for the sensory, as well as for the total score from 0.880 to 0.815. Adequate test-retest reliability by intraclass correlation coefficient (ICC) were shown in the cognitive 0.712 (95% CI 0.636 to 0.775), the affective 0.929 (95% CI 0.906 to 0.946), the sensory 0.753 (95% CI 0.685 to 0.808), and the total score 0.932 (95% CI 0.910 to 0.948). Adequate item-total correlations were shown for the cognitive from 0.848 to 0.825, the affective from 0.918 to 0.908, and the sensory from 0.943 to 0.855. LIMITATIONS: The original ROFPAQ with 39 items was developed from a podiatry department of the health care national service of the United Kingdom. CONCLUSIONS: The ROFPAQ-C can be used as a valid and reliable tool for chronic foot pain in the Chinese population.


Subject(s)
Chronic Pain , Foot Diseases , Sorbus , China , Cross-Sectional Studies , Humans , Pain Measurement/methods , Polyesters , Psychometrics , Reproducibility of Results , Surveys and Questionnaires
7.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 30(2): 627-630, 2022 Apr.
Article in Chinese | MEDLINE | ID: mdl-35396008

ABSTRACT

Follicular lymphoma is an indolent malignant tumor originating from lymph nodes and lymphoid tissues, which may affect the patients' quality of survival due to the recurrence and progression. In recent years, with the deepening understand of the molecular biology and signaling pathways, many new targeted drugs for follicular lymphoma have been discovered, such as monoclonal antibodies, checkpoint inhibitors, epigenetic regulation related targeted therapies and signaling pathway inhibitors. In this review, the new progress of immunotherapy for follicular lymphoma is summarized briefly.


Subject(s)
Antineoplastic Agents , Lymphoma, Follicular , Antineoplastic Agents/pharmacology , Epigenesis, Genetic , Humans , Immunologic Factors/pharmacology , Immunologic Factors/therapeutic use , Immunotherapy , Lymphoma, Follicular/drug therapy
8.
J Orthop Surg Res ; 16(1): 709, 2021 Dec 07.
Article in English | MEDLINE | ID: mdl-34876177

ABSTRACT

OBJECTIVE: To investigate whether thoracolumbar flexion dysfunctions increase the risk of thoracolumbar compression fractures in postmenopausal women. METHODS: The records of postmenopausal women with thoracolumbar vertebral compression fractures and without vertebral compression fractures were surveyed. Demographic data, clinical data, and quantitative computed tomography (QCT) findings were compared between the groups. Chi-squared tests, unpaired t-tests, Spearman, and Mann-Whitney U were used to assess the group characteristics and proportions. The relationship between the risk of fracture and the difference of Cobb's angle of thoracolumbar segment (DCTL) was evaluated by logistic regression. DCTL was calculated by subtracting thoracolumbar Cobb's angles (TLCobb's) from thoracolumbar hyperflexion Cobb's angles (TLHCobb's). Quantitative computed tomography (QCT) values and spinal osteoarthritis (OA) of postmenopausal women in the two groups were compared. RESULTS: 102 of 312 were enrolled to the study group of postmenopausal women with the fracture, and 210 of 312 were enrolled to the control group of postmenopausal women without the fracture. There were significant differences in QCT values and spinal OA including disc narrowing (DSN) and osteophytes (OPH) between the two groups (p < 0.001 for all four). The risk of thoracolumbar compression fractures in the postmenopausal women with DCTL ≤ 8.7° was 9.95 times higher (95% CI 5.31-18.64) than that with > 8.7° after adjusting for age, BMI, and QCT values. CONCLUSION: Low DCTL may be a risk factor of thoracolumbar compression fractures in postmenopausal women, and a DCTL ≤ 8.7° can be a threshold value of thoracolumbar compression fractures.


Subject(s)
Fractures, Compression , Spinal Fractures , Female , Fractures, Compression/diagnostic imaging , Humans , Lumbar Vertebrae/diagnostic imaging , Lumbar Vertebrae/injuries , Postmenopause , Retrospective Studies , Spinal Fractures/diagnostic imaging
9.
BMC Musculoskelet Disord ; 21(1): 353, 2020 Jun 06.
Article in English | MEDLINE | ID: mdl-32505204

ABSTRACT

BACKGROUND: Minimally invasive surgery (MIS) is a common treatment option for paravertebral or psoas abscesses (PAs) in patients with spinal tuberculosis (ST). However, its efficacy remains controversial. The aim of the study was to evaluate the efficacy of MIS for PA with ST combined with anti-tuberculous chemotherapy. METHODS: A total of 106 consecutive patients who underwent MIS for ST with PA from January 2002 to Oct 2012 were reviewed. The MIS involved computed tomography (CT)-guided percutaneous catheter drainage and percutaneous catheter infusion chemotherapy. Clinical outcomes were evaluated based on the changes observed on preoperative and postoperative physical examination, inflammatory marker testing, and magnetic resonance imaging (MRI). RESULTS: The mean follow-up period was 7.21 ± 3.15 years. All surgeries were successfully completed under CT-guidance without intraoperative complications and all patients experienced immediate relief of their symptoms, which included fever and back pain. The preoperatively elevated erythrocyte sedimentation rate and C-reactive protein values returned to normal at a mean period of 3 months postoperatively. Solid bony union was observed in 106 patients and no abscesses were found on MRI examination. CONCLUSION: MIS carries advantages in terms of less invasiveness, precise drainage, and enhanced local drug concentration. While the technique has not been fully characterized and clinically prove, its use in addition to conservative chemotherapy and open debridement and instrumental fixation may be recommended for patients with ST and PA.


Subject(s)
Antitubercular Agents/therapeutic use , Minimally Invasive Surgical Procedures , Psoas Abscess/surgery , Radiography, Interventional , Tuberculosis, Spinal/complications , Beijing , Debridement , Disability Evaluation , Drainage , Female , Humans , Longitudinal Studies , Lumbar Vertebrae/microbiology , Lumbar Vertebrae/surgery , Magnetic Resonance Imaging , Male , Psoas Abscess/microbiology , Retrospective Studies , Thoracic Vertebrae/microbiology , Thoracic Vertebrae/surgery , Tomography, X-Ray Computed , Tuberculosis, Spinal/therapy , Visual Analog Scale
10.
Immunopharmacol Immunotoxicol ; 42(3): 280-285, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32326777

ABSTRACT

Background: Sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection. Inflammatory response and oxidative stress play an important role in the pathophysiological process of sepsis. Thioredoxin-1 (Trx-1) is a small ubiquitous thiol protein with redox/inflammation modulatory properties relevant to the pathogenesis of sepsis. We therefore investigated the expression level and significance of Trx-1, inflammatory factors and oxidative stress in peripheral blood of sepsis patients, and to explore Trx-1 relationship with inflammatory factors and oxidative stress.Methods: Plasma samples were collected from patients with sepsis and those with healthy control. Enzyme-linked immunosorbent assays (ELISA) were used to detect for interleukin (IL-1ß), IL-6, tumor necrosis factor (TNF-α), E-selectin, endothelin-1 (ET-1), thioredoxin-1, C-reactive protein (CRP), procalcitonin (PCT) for human plasma samples; RT-PCR detection of Trx-1 and thioredoxin-interacting protein (TXNIP) mRNA levels. Colorimetric assay for glutathione (GSH) and malondialdehyde (MDA) expression level in peripheral blood of patients with sepsis; Disease severity was assessed as APACHE II.Results: The expression levels of Trx-1, inflammatory factors and oxidative stress in plasma of patients with sepsis were significantly increased, TXNIP opposite.Conclusion: Our results show that Trx-1 play important role in inflammation and oxidative stress in sepsis patients. Trx-1 may be a potential therapeutic target in sepsis.


Subject(s)
Cytokines/genetics , Gene Expression , Oxidative Stress/immunology , Sepsis/blood , Thioredoxins/genetics , Case-Control Studies , Cohort Studies , Cytokines/blood , Enzyme-Linked Immunosorbent Assay , Female , Gene Expression/immunology , Humans , Male , Middle Aged , Oxidative Stress/genetics , Real-Time Polymerase Chain Reaction , Sepsis/immunology , Thioredoxins/blood
11.
Environ Sci Pollut Res Int ; 27(16): 19703-19713, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32221831

ABSTRACT

The effect of climate warming on soil organic carbon (SOC) of sediment in wetlands is important for accurately projecting SOC content. Thus, understanding the mechanism influencing SOC content under climate warming is necessary. Field investigation and a laboratory incubation experiment were conducted in Hulunbeier steppe wetland during 2016 and 2017. Four types of wetland were selected to incubate with ambient temperature and temperature increased by 2.5 °C. The results showed that SOC content was negatively affected by temperature warming. The SOC content reduction in sediment caused by increasing temperature was ranged from - 2.34 to 39.52%. In addition, the content of sand, silt, total phosphorus (TP), calcium phosphate tribasic (Ca-P), total nitrogen (TN), and sediment moisture (MC) should be considered in models of SOC content in steppe wetland. However, it requires further validation, in particular how SOC content varies with warming temperatures, the duration of incubation, and other abiotic and biotic factors. These findings provide evidence that both climate warming and original characteristics of sediment can control the SOC storage dynamics in the steppe wetland. Graphical abstract.


Subject(s)
Carbon/analysis , Wetlands , China , Climate , Nitrogen/analysis , Soil
12.
Chemosphere ; 241: 125137, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31683449

ABSTRACT

Phosphorus (P) losses from terrestrial soils contribute to eutrophication of surface waters. As priority non-point source pollution ways, rainfall runoff (RS1) and snowmelt runoff (RS2) are the main carrier of P loss from terrestrial ecosystem. The aim of this study was to investigate the similarities and differences between P loss with RS1 and RS2 of the same soil type. Six types of soil were used in this experiment. Results have shown that 1), Different types of soil have different P loss with RS1 and RS2 under different slope, and the changes ranged from 0.003 to 0.370 mg L-1. 2), The effects of soil type, slope and runoff type on P loss with surface runoff was not independent, both individual effects of all factors and their interaction with the other two factors effected the P loss with runoff. 3), In our experiment, some soils showed no significant difference between P content in RS1 and RS2. In some soils, P loss with RS1 was higher than that with RS2 while the opposite conclusion was showed in Bog soil (BS) which with higher soil water content. 4), The P loss with RS1 and RS2 of different soils were both mainly affected by soil water content (SW), Olsen-P content (OP) and soil organic matter content (OM). These results can help us understand the P loss with different patterns of surface runoff better and are expected to provide pertinent opinions on the analysis of P loss with runoff and its influencing factors of grassland soils.


Subject(s)
Phosphorus/analysis , Water Movements , Wetlands , Eutrophication , Non-Point Source Pollution , Rain , Snow , Soil/chemistry
13.
Ecol Evol ; 8(23): 11954-11963, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30598790

ABSTRACT

Plant-plant interactions play a key role in the function and structure of communities. The combined effect of drought stress and grazing disturbance on shaping plant-plant interactions is still poorly understood, while this combination is common in semiarid ecosystems. Four species including Stipa grandis, which is dominant in the typical steppe, and Stipa krylovii, Artemisia frigida, and Cleistogenes squarrosa, which are dominant species in the S. grandis degraded communities, were selected as study targets. We conducted a competition experiment (uniformly dense monoculture or mixture, respectively) under controlled conditions, including both drought stress and mowing disturbance, and calculated the relative interaction index (RII) of tiller number and RII of biomass for each species under each condition. (a) Under the same condition, the RII of tiller number and that of biomass for the same species usually showed reverse trends. (b) Mowing disturbance rather than drought stress played a negative role in influencing S. grandis' or S. krylovii's RII of tiller number and played a positive role in influencing A. frigida's RII of biomass. (c) Drought stress rather than mowing disturbance played a positive role in influencing C. squarrosa's RII of tiller number. (d) Neighbor species significantly influenced S. grandis' RII of tiller number, S. krylovii's RII of tiller number, A. frigida's RII of tiller number and biomass, and C. squarrosa's RII of biomass. These results could provide an explanation for why S. krylovii, A. frigida, and C. squarrosa can replace S. grandis and become the dominant species when S. grandis communities undergo a process of degradation due to overgrazing or climatic drought in natural communities. The present study provided powerful evidences for species replacement in the typical steppe of Inner Mongolia and elucidated the driving mechanisms of S. grandis communities' retrogressive succession.

14.
Environ Monit Assess ; 189(12): 617, 2017 Nov 08.
Article in English | MEDLINE | ID: mdl-29119330

ABSTRACT

Phosphorus (P) flux potential can predict the trend of phosphorus release from wetland sediments to water and provide scientific parameters for further monitoring and management for phosphorus flux from wetland sediments to overlying water. Many studies have focused on factors affecting sediment P flux potential in sediment-water interface, but rarely on the relationship among these factors. In the present study, experiment on sediment P flux potential in sediment-water interface was conducted in six wetlands in Hulun Buir grassland, China and the relationships among sediment P flux potential in sediment-water interface, sediment physical properties, and sediment chemical characteristics were examined. Principal component analysis and path analysis were used to discuss these data in correlation coefficient, direct, and indirect effects on sediment P flux potential in sediment-water interface. Results indicated that the major factors affecting sediment P flux potential in sediment-water interface were amount of organophosphate-degradation bacterium in sediment, Ca-P content, and total phosphorus concentrations. The factors of direct influence sediment P flux potential were sediment Ca-P content, Olsen-P content, SOC content, and sediment Al-P content. The indirect influence sediment P flux potential in sediment-water interface was sediment Olsen-P content, sediment SOC content, sediment Ca-P content, and sediment Al-P content. And the standard multiple regression describing the relationship between sediment P flux potential in sediment-water interface and its major effect factors was Y = 5.849 - 1.025X 1 - 1.995X 2 + 0.188X 3 - 0.282X 4 (r = 0.9298, p < 0.01, n = 96), where Y is sediment P flux potential in sediment-water interface, X 1 is sediment Ca-P content, X 2 is sediment Olsen-P content, X 3 is sediment SOC content, and X 4 is sediment Al-P content. Therefore, future research will focus on these sediment properties to analyze the interrelation among sediment properties factors, main vegetable factors, and environment factors which influence the sediment P flux potential in sediment-water interface.


Subject(s)
Bacteria/metabolism , Environmental Monitoring , Geologic Sediments/chemistry , Geologic Sediments/microbiology , Organophosphates/metabolism , Phosphorus/analysis , Water Pollutants, Chemical/analysis , China , Factor Analysis, Statistical , Grassland , Organophosphates/analysis , Principal Component Analysis , Water/analysis , Wetlands
15.
Sci Rep ; 7: 44525, 2017 03 27.
Article in English | MEDLINE | ID: mdl-28344355

ABSTRACT

Enclosures (fenced, grazing or clipping) within a certain period of years are the most common tools for restoration of degraded grasslands in temperate regions. Short-term enclosures can improve biodiversity and productivity by effectively relieving grazing pressure, while long-term enclosures can reduce species diversity. We therefore carried out a field experiment to investigate the specific causes of the reduced species diversity in Hulunbeier grassland of northern China. After eight years of enclosure, the significantly increased soil available nitrogen (AN) and available phosphorus (AvP) in enclosure community reduced nitrogen (N) limitation but most vegetation was still N limited. Many environmental factors led to decreased species richness, but increased soil AN and decreased light intensity at the community bottom were the most significant ones. Community density decreased independently of soil nutrition but significantly related to decreased species richness. Density of dominant canopy species increased, while dominant understory species decreased during assemblage-level thinning; therefore, the random-loss hypothesis was not supported. The dominant understory species responded to lower light availability by increasing their height, leaf area, and chlorophyll content. Moreover, our results were expected to provide some specific guidance for the restoration mode selection of degraded grasslands in northern China.


Subject(s)
Carbon/metabolism , Conservation of Natural Resources/methods , Nitrogen/metabolism , Poaceae/physiology , Soil/chemistry , Biodiversity , Biomass , China , Grassland , Herbivory , Light , Poaceae/radiation effects
16.
Ecol Evol ; 7(1): 14-25, 2017 01.
Article in English | MEDLINE | ID: mdl-28070271

ABSTRACT

Increasing attention has been paid to the relationship between biodiversity and ecosystem functioning (BEF) because of the rapid increase in species loss. However, over the past 20 years, most BEF studies only focused on the effect of species diversity on one or a few ecosystem functions, and only a few studies focused on ecosystem multifunctionality (i.e., the simultaneous provision of several ecosystem functions). Grassland ecosystems have important economic, environmental, and esthetic value; thus, this study focused on the heterogeneous microcommunities in grasslands under three management modes. The multifunctionality index (M-index) was assessed at community and microcommunity scales, and the relationship between species diversity and multifunctionality was investigated. The communities were found to be respectively composed of one, three, and six microcommunities in grazing, clipping, and enclosure management, based on a two-way indicator species analysis (TWINSPAN) and detrended correspondence analysis (DCA) for community structure. Biodiversity and soil indicators showed an apparent degradation of the grazing community, which had the worst M-index. Clipping and enclosure communities showed no significant difference in biodiversity indices, soil variables, and M-index; however, these indices were clearly different among microcommunities. Therefore, the microcommunity scale may be suitable to investigate the relationship between vegetation and multifunctionality in seminatural grassland ecosystems. Dominant species richness had more explanatory power for ecosystem multifunctionality than subdominant species richness, rare species richness, and the number of all species. Therefore, it is important to distinguish the role and rank of different species in the species richness-multifunctionality model; otherwise, the model might include redundant and unclear information. Communities with more codominant species whose distribution is also even might have better multifunctionality.

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