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1.
Aging (Albany NY) ; 15(23): 13669-13679, 2023 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-38048213

RESUMEN

Mild cognitive impairment (MCI) is a common symptom observed in people over 60 years old and is found to be aggravated by hypercholesterolemia. Severe neuroinflammation induced by BBB dysfunction and monocyte infiltration might be responsible for neuron damage and cognitive impairment. Atorvastatin is a lipid-lowering drug that is widely applied for the treatment of cardiovascular diseases. However, the potential function of Atorvastatin in hypercholesterolemia-induced MCI remains uncertain. Our research will explore the potential therapeutic function of Atorvastatin in memory deficits induced by chronic hypercholesterolemia. ApoE-/- mice were utilized to mimic the state of chronic hypercholesterolemia and were divided into four groups. Animals in the WT and ApoE-/-groups were orally administered with normal saline, while WT mice in the Atorvastatin group and ApoE-/- mice in the ApoE-/-+ Atorvastatin group were orally administered with 10 mg/kg/day Atorvastatin. Markedly increased plasma cholesterol levels reduced RI in the long-term memory test and the spatial short-term memory test, declined mobility in the open field test, and downregulated PSD-95 and BDNF were observed in ApoE-/- mice, all of which were signally reversed by Atorvastatin. Moreover, the percentages of brain Ly6Chi CD45+ cells and CD3+ CD45+ cells, as well as the blood Ly6Chi CD45+ cells, plasma IL-12/IL-23 levels and IL-17 level were found notably increased in ApoE-/- mice, all of which were largely repressed by Atorvastatin. Lastly, the increased BBB permeability, decreased ZO-1 and occludin levels, and reduced KLF2 level were markedly abolished by Atorvastatin. Collectively, Atorvastatin mitigated memory deficits and brain monocyte infiltration in ApoE-/- mice.


Asunto(s)
Ácidos Heptanoicos , Hipercolesterolemia , Hiperlipidemias , Humanos , Ratones , Animales , Atorvastatina/farmacología , Atorvastatina/uso terapéutico , Hipercolesterolemia/complicaciones , Hipercolesterolemia/tratamiento farmacológico , Monocitos/metabolismo , Ácidos Heptanoicos/farmacología , Ácidos Heptanoicos/uso terapéutico , Pirroles/farmacología , Hiperlipidemias/tratamiento farmacológico , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Encéfalo/metabolismo
2.
Asian J Psychiatr ; 61: 102689, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34004459

RESUMEN

Although local government staff are crucial in post-quake reconstruction, their long-term psychological and professional consequences remain unclear. This longitudinal study investigated changes of posttraumatic stress disorder (PTSD) and professional burnout over seven years, and their underlying relationship. The study assessed 250 staff at one year (T1y) after the earthquake, and 162 (64.8 %) were followed up at seven years (T7y). PTSD and professional burnout were assessed with the Short Screening Scale for DSM-IV PTSD and the burnout subscale of Professional Quality of Life Scale (ProQOL), respectively, at both time points. Longitudinal changes in PTSD and burnout were examined and cross-lagged panel analyses were conducted to test the relationship between PTSD and burnout. The rates of positive cases of PTSD screening were 23.2 % at T1y and 11.1 % at T7y. The percentages of moderate burnout were 61.7 % at T1y and 23.5 % at T7y. Scores of PTSD (z = -5.70, p < 0.001) and burnout (t = 10.07, p < 0.001) from T1y to T7y decreased. The cross-lagged analysis indicated that burnout at T1y predicted PTSD at T7y (ß = 0.19, p = 0.025). In conclusion, the Wenchuan earthquake has long-lasting negative effects on local government staff, although they can recover over time. Interventions to reduce professional burnout after disaster may does be beneficial to decrease the risk of PTSD in the long run.


Asunto(s)
Agotamiento Profesional , Terremotos , Trastornos por Estrés Postraumático , Agotamiento Profesional/epidemiología , China/epidemiología , Humanos , Gobierno Local , Estudios Longitudinales , Calidad de Vida , Factores de Riesgo , Trastornos por Estrés Postraumático/epidemiología
3.
BMC Public Health ; 21(1): 702, 2021 04 09.
Artículo en Inglés | MEDLINE | ID: mdl-33836705

RESUMEN

BACKGROUND: The current study examined the change in local government staff's emotional distress over 7 years after the 2008 Wenchuan earthquake, and the influence of earthquake exposure and professional quality of life (ProQOL) on emotional distress. METHODS: This longitudinal study assessed 250 participants at 1 year after the earthquake; 162 (64.8%) were followed up at 7 years. Emotional distress was assessed with the Self-Reporting Questionnaire (SRQ) at both time points. We assessed ProQOL, including compassion satisfaction, burnout, and secondary traumatic stress, and earthquake exposure at 1 year. Wilcoxon signed-rank tests were performed to test longitudinal changes in emotional distress. Hierarchical multiple regression was conducted to examine the effect of earthquake exposure and ProQOL. RESULTS: The positive screening rate of emotional distress (SRQ ≥ 8) was 37.6 and 15.4% at one and 7 years, respectively. Emotional distress scores declined over time (p < 0.001). Earthquake exposure and ProQOL predicted one-year (ps < 0.05) but not seven-year emotional distress, whereas burnout predicted both one-year (p = 0.018) and seven-year (p = 0.047) emotional distress. CONCLUSIONS: Although emotional distress can recover over time, it persists even 7 years later. Actions to reduce burnout during the early stage of post-disaster rescue have long-term benefits to staff's psychological outcomes.


Asunto(s)
Terremotos , Distrés Psicológico , Trastornos por Estrés Postraumático , China/epidemiología , Humanos , Gobierno Local , Estudios Longitudinales , Calidad de Vida , Encuestas y Cuestionarios
4.
Mar Pollut Bull ; 116(1-2): 103-112, 2017 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-28057328

RESUMEN

Three one-off burial treatments were designed in intertidal zone of the Yellow River estuary to determine the effects of sediment burial on decomposition and heavy metal levels of Suaeda salsa. Sediment burial showed significant effect on decomposition rate of S. salsa. With increasing burial depth, Cu, Zn, Cd and Co levels generally increased, while Cr and Mn levels decreased. Except for Zn, Mn, Cd and Co, stocks of Pb, Cr, Cu, Ni and V in S. salsa among burials were greatly different. The S. salsa in three burials was particular efficient in binding V and Co and releasing Pb, Zn and Cd, and, with increasing burial depth, stocks of Cr, Cu, Ni and Mn shifted from accumulation to release. In future, the eco-toxic risk of Pb, Cr, Cu, Zn, Ni, Mn and Cd exposure might be serious as the strong burial episodes occurred in S. salsa marsh.


Asunto(s)
Chenopodiaceae/química , Estuarios , Sedimentos Geológicos/química , Metales Pesados/análisis , Contaminantes Químicos del Agua/análisis , China , Monitoreo del Ambiente , Ríos
5.
Chemosphere ; 147: 163-72, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26766352

RESUMEN

The concentrations of C, Pb, Cr, Cu, Zn, Ni and Mn were determined in decomposing litters of Phragmites australis, Suaeda salsa and Suaeda glauca in three plots of the Yellow River estuary to investigate the variations of metal stocks. Results showed that the decomposition rates significantly differed among species (p < 0.05), in the order of S. glauca (0.002010 d(-1)) > S. salsa (0.000814 d(-1)) > P. australis (0.000766 d(-1)). The concentrations of Cu and Zn in the three litters (particularly S. glauca) generally showed increasing tendency, while those of Pb, Cr, Ni and Mn exhibited different temporal variations. Compared to P. australis and S. salsa, the key mechanisms affecting the variation of metals in S. glauca might be more complex. In most periods, Pb stocks in P. australis, S. salsa and S. glauca, Zn stocks in S. salsa and S. glauca, and Cr, Ni and Mn stocks in P. australis and S. glauca were lower than the initial ones, implying that release exceeded incorporation. Comparatively, Zn stocks in P. australis, Cr, Ni and Mn stocks in S. salsa and in particular Cu stocks in the three litters were generally positive, evidencing incorporation of these metals in most sampling times. The three halophytes were particular efficient in binding Cu and releasing Pb, indicating that the potential eco-toxic risk of Pb exposure might be serious. This study emphasized the strong influences of key biotic (litter types, carbon/metal ratios and activities of microbial organisms) and abiotic variables (salinity, sediment resuspension induced by tidal inundation and passive sorption onto recalcitrant organic fractions) on metal cycling in coastal marshes of the Yellow River estuary.


Asunto(s)
Chenopodiaceae/química , Metales Pesados/química , Poaceae/química , Plantas Tolerantes a la Sal/química , Contaminantes del Suelo/análisis , Contaminantes Químicos del Agua/análisis , China , Monitoreo del Ambiente , Estuarios , Especificidad de la Especie , Humedales
6.
Environ Sci Pollut Res Int ; 23(6): 5189-202, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26555885

RESUMEN

From April 2008 to November 2009, a field decomposition experiment was conducted to investigate the effects of sediment burial on macro (C, N) and microelement (Pb, Cr, Cu, Zn, Ni, and Mn) variations in decomposing litter of Phragmites australis in the coastal marsh of the Yellow River estuary. Three one-off sediment burial treatments [no sediment burial (0 mm year(-1), S0), current sediment burial (100 mm year(-1), S10), and strong sediment burial (200 mm year(-1), S20)] were laid in different decomposition sites. Results showed that sediment burials showed significant influence on the decomposition rate of P. australis, in the order of S10 (0.001990 day(-1)) ≈ S20 (0.001710 day(-1)) > S0 (0.000768 day(-1)) (p < 0.05). The macro and microelement in decomposing litters of the three burial depths exhibited different temporal variations except for Cu, Zn, and Ni. No significant differences in C, N, Pb, Cr, Zn, and Mn concentrations were observed among the three burial treatments except for Cu and Ni (p > 0.05). With increasing burial depth, N, Cr, Cu, Ni, and Mn concentrations generally increased, while C, Pb, and Zn concentrations varied insignificantly. Sediment burial was favorable for C and N release from P. australis, and, with increasing burial depth, the C release from litter significantly increased, and the N in litter shifted from accumulation to release. With a few exceptions, Pb, Cr, Zn, and Mn stocks in P. australis in the three treatments evidenced the export of metals from litter to environment, and, with increasing burial depth, the export amounts increased greatly. Stocks of Cu and Ni in P. australis in the S10 and S20 treatments were generally positive, evidencing incorporation of the two metals in most sampling times. Except for Ni, the variations of C, N, Pb, Cr, Cu, Zn, and Mn stocks in P. australis in the S10 and S20 treatments were approximated, indicating that the strong burial episodes (S20) occurred in P. australis marsh in the future would have little influence on the stocks of these elements. With increasing burial depths, the P. australis was particularly efficient in binding Cu and Ni and releasing C, N, Pb, Cr, Zn, and Mn, implying that the potential eco-toxic risk of Pb, Cr, Zn, and Mn exposure might be very serious. This study emphasized the effects of different burials on nutrient and metal cycling and mass balance in the P. australis marsh of the Yellow River estuary.


Asunto(s)
Biodegradación Ambiental , Sedimentos Geológicos/química , Poaceae/metabolismo , Ríos , China , Elementos Químicos , Estuarios , Ríos/química , Humedales
7.
Environ Int ; 79: 25-41, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25771079

RESUMEN

China has approximately 5.80×10(6)ha coastal wetlands by 2014, accounting for 10.82% of the total area of natural wetlands. Healthy coastal wetland ecosystems play an important role in guaranteeing the territory ecological security and the sustainable development of coastal zone in China. In this paper, the natural geography and the past and present status of China's coastal wetlands were introduced and the five stages (1950s-1970s, 1980s-1991, 1992-2002, 2003-2010 and 2011-present) of China's coastal wetlands conservation from the foundation of the People's Republic in 1949 to present were distinguished and reviewed. Over the past decades, China has made great efforts in coastal wetland conservation, as signified by the implementation of coastal wetland restoration projects, the construction of coastal wetland nature reserves, the practice of routine ecological monitoring and two national wetland surveys, the promulgation of local wetland conservation statutes and specific regulations, the coordination mechanism to enhance management capacity, the wide development of coastal wetland research and public participation, and the extensive communication to strengthen international cooperation. Nonetheless, six major issues recently emerged in China's coastal wetland conservation are evidently existed, including the increasing threats of pollution and human activities, the increasing adverse effects of threaten factors on ecosystem function, the increasing threats of coastal erosion and sea-level rising, the insufficient funding for coastal wetlands conservation, the imperfect legal and management system for coastal wetlands, and the insufficient education, research and international cooperation. Although the threats and pressures on coastal wetlands conservation are still apparent, the future of China's coastal wetlands looks promising since the Chinese government understands that the sustainable development in coastal zone requires new attitudes, sound policies and concerted efforts at all levels. The major strategies for future improvement of China's coastal wetland conservation include: exploring effective measures in response to major threaten factors; improving the conservation and compensation system for coastal wetlands; strengthening coastal wetland legislation and management; increasing funds for coastal wetland conservation and research; and strengthening coastal wetland education and international cooperation.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Humedales , China , Conservación de los Recursos Naturales/legislación & jurisprudencia , Ecosistema , Contaminación Ambiental/prevención & control , Humanos
8.
J Mol Neurosci ; 54(1): 41-8, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24488604

RESUMEN

Microglia cells have been reported to mediate hypoxia-induced inflammation through the production of proinflammatory cytokines, including interleukin-1 beta (IL-1ß), tumor necrosis factor alpha (TNF-α), and IL-6. Given the fact that the activation of the type 2 cannabinoid receptor (CB2R) provides antioxidative and anti-inflammatory results, it is suspected that its selective agonist, trans-caryophyllene (TC), may have protective effects against hypoxia-induced neuroinflammatory responses. In this study, TC was found to significantly inhibit hypoxia-induced cytotoxicity as well as the release of proinflammatory cytokines, including IL-1ß, TNF-α, and IL-6, through activation of BV2 microglia following hypoxic exposure (1 % O2, 24 h). Furthermore, TC significantly inhibited hypoxia-induced generation of reactive oxygen species (ROS) in mitochondria as well as the activation of nuclear factor kappa B (NF-κB) in microglia. Importantly, TC's effects on inhibiting the activation of NF-κB and the secretion of inflammatory cytokines can be abolished by muting the CB2R using small RNA interference. These observations indicate that TC suppresses the hypoxia-induced neuroinflammatory response through inhibition of NF-κB activation in microglia. Therefore, TC may be beneficial in preventing hypoxia-induced neuroinflammation.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Microglía/efectos de los fármacos , FN-kappa B/metabolismo , Sesquiterpenos/farmacología , Animales , Hipoxia de la Célula , Línea Celular , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Ratones , Microglía/metabolismo , Mitocondrias/genética , Mitocondrias/metabolismo , FN-kappa B/genética , Sesquiterpenos Policíclicos , Especies Reactivas de Oxígeno/metabolismo , Receptor Cannabinoide CB2/antagonistas & inhibidores , Receptor Cannabinoide CB2/genética , Receptor Cannabinoide CB2/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo
9.
Environ Sci Pollut Res Int ; 21(1): 419-33, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23784055

RESUMEN

To investigate the spatial and seasonal variations of nitrous oxide (N2O) fluxes and understand the key controlling factors, we explored N2O fluxes and environmental variables in high marsh (HM), middle marsh (MM), low marsh (LM), and mudflat (MF) in the Yellow River estuary throughout a year. Fluxes of N2O differed significantly between sampling periods as well as between sampling positions. During all times of day and the seasons measured, N2O fluxes ranged from -0.0051 to 0.0805 mg N2O m(-2) h(-1), and high N2O emissions occurred during spring (0.0278 mg N2O m(-2) h(-1)) and winter (0.0139 mg N2O m(-2) h(-1)) while low fluxes were observed during summer (0.0065 mg N2O m(-2) h(-1)) and autumn (0.0060 mg N2O m(-2) h(-1)). The annual average N2O flux from the intertidal zone was 0.0117 mg N2O m(-2) h(-1), and the cumulative N2O emission throughout a year was 113.03 mg N2O m(-2), indicating that coastal marsh acted as N2O source. Over all seasons, N2O fluxes from the four marshes were significantly different (p < 0.05), in the order of HM (0.0256 ± 0.0040 mg N2O m(-2) h(-1)) > MF (0.0107 ± 0.0027 mg N2O m(-2) h(-1)) > LM (0.0073 ± 0.0020 mg N2O m(-2) h(-1)) > MM (0.0026 ± 0.0011 mg N2O m(-2) h(-1)). Temporal variations of N2O emissions were related to the vegetations (Suaeda salsa, Phragmites australis, and Tamarix chinensis) and the limited C and mineral N in soils during summer and autumn and the frequent freeze/thaw cycles in soils during spring and winter, while spatial variations were mainly affected by tidal fluctuation and plant composition at spatial scale. This study indicated the importance of seasonal N2O contributions (particularly during non-growing season) to the estimation of local N2O inventory, and highlighted both the large spatial variation of N2O fluxes across the coastal marsh (CV = 158.31%) and the potential effect of exogenous nitrogen loading to the Yellow River estuary on N2O emission should be considered before the annual or local N2O inventory was evaluated accurately.


Asunto(s)
Contaminantes Atmosféricos/análisis , Atmósfera/química , Estuarios , Óxido Nitroso/análisis , Ríos/química , Humedales , Contaminación del Aire/estadística & datos numéricos , China , Monitoreo del Ambiente , Nitrógeno/análisis , Nitrógeno/metabolismo , Poaceae/fisiología , Estaciones del Año
10.
Chemosphere ; 90(2): 856-65, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23134757

RESUMEN

The spatial and temporal variations of the fluxes of nitrous oxide (N(2)O) and methane (CH(4)) and associated abiotic sediment parameters were quantified for the first time across the coastal marsh dominated by Suaeda salsa in the Yellow River estuary during 2009/2010. During all times of day and the seasons measured, N(2)O and CH(4) fluxes from coastal marsh ranged from -0.0147 mg N(2)O m(-2) h(-1) to 0.0982 mg N(2)O m(-2) h(-1) and -0.7421 mg CH(4) m(-2) h(-1) to 0.4242 mg CH(4) m(-2) h(-1), respectively. The mean N(2)O fluxes in spring, summer, autumn and winter were 0.0325 mg N(2)O m(-2) h(-1), 0.0089 mg N(2)O m(-2) h(-1), 0.0119 mg N(2)O m(-2) h(-1) and 0.0140 mg N(2)O m(-2) h(-1), and the average CH(4) fluxes were -0.0109 mg CH(4) m(-2) h(-1), -0.0174 mg CH(4) m(-2) h(-1), -0.0141 mg CH(4) m(-2) h(-1) and -0.0089 mg CH(4) m(-2) h(-1), respectively, indicating that the coastal marsh acted as N(2)O source and CH(4) sink. Both N(2)O and CH(4) fluxes differed significantly between times of day of sampling. N(2)O fluxes differed significantly between sampling seasons as well as between sampling positions, while CH(4) fluxes had no significant differences between seasons or positions. Temporal variations of N(2)O emissions were probably related to the effects of vegetation (S. salsa) during summer and autumn and the frequent freeze/thaw cycle of sediment during spring and winter, while those of CH(4) fluxes were controlled by the interactions of thermal conditions and other abiotic factors (soil moisture and salinity). Spatial variations of N(2)O and CH(4) fluxes were primarily affected by soil moisture fluctuation derived from astronomic tide, sediment substrate and vegetation composition. N(2)O and CH(4) fluxes, expressed as CO(2)-equivaltent (CO(2)-e) emissions, showed that N(2)O comprised the principal part of total calculated CO(2)-e emissions during spring and winter, while the contributions of CH(4) could not be ignored during summer and autumn. This study highlights the importance of seasonal N(2)O and CH(4) contributions, particularly during times of significant CH(4) consumption. For the accurate up-scaling of N(2)O and CH(4) fluxes to annual rates, a careful sampling design at site-level is required to capture the potentially considerable temporal and spatial variations of N(2)O and CH(4) emissions.


Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminación del Aire/estadística & datos numéricos , Chenopodiaceae , Metano/análisis , Óxido Nitroso/análisis , Humedales , China , Monitoreo del Ambiente , Estuarios
11.
Huan Jing Ke Xue ; 34(11): 4411-9, 2013 Nov.
Artículo en Chino | MEDLINE | ID: mdl-24455953

RESUMEN

The spatial distribution characteristics of Fe and Mn contents in soils of nine different vegetation communities, located in the new-born marshes of the northern Yellow River estuary, were studied in May 2009. The results showed that the horizontal distributions of Fe and Mn contents showed an increasing tendency from Sparganiaceae-Potentilla supina marsh to bare flat. The vertical distribution characteristics of Fe and Mn contents in different marsh soils fluctuated significantly with the vegetation succession. The soil parent materials determined the Fe, Mn contents in the new-born marshes, and seawater, vegetations and soil fine particle also had important influences on their contents. Further analysis showed that Fe contents had significant positive correlation with Mn contents (P < 0.01). Fe, Mn contents also showed significant correlations with silt, clay, TN, NO3(-) -N and organic matter (P < 0.05), indicating that Fe and Mn had close relationships with nitrogen, and the contents of soil fine particles and organic matter were the dominant factors affecting the distribution of Fe and Mn in soils. In addition, the Fe contents ranged from 16.49 g x kg(-1) to 33.11 g x kg(-1) and the average was 22.54 g x kg(-1), which was close to the Fe contents in the tidal marshes of north Jiangsu, the Loess Plateau and the China soil background value, but slightly lower than those in the marshes of the Yangtse River estuary, the mangrove swamps and inland lake wetland. The Mn contents ranged from 305.87 mg x kg(-1) to 711.39 mg x kg(-1) and the average was 451.09 mg x kg(-1), which was lower than the Mn contents in the Loess Plateau and the China soil background value. Hydrology and Water Resources Survey Bureau of the Yellow River Estuary, Dongying 257091, China)


Asunto(s)
Hierro/análisis , Manganeso/análisis , Ríos/química , Humedales , China , Estuarios , Nitrógeno/química , Agua de Mar/química , Suelo/química
12.
Huan Jing Ke Xue ; 33(7): 2482-9, 2012 Jul.
Artículo en Chino | MEDLINE | ID: mdl-23002631

RESUMEN

Using static chamber-GC techniques, the short-term effects of nitrogen input on the emission fluxes of CH4 and N2O from a Cyperus malaccensis wetland were determined. The results showed that the emission of CH4 was increased by high nitrogen input at all sampling times, whereas the low nitrogen input exhibited different variation characteristics at different time points. Compared to the control treatment, the CH4 emission flux in the two nitrogen input treatments (N1, N2) was increased by -44.35%-1 057.35% and 7.15%-667.37%, respectively. The input of exogenous nitrogen had positive priming effect on N2O emission flux within 24 hours, increased by up to 171.60 folds and 177.79 folds, respectively. After 8 days, the priming effect by the nitrogen input weakened or disappeared. There was no significant effect of nitrogen input on the Ec, pH and Eh of soil at different depths in the salt marsh during the experiment. In the control treatment, the CH4 emission flux was negatively correlated solely with Eh of soil at 5 cm depth, whereas in the N1 treatment, it was negatively correlated solely with soil temperature at 10 cm depth. In the N2 treatment, there was negative correlation between the CH4 emission flux and Ec of soil at 5cm depth, pH of soil at 0, 5 cm depths, and Eh of soil at 0, 5, 10 cm depths. However, no significant correlation between the N2O emission flux and the environmental variables in the wetland was found. This study indicated that the temporal variability should be taken into consideration when examining the effects of nitrogen input on the emission of greenhouse gases in the wetlands.


Asunto(s)
Cyperus/metabolismo , Metano/análisis , Nitrógeno/química , Óxido Nitroso/análisis , Humedales , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/química , China , Cyperus/genética , Metano/química , Óxido Nitroso/química , Ríos
13.
Huan Jing Ke Xue ; 33(2): 565-73, 2012 Feb.
Artículo en Chino | MEDLINE | ID: mdl-22509598

RESUMEN

The characteristics of methane (CH4) fluxes from tidal wetlands of the Yellow River estuary were observed in situ with static-chamber and GC methods in September and October 2009, and the key factors affecting CH4 fluxes were discussed. From the aspect of space, the CH4 flux ranges in high tidal wetland, middle tidal wetland, low tidal wetland, bare flat are - 0.206-1.264, -0.197-0.431, -0.125-0.659 and -0.742-1.767 mg x (m2 x h)(-1), the day average fluxes are 0.089, 0.038, 0.197 and 0.169 mg x (m2 x h)(-1), respectively, indicating that the tidal wetlands are the sources of CH4 and the source function of CH4 differed among the four study sites, in the order of low tidal wetland > bare flat > high tidal wetland > middle tidal wetland. From the aspect of time, the ranges of CH4 fluxes from the tidal wetland ecosystems are -0.444-1.767 and - 0.742- 1.264 mg x (m2 x h)(-1), and the day average fluxes are 0.218 and 0.028 mg x (m2 x h)(-1) in September and October, respectively. The CH4 fluxes in each tidal wetland in September are higher than those in October except that the high tidal wetland acts as weak sink in September. Further studies indicate that the changes of environmental factors in the Yellow River estuary are complicated, and the CH4 fluxes are affected by multiple factors. The differences of CH4 fluxes characteristics among different tidal wetlands in autumn are probably related to temperature (especially atmospheric temperature) and vegetation growth status, while the effects of water or salinity condition and tide status on the CH4 flux characteristics might not be ignored.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Metano/análisis , Contaminantes Químicos del Agua/análisis , Humedales , China , Océanos y Mares , Ríos , Estaciones del Año , Olas de Marea
14.
J Environ Sci (China) ; 23(6): 958-67, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22066219

RESUMEN

The nitrogen (N) biological cycle of the Suaeda salsa marsh ecosystem in the Yellow River estuary was studied during 2008 to 2009. Results showed that soil N had significant seasonal fluctuations and vertical distribution. The N/P ratio (15.73 +/- 1.77) of S. salsa was less than 16, indicating that plant growth was limited by both N and P. The N absorption coefficient of S. salsa was very low (0.007), while the N utilization and cycle coefficients were high (0.824 and 0.331, respectively). The N turnover among compartments of S. salsa marsh showed that N uptake from aboveground parts and roots were 2.539 and 0.622 g/m2, respectively. The N translocation from aboveground parts to roots and from roots to soil were 2.042 and 0.076 g/m2, respectively. The N translocation from aboveground living bodies to litter was 0.497 g/m2, the annual N return from litter to soil was far less than 0.368 g/m2, and the net N mineralization in topsoil during the growing season was 0.033 g/m2. N was an important limiting factor in S. salsa marsh, and the ecosystem was classified as unstable and vulnerable. S. salsa was seemingly well adapted to the low-nutrient status and vulnerable habitat, and the nutrient enrichment due to N import from the Yellow River estuary would be a potential threat to the S. salsa marsh. Excessive nutrient loading might favor invasive species and induce severe long-term degradation of the ecosystem if human intervention measures were not taken. The N quantitative relationships determined in our study might provide a scientific basis for the establishment of effective measures.


Asunto(s)
Chenopodiaceae/química , Chenopodiaceae/metabolismo , Ecosistema , Ciclo del Nitrógeno , Ríos/química , Suelo/química , Humedales , Biomasa , Chenopodiaceae/anatomía & histología , China , Humanos , Nitrógeno/metabolismo , Estaciones del Año
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