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1.
Ecotoxicol Environ Saf ; 147: 306-312, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28858703

RESUMEN

In order to investigate the tolerance and bioaccumulation of Cd and Cu in the halophyte Sesuvium portulacastrum, seedlings were hydroponically cultured for 30 days using the modified 1/2 Hoagland nutrient solution with different concentrations of Cd (0, 5, 10, 15, and 20mgL-1) and Cu (0, 2.5, 5, 7.5, and 10mgL-1). Afterwards, the seedling height, leaf area, biomass, and mineral element contents (Fe, Mg, Cu, and Zn) in the roots, stems and leaves were measured, and the tolerance index, bioconcentration factor (BCF), transportation index, and removal rate were calculated. The effects of salinity (0‰-30‰) on the growth and bioaccumulation ability of S. portulacastrum under combined Cu/Cd (5mgL-1) exposure were also determined. The results showed that, with an increasing Cd concentration, the biomass and seedling height of S. portulacastrum initially increased and then decreased. The highest leaf biomass and seedlings height was observed in the 10mgL-1 and 5mgL-1 Cd treatment group, respectively. Salinity did not affect the biomass of S. portulacastrum but decreased Cd concentration in roots and aboveground tissues and Cu concentration in roots of S. portulacastrum. Cu treatment significantly facilitated the absorption of Mg, Cu, and Zn in roots. With an increasing Cu concentration, the Mg and Fe contents increased in the leaves of S. portulacastrum. In comparison to the above-ground portions, the root showed a higher bioaccumulation ability of Cd and Cu, with the BCF of 341.5 and 211.9, respectively. The BCF and translocation factor (TF) values indicated that S. portulacastrum was not a hyperaccumulator for Cd and Cu, but could be used as a phytostablization plant in heavy metal contaminated coastal environments.


Asunto(s)
Aizoaceae/efectos de los fármacos , Cadmio/metabolismo , Cobre/metabolismo , Plantas Tolerantes a la Sal/efectos de los fármacos , Contaminantes Químicos del Agua/metabolismo , Aizoaceae/crecimiento & desarrollo , Biodegradación Ambiental , Biomasa , Tolerancia a Medicamentos , Hidroponía , Salinidad , Plantas Tolerantes a la Sal/crecimiento & desarrollo
2.
Int J Appl Earth Obs Geoinf ; 48: 96-109, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29599664

RESUMEN

To assess growing season conditions where ground based observations are limited or unavailable, food security and agricultural drought monitoring analysts rely on publicly available remotely sensed rainfall and vegetation greenness. There are also remotely sensed soil moisture observations from missions like the European Space Agency (ESA) Soil Moisture and Ocean Salinity (SMOS) and NASA's Soil Moisture Active Passive (SMAP), however these time series are still too short to conduct studies that demonstrate the utility of these data for operational applications, or to provide historical context for extreme wet or dry events. To promote the use of remotely sensed soil moisture in agricultural drought and food security monitoring, we use East Africa as a case study to evaluate the quality of a 30+ year time series of merged active-passive microwave soil moisture from the ESA Climate Change Initiative (CCI-SM). Compared to the Normalized Difference Vegetation index (NDVI) and modeled soil moisture products, we found substantial spatial and temporal gaps in the early part of the CCI-SM record, with adequate data coverage beginning in 1992. From this point forward, growing season CCI-SM anomalies were well correlated (R>0.5) with modeled, seasonal soil moisture, and in some regions, NDVI. We use correlation analysis and qualitative comparisons at seasonal time scales to show that remotely sensed soil moisture can add information to a convergence of evidence framework that traditionally relies on rainfall and NDVI in moderately vegetated regions.

3.
Sci Rep ; 13(1): 3411, 2023 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-36854885

RESUMEN

Hydrologic extremes often involve a complex interplay of several processes. For example, flood events can have a cascade of impacts, such as saturated soils and suppressed vegetation growth. Accurate representation of such interconnected processes while accounting for associated triggering factors and subsequent impacts of flood events is difficult to achieve with conceptual hydrological models alone. In this study, we use the 2019 flood in the Northern Mississippi and Missouri Basins, which caused a series of hydrologic disturbances, as an example of such a flood event. This event began with above-average precipitation combined with anomalously high snowmelt in spring 2019. This series of anomalies resulted in above normal soil moisture that prevented crops from being planted over much of the corn belt region. In the present study, we demonstrate that incorporating remote sensing information within a hydrologic modeling system adds substantial value in representing the processes that lead to the 2019 flood event and the resulting agricultural disturbances. This remote sensing data infusion improves the accuracy of soil moisture and snowmelt estimates by up to 16% and 24%, respectively, and it also improves the representation of vegetation anomalies relative to the reference crop fraction anomalies.

4.
Mar Pollut Bull ; 131(Pt A): 416-421, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29886966

RESUMEN

Sesuvium portulacastrum was treated with mixture of copper, zinc, and cadmium for 60 days, with the concentration of each metal ranging from 0 to 20 mg/L. The tolerance of plants and bioaccumulation of heavy metals were then investigated. The height of S. portulacastrum decreased significantly with increasing heavy metal concentrations from 1 to 20 mg/L. The biomass was adversely impacted when the concentration exceeded 5 mg/L. There were no significant differences in malondialdehyde (MDA) concentration among different treatment groups, while the soluble protein content and superoxide dismutase (SOD) activity decreased with increasing heavy metal concentration. However, the BCF values of the three metals were all higher than 10 and the tolerance in root was up to 1000 mg/kg without causing significant growth inhibition, suggesting that S. portulacastrum should be a potential candidate for phytostabilization for the phytoremediation of polymetallic contaminations in coastal environments.


Asunto(s)
Aizoaceae/efectos de los fármacos , Cadmio/farmacocinética , Cobre/toxicidad , Zinc/farmacocinética , Aizoaceae/crecimiento & desarrollo , Aizoaceae/metabolismo , Biodegradación Ambiental , Biomasa , Cadmio/toxicidad , China , Malondialdehído/metabolismo , Proteínas de Plantas/metabolismo , Plantas Tolerantes a la Sal/efectos de los fármacos , Plantas Tolerantes a la Sal/crecimiento & desarrollo , Plantas Tolerantes a la Sal/metabolismo , Superóxido Dismutasa/metabolismo , Zinc/toxicidad
5.
Sci Data ; 4: 170012, 2017 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-28195575

RESUMEN

Seasonal agricultural drought monitoring systems, which rely on satellite remote sensing and land surface models (LSMs), are important for disaster risk reduction and famine early warning. These systems require the best available weather inputs, as well as a long-term historical record to contextualize current observations. This article introduces the Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS), a custom instance of the NASA Land Information System (LIS) framework. The FLDAS is routinely used to produce multi-model and multi-forcing estimates of hydro-climate states and fluxes over semi-arid, food insecure regions of Africa. These modeled data and derived products, like soil moisture percentiles and water availability, were designed and are currently used to complement FEWS NET's operational remotely sensed rainfall, evapotranspiration, and vegetation observations. The 30+ years of monthly outputs from the FLDAS simulations are publicly available from the NASA Goddard Earth Science Data and Information Services Center (GES DISC) and recommended for use in hydroclimate studies, early warning applications, and by agro-meteorological scientists in Eastern, Southern, and Western Africa.

6.
Ying Yong Sheng Tai Xue Bao ; 21(2): 391-8, 2010 Feb.
Artículo en Zh | MEDLINE | ID: mdl-20462011

RESUMEN

Based on the theories of wetland ecosystem health and by using "Pressure-State-Response" model, a health assessment indicator system for Qi' ao Island mangrove wetland ecosystem in Pearl River Estuary was built, and the assessment indices, assessment criteria, indices weighted values, assessment grades, and assessment methods were established to assess the health state of this ecosystem. In 2008, the overall health index of this ecosystem was 0.6580, health level was of grade II (healthy), and the pressure, state, and response indices were 0.3469, 0.8718, and 0.7754, respectively, suggesting that this ecosystem was good in state and response, but still had definite pressure. As a provincial nature reserve, this ecosystem was to be further improved in its health level. However, the research on the health assessment of mangrove wetland ecosystem was still young. Further studies should be made on the selection of assessment indices, long-term oriented monitoring of these indices, and quantification of the relations between ecosystem health level and ecosystem services.


Asunto(s)
Salud Ambiental , Modelos Teóricos , Rhizophoraceae/crecimiento & desarrollo , Humedales , China , Medición de Riesgo , Ríos
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