scholarly journals How to Choose a Hydrological Recovery Mode for Degraded Semiarid Wetland in China? A Case Study on Restoration of Phragmites australis Saline-Alkaline Wetland

2020 ◽  
Vol 12 (23) ◽  
pp. 10103
Author(s):  
Shuling Yu ◽  
Xiaoyu Li ◽  
Subang An ◽  
Yanli Yang ◽  
Na Zhang ◽  
...  
Keyword(s):  
Plant Height ◽  
Phragmites Australis ◽  
Photosynthetic Parameters ◽  
Occurrence Time ◽  
Photosynthetic Physiology ◽  
High K ◽  
Flooding Duration ◽  
Flooding Frequency ◽  
Flooding Depth ◽  
And Function

Hydrological recovery is the basis for restoring the structure and function of wetlands in semiarid and arid areas of China. Selecting an appropriate hydrological recovery mode may be helpful for improving the effectiveness of wetland restoration. We conducted pot experiments to study the effects of the flooding frequency, duration, depth, and occurrence time on the height, biomass, ion contents, and photosynthetic physiology of Phragmites australis in degraded saline–alkaline marsh in the West Songnen Plain, China. At the end of the growing season, we found that the biomass, photosynthetic parameters, and water use efficiency (WUE) of the leaves increased, whereas the Na+ concentration decreased, and the K+ content remained unchanged under an increased flooding frequency treatment. As the flooding depth increased, the plant height increased, but there were no differences in the photosynthetic parameters, biomass, and WUE under flooding at 5 cm and 10 cm. Under different flooding duration treatments, the plant height and biomass were greater, but the photosynthetic parameters and Na+ and K+ contents were lower under a flooding duration of three months. The flooding occurrence time had little effect on the growth of P. australis. Our results indicate that the flooding frequency and duration had greater effects than the flooding depth and occurrence time in the hydrological recovery model for P. australis restoration. The biomass accumulated by P. australis was related to lower Na+ contents and the maintenance of a high K+/Na+ contents, and WUE increased by adjusting photosynthesis under a moderate flooding frequency and duration. These results have important implications for the restoration of degraded semiarid wetlands with man-made channel systems in conditions with limited freshwater resources.

scholarly journals Effects of different levels of flooding and additional application of two nutrients on boro rice (Binadhan-8) in saline soil

2015 ◽  
Vol 2 (3) ◽  
pp. 439-443
Author(s):  
Md Zahir Raihan ◽  
Md Saeed Hasan ◽  
Abu Zofar Md. Moslehuddin ◽  
Md Mahbubul Alam Tarafder ◽  
Md Ekramul Haque
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Growth And Yield ◽  
Panicle Length ◽  
Yield Attributes ◽  
Straw Yield ◽  
Remarkable Effect ◽  
Continuous Flooding ◽  
Flooding Duration ◽  
Boro Rice

A field experiment was conducted at Kalikapur village of Kaliganj upazila under Satkhira district in order to observe the effects of flooding duration and additional application of K and S on transplanted boro rice cv. Binadhan-8 during January - May 2013. The experiment was laid out in a split-plot design where the main plots comprised of five flooding levels viz. continuous flooding (W1), flooding for 10 days (W2), flooding for 20 days (W3), flooding for 30 days (W4), flooding for 40 days (W5), and the sub-plots of four additional (over the recommended dose) nutrients rates viz. S43 + K25 (T1), K38 (T2), S32 + K38 (T3), and K50 (T4), with three replications. The duration of flooding showed significant positive effect on the yield and yield components of boro rice cv. Binadhan-8. The highest values for plant height (106.8 cm), panicle length (28.4 cm), number of plants hill-1 (15.3), grain yield (4.8 t ha-1) and straw yield (6.5 t ha-1) were recorded in continuous flooding (W1) while these values were decreased with the decrease in the duration of flooding from 40 days to 10 days. Additional application of K and S also significantly influenced all of the parameters. Results revealed that the highest values for plant height (102.8 cm), panicle length (26.6 cm), plants hill-1 (15.4), 1000-grain weight (23.9 g), grain yield (4.8 t ha-1) and straw yield (6.1t ha-1) were obtained from T3 where S and K were applied @ 32 and 38 Kg ha-1 in addition to the recommended fertilizer rate. The interaction of flooding and nutrients significantly manipulated the yield and yield attributes. Due to interaction of flooding and nutrients, the highest growth and yield was observed in continuous flooding with S32 + K38 (W1T3). The results indicated that the flooding with fresh water and use of additional nutrients (K and S) had a remarkable effect in growing boro rice cv. Binadhan-8 in saline soils of Bangladesh.Res. Agric., Livest. Fish.2(3): 439-443, December 2015

Myosin isoform shifts and decreased reactivity in hypoxia-induced hypertensive pulmonary arterial muscle

1998 ◽  
Vol 274 (5) ◽  
pp. L775-L785 ◽  
Author(s):  
C. S. Packer ◽  
J. E. Roepke ◽  
N. H. Oberlies ◽  
R. A. Rhoades
Keyword(s):  
Pulmonary Hypertension ◽  
Wall Thickness ◽  
Structural Changes ◽  
Male Rats ◽  
Response Curves ◽  
High K ◽  
Alveolar Hypoxia ◽  
Pulmonary Arterial ◽  
Pulmonary Arterial Smooth Muscle ◽  
And Function

The principal stimulus that evokes pulmonary hypertension is chronic alveolar hypoxia. Pulmonary hypertension is associated with remodeling of the vessel walls, involving hypertrophy and hyperplasia of pulmonary arterial smooth muscle (PASM) and a concomitant increase in the deposition of connective tissue, resulting in increased wall thickness. The purpose of the present study was to determine the effect of hypoxia-induced hypertension on the structure and function of PASM. Experiments were designed to determine whether hypoxia-induced pulmonary hypertension is associated with alterations in PASM: 1) reactivity to a variety of agonists, 2) contractile protein proportions and isoforms, and 3) structural properties. Young adult male rats were made hypoxic by lowering the fraction of inspired O2 (10%) for 14 days. Pulmonary arterial segments were isolated and dose-response curves to various agonists (high K+, norepinephrine, serotonin, angiotensin II, and adenosine) were generated. Gel electrophoresis was used to measure changes in the relative amounts of actin or myosin and of myosin heavy chain (MHC) isoforms. Structural changes were correlated with the pharmacological and biochemical data. Hypoxia-induced pulmonary hypertension caused a general decreased reactivity, an increase in the proportion of nonmuscle to muscle MHC isoforms in PASM, and an increase in arterial wall thickness with PASM hypertrophy or hyperplasia.

scholarly journals Environmental conditions of a salt-marsh biodiversity experiment on the island of Spiekeroog (Germany)

2018 ◽  
Author(s):  
Oliver Zielinski ◽  
Daniela Meier ◽  
Kertu Löhmus ◽  
Thorsten Balke ◽  
Michael Kleyer ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Ecosystem Functioning ◽  
Intertidal Zone ◽  
Field Experiments ◽  
Data Quality Control ◽  
Data Loggers ◽  
Flooding Duration ◽  
Flooding Frequency ◽  
Set Up ◽  
Wave Recorder

Abstract. Field experiments investigating biodiversity and ecosystem functioning require observation of abiotic parameters, especially when carried out in the intertidal zone. An experiment for biodiversity-ecosystem functioning at the intersection of land and sea was set up in the intertidal zone of the back-barrier salt marsh of Spiekeroog Island in the German Bight. Here we report the accompanying instrumentation, maintenance, data acquisition, data handling and data quality control as well as monitoring results observed over a continuous period from September 2014 through April 2017. Time series of abiotic conditions were measured at several sites in the vicinity of newly built experimental "salt-marsh islands" on the tidal flat. Meteorological measurements were conducted from a weather station (WS, doi:10.1594/PANGAEA.870988), oceanographic conditions were sampled through a bottom mounted recording current meter (RCM, doi:10.1594/PANGAEA.877265) and a bottom mounted tide and wave recorder (TWR, doi:10.1594/PANGAEA.877258). Tide data are essential to calculate flooding duration and flooding frequency with respect to different salt marsh elevation zones. Data loggers (DL) for measuring water level (DL-W, doi:10.1594/PANGAEA.877267), temperature (DL-T, doi:10.1594/PANGAEA.877257), light intensity (DL-L, doi:10.1594/PANGAEA.877256) and conductivity (DL-C, doi:10.1594/PANGAEA.877266) were deployed at different elevational zones within the experimental islands and the investigated salt marsh plots.

scholarly journals Economic assessment of flood damage

2021 ◽  
Vol 244 ◽  
pp. 10055
Author(s):  
Tatyana Miroshnikova
Keyword(s):  
Cost Model ◽  
Economic Assessment ◽  
Multivariate Regression Analysis ◽  
Flood Damage ◽  
Analysis Tool ◽  
Economic Criterion ◽  
Flood Resistance ◽  
Wear And Tear ◽  
Flooding Duration ◽  
Flooding Depth

Flooding is a natural hazard. In this regard, the topic of floodprone area management is being actively explored. The study of this issue is a combination of two aspects - environmental and economic. The economic assessment of the consequences of flooding is a single cost model based on an economic criterion. Characteristics such as flooding depth, flooding duration and flooding rate have the greatest influence on the severity of subsequent damage. Standard damage tables are usually based on some damage versus flooding depth. Assuming that the conceptual basis for estimating damages is the same, the expected damages from flooding might be expected to vary between two countries if the flood characteristics are different and the damageability of properties varies between the two countries. The main factors identified by the authors in the course of the study, influencing the amount of damage from flooding, are: flood resistance group; existing physical wear and tear; flooding level. The damage is considered as a percentage of the decrease in the real value of the object. To improve the accuracy of determining flood damage, a multivariate regression analysis tool with the interdependence of influencing factors was selected. It should be noted that the most significant factor is the level (depth) of flooding. The factor of the flood resistance group, which depends on the capital group of the object, seems to be less significant. The least significant factor is the degree of physical deterioration of the object.

scholarly journals Photosynthetic Physiology Comparisons between No Tillage and Sod Culture of Citrus Farming in Different Seasons under Various Light Intensities

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1805
Author(s):  
Chung-I. Chen ◽  
Kuan-Hung Lin ◽  
Meng-Yuan Huang ◽  
Chih-Kai Yang ◽  
Yu-Hsiu Lin ◽  
...  
Keyword(s):  
Dark Respiration ◽  
Photosynthetic Apparatus ◽  
Net Photosynthesis ◽  
Photochemical Quenching ◽  
Photosynthetic Parameters ◽  
Light Quantum ◽  
No Tillage ◽  
Photosynthetic Physiology ◽  
Light Intensities ◽  
Different Seasons

Sod culture (SC) and no tillage (NT) are modern orchard management systems, and are two different bases for the sustainable development and production of citrus orchards in Taiwan. However, there is no information about the efficiency of either NT or SC on the photosynthetic physiology of farmed citrus under different seasons and varying light intensities. The objective of this study was to clarify the impacts of SC and NT under eco-friendly farming management on the photosynthetic apparatus of an important plantation citrus species in response to varying light intensities over the seasons. The results showed that Rd (dark respiration rate of CO2), Qy (light quantum yield of CO2), LCP (light compensation point), Amax (maximum net assimilation of CO2), and Fv/Fm values of citrus plants under SC were somewhat higher under NT in the same season, particularly in the fall and in winter. As light intensity increased from 200 to 2000 μmol photon m−2 s−1 PPFD, higher Pn (net photosynthesis rate), Gs (stomatal conductance), ETR (electron transport rate), NPQ (non-photochemical quenching), and Fv/Fm (potential quantum efficiency of PSII) values were observed in spring and summer compared to the fall and winter, and increasing NPQ and decreasing Fv/Fm values were observed in all seasons. Positive and significant correlations were shown between the Pn and Gs under NT and SC in all seasons with all light illuminations, whereas significant and negative relationships were observed between the ETR and NPQ under NT in fall and winter at 1200~2000 PPFD. In short, ETR was useful for non-destructive estimations of Pn and NPQ since these indices were significantly and positively correlated with ETR in citrus leaves exposed to 0~1200 PPFD in all seasons and 1200~2000 PPFD in spring, the fall, and winter, providing a quick means to identify the physiological condition of plants under various seasons and tillages. The precise management of photosynthetic parameters such as ETR in response to light irradiances under varied seasons also provides implications for sustainable citrus production for tillage cropping systems in future higher CO2 and potentially wetter or drier environments. The tillages may hold promise for maximizing the economic efficiency of the growth and development of citrus plants grown in the field.

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