scholarly journals Nutrient Absorption by the Submerged Macrophyte Egeria densa Planch.: Effect of Ammonium and Phosphorus Availability in the Water Column on Growth and Nutrient Uptake

Limnetica ◽  
2002 ◽  
Vol 21 (1) ◽  
pp. 93-104
Author(s):  
Claudia Feijóo
Keyword(s):  
Nutrient Uptake ◽  
Water Column ◽  
Phosphorus Availability ◽  
Nutrient Absorption ◽  
Submerged Macrophyte ◽  
Egeria Densa

Effects of Pb stress on nutrient uptake and secondary metabolism in submerged macrophyte Vallisneria natans

2011 ◽  
Vol 74 (5) ◽  
pp. 1297-1303 ◽  
Author(s):  
Chao Wang ◽  
Jie Lu ◽  
Songhe Zhang ◽  
PeiFang Wang ◽  
Jun Hou ◽  
...  
Keyword(s):  
Nutrient Uptake ◽  
Secondary Metabolism ◽  
Submerged Macrophyte ◽  
Pb Stress ◽  
Vallisneria Natans

Effects of high ammonium enrichment in water column on the clonal growth of submerged macrophyte Vallisneria natans

2018 ◽  
Vol 25 (32) ◽  
pp. 32735-32746 ◽  
Author(s):  
Qingyang Rao ◽  
Xuwei Deng ◽  
Haojie Su ◽  
Wulai Xia ◽  
Yao Wu ◽  
...  
Keyword(s):  
Water Column ◽  
Clonal Growth ◽  
Submerged Macrophyte ◽  
Vallisneria Natans

Review lecture: Ectomycorrhizas as nutrient absorbing organs

1978 ◽  
Vol 203 (1150) ◽  
pp. 1-21 ◽  
Keyword(s):  
Oxygen Uptake ◽  
Nutrient Uptake ◽  
Metabolic Control ◽  
Nutrient Absorption ◽  
Factors Affecting ◽  
Phosphate Absorption ◽  
Linear Relations

Early work on ectomycorrhizas indicated that they were probably adapted to efficient nutrient absorption. The use of excised mycorrhizas has allowed study of their properties as absorbing organs. The factors affecting their rates of nutrient uptake are similar to those of other absorbing organs but their rates are often greater. On absorption the nutrient is primarily accumulated in the fungal layer but may be mobilized later by reactions under metabolic control. Phosphate is accumulated in particularly large quantities as polyphosphate, which probably explains the linear relations of phosphate absorption and oxygen uptake in certain conditions. Hyphal connections between the fungal sheath and the substrate are variable, and this poses problems about absorption of ions of low mobility, and about the function of surface phosphatases. The fungal sheath is dependent on the host for carbohydrate and the drain on it may be considerable.

scholarly journals Nutrient uptake of the criolla potato (Solanum phureja var. Galeras) for the determination of critical nutritional levels

2014 ◽  
Vol 32 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Carlos A. Suarez M. ◽  
Jaime Torres B.
Keyword(s):  
Statistical Analysis ◽  
Economic Analysis ◽  
Nutrient Uptake ◽  
Critical Level ◽  
Block Design ◽  
Nutrient Absorption ◽  
Repeated Measurements ◽  
Solanum Phureja ◽  
Over Time

Based on the nutrient uptake of the criolla potato (Solanum phureja var. Galeras), the critical nutritional levels were determined on a farm in the Carrizal district of the municipality of Granada (Cundinamarca). Five fertilizing treatments were used: 0 fertilization (control), commercial control (CC), proposed recommendation + 50% (PR + 50%), proposed recommendation (PR), proposed recommendation - 50% (PR - 50%); organized with a random complete block design with three repetitions and repeated measurements over time; in each one, the material and nutrient absorption were evaluated in four phonological stages; in which the harvest, yield and profitability were measured. It was observed that the dry material increased rapidly until 113 days after planting (dap) and was higher in treatments CC and PR + 50% with 8,818 and 7,743 kg ha-1 , respectively. The statistical analysis showed that the elements: N, P, K, Ca, Mg, S, Zn, Cu and B did not present significant differences over time after 77 dap in treatments CC and PR + 50%. There were no significant differences in yield for treatments CC and PR + 50% but there were significant differences between these treatments and the others. The economic analysis showed that treatment CC had the highest profitability, confirming this as the critical level for the Galeras variety in Granada (Cundinamarca).

scholarly journals Uptake and Effects of Cylindrospermopsin: Biochemical, Physiological and Biometric Responses in The Submerged Macrophyte Egeria densa Planch

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2997
Author(s):  
Nelida Cecilia Flores-Rojas ◽  
Maranda Esterhuizen
Keyword(s):  
Surface Waters ◽  
Prolonged Exposure ◽  
Plant Biomass ◽  
Growth Stimulation ◽  
Antioxidative Enzyme ◽  
Submerged Macrophyte ◽  
Protein Synthesis Inhibition ◽  
Egeria Densa ◽  
Environmental Concentrations ◽  
Antioxidative Enzyme Activities

Cylindrospermopsin (CYN) is being detected in surface waters more commonly and frequently worldwide. This stable, extracellular cyanotoxin causes protein synthesis inhibition, thus posing a risk to aquatic biota, including macrophytes, which serve as primary producers. Nevertheless, data regarding the effects caused by environmental concentrations of CYN is still limited. In the presented study, the uptake of CYN at environmental concentrations by the submerged macrophyte Egeria densa was investigated. Bioaccumulation, changes in the plant biomass, as well as shoot-length were assessed as responses. Variations in the cellular H2O2 levels, antioxidative enzyme activities, as well as concentrations and ratios of the photosynthetic pigments were also measured. E. densa removed 54% of CYN within 24 h and up to 68% after 336 h; however, CYN was not bioaccumulated. The antioxidative enzyme system was activated by CYN exposure. Pigment concentrations decreased with exposure but normalized after 168 h. The chlorophyll a to b ratio increased but normalized quickly thereafter. Carotenoids and the ratio of carotenoids to total chlorophylls increased after 96 h suggesting participation in the antioxidative system. Growth stimulation was observed. The ability to remove CYN and resistance to CYN toxicity within 14 days proved E. densa as suitable for phytoremediation; nonetheless, prolonged exposure (32 days) resulted in adverse effects related to CYN uptake, which needs to be studied further.

Residence Time in Hyporheic Bioactive Layers Explains Nutrient Uptake in Streams

2021 ◽  
Author(s):  
Eugènia Martí ◽  
Angang Li ◽  
Susana Bernal ◽  
Brady Kohler ◽  
Steven A. Thomas ◽  
...  
Keyword(s):  
Nutrient Uptake ◽  
Water Column ◽  
Residence Time ◽  
Hyporheic Zone ◽  
Morphological Characteristics ◽  
Subsurface Water ◽  
Water Residence Time ◽  
Stream Channels ◽  
Nutrient Spiraling ◽  
Tracking Model

<p>Human activities negatively impact water quality by supplying excessive nutrients to streams. To investigate the capacity of streams to take up nutrients from the water column, we usually add nutrients to stream reaches, calculate the fraction of added nutrients that is taken up, and identify the environmental conditions controlling nutrient uptake. A common idea is that nutrient uptake increases with increasing water residence time because of increased contact time between solutes and organisms. Yet, water residence time only partially explains the temporal and spatial variability of nutrient uptake, and the reasons behind this variability are still not well understood. In this talk I’ll present a study which shows that good characterization of spatial heterogeneity of surface-subsurface flow paths and bioactive hot spots within streams is essential to understanding the mechanisms of in-stream nutrient uptake. The basis of this study arises from the use and interpretation of nutrient uptake results from the Tracer Additions for Spiraling Curve Characterization (TASCC) method. This model has been rapidly adopted to interpret in-stream nutrient spiraling metrics (e.g, nutrient uptake) over a range of concentrations from breakthrough curves (BTCs) obtained during pulse solute injection experiments. TASCC analyses often identify hysteresis in the relationship between spiraling metrics and concentration as nutrient concentration in BTCs rises and falls. The mechanisms behind these hysteresis patterns have yet to be determined. We hypothesized that difference in the time a solute is exposed to bioactive environments (i.e., biophysical opportunity) between the rising and falling limbs of BTCs causes hysteresis in TASCCs. We tested this hypothesis using nitrate empirical data from a solute addition combined with a process-based particle-tracking model representing travel times and transformations along each flow path in the water column and hyporheic zone, from which the bioactive zone comprised only a thin superficial layer. In-stream nitrate uptake was controlled by hyporheic exchange and the cumulative time nitrate spend in the bioactive layer. This bioactive residence time generally increased from the rising to the falling limb of the BTC, systematically generating hysteresis in the TASCC curves. Hysteresis decreased when nutrient uptake primarily occurred in the water column compared to the hyporheic zone, and with increasing the distance between the injection and sampling points. Hysteresis increased with the depth of the hyporheic bioactive layer. Our results indicate that the organisms responsible for nutrient uptake are confined within a thin layer in the stream sediments and that the bioactive residence time at the surface-subsurface water interface is important for nutrient uptake. I will end the talk illustrating how these findings can have important implications for in-stream nutrient uptake within the context of restoration practices addressed to modify the hydro-morphological characteristics of stream channels.</p>

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