scholarly journals Survey on the behavior of flood induced particulate nutrients in a lake.

1985 ◽  
Vol 8 (4) ◽  
pp. 233-238 ◽  
Author(s):  
Hiroaki MORITA ◽  
Yukio YAMADA ◽  
Tokuji ANNAKA
Keyword(s):  
Particulate Nutrients

scholarly journals A novel approach of combining isotopic and geochemical signatures to differentiate the sources of sediments and particulate nutrients from different land uses

2019 ◽  
Vol 655 ◽  
pp. 129-140 ◽  
Author(s):  
Mohammad Bahadori ◽  
Chengrong Chen ◽  
Stephen Lewis ◽  
Mehran Rezaei Rashti ◽  
Freeman Cook ◽  
...  
Keyword(s):  
Land Uses ◽  
Novel Approach ◽  
Particulate Nutrients

scholarly journals Floodplain plant productivity is better predicted by particulate nutrients than by dissolved nutrients in floodwater

2018 ◽  
Vol 119 ◽  
pp. 54-63 ◽  
Author(s):  
F.M. Keizer ◽  
G.H. Van der Lee ◽  
P.P. Schot ◽  
I. Kardel ◽  
A. Barendregt ◽  
...  
Keyword(s):  
Plant Productivity ◽  
Dissolved Nutrients ◽  
Particulate Nutrients

Influences of a River Dam on Delivery and Fate of Sediments and Particulate Nutrients to the Adjacent Estuary: Case Study of Conowingo Dam and Chesapeake Bay

2019 ◽  
Vol 42 (8) ◽  
pp. 2072-2095 ◽  
Author(s):  
Cindy M. Palinkas ◽  
Jeremy M. Testa ◽  
Jeffrey C. Cornwell ◽  
Ming Li ◽  
Lawrence P. Sanford
Keyword(s):  
Chesapeake Bay ◽  
Particulate Nutrients

scholarly journals The energetics of passive suspension feeding: ecological and evolutionary consequences for crinoids

1992 ◽  
Vol 6 ◽  
pp. 20-20
Author(s):  
Tomasz K. Baumiller
Keyword(s):  
Current Velocity ◽  
Behavioral Flexibility ◽  
Standard Metabolic Rate ◽  
Evolutionary Rates ◽  
Energy Deficit ◽  
Passive Suspension ◽  
Energy Expenditures ◽  
Extinction Rates ◽  
Evolutionary Innovation ◽  
Particulate Nutrients

Do organismal characteristics influence evolutionary histories of taxa? This important question has been answered in the affirmative for a variety of organisms, and here it is applied to the echinoderm class Crinoidea. The approach used in answering this question involves (1) identifying a relevant trait through functional analysis, (2) demonstrating its ecological significance, and (3) testing the hypothesis that the ecological characteristics affect evolutionary rates.Crinoids, like all passive suspension feeders, depend on externally driven flows to supply them with necessary particulate nutrients. Particles are captured with feeding appendages which function as filters. Filters act as obstacles to the flow and their morphology influences how much fluid can be filtered at a given current velocity: fine filters, because of their higher resistance to flow, sample less fluid and fewer potential food items than coarse filters. This suggests that filter morphology may be important in controlling the distributions of crinoids among different environments: at low current velocities fine-filtered crinoids may not capture sufficient particulate nutrients to satisfy their energy needs.To quantify the effect of filter morphology on particulate nutrient capture, an energy budget equation was solved for two crinoid morphologies representing the fine (pinnulate) and coarse (non-pinnulate) filters. In this equation, energy inputs in the form of captured and metabolized nutrients had to exceed energy expenditures, expressed as the standard metabolic rate. The solution of the equation showed that the current velocity below which crinoids are at an energy deficit is higher for the fine-filtered (pinnulate) than the coarse-filtered (non-pinnulate) taxa.The higher minimum velocity of fine-filtered crinoids restricts them to environments with higher current velocities; coarse-filtered taxa are less constrained and may occupy a broader range of environments. This pattern is borne out by the distribution of Mississippian crinoids studied by Kammer and Ausich (1987). With regard to current velocities, the fine-filtered crinoids may be described as “specialists” and the coarse-filtered crinoids as “generalists”. The specialist/generalist strategies of the two groups suggest an evolutionary scenario in which the fine-filtered crinoids are more prone to speciation and extinction.To test the above scenario the evolutionary rates of two morphological groups, fine-filtered crinoids (camerates) and coarse-filtered crinoids (non-pinnulate Paleozoic crinoids), were compared. As predicted, the former group had higher extinction and origination rates. A “bootstrapping” technique revealed that the differences in extinction rates were statistically significant (P < 0.05).The filter morphology-evolutionary rate scenario, however, fails to predict the durations of two other fine-filtered (pinnulate) crinoid groups: the Paleozoic cladids and their descendants, the post-Paleozoic articulates. Though fine-filtered, these taxa had broad environmental distributions and the lowest extinction rates among the Crinoidea. They are also the only crinoids with muscular arm articulations. This “evolutionary innovation”, by allowing a greater degree of morphological and behavioral flexibility, allowed these crinoids to occupy a broader range of environments and may in part explain their “anomalous” evolutionary rates.

Effects of sheep grazing episodes on sediment and nutrient loss in overland flow

Soil Research ◽  
2004 ◽  
Vol 42 (2) ◽  
pp. 213 ◽  
Author(s):  
A. H. Elliott ◽  
W. T. Carlson
Keyword(s):  
Overland Flow ◽  
Infiltration Rate ◽  
Nutrient Loss ◽  
Late Winter ◽  
Nutrient Loads ◽  
Sheep Grazing ◽  
Bare Ground ◽  
Nitrogen And Phosphorus ◽  
Particulate Nutrients ◽  
Grass Growth

The effect of sheep grazing on the loss of sediment and nutrients in overland flow was investigated on a hill-country farm in the Waikato, New Zealand. The losses were measured in runoff produced artificially with small (0.5 m2) and large (1050 m2) rainfall simulators. Immediately after intensive winter grazing, rainfall applied at high intensity increased concentrations by a factor of 13–16 for sediment and particulate nutrients, 33–76 for dissolved reactive phosphorus and ammonium-nitrogen, and 5–7 for dissolved organic nitrogen and phosphorus. During summer, when there was less removal of vegetative cover, there was a smaller effect of grazing. The concentrations of sediment and particulate nutrients in overland flow were strongly correlated with the percentage of bare ground. The concentrations returned to background levels within 6 weeks after grazing, and the infiltration rate and ground cover also recovered from grazing in this time. The small rainfall simulator experiments showed that the infiltration rate decreases with grazing, which results in greater runoff after grazing. The greater runoff combines with the increased concentrations to give higher loads after grazing. In late winter, the infiltration rates were approximately half the summer values and the soil erodibility was approximately double, so the risk of high sediment and nutrient loads is greatest in winter, especially considering the higher rainfall and lower grass growth. The management implications are that exposure of bare ground associated with intensive grazing should be avoided, especially in winter.

scholarly journals A novel bioassay to assess phytoplankton responses to soil-derived particulate nutrients

2018 ◽  
Vol 636 ◽  
pp. 1470-1479 ◽  
Author(s):  
Hannah M. Franklin ◽  
Alexandra Garzon-Garcia ◽  
Joanne Burton ◽  
Philip W. Moody ◽  
Robert W. De Hayr ◽  
...  
Keyword(s):  
Particulate Nutrients

Spatial and seasonal variations, partitioning and fluxes of dissolved and particulate nutrients in Jiaozhou Bay

2018 ◽  
Vol 171 ◽  
pp. 140-149 ◽  
Author(s):  
Huamao Yuan ◽  
Jinming Song ◽  
Jianwei Xing ◽  
Xuegang Li ◽  
Ning Li ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Jiaozhou Bay ◽  
Particulate Nutrients

scholarly journals Hydromorphological restoration stimulates river ecosystem metabolism

2017 ◽  
Vol 14 (7) ◽  
pp. 1989-2002 ◽  
Author(s):  
Benjamin Kupilas ◽  
Daniel Hering ◽  
Armin W. Lorenz ◽  
Christoph Knuth ◽  
Björn Gücker
Keyword(s):  
Ecosystem Functioning ◽  
Open Channel ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
Ecosystem Metabolism ◽  
Transient Storage ◽  
Ecosystem Structure ◽  
Goods And Services ◽  
Wetted Area ◽  
Particulate Nutrients

Abstract. Both ecosystem structure and functioning determine ecosystem status and are important for the provision of goods and services to society. However, there is a paucity of research that couples functional measures with assessments of ecosystem structure. In mid-sized and large rivers, effects of restoration on key ecosystem processes, such as ecosystem metabolism, have rarely been addressed and remain poorly understood. We compared three reaches of the third-order, gravel-bed river Ruhr in Germany: two reaches restored with moderate (R1) and substantial effort (R2) and one upstream degraded reach (D). Hydromorphology, habitat composition, and hydrodynamics were assessed. We estimated gross primary production (GPP) and ecosystem respiration (ER) using the one-station open-channel diel dissolved oxygen change method over a 50-day period at the end of each reach. Moreover, we estimated metabolic rates of the combined restored reaches (R1 + R2) using the two-station open-channel method. Values for hydromorphological variables increased with restoration intensity (D  <  R1  <  R2). Restored reaches had lower current velocity, higher longitudinal dispersion and larger transient storage zones. However, fractions of median travel time due to transient storage were highest in R1 and lowest in R2, with intermediate values in D. The share of macrophyte cover of total wetted area was highest in R2 and lowest in R1, with intermediate values in D. Station R2 had higher average GPP and ER than R1 and D. The combined restored reaches R1 + R2 also exhibited higher GPP and ER than the degraded upstream river (station D). Restoration increased river autotrophy, as indicated by elevated GPP : ER, and net ecosystem production (NEP) of restored reaches. Temporal patterns of ER closely mirrored those of GPP, pointing to the importance of autochthonous production for ecosystem functioning. In conclusion, high reach-scale restoration effort had considerable effects on river hydrodynamics and ecosystem functioning, which were mainly related to massive stands of macrophytes. High rates of metabolism and the occurrence of dense macrophyte stands may increase the assimilation of dissolved nutrients and the sedimentation of particulate nutrients, thereby positively affecting water quality.

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