Light intensity regulates stoichiometry of benthic grazers through changes in the quality of stream periphyton

2019 ◽  
Vol 38 (2) ◽  
pp. 391-405 ◽  
Author(s):  
Nicolás Martyniuk ◽  
Beatriz Modenutti ◽  
Esteban G. Balseiro
Keyword(s):  
Light Intensity ◽  
Stream Periphyton

Beech sapling architecture following small and medium gap disturbances in silver fir-beech old-growth forests in Slovenia

2005 ◽  
Vol 156 (12) ◽  
pp. 481-486 ◽  
Author(s):  
Jurij Diaci ◽  
Lahorka Kozjek
Keyword(s):  
Light Intensity ◽  
Quality Characteristics ◽  
Stem Length ◽  
Silver Fir ◽  
Beech Forests ◽  
Vertical Growth ◽  
Relative Light Intensity ◽  
Stem Bending ◽  
Negative Effect

The objective of our research was to examine the effect of canopy shading on beech sapling architecture in the oldgrowth silver fir-beech forests of Pecka and Rajhenavski Rog. In August 2003 we sampled one plot (352 m2) in a large gap in Pecka, which was a result of a strong windstorm in 1983, and eight small gaps (26–78 m2) with similar sapling heights (3.8–8 m). A ground view of each gap was drawn including the characteristics of gap border trees and the density of separate sapling layers was recorded. The height and diameter were measured for each sapling, as well as the following quality characteristics on selected dominant saplings: width of the crown,number of larger branches and knots (>1/3 DBH), intensity of stem bending, deviation from vertical growth, number of terminal shoots, and the type of damage. The results show a negative effect of high canopy shading (estimated relative light intensity was below 5%) on the architectural quality of saplings. A lower overall density of saplings, greater intensity of bending and deviation from vertical growth, a shorter stem length without branches, a larger number of saplings with two terminal shoots, and a larger number of damaged saplings were observed in small gaps.

Enteric Bacteria Survival Factors

1992 ◽  
Vol 25 (12) ◽  
pp. 93-103 ◽  
Author(s):  
M. Pommepuy ◽  
J. F. Guillaud ◽  
E. Dupray ◽  
A. Derrien ◽  
F. Le Guyader ◽  
...  
Keyword(s):  
Water Quality ◽  
Light Intensity ◽  
Sewage Treatment ◽  
Enteric Bacteria ◽  
Bactericidal Effect ◽  
Mediterranean Coast ◽  
Shellfish Farming ◽  
Two Parameters ◽  
Very High

In order to improve bacterial water quality of shellfish farming areas, studies were conducted in the English Channel (Morlaix) and on the Mediterranean coast (Toulon). These two areas were chosen in order to compare behaviour of fecal bacteria in two different ecosystems. In the estuary of Morlaix sediments are polluted by way of settlement, but most of the bacteria are mixed with turbid waters and are able to survive a very long time (T90 are in a range of several hours to several days). By measuring the increase in salt tolerance of the strains grown in natural organic matter, it was demonstrated that Salmonella can tolerate coastal water salinities. Moreover, because light penetration is prevented by suspended matter, the solar bactericidal effect is very low. On the contrary, through lack of nutrients and very high sunlight intensity, die-off rates in Mediterranean waters are very high (at the surface T90 are less than 2 hours, and several hours in deep waters). A close relationship was found between the light intensity received by bacteria and the T90. Predicted T90 must be found using these two parameters(including turbidity and deep effect on light intensity). The authors suggest that precautions must be taken to carry out impact studies depending on water quality of the area, especially in turbid areas. The knowledge of these mechanisms is very important to evaluate waste water impact on the quality of shellfish farming areas, and to improve elimination of fccal bacteria in sewage treatment plants.

Growth and quality of sprouts of six vegetables cultivated under different light intensity and quality

2015 ◽  
Vol 56 (4) ◽  
pp. 437-443 ◽  
Author(s):  
Yurina Kwack ◽  
Kyoung Koo Kim ◽  
Hyunseung Hwang ◽  
Changhoo Chun
Keyword(s):  
Light Intensity

scholarly journals Influence of Light Intensity on the Yield and Quality of Houttuynia cordata

2015 ◽  
Vol 18 (4) ◽  
pp. 522-528 ◽  
Author(s):  
Aimin Li ◽  
Shenghua Li ◽  
Xianjin Wu ◽  
Hongmei Lu ◽  
Min Huang ◽  
...  
Keyword(s):  
Light Intensity ◽  
Houttuynia Cordata ◽  
Yield And Quality

scholarly journals Vernalization Duration and Light Intensity Influence Flowering of Three Hybrid Nobile Dendrobium Cultivars

HortScience ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 406-410 ◽  
Author(s):  
Min Lin ◽  
Terri W. Starman ◽  
Yin-Tung Wang ◽  
Genhua Niu
Keyword(s):  
Light Intensity ◽  
Flowering Time ◽  
Photon Flux ◽  
Flower Initiation ◽  
Flower Longevity ◽  
Photosynthetic Photon Flux ◽  
Flower Diameter ◽  
Flower Quality ◽  
Delayed Flowering

The flowering time and flower quality of three hybrid Dendrobium nobile cultivars in relation to light intensity during cooling and duration of vernalization were studied in the first experiment. Mature Dendrobium Red Emperor ‘Prince’, Den. Sea Mary ‘Snow King’, and Den. Love Memory ‘Fizz’ plants were vernalized at 10 °C under 300 to 350 μmol·m−2·s−1 photosynthetic photon flux (PPF) (12-h photoperiod) or darkness, each with four cooling durations (2, 4, 6, or 8 weeks). Plants were forced in a greenhouse after vernalization. At least 4 weeks of 10 °C cooling in light was needed for complete flower initiation of Den. Red Emperor ‘Prince’, whereas Den. Sea Mary ‘Snow King’ and Den. Love Memory ‘Fizz’ only needed 2 weeks of 10 °C cooling regardless of light. For all three cultivars, darkness during vernalization slightly delayed flowering and resulted in fewer but larger flowers. Longer cooling duration delayed flowering, decreased flower longevity, and produced more and larger flowers. In a second experiment, Den. Love Memory ‘Fizz’ plants were vernalized at 15 °C for 4 weeks under a 12-h photoperiod and PPF of 0, 50, 100, or 200 μmol·m−2·s−1. Compared with 200 μmol·m−2·s−1, low PPF at 50 or 100 μmol·m−2·s−1 did not affect flowering time or flower qualities; however, darkness delayed flowering and reduced flower qualities except flower diameter.

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