Gas Exchange in Relation to Nitrogen and Phosphorus Distribution in the Onion Root Tip

1956 ◽  
Vol 117 (3) ◽  
pp. 223-231 ◽  
Author(s):  
W. E. Norris,
Keyword(s):  
Gas Exchange ◽  
Root Tip ◽  
Nitrogen And Phosphorus ◽  
Onion Root ◽  
Phosphorus Distribution

scholarly journals Effects of Maytenus ilicifolia Mart. and Bauhinia candicans Benth infusions on onion root-tip and rat bone-marrow cells

2002 ◽  
Vol 25 (1) ◽  
pp. 85-89 ◽  
Author(s):  
Marjori Leiva Camparoto ◽  
Rosangela de Oliveira Teixeira ◽  
Mário Sérgio Mantovani ◽  
Veronica Elisa Pimenta Vicentini
Keyword(s):  
Bone Marrow ◽  
Bone Marrow Cells ◽  
Root Tip ◽  
Onion Root ◽  
Maytenus Ilicifolia ◽  
Rat Bone ◽  
Marrow Cells

scholarly journals Element budgets in an Arctic mesocosm CO<sub>2</sub> perturbation study

2012 ◽  
Vol 9 (8) ◽  
pp. 11885-11924 ◽  
Author(s):  
J. Czerny ◽  
K. G. Schulz ◽  
T. Boxhammer ◽  
R. G. J. Bellerby ◽  
J. Büdenbender ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Ocean Acidification ◽  
Nutrient Dynamics ◽  
Temporal Dynamics ◽  
Nitrogen And Phosphorus ◽  
Nutrient Pools ◽  
Dissolved Organics ◽  
Elemental Stoichiometry ◽  
Element Budgets ◽  
Wall Growth

Abstract. Recent studies on the impacts of ocean acidification on pelagic communities have identified changes in carbon to nutrient dynamics with related shifts in elemental stoichiometry. In principle, mesocosm experiments provide the opportunity of determining the temporal dynamics of all relevant carbon and nutrient pools and, thus, calculating elemental budgets. In practice, attempts to budget mesocosm enclosures are often hampered by uncertainties in some of the measured pools and fluxes, in particular due to uncertainties in constraining air/sea gas exchange, particle sinking, and wall growth. In an Arctic mesocosm study on ocean acidification using KOSMOS (Kiel Off-Shore Mesocosms for future Ocean Simulation) all relevant element pools and fluxes of carbon, nitrogen and phosphorus were measured, using an improved experimental design intended to narrow down some of the mentioned uncertainties. Water column concentrations of particulate and dissolved organic and inorganic constituents were determined daily. New approaches for quantitative estimates of material sinking to the bottom of the mesocosms and gas exchange in 48 h temporal resolution, as well as estimates of wall growth were developed to close the gaps in element budgets. Future elevated pCO2 was found to enhance net autotrophic community carbon uptake in 2 of the 3 experimental phases but did not significantly affect particle elemental composition. Enhanced carbon consumption appears to result in accumulation of dissolved organic compounds under nutrient recycling summer conditions. This carbon over-consumption effect becomes evident from budget calculations, but was too small to be resolved by direct measurements of dissolved organics. The out-competing of large diatoms by comparatively small algae in nutrient uptake caused reduced production rates under future ocean CO2 conditions in the end of the experiment. This CO2 induced shift away from diatoms towards smaller phytoplankton and enhanced cycling of dissolved organics was pushing the system towards a retention type food chain with overall negative effects on export potential.

Gas-Exchange Rates in a Small Lake as Determined by the Radon Method

1973 ◽  
Vol 30 (10) ◽  
pp. 1475-1484 ◽  
Author(s):  
Steve Emerson ◽  
Wallace Broecker ◽  
D. W. Schindler
Keyword(s):  
Exchange Rate ◽  
Gas Exchange ◽  
Exchange Rates ◽  
Partial Pressure ◽  
Lake Water ◽  
Radon Concentration ◽  
Natural Waters ◽  
Carbon Dioxide Partial Pressure ◽  
Nitrogen And Phosphorus ◽  
Gas Exchange Rate

The radon method, used previously in ocean-atmosphere systems, is used here to determine the gas-exchange rate between the atmosphere and lake 227 of the Experimental Lakes Area. Fertilization of the lake with nitrogen and phosphorus caused the carbon dioxide partial pressure in the lake water to drop well below atmospheric levels; hence, in order to better understand the carbon budget of the lake, an estimate of the CO2 gas-exchange rate was necessary.To determine gas-exchange rates by measuring radon evasion to the atmosphere the source of radon in the lake water must be dissolved radium. Since the radon concentration in lakes derives not only from the decay of dissolved radium but also from the inflow of radon-rich groundwaters, radium was added to the lake to increase the radon concentration well above this fluctuating background level. Although this procedure was complicated by algal uptake of the radium in the lake (Emerson and Hesslein 1973), we were able to place limits on the gas-exchange rate.Our results indicate that the "stagnant boundary layer" thickness is approximately 300 μ. This value is among the largest observed in natural waters. Using this value and the partial pressure of CO2 in the lake water we have calculated an invasion rate of 17 ± 8 mmoles CO2/m2 day.

Tea planting affects soil acidification and nitrogen and phosphorus distribution in soil

2018 ◽  
Vol 254 ◽  
pp. 20-25 ◽  
Author(s):  
Peng Yan ◽  
Chen Shen ◽  
Lichao Fan ◽  
Xin Li ◽  
Liping Zhang ◽  
...  
Keyword(s):  
Soil Acidification ◽  
Nitrogen And Phosphorus ◽  
Phosphorus Distribution

Carbon, Nitrogen, and Phosphorus Distribution in Particle Size-Fractionated Separated Pig and Cattle Slurry

2011 ◽  
Vol 40 (1) ◽  
pp. 224-232 ◽  
Author(s):  
Karin Peters ◽  
Maibritt Hjorth ◽  
Lars Stoumann Jensen ◽  
Jakob Magid
Keyword(s):  
Particle Size ◽  
Cattle Slurry ◽  
Nitrogen And Phosphorus ◽  
Phosphorus Distribution
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