scholarly journals Biogeochemical cycles of chlorine in the coniferous forest ecosystem: practical implications

2010 ◽  
Vol 56 (No. 8) ◽  
pp. 357-367 ◽  
Author(s):  
M. Matucha ◽  
N. Clarke ◽  
Z. Lachmanová ◽  
S.T. Forczek ◽  
K. Fuksová ◽  
...  
Keyword(s):  
Forest Ecosystem ◽  
Forest Ecosystems ◽  
Coniferous Forest ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Natural Ecosystems ◽  
Chlorinated Organic Compounds ◽  
The Czech Republic ◽  
Natural Processes ◽  
Chlorinated Organic

Chlorine – one of the most widespread elements on the Earth – is present in the environment as chloride ion or bound to organic substances. The main source of chloride ions is the oceans while organically bound chlorine (OCl) comes from various sources, including anthropogenic ones. Chlorinated organic compounds were long considered to be only industrial products; nevertheless, organochlorines occur plentifully in natural ecosystems. However, recent investigations in temperate and boreal forest ecosystems have shown them to be products of biodegradation of soil organic matter under participation of chlorine. It is important to understand both the inorganic and organic biogeochemical cycling of chlorine in order to understand processes in the forest ecosystem and dangers as a result of human activities, i.e. emission and deposition of anthropogenic chlorinated compounds as well as those from natural processes. The minireview presented below provides a survey of contemporary knowledge of the state of the art and a basis for investigations of formation and degradation of organochlorines and monitoring of chloride and organochlorines in forest ecosystems, which has not been carried out in the Czech Republic yet.

The Influence of Fires on Forest Ecosystems

2020 ◽  
pp. 345-366 ◽  
Author(s):  
Olga Anatolievna Pasko ◽  
Vasily Fedorovich Kovyavin ◽  
Nadezhda Anatolyevna Lebedeva
Keyword(s):  
Forest Ecosystem ◽  
Forest Fires ◽  
Forest Restoration ◽  
Forest Ecosystems ◽  
Negative Impact ◽  
Ground Cover ◽  
Social Consequences ◽  
Natural Ecosystems

The chapter focuses on the role of fire as an environmental factor affecting the components of the forest ecosystem. The classification of forest fires according to the fire location in the forest ecosystem is given. Negative impact of fire on communities and people, components of forest ecosystems: a phytocoenosis (the forest under-growth, understory, ground cover), tocinos (animal world), klimatop (atmosphere and climate) and adatom (topography and soil) are discussed. The role of fire as a factor of organisms and natural ecosystems' evolution in general is studied. The problems of forest restoration on fires (fumes) are considered. Research established that the degree of damage to the ecosystem components and social consequences depend on the forest fire type, natural conditions, and forest conditions of the region.

Wald und Klimawandel in der inneralpinen Trockenregion Visp

2012 ◽  
Vol 163 (12) ◽  
pp. 481-492
Author(s):  
Andreas Rigling ◽  
Ché Elkin ◽  
Matthias Dobbertin ◽  
Britta Eilmann ◽  
Arnaud Giuggiola ◽  
...  
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Forest Management ◽  
Forest Ecosystem ◽  
Bark Beetles ◽  
Forest Ecosystems ◽  
Field Experiments ◽  
Forest Monitoring ◽  
Management Interventions ◽  
Forest Ecosystem Services

Forest and climate change in the inner-Alpine dry region of Visp Over the past decades, observed increases in temperature have been particularly pronounced in mountain regions. If this trend should continue in the 21st Century, frequency and intensity of droughts will increase, and will pose major challenges for forest management. Under current conditions drought-related tree mortality is already an important factor of forest ecosystems in dry inner-Alpine valleys. Here we assess the sensitivity of forest ecosystems to climate change and evaluate alternative forest management strategies in the Visp region. We integrate data from forest monitoring plots, field experiments and dynamic forests models to evaluate how the forest ecosystem services timber production, protection against natural hazards, carbon storage and biodiver-sity will be impacted. Our results suggest that at dry low elevation sites the drought tolerance of native tree species will be exceeded so that in the longer term a transition to more drought-adapted species should be considered. At medium elevations, drought and insect disturbances as by bark beetles are projected to be important for forest development, while at high elevations forests are projected to expand and grow better. All of the ecosystem services that we considered are projected to be impacted by changing forest conditions, with the specific impacts often being elevation-dependent. In the medium term, forest management that aims to increase the resilience of forests to drought can help maintain forest ecosystem services temporarily. However, our results suggest that relatively rigid management interventions are required to achieve significant effects. By using a combination of environmental monitoring, field experiments and modeling, we are able to gain insight into how forest ecosystem, and the services they provide, will respond to future changes.

Calcium Budgets for Catchments as Interpreted by Strontium Isotopes

1989 ◽  
Vol 20 (2) ◽  
pp. 85-96 ◽  
Author(s):  
Gunnar Jacks ◽  
Göran Åberg ◽  
P. Joseph Hamilton
Keyword(s):  
Steady State ◽  
Forest Ecosystem ◽  
Coniferous Forest ◽  
Strontium Isotopes ◽  
Runoff Water ◽  
Weathering Rate ◽  
Weathering Rates ◽  
Exchangeable Calcium

Strontium isotopes in precipitation, soil and runoff water can be used to establish a ratio of wet plus dry deposited Sr to Sr released by weathering. This ratio is especially enhanced in areas with old acid Proterozoic rocks (0.6-2.5 Ga) and Archean rocks (>2.5 Ga). Since Sr and Ca behave in an analogous way in the coniferous forest ecosystem the results for Sr can be used for the determination of Ca. If the deposition of calcium can be calculated reasonably accurately the weathering rate can also be estimated. Five catchments have been investigated using this approach. Three of them seem to be close to a steady state, wherein the losses and gains of calcium to the system are equal. In the two southern-most catchments there seems to be an ongoing loss of exchangeable calcium. The loss by runoff occurs with sulphate being the dominant anion. Weathering rates of 1.5 to 4.8 kg Ca/ha year have been estimated.

Henry's constants and mass transfer coefficients of halogenated organic pollutants in an air stripping packed column

1998 ◽  
Vol 38 (6) ◽  
pp. 287-294 ◽  
Author(s):  
Pen-C. Chiang ◽  
Chung-H. Hung ◽  
J. C. Mar ◽  
E. E. Chang
Keyword(s):  
Mass Transfer ◽  
Methylene Chloride ◽  
Packed Column ◽  
Transfer Coefficients ◽  
Chlorinated Organic Compounds ◽  
Air Stripping ◽  
Mass Transfer Coefficients ◽  
Equilibrium Partition ◽  
Henry's Constants ◽  
Chlorinated Organic

Both Henry's constants and volumetric mass transfer coefficients (KLa) of eight priority chlorinated organic compounds including 1,1-dichloroethene, methylene chloride, chloroform, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and 1,4-dichlorobenzene in an air stripping packed column were investigated in this study. The liquid and gas phase EPICS (Equilibrium Partition in Closed System) and direct calculating methods were applied to determine the Henry's constants of VOCs. The interference of co-solute on Henry's constants was also investigated. Experimental results indicated that decrease in Henry's constants of VOCs was observed in the presence of humic acid but no apparent effect on Henry's constants was detected when there was NaCl and surfactant in solution. Four different configurations of packing media including Intalox Saddle, Super Intalox Saddle, Telleret, and Hedgehog made of polypropylene were respectively packed in the air stripping tower and investigated in the study. The dependence of hydraulic loading, air-water ratio, and configurations of packing media on mass transfer coefficients of VOCs was discussed.

scholarly journals Experimental Study and Simulation Calculation of the Chloride Resistance of Concrete under Multiple Factors

2021 ◽  
Vol 11 (12) ◽  
pp. 5322
Author(s):  
Yang Ding ◽  
Tong-Lin Yang ◽  
Hui Liu ◽  
Zhen Han ◽  
Shuang-Xi Zhou ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Penetration Depth ◽  
Chloride Ion ◽  
Cementitious Materials ◽  
Chloride Ions ◽  
Finite Element Software ◽  
Chloride Resistance ◽  
Simulation Calculation ◽  
Marine Concrete ◽  
Resistance Performance

Cement is widely used in marine concrete, and its resistance to chloride ion corrosion has been widely considered. In this paper, based on a laboratory test, the influence of different hydrostatic pressures, coarse aggregate contents and w/c ratios on the chloride resistance performance is analyzed. Based on COMSOL finite element software, a two-dimensional cementitious materials model is established, and the simulation results are compared with the experimental results. The results show that the penetration depth of chloride ions in cement increases with the increase of the w/c ratio. Under the hydrostatic pressure of 0 MPa, when the w/c ratio is 0.35, the penetration depth of chloride ions is 7.4 mm, and the simulation result is 8.0 mm. When the w/c ratio is 0.45, the penetration depth of chloride ions is 9.3 mm, and the simulation result is 9.9 mm. When the w/c ratio is 0.55, the penetration depth of chloride ions is 12.9 mm, and the simulation result is 12.1 mm. Under different hydrostatic pressures, the penetration depth of chloride ions obviously changes, and with the increase in hydrostatic pressure, the penetration depth of chloride ions deepens. Under the w/c ratio of 0.35, when the hydrostatic pressure is 0.5 MPa, the penetration depth of chloride ions is 11.3 mm, and the simulation result is 12.1 mm. When the hydrostatic pressure is 1.0 MPa, the penetration depth of chloride ions is 16.2 mm, and the simulation result is 17.5 mm.

scholarly journals Broadband dielectric spectroscopy for monitoring temperature-dependent chloride ion motion in BiOCl plates

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Adrian Radoń ◽  
Dariusz Łukowiec ◽  
Patryk Włodarczyk
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Spectroscopy ◽  
Low Frequency ◽  
Chloride Ion ◽  
Ion Source ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Broadband Dielectric Spectroscopy ◽  
Free Chloride ◽  
Structure Rebuilding

AbstractThe dielectric properties and electrical conduction mechanism of bismuth oxychloride (BiOCl) plates synthesized using chloramine-T as the chloride ion source were investigated. Thermally-activated structure rebuilding was monitored using broadband dielectric spectroscopy, which showed that the onset temperature of this process was 283 K. This rebuilding was related to the introduction of free chloride ions into [Bi2O2]2+ layers and their growth, which increased the intensity of the (101) diffraction peak. The electrical conductivity and dielectric permittivity were related to the movement of chloride ions between plates (in the low-frequency region), the interplanar motion of Cl− ions at higher frequencies, vibrations of these ions, and charge carrier hopping at frequencies above 10 kHz. The influence of the free chloride ion concentration on the electrical conductivity was also described. Structure rebuilding was associated with a lower concentration of free chloride ions, which significantly decreased the conductivity. According to the analysis, the BiOCl plate conductivity was related to the movement of Cl− ions, not electrons.

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