The vertical gradient of bark pH of twigs and macrolichens in a Picea abies canopy not affected by acid rain

2001 ◽  
Vol 33 (4) ◽  
pp. 353-359 ◽  
Author(s):  
Thale Kermit ◽  
Yngvar Gauslaa
Keyword(s):  
Picea Abies ◽  
Species Composition ◽  
Acid Rain ◽  
Vertical Gradient ◽  
Small Scale ◽  
High Ph ◽  
Ph Values ◽  
Constant Ph ◽  
Horizontal Variation ◽  
Cyanobacterial Lichens

AbstractThe pH of 192 thin, even-aged twigs from 4 height levels of 12 randomly selected trees within a boreal Picea abies canopy naturally exposed to rainfall with a high pH (>5·2) was measured. The largest variation in bark pH was due to the height above the ground. However, a highly significant horizontal variation between trees was also found, apparently due to small-scale soil variations. The biomass of alectorioid lichens increased with increasing height above die ground to at least 12 m, a height interval with fairly constant pH values. The uppermost twigs had an unusually high pH and an abnormal species composition for P. abies, with dominance of the foliose Melanelia exasperatula. The canopy hosted several cyanobacterial lichens, but these were scattered and had low biomass, restricted to lower branches of the trees with the highest bark pH.

Impact of climate and bulking materials on characteristics of compost from ecological toilets

2012 ◽  
Vol 2 (2) ◽  
pp. 79-86 ◽  
Author(s):  
James W. McKinley ◽  
Rebecca E. Parzen ◽  
Álvaro Mercado Guzmán
Keyword(s):  
Low Carbon ◽  
Pathogen Inactivation ◽  
High Ph ◽  
Moisture Contents ◽  
Urine Diversion ◽  
Ph Values ◽  
Dominant Process ◽  
Nitrogen Ratio ◽  
Storage Times ◽  
Carbon Concentrations

Urine-diversion dehydration toilets (UDDT) are common throughout the developing world, and the toilet product is widely used as compost. There is no comprehensive research to date that characterizes the compost to determine its quality, extent of pathogen inactivation, and the effects of climate and bulking materials on the compost. Compost was collected from 45 UDDT in Bolivia and analyzed for physical, chemical, and biological parameters. Eighty percent and 56% of samples did not meet acceptable compost guidelines for moisture content and pH, respectively, indicating desiccation was the dominant process in UDDT. Bulking materials significantly impacted compost characteristics in terms of pH, carbon, carbon-to-nitrogen ratio, and carbon stability (P < 0.05). Composts with ash exhibited, on average, low carbon concentrations (4.9%) and high pH values (9.7), which can be harmful to plants and composting microorganisms. Composts with sawdust exhibited, on average, high carbon concentrations (40.0%) and carbon-to-nitrogen ratios (31.0). Climate had no significant impact on chemical characteristics, however composts from humid regions had significantly higher moisture contents (34.4%) than those from arid climates (24.8%) (P < 0.05). Viable Ascaris lumbricoides ova were identified in 31% of samples, including samples with high pH, low moisture contents, and long storage times.

Scales of heterogeneity in prairie and forest

1999 ◽  
Vol 77 (3) ◽  
pp. 370-376 ◽  
Author(s):  
Heather R Kleb ◽  
Scott D Wilson
Keyword(s):  
Species Composition ◽  
Small Scale ◽  
Light Penetration ◽  
Pocket Gopher ◽  
Available N ◽  
Litter Mass ◽  
Thomomys Talpoides ◽  
Mixed Grass ◽  
Below Ground ◽  
Aspen Forest

Few studies have compared scales of heterogeneity among plant communities. We predicted that differences in the sizes of dominant species should allow us to detect small-scale (<256 cm) heterogeneity in mixed-grass prairie but not in adjacent aspen forest. We examined light penetration, soil moisture, available N, elevation, species composition, and plant mass at 10 locations in prairie and forest in both spring and summer. Variables were measured in 1-cm2 plots arranged in pairs separated by 0-256 cm. Several variables in prairie (elevation, litter mass, light penetration, and species composition) showed significant evidence for scale within the range examined. In contrast, only one variable in forest (light penetration in summer) showed evidence for scale in the same range. The scale of heterogeneity in prairie was consistent with the scale of two possible causes, species composition and elevation variability due to northern pocket gopher (Thomomys talpoides Richardson) activity, both of which varied significantly in prairie but not in forest. Whereas some aboveground factors (light and litter mass) varied within the range examined, belowground factors (water and N) did not, suggesting that the scale of heterogeneity differs between above- and below-ground factors. In total, the results suggest that differences in the scale of heterogeneity between prairie and forest reflect the relative sizes of the dominant plants.Key words: aspen, forest, heterogeneity, light, nitrogen, prairie, scale, soil, water.

scholarly journals Interhemispheric consistency of scale-dependent spatial variation in the structure of intertidal rocky-shore communities

2018 ◽  
Author(s):  
Alexis Catalán ◽  
Nelson Valdivia ◽  
Ricardo Scrosati
Keyword(s):  
Community Structure ◽  
Spatial Variation ◽  
Spatial Scales ◽  
Vertical Gradient ◽  
Sampling Interval ◽  
Biological Variation ◽  
Rocky Intertidal ◽  
Vertical Variation ◽  
Horizontal Variation ◽  
Sampling Intervals

In rocky intertidal environments, the vertical gradient of abiotic stress generates, directly or indirectly, significant spatial variation in community structure. Along shorelines within biogeographic regions, abiotic changes also generate horizontal biological variation, which when measured at large sampling intervals may surpass vertical biological variation. Little is known, however, on how vertical variation compares with horizontal variation measured at multiple spatial scales in habitats with similar environmental conditions. Here, we compare spatial variability in rocky-intertidal communities between vertical stress gradients and three horizontal spatial scales (sampling interval) across habitats experiencing the same wave exposure on the Northwest Atlantic (NWA) and Southeast Pacific (SEP) coasts. For both regions, the vertical variation in species richness and composition (Raup-Crick and Bray-Curtis indices) was higher than the variation measured at all horizontal scales, from a few cm to hundreds of km. The patterns of variation in community structure matched those of abundance for the dominant sessile organisms, the foundation species Ascophyllum nodosum (seaweed) in NWA and Perumytilus purpuratus (mussel) in SEP. This interhemispheric comparison reveals the tight link between environmental and biological variation, indicating that studies comparing spatial scales of biological variation must consider the underlying environmental variation in addition to simply scale alone.

scholarly journals Desorption of metals from Cetraria islandica (L.) Ach. Lichen using solutions simulating acid rain

2014 ◽  
Vol 66 (1) ◽  
pp. 273-284 ◽  
Author(s):  
Ana Cuculovic ◽  
Mirjana Pavlovic ◽  
Jelena Savovic ◽  
D.S. Veselinovic
Keyword(s):  
Detection Limit ◽  
Acid Rain ◽  
Metal Content ◽  
Strong Link ◽  
Ph Values ◽  
Metal Detection ◽  
Logarithmic Dependence ◽  
Solution Volume

Desorption of metals K, Al, Ca, Mg, Fe, Ba, Zn, Mn, Cu and Sr from Cetraria islandica (L.) with solutions whose composition was similar to that of acid rain, was investigated. Desorption of metals from the lichen was performed by five successive desorption processes. Solution mixtures containing H2SO4, HNO3 and H2SO4-HNO3 were used for desorption. Each solution had three different pH values: 4.61, 5.15 and 5.75, so that the desorptions were performed with nine different solutions successively five times, always using the same solution volume. The investigated metals can be divided into two groups. One group was comprised of K, Ca and Mg, which were desorbed in each of the five desorption processes at all pH values used. The second group included Al, Fe, Zn, Ba, Mn and Sr; these were not desorbed in each individual desorption and not at all pH values, whereas Cu was not desorbed at all under any circumstances. Using the logarithmic dependence of the metal content as a function of the desorption number, it was found that potassium builds two types of links and is connected with weaker links in lichen. Potassium is completely desorbed, 80% in the first desorption, and then gradually in the following desorptions. Other metals are linked with one weaker link (desorption 1-38%) and with one very strong link (desorption below the metal detection limit).

scholarly journals Interhemispheric consistency of scale-dependent spatial variation in the structure of intertidal rocky-shore communities

2018 ◽  
Author(s):  
Alexis Catalán ◽  
Nelson Valdivia ◽  
Ricardo Scrosati
Keyword(s):  
Community Structure ◽  
Spatial Variation ◽  
Spatial Scales ◽  
Vertical Gradient ◽  
Sampling Interval ◽  
Biological Variation ◽  
Rocky Intertidal ◽  
Vertical Variation ◽  
Horizontal Variation ◽  
Sampling Intervals

In rocky intertidal environments, the vertical gradient of abiotic stress generates, directly or indirectly, significant spatial variation in community structure. Along shorelines within biogeographic regions, abiotic changes also generate horizontal biological variation, which when measured at large sampling intervals may surpass vertical biological variation. Little is known, however, on how vertical variation compares with horizontal variation measured at multiple spatial scales in habitats with similar environmental conditions. Here, we compare spatial variability in rocky-intertidal communities between vertical stress gradients and three horizontal spatial scales (sampling interval) across habitats experiencing the same wave exposure on the Northwest Atlantic (NWA) and Southeast Pacific (SEP) coasts. For both regions, the vertical variation in species richness and composition (Raup-Crick and Bray-Curtis indices) was higher than the variation measured at all horizontal scales, from a few cm to hundreds of km. The patterns of variation in community structure matched those of abundance for the dominant sessile organisms, the foundation species Ascophyllum nodosum (seaweed) in NWA and Perumytilus purpuratus (mussel) in SEP. This interhemispheric comparison reveals the tight link between environmental and biological variation, indicating that studies comparing spatial scales of biological variation must consider the underlying environmental variation in addition to simply scale alone.

Comparative study of degradation of 4-chlorophenol by ultraviolet irradiation/sodium hypochlorite and ultraviolet irradiation/ozonation

2009 ◽  
Vol 9 (5) ◽  
pp. 601-609 ◽  
Author(s):  
J. Fu ◽  
J. Huang ◽  
Z. Liu ◽  
Q. F. Zeng ◽  
S. Q. An ◽  
...  
Keyword(s):  
Sodium Hypochlorite ◽  
Ultraviolet Irradiation ◽  
Pilot Scale ◽  
Economic Advantage ◽  
Photochemical Oxidation ◽  
Small Scale ◽  
Final Solution ◽  
Ph Values ◽  
Organic Halogens ◽  
Adsorbable Organic Halogens

The photochemical oxidation of 4-chlorophenol solutions by ultraviolet irradiation/sodium hypochlorite (UV/NaClO) and ultraviolet irradiation/ozonation (UV/O3) respectively was studied in a pilot scale photochemical reactor. The degradation efficiency of UV/NaClO was lower than that of UV/O3. The final UV absorption removals of the two processes were approximately 80% and approximately 90% respectively. During the two processes, dihydroxylated chlorophenols were the main intermediates. And pH values decreased with the oxidation being carried on. However, the UV/NaClO process was incomplete and some adsorbable organic halogens, such as ethyl 2-chloroacetate, 3,4-dichlorobut-3-en-2-one, ethyl 2,2-dichloroacetate, 2-chloro-1,1-diethoxyethane, ethyl 2,2,2-trichloroacetate and 2,4,6-trichlorophenol, still existed in the final solution. The costs of the two processes were also estimated. On a small scale, UV/NaClO process had significant economic advantage.

Variability in organic matter lost by combustion in a boreal bog during the 2001 Chisholm fire

2003 ◽  
Vol 33 (12) ◽  
pp. 2509-2513 ◽  
Author(s):  
Brian W Benscoter ◽  
R Kelman Wieder
Keyword(s):  
Organic Matter ◽  
Species Composition ◽  
Spatial Variability ◽  
Spatial Variation ◽  
Fire Severity ◽  
Small Scale ◽  
Western Canada ◽  
Direct Combustion ◽  
Site Variation

Fire directly releases carbon (C) to the atmosphere through combustion of biomass. An estimated 1470 ± 59 km2 of peatland burns annually in boreal, western Canada, releasing 4.7 ± 0.6 Tg C to the atmosphere via direct combustion. We quantified within-site variation in organic matter lost via combustion in a bog peatland in association with the 116 000-ha Chisholm, Alberta, fire in 2001. We hypothesized that for peatlands with considerable small-scale microtopography (bogs and treed fens), hummocks will burn less than hollows. We found that hollows exhibit more combustion than hummocks, releasing nearly twice as much C to the atmosphere. Our results suggest that spatial variability in species composition and site hydrology within a landform and across a landscape could contribute to considerable spatial variation in the amounts of C released via combustion during peatland fire, although the magnitude of this variation may be dependent on fire severity.

Resistance of Spirulina platensis to Ammonia at High pH Values

1991 ◽  
Vol 32 (7) ◽  
pp. 953-958 ◽  
Author(s):  
Shimshon Belkin ◽  
Sammy Boussiba
Keyword(s):  
Spirulina Platensis ◽  
High Ph ◽  
Ph Values

scholarly journals Snowdrift modelling in a wind tunnel: vertical and horizontal variation of the snow flux

1998 ◽  
Vol 26 ◽  
pp. 212-216 ◽  
Author(s):  
Florence Naaim-Bouvet ◽  
Mohamed Naaim
Keyword(s):  
Wind Tunnel ◽  
Cross Section ◽  
Critical Examination ◽  
Small Scale ◽  
Geometrical Parameters ◽  
Drifting Snow ◽  
Horizontal Variation ◽  
Storm Duration ◽  
Recent Developments ◽  
Mean Wind Speed

This paper deals with the influence of the vertical and horizontal variation of Aeolian snow flux on estimations of snow-storm duration and on snowdrift patterns simulated in a wind tunnel.First of all, we shall review recent developments, including our own simulations, concerning the horizontal increase of mass flux until drifting-snow saturation has been reached.Next, after a critical examination of various snowdrift-modelling criteria, we present the results of an experiment undertaken in our wind tunnel: We studied cross-section drill-area changes behind a small-scale snow fence as a function of time for different fetches but for the same mean wind speed at the beginning of the testing section. For each fetch, we carried out vertical profiles of sand particles using image processing and we studied the geometrical parameters of the drift. We conclude dial changes in the cross-section drift area depend on the ablation length and if particle saturation is not reached, the use of a storm-duration scale leads to Overevaluation of prototype storm duration. Moreover, we point out that drift pattern vary as a function of the concentration profiles.

scholarly journals Production of butyric acid at constant pH by a solventogenic strain of Clostridium beijerinckii

2020 ◽  
Vol 38 (No. 3) ◽  
pp. 185-191 ◽  
Author(s):  
Marek Drahokoupil ◽  
Petra Patáková
Keyword(s):  
Flow Cytometry ◽  
Butyric Acid ◽  
Population Viability ◽  
Clostridium Beijerinckii ◽  
Clostridium Tyrobutyricum ◽  
Fluorescence Staining ◽  
Low Concentration ◽  
Ph Values ◽  
Constant Ph ◽  
Acetone Butanol Ethanol

A solventogenic strain of Clostridium beijerinckii, NRRL B-598, was cultured for the production of butyric acid as the main fermentation product. However, unlike typical acetone-butanol-ethanol (ABE) fermentations, where pH is not regulated, in this study the pH was kept constant during fermentation. From the five pH values tested, 6.0, 6.5, 7.0, 7.5 and 8.0, pH 6.5 and 7.0 resulted in the highest concentrations of butyric acid, at 9.69 ± 0.09 g L–1 and 11.5 ± 0.39 g L–1, respectively. However, a low concentration of solvents, 1.8 ± 0.22 g L–1, was only reached at pH 7.0. These results are comparable with those from typical butyric acid producers, i.e. Clostridium butyricum and Clostridium tyrobutyricum strains. At pH 7.0, we succeeded in suppressing sporulation and prolonging the population viability, which was confirmed by flow cytometry combined with double fluorescence staining.

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