Vegetation patterns in the North Black River peatland, northern Minnesota

1983 ◽  
Vol 61 (8) ◽  
pp. 2085-2104 ◽  
Author(s):  
Paul H. Glaser
Keyword(s):  
Water Chemistry ◽  
Landsat Imagery ◽  
Specific Conductivity ◽  
Aerial Photographs ◽  
Raised Bogs ◽  
The North ◽  
Poor Fen ◽  
Wide Range ◽  
Vegetation Water ◽  
Ph Range

Raised bogs and water tracks in the 193-km2 North Black River peatland in northern Minnesota were examined in relation to the vegetation, water chemistry, and surficial water movements as inferred from infrared aerial photographs, LANDSAT imagery, and orthophoto topographic maps. Two noda of bog vegetation were distinguished by the Braun–Blanquet system; both bog noda are associated with relatively dilute, acidic waters (pH range 3.9–4.1; Ca2+ concentration range 0.6–1.6 mg L−1; specific conductivity, Kcorr range 1.3–83 μS cm−1). Rich-fen vegetation in contrast is more variable within this peatland and generally occurs in water tracks with a correspondingly wide range of pH (range 5.0–6.2), Ca2+ concentration (range 3.6–30.4 mg L−1), and Kcorr (range 31 to 182 μS cm−1). Poor-fen vegetation was most distinguishable by the transitional nature of its vegetation and water chemistry with at least a few minerotrophic indicator species present in all cases and intermediate ranges in pH (3.7–5.2), Ca2+ concentration (0.6–5.5 mg L−1), and Kcorr (16–72 μS cm−1). Bog and fen patterns in this peatland are consistently related to topographic features along the upland crest of each peatland watershed, indicating that topography controls the path of minerotrophic runoff draining onto the peatland, and thus creating zones with either enriched minerotrophic flow (in which water tracks develop) or stagnation zones (where bogs develop) on the peatland downslope.

Sphagnum-dominated peatlands of the hyperoceanic British Columbia coast: patterns in surface water chemistry and vegetation

1990 ◽  
Vol 20 (6) ◽  
pp. 696-711 ◽  
Author(s):  
Dale H. Vitt ◽  
Diana G. Horton ◽  
Nancy G. Slack ◽  
Nils Malmer
Keyword(s):  
British Columbia ◽  
Surface Water ◽  
Water Chemistry ◽  
Detrended Correspondence Analysis ◽  
Chloride Ion ◽  
Surface Water Chemistry ◽  
Raised Bogs ◽  
Queen Charlotte Islands ◽  
Poor Fen ◽  
Species Groups

Vegetation from 133 relevés representing a broad spectrum of peatland types from the Prince Rupert area, British Columbia was divided into six relevé groups. The 210 taxa found in these relevés were classified into six species groups. In general, the species groups are related to one another along shade and height (above water level) gradients. Chemical and physiographic gradients that correlate with the relevé distribution pattern on a detrended correspondence analysis ordination are surface water chemistry, shade, and height. In particular, the major gradient influencing the first axis of the ordination is shade. The second axis of the ordination is related to a complex chemical gradient in which hydrogen ion, calcium, and sulphate are the most important components. These chemical changes are influenced by ombrotrophy. Surface water chemistry patterns show enriched ionic conditions on Graham Island (Queen Charlotte Islands), with a decrease inland. Especially important is the decrease of sodium and chloride ion. The peatlands studied include ombrotrophic bogs and soligenous fens. Raised bogs were found in basins, whereas blanket bogs occurred on gentle slopes at the most oceanic site. Pinuscontorta Loud. var. contorta is most abundant on ombrotrophic sites, whereas Chamaecyparisnootkatensis (Lamb.) Spach is dominant in soligenous fens. Soligenous poor fen, characterized by high Sphagnum abundance in lawns and forest islands and pH of 4.4–6.6, is the peatland type most frequently encountered in the study area.

pH-Dependent Thermal Stability of Vibrio cholerae L-asparaginase

2019 ◽  
Vol 26 (10) ◽  
pp. 743-750 ◽  
Author(s):  
Remya Radha ◽  
Sathyanarayana N. Gummadi
Keyword(s):  
Vibrio Cholerae ◽  
Conformational Changes ◽  
Kinetic Studies ◽  
Structural Features ◽  
Structure Stability ◽  
Kcal Mole ◽  
Scanning Calorimetry ◽  
Wide Range ◽  
Ph Dependent ◽  
Ph Range

Background:pH is one of the decisive macromolecular properties of proteins that significantly affects enzyme structure, stability and reaction rate. Change in pH may protonate or deprotonate the side group of aminoacid residues in the protein, thereby resulting in changes in chemical and structural features. Hence studies on the kinetics of enzyme deactivation by pH are important for assessing the bio-functionality of industrial enzymes. L-asparaginase is one such important enzyme that has potent applications in cancer therapy and food industry.Objective:The objective of the study is to understand and analyze the influence of pH on deactivation and stability of Vibrio cholerae L-asparaginase.Methods:Kinetic studies were conducted to analyze the effect of pH on stability and deactivation of Vibrio cholerae L-asparaginase. Circular Dichroism (CD) and Differential Scanning Calorimetry (DSC) studies have been carried out to understand the pH-dependent conformational changes in the secondary structure of V. cholerae L-asparaginase.Results:The enzyme was found to be least stable at extreme acidic conditions (pH< 4.5) and exhibited a gradual increase in melting temperature from 40 to 81 °C within pH range of 4.0 to 7.0. Thermodynamic properties of protein were estimated and at pH 7.0 the protein exhibited ΔG37of 26.31 kcal mole-1, ΔH of 204.27 kcal mole-1 and ΔS of 574.06 cal mole-1 K-1.Conclusion:The stability and thermodynamic analysis revealed that V. cholerae L-asparaginase was highly stable over a wide range of pH, with the highest stability in the pH range of 5.0–7.0.

scholarly journals Evaluating the efficacy of technical measures: a case study of selection device legislation in the UK Crangon crangon (brown shrimp) fishery

2008 ◽  
Vol 65 (2) ◽  
pp. 267-275 ◽  
Author(s):  
Tom L. Catchpole ◽  
Andrew S. Revill ◽  
James Innes ◽  
Sean Pascoe
Keyword(s):  
Brown Shrimp ◽  
Crangon Crangon ◽  
Shrimp Fishery ◽  
The North ◽  
Ex Post ◽  
Wide Range ◽  
The Uk ◽  
The Impact ◽  
Technical Measures

Abstract Catchpole, T. L., Revill, A. S., Innes, J., and Pascoe, S. 2008. Evaluating the efficacy of technical measures: a case study of selection device legislation in the UK Crangon crangon (brown shrimp) fishery. – ICES Journal of Marine Science, 65: 267–275. Bycatch reduction devices are being introduced into a wide range of fisheries, with shrimp and prawn fisheries particularly targeted owing to the heavy discarding common in these fisheries. Although studies are often undertaken to estimate the impact of a technical measure on the fishery before implementation, rarely have the impacts been assessed ex post. Here, the efficacy of the UK legislation pertaining to the use of sievenets in the North Sea Crangon crangon fishery is assessed. Three impacts were evaluated: on fisher behaviour (social), on the level of bycatch (biological), and on vessel profitability (economic). An apparent high level of compliance by skippers was identified despite a low level of enforcement. The estimated reduction in fleet productivity following the introduction of the legislation was 14%, equalling the mean loss of Crangon landings when using sievenets calculated from catch comparison trawls. Sievenets did reduce the unnecessary capture of unwanted marine organisms, but were least effective at reducing 0-group plaice, which make up the largest component of the bycatch. Clearly the legislation has had an effect in the desired direction, but it does not address sufficiently the bycatch issue in the Crangon fishery.

Editorial

2021 ◽  
Vol 23 (1) ◽  
pp. 1-4
Author(s):  
Eva Cendon ◽  
John Butcher
Keyword(s):  
Further Education ◽  
University Education ◽  
Small Scale ◽  
Widening Participation ◽  
The North ◽  
Research Activities ◽  
International Perspectives ◽  
Wide Range ◽  
International Sector ◽  
The Uk

This general edition of the journal provides insights and results of research employing a wide range of approaches and perspectives on widening participation and lifelong learning. Studies from across the UK and international sector utilise different methodological approaches, and as such are particularly interesting, with diverse methods and ways of analysis, including phenomenographic, narrative, and thematic analysis. Overall, the articles range from exploratory case studies and small-scale research to wider range and broad scale studies, highlighting different facets and perspectives. Furthermore, the articles in this volume cover a broad spectrum of institutions and places involved in widening participation, with an emphasis on the (higher) education sector in the UK balanced by international perspectives. The first seven empirical articles are based on research activities in a secondary school, a youth centre, in further education colleges (usually focusing on post-compulsory secondary or pre-university education), in so-called post-92 universities (new(er) universities, formerly Polytechnics and teacher training colleges), and last but not least in a research intensive Russell Group university. They reported challenges from the specific local contexts of different regions in England, from the South (Chichester) to London to the North (Carlisle), and can usefully be framed in the context of international discussions appearing later in the journal.

scholarly journals The influence of the 1991/92 drought on the woody vegetation of the Kruger National Park

Koedoe ◽  
1995 ◽  
Vol 38 (2) ◽  
Author(s):  
A.J. Viljoen
Keyword(s):  
National Park ◽  
Woody Species ◽  
Aerial Photographs ◽  
Woody Vegetation ◽  
General Area ◽  
Variable Intensity ◽  
The North ◽  
Olifants River ◽  
Area North ◽  
The Impact

All observations and data related to the impact of the 1991/92 drought on the woody vegetation, excluding the riverine vegetation of major rivers, are summarised. This includes data from a visual estimate of damage from aerial photographs, surveys on selected sites, and general observations. Despite lower rainfall, the area north of the Olifants River (excluding the far-northern part) was less affected than the area south of it, suggesting that the woody vegetation in the north is more adapted to drought. A characteristic of the drought was the localised distribution pattern and variable intensity of damage to the same species in the same general area. Information on 31 species are presented briefly. Although a large number of woody species was to some extent damaged, when the woody vegetation is considered as a whole, the influence of the drought was not very severe.

scholarly journals Characterizing Soil Physical Properties for Soil Moisture Monitoring with the North Carolina Environment and Climate Observing Network

2012 ◽  
Vol 29 (7) ◽  
pp. 933-943 ◽  
Author(s):  
Weinan Pan ◽  
R. P. Boyles ◽  
J. G. White ◽  
J. L. Heitman
Keyword(s):  
North Carolina ◽  
Soil Moisture ◽  
Physical Properties ◽  
Soil Properties ◽  
Water Content ◽  
Bulk Density ◽  
Soil Physical Properties ◽  
The North ◽  
Wide Range ◽  
Soil Moisture Monitoring

Abstract Soil moisture has important implications for meteorology, climatology, hydrology, and agriculture. This has led to growing interest in development of in situ soil moisture monitoring networks. Measurement interpretation is severely limited without soil property data. In North Carolina, soil moisture has been monitored since 1999 as a routine parameter in the statewide Environment and Climate Observing Network (ECONet), but with little soils information available for ECONet sites. The objective of this paper is to provide soils data for ECONet development. The authors studied soil physical properties at 27 ECONet sites and generated a database with 13 soil physical parameters, including sand, silt, and clay contents; bulk density; total porosity; saturated hydraulic conductivity; air-dried water content; and water retention at six pressures. Soil properties were highly variable among individual ECONet sites [coefficients of variation (CVs) ranging from 12% to 80%]. This wide range of properties suggests very different behavior among sites with respect to soil moisture. A principal component analysis indicated parameter groupings associated primarily with soil texture, bulk density, and air-dried water content accounted for 80% of the total variance in the dataset. These results suggested that a few specific soil properties could be measured to provide an understanding of differences in sites with respect to major soil properties. The authors also illustrate how the measured soil properties have been used to develop new soil moisture products and data screening for the North Carolina ECONet. The methods, analysis, and results presented here have applications to North Carolina and for other regions with heterogeneous soils where soil moisture monitoring is valuable.

Yanik Tepe, Shengavit, and the Khirbet Kerak Ware

1965 ◽  
Vol 15 ◽  
pp. 165-167 ◽  
Author(s):  
Ruth Amiran
Keyword(s):  
Surface Treatment ◽  
Central Anatolia ◽  
Single Element ◽  
The North ◽  
Great Affinity ◽  
Wide Range

The problem dealt with in the following note, concisely worded in the title, has been occupying the attention of many scholars for quite some time, but seems now to have anchored at a haven, from which further research is already in progress. It may be considered a generally consented assumption, that the phenomenon of the Kh. Kerak Ware (which comprises all the occurrences of this distinctive ware, from Tabara el Akrad Levels IV–I, Amuq Phase H, Hama Niveau K5 in the north, to all the sites in Palestine, as far south as Jericho Tomb A, Tomb F4, etc.) is part of a much larger phenomenon, which stretches over a much wider area. It is evident that we cannot understand a single element, the Kh. Kerak Ware, unless we see it as belonging to a whole phenomenon. It is the great affinity, indeed almost homogeneity of the pottery, both shapes, surface treatment and decoration, which unifies the whole wide range of separated regions, from Transcaucasia (the Kura-Arax culture of B. Kuftin), Armenia and Azerbaidjan, through Eastern and Central Anatolia, to the whole length of the Levant, into one phenomenon.

Neptunium(V) Sorption Behavior on Clinoptilolite, Quartz and Montmorillonite

1995 ◽  
Vol 412 ◽  
Author(s):  
F. P. Bertetti ◽  
R. T. Pabalan ◽  
D. R. Turner ◽  
M. G. Almendarez
Keyword(s):  
Nir Spectroscopy ◽  
Electrolyte Solutions ◽  
Yucca Mountain ◽  
Sorption Behavior ◽  
Surface Loading ◽  
Wide Range ◽  
High Level Nuclear Waste ◽  
Ph Range ◽  
High Level ◽  
Carbonate Complexes

AbstractPerformance assessment models have identified 237Np as a radionuclide of concern in meeting release limits established for the geologic disposal of high-level nuclear waste at the proposed repository at Yucca Mountain, Nevada. In this study, quartz, clinoptilolite, and montmorillonite, which are minerals representative of phases that occur both in the rock matrix and as fracture coatings at Yucca Mountain, were reacted with 237Np-bearing solutions to characterize the sorption behavior of Np(V) on these minerals.Batch experiments were conducted over a wide range of conditions in which pH of solution, surface loading, sorbent surface area, initial concentration of Np(V), and partial pressure of CO2 were varied. Initial Np(V) concentrations were between 1 × 10-7 and 1- 10-6 M in electrolyte solutions of 0.1 or 0.01 M NaNO3. The oxidation state of Np in solution was verified with NIR spectroscopy and by solvent extraction. Prior to the start of experiments, minerals were pretreated to eliminate impurities, and the clinoptilolite and montmorillonite were converted to Na-form by ion exchange with NaCI solutions.Results indicate that, for all three minerals, Np(V) sorption begins at pH values coincident with the start of hydrolysis in solution (-7). For solutions undersaturated with respect to atmospheric CO2, sorption increases continuously with increasing pH. Under equilibrium with atmospheric CO2, Np(V) sorption is important in the pH range (7–9.5) where NpO2(OH)°(aq) is significant, whereas sorption is inhibited at higher pH where neptunyl carbonate complexes are the predominant species.

Kean Miltos: The Well-Known Iron Oxides of Antiquity

1997 ◽  
Vol 92 ◽  
pp. 359-371 ◽  
Author(s):  
E. Photos-Jones ◽  
A. Cottier ◽  
A. J. Hall ◽  
L. G. Mendoni
Keyword(s):  
Iron Oxides ◽  
Analytical Techniques ◽  
Field Work ◽  
Archaeological Record ◽  
The North ◽  
Naturally Occurring ◽  
Physico Chemical ◽  
Wide Range ◽  
Industrial Mineral

The island of Kea in the North Cyclades was well known in antiquity for its miltos, a naturally occurring red iron oxide valued for its colour and wide range of applications. By combining geological field work, physico-chemical analytical techniques, simulation (heating) experiments as well as simple laboratory tests, this paper describes the study of Kean iron oxides in an attempt to characterize this material which is still largely elusive in the archaeological record. The present work corroborates previous observations about the superior quality of some Kean iron oxides. Furthermore, it puts forward the hypothesis that miltos may have been considered an industrial mineral, and as such may have been used as an umbrella term for a variety of materials including mineralogically distinct purple as well as red iron oxides.

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