A Comparison Between the Effects of Sporadic and Continuous Loading From Sulphite Paper Mills on Attached Algae in the Ottawa River Near Ottawa, Canada

1975 ◽  
Vol 10 (1) ◽  
pp. 65-72
Author(s):  
Mike Dickman
Keyword(s):  
Species Composition ◽  
Continuous Monitoring ◽  
Large Scale ◽  
Specific Conductivity ◽  
Algal Species ◽  
Extended Period ◽  
Pulp Mills ◽  
Paper Mills ◽  
Ottawa River ◽  
Continuous Release

Abstract Attached algal species composition and specific conductivity were monitored above and below two sulphite pulp and paper mills near Ottawa. Continuous monitoring of the river's specific conductivity below the upstream mill revealed sharp peaks at irregular intervals over the summer. These peaks were interpreted as indications of large scale effluent release by the company as they did not occur on the upstream conductivity monitors. Continuous monitoring of specific conductivity above and below a second (larger) sulphite mill revealed a steady release of effluent without large sporadic releases. The reduction in the total number of periphyton species below each of these pulp mills was similar even though the upstream mill released nearly ten times less effluent than the downstream mill. Furthermore, periphyton species composition and density below the two mills was surprisingly similar even though the larger mill was continuously releasing its effluent. It was concluded that sporadic dumping of concentrated wastes is as harmful to most algal species as continuous release of these same wastes over an extended period of time. Environmental agencies invested with the responsibility of ensuring acceptable water quality conditions should therefore develop a comprehensive network of continuous monitors immediately below major industries which discharge into our lakes, rivers and oceans to discourage industries from shock loading.

scholarly journals Repeated surveying over 6 years reveals that fine-scale habitat variables are key to tropical mountain ant assemblage composition and functional diversity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mulalo M. Muluvhahothe ◽  
Grant S. Joseph ◽  
Colleen L. Seymour ◽  
Thinandavha C. Munyai ◽  
Stefan H. Foord
Keyword(s):  
Climate Change ◽  
Species Composition ◽  
High Altitude ◽  
Functional Diversity ◽  
Large Scale ◽  
Climate Models ◽  
Spatial Scales ◽  
Abiotic Factors ◽  
Composition Analysis ◽  
Fine Scale

AbstractHigh-altitude-adapted ectotherms can escape competition from dominant species by tolerating low temperatures at cooler elevations, but climate change is eroding such advantages. Studies evaluating broad-scale impacts of global change for high-altitude organisms often overlook the mitigating role of biotic factors. Yet, at fine spatial-scales, vegetation-associated microclimates provide refuges from climatic extremes. Using one of the largest standardised data sets collected to date, we tested how ant species composition and functional diversity (i.e., the range and value of species traits found within assemblages) respond to large-scale abiotic factors (altitude, aspect), and fine-scale factors (vegetation, soil structure) along an elevational gradient in tropical Africa. Altitude emerged as the principal factor explaining species composition. Analysis of nestedness and turnover components of beta diversity indicated that ant assemblages are specific to each elevation, so species are not filtered out but replaced with new species as elevation increases. Similarity of assemblages over time (assessed using beta decay) did not change significantly at low and mid elevations but declined at the highest elevations. Assemblages also differed between northern and southern mountain aspects, although at highest elevations, composition was restricted to a set of species found on both aspects. Functional diversity was not explained by large scale variables like elevation, but by factors associated with elevation that operate at fine scales (i.e., temperature and habitat structure). Our findings highlight the significance of fine-scale variables in predicting organisms’ responses to changing temperature, offering management possibilities that might dilute climate change impacts, and caution when predicting assemblage responses using climate models, alone.

scholarly journals Diversity of Algae and Cyanobacteria and Bioindication Characteristics of the Alpine Lake Nesamovyte (Eastern Carpathians, Ukraine) from 100 Years Ago to the Present

Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 256
Author(s):  
Petro M. Tsarenko ◽  
Olena P. Bilous ◽  
Olha M. Kryvosheia-Zakharova ◽  
Halyna H. Lilitska ◽  
Sophia Barinova
Keyword(s):  
Species Composition ◽  
Structural Changes ◽  
Algal Species ◽  
Taxonomic Composition ◽  
Alpine Lake ◽  
Algal Flora ◽  
Ecological Analysis ◽  
Modern Species ◽  
Eastern Carpathians ◽  
Infraspecific Taxa

The species diversity and changes in the structural dynamics of the algal flora from the alpine lake Nesamovyte has been studied for 100 years. During the period of investigations, 234 species (245 infraspecific taxa) were revealed to cover more than 70% of the modern species composition of the studied lake. The modern biodiversity of algae is characterized by an increase in the number of widespread forms, a change from the baseline “montane” complex in comparison to the beginning of the 20th century. Nevertheless, the Nesamovyte Lake still has a unique algae composition that is typical for high-mountainous European lakes. The presence of a different complex of conventionally arctic species of algae, in particular, diatoms is discussed. Structural changes in the taxonomic composition of the algal flora of the lake as well as in the complex of the leading genera, species and their diversity are revealed. An ecological analysis of the algal species composition of the lake showed vulnerability and degradation to the ecosystem of the lake. On this basis, the issue regarding the question of protection and preservation of the algae significance and uniqueness of the flora of algae in the Nesamovyte Lake are discussed.

Ecological processes maintaining differential tree species distributions in an Australian subtropical rain forest: implications for models of species coexistence

2000 ◽  
Vol 16 (3) ◽  
pp. 387-415 ◽  
Author(s):  
Igor Debski ◽  
David F. R. P. Burslem ◽  
David Lamb
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Rain Forest ◽  
Large Scale ◽  
Species Coexistence ◽  
Common Species ◽  
Size Class ◽  
Differential Mortality ◽  
Mixed Composition ◽  
Large Scale Disturbance

All stems ≥ 1 cm dbh were measured, tagged, mapped and identified on a 1-ha plot of rain forest at Gambubal State Forest, south-east Queensland, Australia. The spatial patterns and size class distributions of 11 common tree species on the plot were assessed to search for mechanisms determining their distribution and abundance. The forest was species-poor in comparison to many lowland tropical forests and the common species are therefore present at relatively high densities. Despite this, only limited evidence was found for the operation of density-dependent processes at Gambubal. Daphnandra micrantha saplings were clumped towards randomly spaced adults, indicating a shift of distribution over time caused by differential mortality of saplings in these adult associated clumps. Ordination of the species composition in 25-m × 25-m subplots revealed vegetation gradients at that scale, which corresponded to slope across the plot. Adult basal area was dominated by a few large individuals of Sloanea woollsii but the comparative size class distributions and replacement probabilities of the 11 common species suggest that the forest will undergo a transition to a more mixed composition if current conditions persist. The current cohort of large S. woollsii individuals probably established after a large-scale disturbance event and the forest has not attained an equilibrium species composition.

scholarly journals Adult caddisflies (Trichoptera) attracted to artificial lights in the middle reaches of the Shinano River from 2005 to 2007

Zoosymposia ◽  
2011 ◽  
Vol 5 (1) ◽  
pp. 143-146 ◽  
Author(s):  
KIMIO HIRABAYASHI ◽  
GORO KIMURA ◽  
EISO INOUE
Keyword(s):  
Species Composition ◽  
Air Temperature ◽  
Large Scale ◽  
Abundant Species ◽  
The Other ◽  
Seasonal Abundance ◽  
Other Hand ◽  
The Mean ◽  
Summer Flood

The species composition and abundance of adult caddisflies attracted to the illuminated showcase of a vending machine set along the middle reaches of the Shinano River were investigated every Sunday night from April to November in 2005 to 2007. A total of 1,405 adult caddisflies was collected during the investigation periods. We identified a total of 13 species belonging to 11 genera of 8 families. The most abundant species was Psychomyia acutipennis (Ulmer 1908) each year. Psychomyia acutipennis adults were collected from mid-May to the beginning of October (the range of mean air temperature was 13.8 to 27.7°C), with its seasonal abundance divided into several peaks, i.e., the end of May, the beginning of June, and the end of August to the beginning of September in both 2006 and 2007. On the other hand, in 2005 when there was no large-scale summer flood and there were no marked abundance peaks. The present study suggests that the mean air temperature and summer floods impacted the seasonal abundance of P. acutipennis adults.

scholarly journals Development of forest soils in the Krkonoše Mts. in the period 1980–2009

2010 ◽  
Vol 56 (No. 11) ◽  
pp. 485-504 ◽  
Author(s):  
K. Matějka ◽  
S. Vacek ◽  
V. Podrázský
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Large Scale ◽  
Vegetation Change ◽  
Soil Conditions ◽  
Available Phosphorus ◽  
Mountain Range ◽  
Site Conditions ◽  
Tree Species Composition ◽  
Spruce Stands

This paper documents the development of soil conditions in the set of 32 permanent research plots in the Krkonoše (Giant) Mts. These plots represent an altitudinal gradient covering the ecosystems of beech, mixed beech-spruce and spruce stands. In all plots, representing the site conditions of the highest areas of the mountain range, standard soil pits were prepared and the soil sampling was performed in autumn of years 1980, 1993, 1998, 2003 and 2009. The results reflect extreme site conditions, soil acidification, large scale surface liming and in minor extent also different tree species composition of the stands. The general type of the soil-genesis is represented by the podzolisation, overlapping the other soil-genetic factors, including the tree species composition. Nevertheless, this development is mostly expressed in the spruce stands. The beech dominance and/or co-dominance are reflected especially by more efficient N-cycling, higher pH, S and V values and fluctuation and lower extractable Al3+ content. More efficient cycling in beech ecosystems is insignificantly documented for plant available phosphorus, calcium and magnesium contents; on the contrary higher dynamics for iron ions was registered in the spruce stands. The long-term soil dynamics with a hysteresis (evident on the base of ordination analysis) can be divided into some periods – processes of acidification (typical in the 1980's samples), liming (main effect in 1993 and 1998) and regeneration (2003, 2009). Other features, important for the soil development, are probably related to the vegetation change, but this relation is not statistically significant.

scholarly journals Expansion of Human Pluripotent Stem Cell-derived Early Cardiovascular Progenitor Cells by a Cocktail of Signaling Factors

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sadaf Vahdat ◽  
Sara Pahlavan ◽  
Elena Mahmoudi ◽  
Maryam Barekat ◽  
Hassan Ansari ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Large Scale ◽  
Culture Medium ◽  
Gene Expression Pattern ◽  
Extended Period ◽  
Scale Production ◽  
Chemical Screening ◽  
Wide Range ◽  
Cell Sources

Abstract Cardiovascular progenitor cells (CPCs) derived from human pluripotent stem cells (hPSCs) are proposed to be invaluable cell sources for experimental and clinical studies. This wide range of applications necessitates large-scale production of CPCs in an in vitro culture system, which enables both expansion and maintenance of these cells. In this study, we aimed to develop a defined and efficient culture medium that uses signaling factors for large-scale expansion of early CPCs, called cardiogenic mesodermal cells (CMCs), which were derived from hPSCs. Chemical screening resulted in a medium that contained a reproducible combination of three factors (A83-01, bFGF, and CHIR99021) that generated 1014 CMCs after 10 passages without the propensity for tumorigenicity. Expanded CMCs retained their gene expression pattern, chromosomal stability, and differentiation tendency through several passages and showed both the safety and possible cardio-protective potentials when transplanted into the infarcted rat myocardium. These CMCs were efficiently cryopreserved for an extended period of time. This culture medium could be used for both adherent and suspension culture conditions, for which the latter is required for large-scale CMC production. Taken together, hPSC-derived CMCs exhibited self-renewal capacity in our simple, reproducible, and defined medium. These cells might ultimately be potential, promising cell sources for cardiovascular studies.

scholarly journals Shadowing as a Tool for Studying Political Elites

2020 ◽  
Vol 28 (4) ◽  
pp. 469-486 ◽  
Author(s):  
Jennifer Bussell
Keyword(s):  
Data Collection ◽  
Large Scale ◽  
Extended Period ◽  
Observational Research ◽  
Daily Routine ◽  
Political Elites ◽  
Large Scale Data ◽  
Interview Guide ◽  
Larger Sample ◽  
Collection Methods

This article offers a description and discussion of “shadowing” as a data collection and analytic tool, highlighting potential research opportunities related to the direct observation of individuals—principally political elites—in their normal daily routine for an extended period of time, often between one day and one week. In contrast with large-scale data collection methods, including surveys, shadowing enables researchers to develop detailed observations of political behavior that are not limited by the availability of administrative data or the constraints of a questionnaire or an interview guide. Unlike more in-depth qualitative methods, such as ethnography, shadowing is scalable in a manner that allows for larger sample sizes and the potential for medium-N inference. I provide a detailed account of how to design and conduct a shadowing study, including sampling strategies, techniques for coding shadowing data, and processes for drawing inferences about the behavior of shadowed subjects, drawing on examples from a completed shadowing-based study. I also discuss ways to mitigate selection and observer biases, presenting results that suggest these can be no more pronounced when shadowing political elites than in other forms of observational research.

Algal biofuels from wastewater treatment high rate algal ponds

2011 ◽  
Vol 63 (4) ◽  
pp. 660-665 ◽  
Author(s):  
R. J. Craggs ◽  
S. Heubeck ◽  
T. J. Lundquist ◽  
J. R. Benemann
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Large Scale ◽  
Low Cost ◽  
Algal Species ◽  
Climatic Conditions ◽  
Biofuel Production ◽  
High Rate ◽  
Algal Production ◽  
High Rate Algal Ponds

This paper examines the potential of algae biofuel production in conjunction with wastewater treatment. Current technology for algal wastewater treatment uses facultative ponds, however, these ponds have low productivity (∼10 tonnes/ha.y), are not amenable to cultivating single algal species, require chemical flocculation or other expensive processes for algal harvest, and do not provide consistent nutrient removal. Shallow, paddlewheel-mixed high rate algal ponds (HRAPs) have much higher productivities (∼30 tonnes/ha.y) and promote bioflocculation settling which may provide low-cost algal harvest. Moreover, HRAP algae are carbon-limited and daytime addition of CO2 has, under suitable climatic conditions, the potential to double production (to ∼60 tonnes/ha.y), improve bioflocculation algal harvest, and enhance wastewater nutrient removal. Algae biofuels (e.g. biogas, ethanol, biodiesel and crude bio-oil), could be produced from the algae harvested from wastewater HRAPs, The wastewater treatment function would cover the capital and operation costs of algal production, with biofuel and recovered nutrient fertilizer being by-products. Greenhouse gas abatement results from both the production of the biofuels and the savings in energy consumption compared to electromechanical treatment processes. However, to achieve these benefits, further research is required, particularly the large-scale demonstration of wastewater treatment HRAP algal production and harvest.

scholarly journals Diversity and Species Composition of Subaerial Algal Communities in Forested Areas of Meghalaya, India

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Diana Kharkongor ◽  
Papiya Ramanujam
Keyword(s):  
Relative Humidity ◽  
Species Composition ◽  
Algal Species ◽  
Sacred Grove ◽  
Algal Communities ◽  
Tree Barks ◽  
Significant Difference ◽  
Forested Areas ◽  
Mixed Plantation ◽  
Disturbed Forest

The study deals with a comparative study on diversity and species composition of subaerial algal communities from tree barks of closed undisturbed sacred grove, mixed plantation, and open disturbed forest. A total of 85 taxa had been recorded, 30 cyanobacteria and 55 algal species belonging to six classes of algae. Sacred grove harboured the highest subaerial algal diversity compared to those of plantation and open disturbed forest. There was a strong significant difference in species composition among the three different sampling areas. High number of diatoms with 14 species was recorded in sacred grove. Cyanobacteria with 22 species were the frequent group in disturbed forest whereas Trentepohliales dominated in plantation. Canonical correspondence analysis confirmed that high photon irradiance favored the growth of cyanobacteria in disturbed forest. The abundance of Trentepohliales members correlated to high rainfall and photon irradiance. High diversity and presence of many diatom species in undisturbed Mawphlang sacred grove were associated with low photon irradiance and high relative humidity and could also be due to a presence of suitable substrata formed by the growth of mosses. Sunlight, relative humidity, and rainfall were the important factors which played a major role in determining the diversity and distribution of subaerial algal communities.

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