scholarly journals Spontaneous revegetation of mined peatlands in eastern Canada

2005 ◽  
Vol 83 (5) ◽  
pp. 539-557 ◽  
Author(s):  
Monique Poulin ◽  
Line Rochefort ◽  
François Quinty ◽  
Claude Lavoie
Keyword(s):  
Vegetation Structure ◽  
Vascular Plants ◽  
Percent Cover ◽  
Eastern Canada ◽  
Low Diversity ◽  
Vacuum Fields ◽  
Colonization Patterns ◽  
The Impact ◽  
Block Cutting ◽  
High Diversity

Many North American peatlands previously mined for horticultural peat have been abandoned recently, allowing natural recolonization to occur. The two dominant methods for peat extraction, hand block-cutting and vacuum-mining, have created distinctly different abandoned surfaces, leading to different recolonization patterns. Both types of exploitation can be found throughout eastern Canada where we conducted a vast survey of 26 abandoned mined peatlands in the provinces of Québec and New Brunswick. The aim of this study is to describe the revegetation patterns and to assess the impact of local and regional variables as well as the time since abandonment on Sphagnum re-colonization. We inventoried the vegetation structure in all trenches (2571) and baulks (2595) of abandoned block-cut areas as well as in all vacuum fields (395) of the mechanically mined areas. We also conducted detailed species relevés in 242 of these peat fields. In comparison to vacuum-mined peatlands, block-cut peatlands regenerated remarkably well. Approximately 80% of all baulks and trenches in block-cut peatlands had 50% or higher cover of ericaceous shrubs compared with only 16% found on vacuum fields. Herb cover in the three types of abandoned fields was similar to that in natural peatlands. However, Sphagnum percent cover was below 2% in baulks and vacuum fields and was 30% on average in the trenches, which is clearly below cover estimates in natural peatlands. Sphagnum cover and richness were both higher in trenches with thin residual peat deposit, and Sphagnum richness increased with latitude. Our surveys revealed that abandoned mined peatlands have a high diversity of peatland vascular plants species and a low diversity of non-peatland species.Key words: cutover peatlands, regeneration, milled peatlands, block-cut peatlands, vacuum-mined peatlands, colonization patterns.

Plant diversity, composition, and rarity in the southern boreal peatlands of Manitoba, Canada

2006 ◽  
Vol 84 (6) ◽  
pp. 940-955 ◽  
Author(s):  
David A. Locky ◽  
Suzanne E. Bayley
Keyword(s):  
Plant Diversity ◽  
Environmental Variables ◽  
Vascular Plants ◽  
Black Spruce ◽  
General Pattern ◽  
Boreal Peatlands ◽  
Environmental Extremes ◽  
Low Diversity ◽  
Total Diversity ◽  
High Diversity

Plant diversity and rarity have been relatively well studied for bryophytes in Canadian western boreal peatlands, but little information exists for vascular plants. Diversity, community composition, and rarity of bryophytes and vascular plants were determined and relationships examined among these and environmental variables in five peatland types at Duck Mountain, Manitoba: wooded bogs, black spruce swamps, wooded moderate-rich fens, open moderate-rich fens, and open extreme-rich fens. Total diversity was 298 species comprising 86 bryophytes and 212 vascular plants. Mean diversity followed a unimodal distribution over a bog – rich fen gradient. Wooded moderate-rich fens (59.0) and black spruce swamps (53.4) had the highest mean diversity, whereas wooded bogs (32.3) and open extreme-rich fens (34.7) had the lowest mean diversity. Occurrences of locally rare species followed the same general pattern, and provincially rare vascular plants were found primarily in wooded moderate-rich fens and black spruce swamps and were mostly orchids. Reasons for these patterns are complex, but high diversity appears to be related to high habitat heterogeneity and moderate environmental variables, e.g., pH and alkalinity, and low diversity appears to be related to environmental extremes, e.g., pH and alkalinity. Boreal wooded moderate-rich fens and black spruce swamps have comparatively high plant diversity and rarity and require consideration if the focus is biodiversity conservation. This will become increasingly important in landscapes where development pressures are high.

Recent Rapid Climate Changes in Antarctic and their Influence on Low Diversity Ecosystems

2010 ◽  
Vol 17 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Katarzyna J. Chwedorzewska
Keyword(s):  
Environmental Variables ◽  
Climate Changes ◽  
Biological Significance ◽  
Global Changes ◽  
Factors Affecting ◽  
Low Diversity ◽  
Main Factors ◽  
The Antarctic ◽  
High Diversity ◽  
Temperature Water

ABSTRACTThe geographic position, astronomic factors (e.g. the Earth’s maximum distance from the Sun during winter), ice cover and altitude are the main factors affecting the climate of the Antarctic, which is the coldest place on Earth. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. Climate changes are occurring throughout Antarctica, affecting three major groups of environmental variables of considerable biological significance: temperature, water, UV-B radiation.Low diversity ecosystems are expected to be more vulnerable to global changes than high diversity ecosystems

Increasing revenue and attendance in Canadian Baptist churches

2015 ◽  
Vol 42 (12) ◽  
pp. 1071-1089
Author(s):  
Alan Chan ◽  
Bruce G. Fawcett ◽  
Shu-Kam Lee
Keyword(s):  
Church Health ◽  
Eastern Canada ◽  
Data Set ◽  
Content Type ◽  
Factors Affecting ◽  
Scarce Resources ◽  
Baptist Churches ◽  
And Performance ◽  
The Impact ◽  
Simulation Exercises

Purpose – Church giving and attendance are two important indicators of church health and performance. In the literature, they are usually understood to be simultaneously determined. The purpose of this paper is to estimate if there a sustainable church congregation size using Wintrobe’s (1998) dictatorship model. The authors want to examine the impact of youth and adult ministry as well. Design/methodology/approach – Using the data collected from among Canadian Baptist churches in Eastern Canada, this study investigates the factors affecting the level of the two indicators by the panel-instrumental variable technique. Applying Wintrobe’s (1998) political economy model on dictatorship, the equilibrium level of worship attendance and giving is predicted. Findings – Through various simulation exercises, the actual church congregation sizes is approximately 50 percent of the predicted value, implying inefficiency and misallocation of church resources. The paper concludes with insights on effective ways church leaders can allocate scarce resources to promote growth within churches. Originality/value – The authors are the only researchers getting the permission from the Atlantic Canada Baptist Convention to use their mega data set on church giving and congregation sizes as per the authors’ knowledge. The authors are also applying a theoretical model on dictatorship to religious/not for profits organizations.

Diversity and community structure of Ephemeroptera in freshwater stream of Megamalai hills, Tamil Nadu, India

ENTOMON ◽  
2021 ◽  
Vol 46 (4) ◽  
pp. 279-284
Author(s):  
S. Barathy ◽  
T. Sivaruban ◽  
Srinivasan Pandiarajan ◽  
Isack Rajasekaran ◽  
M. Bernath Rosi
Keyword(s):  
Community Structure ◽  
Species Diversity ◽  
Air Temperature ◽  
Tamil Nadu ◽  
Dominant Species ◽  
Diversity Indices ◽  
Low Diversity ◽  
Freshwater Stream ◽  
Species Diversity Indices ◽  
High Diversity

In the study on the diversity and community structure of Ephemeroptera in the freshwater stream of Chinnasuruli falls on Megamalai hills, a total of 523 specimens belonging to thirteen genera and five families were collected in six month periods. Of the five families, Teloganodidae and Leptophlebiidae exhibited high diversity and Caenidae showed low diversity. Choroterpes alagarensis (Leptophlebiidae) is the most dominant species. Diversity indices such as Shannon and Simpson indices showed that diversity was maximum in November and December and it was minimum in August and January. Canonical Correspondence Analysis revealed that rainfall, water flow, turbidity, and air temperature were the major stressors in affecting the Ephemeropteran community structure.

scholarly journals Invasive Scots Pine, Pinus sylvestris, Replacing Corema, Corema conradii, Heathland in the Annapolis Valley, Nova Scotia

2005 ◽  
Vol 119 (2) ◽  
pp. 237 ◽  
Author(s):  
Paul M. Catling ◽  
Susan Carbyn
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Vascular Plants ◽  
Dominant Species ◽  
Vascular Plant ◽  
Agricultural Crops ◽  
Deschampsia Flexuosa ◽  
Natural Habitats ◽  
Annapolis Valley ◽  
The Impact

Examination of air photos from 1930, 1970 and 2002 revealed stands of the European Scots Pine (Pinus sylvestris) invading remnants of natural Corema (Corema conradii) heathland in the Annapolis valley. To document the impact of the introduced pines, four natural habitats were compared with two adjacent habitats already invaded by the pines. All surveyed habitats had been dominated by Corema heath based on air photos taken in 1930. Twenty 1 m2 quadrats were used to record presence and cover of vascular plants at each site. The invasive alien pines reduce the native cover to 12%. Vascular plant biodiversity is reduced to less than 42% and the cover of the heathland dominant, Corema conradii, is reduced from over 100 % to less than 2%. with Deschampsia flexuosa becoming the dominant species. The modified ecosystem and loss of biodiversity has economic impacts through loss of pollinators of agricultural crops and loss of germplasm of native crop relatives.

IMPACT OF WEEDS ON DIVERSITY OF SOIL ARTHROPODS IN Bt COTTON FIELD IN FAISALABAD PAKISTAN

2020 ◽  
Vol 27 (2) ◽  
pp. 119-129
Author(s):  
Iqra Munir ◽  
Abdul Ghaffar ◽  
Asad Aalam ◽  
Muhammad Khuram Shahzad ◽  
Muhammad Jafir
Keyword(s):  
Diversity Index ◽  
Research Area ◽  
Cotton Field ◽  
Control Group ◽  
Bt Cotton ◽  
Soil Arthropods ◽  
And Control ◽  
The Impact ◽  
High Diversity

The present study was conducted to check the impact of weeds on diversity of soil arthropods in Bt cotton field by using RCBD design with four treatments and three replications at Research Area of Department of Entomology, University of Agriculture Faisalabad. Treatments were consisted of different combination of weeds and control group Total 228 samples were collected and from these samples 14 different taxons of soil arthropods were reported and from these taxons, mites showed high diversity index. Maximum diversity of soil arthropods was recorded (H´=2.07) from itsit + sawanki and minimum diversity of soil arthropods was recorded (H´=1.90) from itsit + chulai. Maximum mean richness of soil arthropods ( S=3.18±0.24) was reported from Itsit+chulai, while minimum mean richness of soil arthropods (S=3±0.23) was reported from Control group. Maximum mean abundance of soil arthropods (14.7±4.11) was reported from Itsit+sawanki while minimum mean abundance of soil arthropods (11.5±2.26) was reported from control group.

scholarly journals Measuring the shape of the biodiversity-disease relationship across systems reveals new findings and key gaps

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Fletcher W. Halliday ◽  
Jason R. Rohr
Keyword(s):  
Spatial Scale ◽  
Parasite Species ◽  
Biodiversity Loss ◽  
Field Studies ◽  
New Findings ◽  
Small Scales ◽  
Low Diversity ◽  
Wildlife Populations ◽  
Dilution Effects ◽  
High Diversity

Abstract Diverse host communities commonly inhibit the spread of parasites at small scales. However, the generality of this effect remains controversial. Here, we present the analysis of 205 biodiversity–disease relationships on 67 parasite species to test whether biodiversity–disease relationships are generally nonlinear, moderated by spatial scale, and sensitive to underrepresentation in the literature. Our analysis of the published literature reveals that biodiversity–disease relationships are generally hump-shaped (i.e., nonlinear) and biodiversity generally inhibits disease at local scales, but this effect weakens as spatial scale increases. Spatial scale is, however, related to study design and parasite type, highlighting the need for additional multiscale research. Few studies are unrepresentative of communities at low diversity, but missing data at low diversity from field studies could result in underreporting of amplification effects. Experiments appear to underrepresent high-diversity communities, which could result in underreporting of dilution effects. Despite context dependence, biodiversity loss at local scales appears to increase disease, suggesting that at local scales, biodiversity loss could negatively impact human and wildlife populations.

ENVIRONMENTAL IMPACT OF SEISMIC OPERATIONS IN THE OTWAY BASIN, SOUTH AUSTRALIA

1994 ◽  
Vol 34 (1) ◽  
pp. 741 ◽  
Author(s):  
M. L. Williams ◽  
A. J. Boulton ◽  
M. Hyde ◽  
A. J. Kinnear ◽  
C. D. Cockshell
Keyword(s):  
Environmental Management ◽  
Environmental Impact ◽  
Vegetation Structure ◽  
South Australia ◽  
Petroleum Exploration ◽  
Seismic Exploration ◽  
Native Vegetation ◽  
Seismic Line ◽  
The Impact ◽  
Seismic Lines

The Department of Mines and Energy, South Australia (DME) contracted Michael Williams and Associates Pty Ltd to audit the environmental management of seismic exploration operations in the South Australian Otway Basin. The audit was carried out in early 1992 and covered petroleum exploration operators and DME environmental management systems. An innovative field sampling technique was developed to compare the environmental impact of two different seismic line clearing techniques. Recovery of native vegetation as measured by vegetation structure was also quantified.The audit found DME to have a dynamic and integrated environmental management system while company systems varied in standard. Wide consultation assisted the audit process.As a result of clearing for agriculture, native vegetation covers only six per cent of the Otway Basin. With the strict limitations to broad-scale vegetation clearance since the mid-1980s and the cessation since 1991, the greatest environmental impact of seismic exploration is the clearance of native vegetation for access by seismic vehicles. Native vegetation structure and associated abiotic variables on seismic lines and adjacent control sites, were subject to a classification and ordination analysis which compared the impact of seismic lines constructed by bulldozer or Hydro-ax (industrial slasher). Post-seismic recovery rates of three different vegetation associations were also determined. This analytical technique permits the effects of seismic line clearance to be compared with the natural variability of specific vegetation associations within a region. In interpreting the results however, there is a confounding effect of line type and year as most of the more recent seismic lines were constructed using a Hydro-ax. Results indicate that Hydro-ax clearing affects vegetation structure less than bulldozing. Most Hydro-ax sites recovered within a few years whereas some sites, bulldozed as early as 1971, particularly tussock grasslands, have not yet recovered.This study provides a significant break-through in the debate about the persistence of seismic impacts on native vegetation. As a rapid preliminary assessment, sampling vegetation structure rather than floristics, provides a cost-effective audit and monitoring technique which can be used by non-specialists in a range of petroleum exploration environments. Any significant structural differences may require more detailed analysis to determine if floristic composition also differed.

Changes in colonial development, intraspecific heterochrony, morphological integration, and character heritabilities in two populations of the bryozoan species Batostoma jamesi from the Kope Formation (Upper Ordovician, Cincinnatian)

2002 ◽  
Vol 76 (2) ◽  
pp. 197-210 ◽  
Author(s):  
Joseph F. Pachut ◽  
Margaret M. Fisherkeller
Keyword(s):  
Colony Growth ◽  
Early Growth ◽  
Morphological Integration ◽  
Growth Stages ◽  
Stabilizing Selection ◽  
Upper Ordovician ◽  
Surface Areas ◽  
Low Diversity ◽  
Kope Formation ◽  
High Diversity

Populations of the Upper Ordovician trepostome bryozoan Batostoma jamesi were collected from two different paleoenvironmental settings in the Kope Formation of southeastern Indiana. Within each colony and population, morphologic changes were analyzed during colony growth, or astogeny. Morphological measurements of zooecia, mesozooecia, and acanthostyles display similar patterns of change during colony growth in both populations but magnitudes are generally larger in the high diversity population.Canonical variates analyses provided multivariate confirmation of univariate character differences found within each population. Statistically significant multivariate morphological differences between growth stages persist even if assignments of colonies to populations are ignored. Results suggest different potentials for altering growth trajectories in different environments with early growth stage flexibility in colonies from lower diversity settings and later-stage flexibility in colonies from higher diversity settings.Heterochronic changes occur between species populations. Relative to the high-diversity population, the low-diversity population displays the following: 1) progenesis and hypermorphosis for zooecia, reflecting the ability to exist over a broader range of areal densities and surface areas than in populations from high-diversity associations; 2) postdisplacement and progenesis for mesozooecia, producing mature mesozooecial densities earlier in growth and at smaller sizes while the onset of mesozooecial development is delayed; and 3) acceleration, predisplacement, and progenesis for acanthostyles, resulting in a more rapid rate of development, an earlier onset of style development and more styles, and an earlier time of maturation, respectively.The estimated level of morphological integration is higher in the high diversity population regardless of stage of colony growth. Within populations, integration is stronger during early growth stages in colonies from high diversity settings and during later growth stages in colonies from low diversity settings. Character heritabilities are high in both diversity-level populations, suggesting that these patterns of morphological integration were not the result of non-heritable phenotypic plasticity. Mean heritability is greater in the high diversity population and differs statistically only between the late growth stages of populations. Patterns of morphological integration may result from differing levels of stabilizing selection in different environments. Depending on the timing of selection, these different levels of integration are capable of affecting the outcome of selection on species populations.

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