scholarly journals Long-term changes in the species and functional diversity of a fine sand macrobenthic community in the English Channel

2018 ◽  
Author(s):  
Lise Bacouillard ◽  
Noémie Baux ◽  
Jean-Claude Dauvin ◽  
Nicolas Desroy ◽  
Katja Juliana Geiger ◽  
...  
Keyword(s):  
Community Structure ◽  
Functional Diversity ◽  
Regional Scale ◽  
Monitoring Program ◽  
Diversity Indices ◽  
Population Fluctuations ◽  
Α Diversity ◽  
Long Term Changes ◽  
Functional Diversity Indices

In the eastern Bay of Seine, which is a representative area of coastal zones exposed to numerous anthropogenic disturbances, data from a long-term monitoring program of the benthic macrofauna based on a framework of 60 stations sampled during 7 cruises from 1988 to 2016 were used to investigate the link between species and functional diversity at different scales and assess how long-term changes in the community structure may have altered the ecosystem functioning. To cover the different facets of α-diversity, a selection of species and functional diversity indices were calculated and the links between these metrics were determined from a Principal Component Analysis. The β-diversity was analysed by applying multivariate methods on both species and traits composition matrices. Population fluctuations of a few very abundant species led to the major variations observed in the structure of the community in both taxonomic and functional aspects. A certain redundancy was found among species and functional diversity indices in terms of richness, evenness and heterogeneity. Likewise, at regional scale, similar patterns were reported on the spatial structure of the community in terms of species and trait composition. These patterns persist over time suggesting that the community structure and its functioning are rather resilient.

scholarly journals Long-term changes in the species and functional diversity of a fine sand macrobenthic community in the English Channel

2018 ◽  
Author(s):  
Lise Bacouillard ◽  
Noémie Baux ◽  
Jean-Claude Dauvin ◽  
Nicolas Desroy ◽  
Katja Juliana Geiger ◽  
...  
Keyword(s):  
Community Structure ◽  
Functional Diversity ◽  
Regional Scale ◽  
Monitoring Program ◽  
Diversity Indices ◽  
Population Fluctuations ◽  
Α Diversity ◽  
Long Term Changes ◽  
Functional Diversity Indices

In the eastern Bay of Seine, which is a representative area of coastal zones exposed to numerous anthropogenic disturbances, data from a long-term monitoring program of the benthic macrofauna based on a framework of 60 stations sampled during 7 cruises from 1988 to 2016 were used to investigate the link between species and functional diversity at different scales and assess how long-term changes in the community structure may have altered the ecosystem functioning. To cover the different facets of α-diversity, a selection of species and functional diversity indices were calculated and the links between these metrics were determined from a Principal Component Analysis. The β-diversity was analysed by applying multivariate methods on both species and traits composition matrices. Population fluctuations of a few very abundant species led to the major variations observed in the structure of the community in both taxonomic and functional aspects. A certain redundancy was found among species and functional diversity indices in terms of richness, evenness and heterogeneity. Likewise, at regional scale, similar patterns were reported on the spatial structure of the community in terms of species and trait composition. These patterns persist over time suggesting that the community structure and its functioning are rather resilient.

scholarly journals Long-Term Changes in Thecomposition, Abundance and Diversity of Phytoplankton Community of Oshika Rivers State

2021 ◽  
pp. 92-116
Author(s):  
Nkechinyere Gladys Nwambara ◽  
John Onwuteaka ◽  
Onyinye Prince Choko
Keyword(s):  
Community Structure ◽  
Oil Spill ◽  
Phytoplankton Community ◽  
Species Turnover ◽  
Diversity Indices ◽  
Dry Season ◽  
Wet Season ◽  
Long Term Changes ◽  
Abundance And Diversity

This study was aimed at determining the long-term changes in composition, abundance, and diversity of the phytoplankton community of the Oshika freshwater biota. Phytoplankton samples at Oshika lake were collected from the same stations and similar months as in the year 1983 study of the 5000 barrels of oil spill. The samples were handled with optimum care and treated according to standard practices in order to preserve the plankton for further analysis and identification. The results of the analysis showed that the phytoplankton yielded a total of 40 species belonging to three groups in 1983 and 36 species belonging to four groups in 2019. Xanthophyceae was the group absent in 1983 but present in 2019, while Chlorophyceae, Cyanophyceae and Bacilariophyceae were common to both 1983 and 2019. Generally, the abundance of phytoplankton in each group in 1983 was significantly different from those of 2019. The Chlorophyceae was the most abundant in both 1983(12.31-186.5) and 2019 (1.27-6.58). The diversity indices result showed that the phytoplankton in 1983 (2.123- 2.563) had lower diversity compared to 2019 (2.381- 2.815). The cluster analysis revealed two groups in 1983 viz the generalist and the dry season specialist, while three groups viz the dry season specialist, wet season specialist and the generalist were observed in 2019. More so, greater data variations were observed in 1983 than 2019. Hence, we infer that there were changes in the phytoplankton community structure between 1983 and 2019. There were changes in the biological community structure between 1983 and 2019. These changes cannot be linked to the oil spill but seems more likely a result of natural variation since results of studies on the hydrocarbon values in water were very insignificant. Since the lake-riverine system is subject to flooding it can be concluded that new plankton from unaffected areas are transported into this area during the flood. The mixing of the water over the years leads to the high variable change. The high variable change brings about high species turnover given the unrestricted hydrodynamics of the River Niger flooding system and its influence on the floodplain Oshika lake.

scholarly journals The discontinuity of environmental effects monitoring in the Lower Athabasca region of Alberta, Canada: institutional challenges to long-term monitoring and cumulative effects management

2018 ◽  
Vol 26 (2) ◽  
pp. 169-180 ◽  
Author(s):  
Joshua G. Cronmiller ◽  
Bram F. Noble
Keyword(s):  
Decision Making ◽  
Environmental Monitoring ◽  
Environmental Effects ◽  
Regional Scale ◽  
Monitoring Program ◽  
Institutional Arrangements ◽  
Cumulative Effects ◽  
Regulatory Decision ◽  
Monitoring Programs

Long-term regional environmental monitoring, coupled with shorter-term and more localized monitoring carried out under regulatory permitting processes, is foundational to identifying, understanding, and effectively managing cumulative environmental effects. However, monitoring programs that emerge to support cumulative effects science are often short-lived initiatives or disconnected from land use planning and regulatory decision making. This paper examines the history and evolution of environmental monitoring in the Lower Athabasca region of Alberta, Canada, and the enabling and constraining influences of institutional arrangements. Methods involved a review of regional-scale monitoring programs based on an analysis of monitoring agency mandates, performance reports, and external program reviews, supplemented by discussions with monitoring program or agency key informants to triangulate results. Results show that monitoring to support cumulative effects understanding in the Lower Athabasca has advanced considerably, especially since the mid-1990s, but its relevance to, and impact on, cumulative effects management and decision making has been stifled by institutional arrangements. Monitoring has been episodic, reflecting shifting priorities and competing mandates; criticized by stakeholders based on concerns about transparency, credibility, influence over decision making; and characterized by short-lived commitments by the agencies involved. This has generated significant uncertainty about the stability of institutional arrangements to support long-term environmental monitoring, and tensions between the need for scientific autonomy for credible science whilst ensuring the pursuit of monitoring questions that are relevant to the day-to-day needs of regulatory decision makers. Regional monitoring programs require, at a minimum, clear vision and agreed-upon monitoring questions that are of scientific and management value, meaningful and balanced stakeholder engagement, and a clear governance process to ensure credibility and influence of monitoring results on decision making.

Long-term Changes in Parasite Population and Community Structure: A Case History

1997 ◽  
Vol 137 (2) ◽  
pp. 369 ◽  
Author(s):  
Gerald W. Esch ◽  
Eric J. Wetzel ◽  
Derek A. Zelmer ◽  
Anna M. Schotthoefer
Keyword(s):  
Community Structure ◽  
Case History ◽  
Parasite Population ◽  
Long Term Changes

scholarly journals FUNCTIONAL DIVERSITY AND ITS ATTRIBUTE FACTORS IN THE YUNMENG MOUNTAIN NATIONAL FOREST PARK IN BEIJING, CHINA

CERNE ◽  
2017 ◽  
Vol 23 (1) ◽  
pp. 75-84
Author(s):  
Jin-Tun Zhang ◽  
Xiaohang Bai ◽  
Dan Shao
Keyword(s):  
Functional Diversity ◽  
Altitudinal Gradient ◽  
Soil Depth ◽  
Functional Divergence ◽  
Diversity Indices ◽  
Slope Position ◽  
National Forest ◽  
Forest Communities ◽  
Forest Park ◽  
Functional Diversity Indices

ABSTRACT The interaction of diversity with environmental gradients is an important topic in ecology. This study investigated the pattern of change in functional diversity in forest communities along an altitudinal gradient in Yunmeng Mountain National Forest Park, China. Forty-two quadrats measuring 10 x 10 m in the forest communities were set up along this altitudinal gradient; plant species, traits and environmental variables were measured and recorded. Six functional diversity indices, namely, Modified functional attribute diversity (MFAD), Functional diversity plot-based dendrogram index (FDp), Functional diversity community-based dendrogram index (FDc), Functional evenness (FEve), Functional divergence (FDiv) and Functional dispersion (FDis), were used to calculate functional diversity. The results showed that functional diversity varied greatly in forest communities in the Yunmeng Mountain Forest Park. Functional diversity was significantly correlated with elevation and slope position and somewhat correlated with soil depth. Functional diversity increased with an increase in the elevation and decreased as the slope position changed from valley bottom to hill ridge. Functional diversity was closely related to species richness. The six functional diversity indices were all applicable to functional diversity studies of forest communities.

NEW MULTIDIMENSIONAL FUNCTIONAL DIVERSITY INDICES FOR A MULTIFACETED FRAMEWORK IN FUNCTIONAL ECOLOGY

Ecology ◽  
2008 ◽  
Vol 89 (8) ◽  
pp. 2290-2301 ◽  
Author(s):  
Sébastien Villéger ◽  
Norman W. H. Mason ◽  
David Mouillot
Keyword(s):  
Functional Diversity ◽  
Diversity Indices ◽  
Functional Ecology ◽  
Functional Diversity Indices
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