scholarly journals Study of Temporal Variations in Species–Environment Association through an Innovative Multivariate Method: MixSTATICO

2021 ◽  
Vol 13 (11) ◽  
pp. 5924
Author(s):  
Mariela González-Narváez ◽  
María José Fernández-Gómez ◽  
Susana Mendes ◽  
José-Luis Molina ◽  
Omar Ruiz-Barzola ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Abiotic Factors ◽  
Skeletonema Costatum ◽  
Species Conservation ◽  
Environmental Parameters ◽  
Biological Indicators ◽  
Temporal Variations ◽  
Multivariate Method ◽  
Eastern Equatorial Pacific ◽  
The Impact

The study of biotic and abiotic factors and their interrelationships is essential in the preservation of sustainable marine ecosystems and for understanding the impact that climate change can have on different species. For instance, phytoplankton are extremely vulnerable to environmental changes and thus studying the factors involved is important for the species’ conservation. This work examines the relationship between phytoplankton and environmental parameters of the eastern equatorial Pacific, known as one of the most biologically rich regions in the world. For this purpose, a new multivariate method called MixSTATICO has been developed, allowing mixed-type data structured in two different groups (environment and species) to be related and measured on a space–time scale. The results obtained show how seasons have an impact on species–environment relations, with the most significant association occurring in November and the weakest during the month of May (change of season). The species Lauderia borealis, Chaetoceros didymus and Gyrodinium sp. were not observed in the coastal profiles during the dry season at most stations, while during the rainy season, the species Dactyliosolen antarcticus, Proboscia alata and Skeletonema costatum were not detected. Using MixSTATICO, species vulnerable to specific geographical locations and environmental variations were identified, making it possible to establish biological indicators for this region.

Diagnosis of the Operation of Power Plants

2007 ◽  
Author(s):  
Jose´ Miguel Gonza´lez-Santalo´ ◽  
Abigail Gonza´lez-Di´az ◽  
Carlos Alberto Marin˜o-Lo´pez
Keyword(s):  
Power Plants ◽  
Environmental Changes ◽  
Environmental Parameters ◽  
Combined Cycle ◽  
Characteristic Parameters ◽  
Operating Variables ◽  
Design Values ◽  
The Individual ◽  
The Impact

A system was developed to diagnose the operation of combined cycle power plants and to determine, when deviations are found, which components are causing the deviations and the impact of each component deviation. The system works by comparing the values of the actual operating variables with some reference values that are calculated by a model that was adjusted to the design heat balances. The model can use the actual values of the environmental parameters as well as the design values, so the effect of environmental changes can be quantified and separated. The determination of the individual equipment impacts is done by adjusting the equipment parameters in order to reproduce the values of the measured variables. The adjustment is done by varying the values of the characteristic parameters of the equipment in order to minimize the sum of the squares of the differences between the values of the measured variables and the calculated values from the model.

scholarly journals The Impact of Climate Change on Cholera: A Review on the Global Status and Future Challenges

Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 449
Author(s):  
Eirini Christaki ◽  
Panagiotis Dimitriou ◽  
Katerina Pantavou ◽  
Georgios K. Nikolopoulos
Keyword(s):  
Climate Change ◽  
Environmental Changes ◽  
Natural Habitat ◽  
Environmental Parameters ◽  
Surveillance Systems ◽  
Educational Strategies ◽  
Global Status ◽  
Water Ecosystems ◽  
Sanitation Systems ◽  
The Impact

Water ecosystems can be rather sensitive to evolving or sudden changes in weather parameters. These changes can result in alterations in the natural habitat of pathogens, vectors, and human hosts, as well as in the transmission dynamics and geographic distribution of infectious agents. However, the interaction between climate change and infectious disease is rather complicated and not deeply understood. In this narrative review, we discuss climate-driven changes in the epidemiology of Vibrio species-associated diseases with an emphasis on cholera. Changes in environmental parameters do shape the epidemiology of Vibrio cholerae. Outbreaks of cholera cause significant disease burden, especially in developing countries. Improved sanitation systems, access to clean water, educational strategies, and vaccination campaigns can help control vibriosis. In addition, real-time assessment of climatic parameters with remote-sensing technologies in combination with robust surveillance systems could help detect environmental changes in high-risk areas and result in early public health interventions that can mitigate potential outbreaks.

Temporal distributions of microplankton populations and relationships to environmental conditions in Jiaozhou Bay, northern China

2012 ◽  
Vol 93 (1) ◽  
pp. 13-26 ◽  
Author(s):  
Yong Jiang ◽  
Henglong Xu ◽  
Mingzhuang Zhu ◽  
Khaled A.S. Al-Rasheid
Keyword(s):  
Species Distribution ◽  
Environmental Conditions ◽  
Environmental Changes ◽  
Temporal Dynamics ◽  
Skeletonema Costatum ◽  
Jiaozhou Bay ◽  
Northern China ◽  
Marine Ecosystems ◽  
Temporal Variations ◽  
Alexandrium Tamarense

To analyse temporal distributions of microplankton populations and relationships to environmental conditions in marine ecosystems, a dataset of microplankton communities was investigated using a range of statistical methods. A total of 164 microplankton species comprising 100 microalgae and 64 ciliates were identified from 120 samples, respectively. Both planktonic microalga and ciliate assemblages showed temporal patterns and were significantly correlated between their temporal variations in abundance. The microplankton communities were characterized by 14 ciliates (e.g. Strombidium sulcatum, Tintinnopsis tubulosoides and Strombidium cheshiri) and 18 microalgae (e.g. Skeletonema costatum and Alexandrium tamarense). Multiple regression analyses showed that the interspecies correlations among these dominant species represented a complex network with a clear seasonal shift. Temporal pattern of microplankton communities was significantly correlated with the environmental variables such as temperature, salinity and nitrate nitrogen. The results suggest the clear species distribution and temporal dynamics of microplankton communities in response to environmental changes, and multivariate statistical approaches were a useful tool to reveal the species distribution patterns and complex microplanktonic interspecies correlations in marine ecosystems.

scholarly journals Plant-microbe Cross-talk in the Rhizosphere: Insight and Biotechnological Potential

2015 ◽  
Vol 9 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Shyamalina Haldar ◽  
Sanghamitra Sengupta
Keyword(s):  
Developmental Stages ◽  
Biological Activities ◽  
Abiotic Factors ◽  
Environmental Parameters ◽  
Host Genotype ◽  
Nature Restoration ◽  
Microbiological Techniques ◽  
Microbe Interactions ◽  
Structural Principles ◽  
The Impact

Rhizosphere, the interface between soil and plant roots, is a chemically complex environment which supports the development and growth of diverse microbial communities. The composition of the rhizosphere microbiome is dynamic and controlled by multiple biotic and abiotic factors that include environmental parameters, physiochemical properties of the soil, biological activities of the plants and chemical signals from the plants and bacteria which inhabit the soil adherent to root-system. Recent advancement in molecular and microbiological techniques has unravelled the interactions among rhizosphere residents at different levels. In this review, we elaborate on various factors that determine plant-microbe and microbe-microbe interactions in the rhizosphere, with an emphasis on the impact of host genotype and developmental stages which together play pivotal role in shaping the nature and diversity of root exudations. We also discuss about the coherent functional groups of microorganisms that colonize rhizosphere and enhance plant growth and development by several direct and indirect mechanisms. Insights into the underlying structural principles of indigenous microbial population and the key determinants governing rhizosphere ecology will provide directions for developing techniques for profitable applicability of beneficial microorganisms in sustainable agriculture and nature restoration.

scholarly journals Stress Resistance in an Extreme Environment: Lessons Learnt from a Temperate Symbiotic Sea Anemone

2021 ◽  
Author(s):  
◽  
Milena Sylwia Palka
Keyword(s):  
Abiotic Factors ◽  
Environmental Parameters ◽  
Extreme Environment ◽  
Sea Anemone ◽  
Tide Pool ◽  
Highly Sensitive ◽  
Wide Range ◽  
Symbiotic Dinoflagellates ◽  
Global Concern ◽  
The Impact

<p>Coral bleaching, the loss of symbiotic dinoflagellates (zooxanthellae) or their photosynthetic pigments in response to environmental stress, is of huge global concern. In contrast to tropical corals, which are highly sensitive to fluctuations in environmental parameters such as temperature, light and salinity, zooxanthellate invertebrates in temperate waters rarely bleach despite highly variable conditions. In this study, we tested the effects of salinity with combined effects of light and temperature stress on the photophysiology and stability of the temperate symbiotic sea anemone, Anthopleura aureoradiata, through chlorophyll fluorescence. In the field it was demonstrated that A. aureoradiata was resilient to abiotic fluctuations of considerable magnitude in the intertidal zone. Salinity was revealed to range naturally between a winter low of 30 and summer high of 40 ppt in an elevated tide pool with no measurable effects on the photophysiology of A. aureoradiata residing within. In a controlled environment, only extreme high and low salinities had an effect on the zooxanthellar photosystem, with a wide range of tolerance between 15-50 ppt dependent on the levels of temperature and light. Both high and low light, and temperature, also impacted upon photophysiology. Moreover, each of these variables independently, as well as combined, exacerbated the impact of salinity stress. In addition, the duration of exposure played an important role in the survival of this symbiosis, with only 48-96 h exposure to the extreme salinities of 5, 10, 55 and 60 ppt inducing irreversible photosynthetic failure, bleaching and death. Thus, the data supports the idea that this anemone-zooxanthellar symbiosis is highly resilient to considerable amounts of abiotic stress, a likely a function of the robust photophysiology of its zooxanthellae. This resilience to bleaching suggests that A. aureoradiata and its zooxanthallae have evolved a combination of powerful defensive mechanisms to help aid against the heterogenous environment from which they come. I will present an overview of these osmoregulatory mechanisms, photoacclimatory strategies and behaviours that this symbiosis likely deploys in order to combat environmentally realistic ranges in abiotic factors. Further studies would be necessary to deduce whether it is the host or zooxanthellae which are responsible for the breakdown of this symbiosis.</p>

scholarly journals Integration of spatio-temporal variations of surface metabolomes and epibacterial communities highlights the importance of copper stress as a major factor shaping host-microbiota interactions within a Mediterranean seaweed holobiont

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Benoît Paix ◽  
Nicolas Layglon ◽  
Christophe Le Poupon ◽  
Sébastien D’Onofrio ◽  
Benjamin Misson ◽  
...  
Keyword(s):  
Trace Metal ◽  
Relative Proportion ◽  
Geographical Area ◽  
Environmental Parameters ◽  
High Specificity ◽  
Temporal Variations ◽  
Mediterranean Coast ◽  
Copper Stress ◽  
Spatio Temporal ◽  
The Impact

Abstract Background Although considered as holobionts, macroalgae and their surface microbiota share intimate interactions that are still poorly understood. Little is known on the effect of environmental parameters on the close relationships between the host and its surface-associated microbiota, and even more in a context of coastal pollutions. Therefore, the main objective of this study was to decipher the impact of local environmental parameters, especially trace metal concentrations, on an algal holobiont dynamics using the Phaeophyta Taonia atomaria as a model. Through a multidisciplinary multi-omics approach combining metabarcoding and untargeted LC-MS-based metabolomics, the epibacterial communities and the surface metabolome of T. atomaria were monitored along a spatio-temporal gradient in the bay of Toulon (Northwestern Mediterranean coast) and its surrounding. Indeed, this geographical area displays a well-described trace metal gradient particularly relevant to investigate the effect of such pollutants on marine organisms. Results Epibacterial communities of T. atomaria exhibited a high specificity whatever the five environmentally contrasted collecting sites investigated on the NW Mediterranean coast. By integrating metabarcoding and metabolomics analyses, the holobiont dynamics varied as a whole. During the occurrence period of T. atomaria, epibacterial densities and α-diversity increased while the relative proportion of core communities decreased. Pioneer bacterial colonizers constituted a large part of the specific and core taxa, and their decrease might be linked to biofilm maturation through time. Then, the temporal increase of the Roseobacter was proposed to result from the higher temperature conditions, but also the increased production of dimethylsulfoniopropionate (DMSP) at the algal surface which could constitute of the source of carbon and sulfur for the catabolism pathways of these taxa. Finally, as a major result of this study, copper concentration constituted a key factor shaping the holobiont system. Thus, the higher expression of carotenoids suggested an oxidative stress which might result from an adaptation of the algal surface metabolome to high copper levels. In turn, this change in the surface metabolome composition could result in the selection of particular epibacterial taxa. Conclusion We showed that associated epibacterial communities were highly specific to the algal host and that the holobiont dynamics varied as a whole. While temperature increase was confirmed to be one of the main parameters associated to Taonia dynamics, the originality of this study was highlighting copper-stress as a major driver of seaweed-epibacterial interactions. In a context of global change, this study brought new insights on the dynamics of a Mediterranean algal holobiont submitted to heavy anthropic pressures.

scholarly journals Changes in the occurrence of rainfall-induced landslides in Calabria, southern Italy, in the 20th century

2015 ◽  
Vol 15 (10) ◽  
pp. 2313-2330 ◽  
Author(s):  
S. L. Gariano ◽  
O. Petrucci ◽  
F. Guzzetti
Keyword(s):  
Southern Italy ◽  
Environmental Changes ◽  
Geographical Area ◽  
Daily Rainfall ◽  
Temporal Variations ◽  
Landslide Risk ◽  
Rainfall Events ◽  
Lack Of Information ◽  
The Impact ◽  
Observation Period

Abstract. Only a few studies have investigated the geographical and temporal variations in the frequency and distribution of rainfall-induced landslides, and the consequences of the variations on landslide risk. Lack of information limits the possibility to evaluate the impact of environmental and climate changes on landslide frequency and risk. Here, we exploit detailed historical information on landslides and rainfall in Calabria, southern Italy, between 1921 and 2010 to study the temporal and the geographical variation in the occurrence of rainfall-induced landslides and in their impact on the population. We exploit a catalogue with information on historical landslides from June 1920 to December 2010, and daily rainfall records obtained by a network of 318 rain gauges in the same period, to reconstruct 448 493 rainfall events (RE). Combining the rainfall and the landslide information, we obtain a catalogue of 1466 rainfall events with landslides (REL), where an REL is the occurrence of one or more landslide during or immediately after a rainfall event. We find that (i) the geographical and the temporal distributions of the rainfall-induced landslides have changed in the observation period, (ii) the monthly distribution of the REL has changed in the observation period, and (iii) the average and maximum cumulated event rainfall that have resulted in landslides in the recent 30-year period 1981–2010 are lower than the rainfall necessary to trigger landslides in previous periods, whereas the duration of the RE that triggered landslides has remained the same. We attribute the changes to variations in the rainfall conditions and to an increased vulnerability of the territory. To investigate the variations in the impact of REL on the population, we compared the number of REL in each of the 409 municipalities in Calabria with the size of the population in the municipalities measured by national Censuses conducted in 1951, 1981, and 2011. We adopted two strategies; the first strategy considered impact as IREL = #REL / P, and the second strategy measured impact as RREL = #REL × P, where #REL is the total number of REL in a period, and P is the size of the population in the same period and geographical area. The analysis has revealed a complex pattern of changes in the impact of rainfall-induced landslides in Calabria in the recent past, with areas where IREL and RREL have increased, and other areas where they have decreased. Municipalities where IREL has increased are mainly in the mountains, and municipalities where RREL has increased are mainly along the coasts. The complexity of the changes in the frequency and impact of rainfall-induced landslides observed in Calabria suggests that it remains difficult and uncertain to predict the possible variations in the frequency and impact of landslide in response to future climatic and environmental changes.

scholarly journals Environmental parameters and diversity of diatoms in the Aïn Dalia dam, Northeast of Algeria

2021 ◽  
Vol 22 (9) ◽  
Author(s):  
KARIMA HERAMZA ◽  
CHOUKRI BAROUR ◽  
AICHA DJABOURABI ◽  
WILLIA KHATI ◽  
CHAHINAISE BOUALLAG
Keyword(s):  
Temporal Dynamics ◽  
Abiotic Factors ◽  
Environmental Parameters ◽  
Biological Indicators ◽  
Aquatic Environments ◽  
Planktonic Diatom ◽  
North Eastern ◽  
Spatio Temporal ◽  
Polluted Waters

Abstract. Heramza K, Barour C, Djabourabi A, Khati W, Bouallag C. 2021. Environmental parameters and diversity of diatoms in the Aïn Dalia dam, Northeast of Algeria. Biodiversitas 22: 3633-3644. Diatoms have long been used as biological indicators of the quality of aquatic environments due to their important capacity to respond to environmental change. As this flora has been very little studied in Algeria, the present study aimed to monitor the Spatio-temporal dynamics of diatoms at the Aïn Dalia dam (north-eastern of Algeria) and determine the main abiotic factors contributing to these variations from June 2017 to May 2018 in four selected stations. Our results showed that the waters of Aïn Dalia dam waters vary from moderately (St1 and St3) to significantly polluted (St2 and St4). They host the community of planktonic diatom flora composed of 72 species. The interspecific biodiversity was marked in summer and autumn (57 and 56 species respectively) and in the St4 station (52 species). In terms of abundance, more than 40% of the overall density was found in the St4 station and the fall period. Among the dominant genera, Cyclotella, Thalassiosira, Synedra and Navicula are found in moderately polluted waters, while Nitzschia, Melosira and Surirella in significantly polluted waters. Some environmental parameters, including nutrients (PO43-and NO2-), SM, temperature, dissolved oxygen, and pH played a key role in the functioning and evolution of this lake. Hence, these parameters demonstrated important fluctuations during our study and influenced directly the diatom distribution. These results showed that diatom assemblages are influenced by anthropogenic disturbances, and can be used as indicators of environmental quality.

scholarly journals Stress Resistance in an Extreme Environment: Lessons Learnt from a Temperate Symbiotic Sea Anemone

2021 ◽  
Author(s):  
◽  
Milena Sylwia Palka
Keyword(s):  
Abiotic Factors ◽  
Environmental Parameters ◽  
Extreme Environment ◽  
Sea Anemone ◽  
Tide Pool ◽  
Highly Sensitive ◽  
Wide Range ◽  
Symbiotic Dinoflagellates ◽  
Global Concern ◽  
The Impact

<p>Coral bleaching, the loss of symbiotic dinoflagellates (zooxanthellae) or their photosynthetic pigments in response to environmental stress, is of huge global concern. In contrast to tropical corals, which are highly sensitive to fluctuations in environmental parameters such as temperature, light and salinity, zooxanthellate invertebrates in temperate waters rarely bleach despite highly variable conditions. In this study, we tested the effects of salinity with combined effects of light and temperature stress on the photophysiology and stability of the temperate symbiotic sea anemone, Anthopleura aureoradiata, through chlorophyll fluorescence. In the field it was demonstrated that A. aureoradiata was resilient to abiotic fluctuations of considerable magnitude in the intertidal zone. Salinity was revealed to range naturally between a winter low of 30 and summer high of 40 ppt in an elevated tide pool with no measurable effects on the photophysiology of A. aureoradiata residing within. In a controlled environment, only extreme high and low salinities had an effect on the zooxanthellar photosystem, with a wide range of tolerance between 15-50 ppt dependent on the levels of temperature and light. Both high and low light, and temperature, also impacted upon photophysiology. Moreover, each of these variables independently, as well as combined, exacerbated the impact of salinity stress. In addition, the duration of exposure played an important role in the survival of this symbiosis, with only 48-96 h exposure to the extreme salinities of 5, 10, 55 and 60 ppt inducing irreversible photosynthetic failure, bleaching and death. Thus, the data supports the idea that this anemone-zooxanthellar symbiosis is highly resilient to considerable amounts of abiotic stress, a likely a function of the robust photophysiology of its zooxanthellae. This resilience to bleaching suggests that A. aureoradiata and its zooxanthallae have evolved a combination of powerful defensive mechanisms to help aid against the heterogenous environment from which they come. I will present an overview of these osmoregulatory mechanisms, photoacclimatory strategies and behaviours that this symbiosis likely deploys in order to combat environmentally realistic ranges in abiotic factors. Further studies would be necessary to deduce whether it is the host or zooxanthellae which are responsible for the breakdown of this symbiosis.</p>

Characterizing the impact of recovering sea otters on commercially important crabs in California estuaries

2020 ◽  
Vol 655 ◽  
pp. 123-137
Author(s):  
TM Grimes ◽  
MT Tinker ◽  
BB Hughes ◽  
KE Boyer ◽  
L Needles ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Sea Otter ◽  
Dungeness Crab ◽  
Sea Otters ◽  
Elkhorn Slough ◽  
Enhydra Lutris Nereis ◽  
Crab Abundance ◽  
Population Sizes ◽  
Commercially Important ◽  
The Impact

Protective legislation and management have led to an increase in California’s sea otter Enhydra lutris nereis population. While sea otter recovery has been linked to ecosystem benefits, sea otter predation may negatively affect commercially valuable species. Understanding the potential influence of sea otters is of particular importance as their range expands into estuaries that function as nurseries for commercially valuable species like Dungeness crab Metacarcinus magister. We consider how sea otter predation has affected the abundance and size of juvenile Dungeness crab in Elkhorn Slough, California, USA, and analyzed cancrid crab abundance and size across 4 California estuaries with and without sea otters to understand how biotic and abiotic factors contribute to observed variation in crab size and abundance. We compared trends in southern sea otters relative to Dungeness crab landings in California to assess whether increasing sea otter abundance have negatively impacted landings. In Elkhorn Slough, juvenile Dungeness crab abundance and size have declined since 2012, coinciding with sea otter population growth. However, the impact of sea otters on juvenile Dungeness crab size was habitat-specific and only significant in unvegetated habitat. Across estuaries, we found that cancrid crab abundance and size were negatively associated with sea otter presence. While abiotic factors varied among estuaries, these factors explained little of the observed variation in crab abundance or size. Although we found evidence that sea otters can have localized effects on cancrid crab populations within estuaries, we found no evidence that southern sea otters, at recent population sizes, have negatively impacted Dungeness crab landings in California from 2000-2014.

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