scholarly journals Bacterial composition reflects fine-scale salinity changes while phylogenetic diversity exhibits a strong salt divide

2021 ◽  
Author(s):  
Ariane L Peralta ◽  
Mario E Muscarella ◽  
Alexandra Stucy ◽  
Jo A Werba ◽  
Michael W McCoy
Keyword(s):  
Phylogenetic Diversity ◽  
Carbon Mineralization ◽  
Aquatic Communities ◽  
Salinity Change ◽  
Bacterial Composition ◽  
Salinity Changes ◽  
Microbial Adaptation ◽  
Freshwater Ponds ◽  
Salinity Levels ◽  
And Function

Climate change induced salinization events are predicted to intensify and lead to increased salt stress in freshwater aquatic ecosystems. As a consequence, formerly distinct abiotic conditions and associated biotic communities merge, and the emergence, loss, and persistence of microbial taxa modify the types and rates of ecosystem processes. This study examined how bacterial taxonomic and phylogenetic diversity and ecosystem function respond to acute salinization events where freshwater and estuarine communities and environments coalesce. We hypothesize that if the salinity change outpaces microbial adaptation or saline microbial populations are not yet established in formerly freshwater conditions, then we predict diminished carbon cycling rates, decreased microbial diversity, and altered the composition of microbial communities compared to historically freshwater communities. We used an experimental mesocosm approach to determine how salinity and the merging of distinct communities influenced resultant bacterial community structure and function. Each mesocosm represented different salinities (0, 5, 9, 13 psu). Two dispersal treatments, representing aquatic communities sourced from brackish 13 psu ponds and a mix of 13 psu and freshwater ponds, were added to all salinity levels and replicated four times. Results revealed that salinity, but not dispersal, decreased bacterial taxonomic and phylogenetic diversity. Carbon mineralization rates were highest in freshwater conditions and associated with low relative abundance indicator taxa. Acute salinity changes, such as localized flooding due to storm surge, will more negatively affect freshwater aquatic communities compared to chronic exposure to salinization where the communities have had time to adapt or turnover resulting in recovered biogeochemical functions.

scholarly journals Tree Diversity Reduces Fungal Endophyte Richness and Diversity in a Large-Scale Temperate Forest Experiment

Diversity ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 234 ◽  
Author(s):  
Eric A. Griffin ◽  
Joshua G. Harrison ◽  
Melissa K. McCormick ◽  
Karin T. Burghardt ◽  
John D. Parker
Keyword(s):  
Phylogenetic Diversity ◽  
Large Scale ◽  
High Throughput Sequencing ◽  
Spatial Scales ◽  
Fungal Endophytes ◽  
Fungal Endophyte ◽  
Tree Diversity ◽  
Trophic Levels ◽  
Community Diversity ◽  
And Function

Although decades of research have typically demonstrated a positive correlation between biodiversity of primary producers and associated trophic levels, the ecological drivers of this association are poorly understood. Recent evidence suggests that the plant microbiome, or the fungi and bacteria found on and inside plant hosts, may be cryptic yet important drivers of important processes, including primary production and trophic interactions. Here, using high-throughput sequencing, we characterized foliar fungal community diversity, composition, and function from 15 broadleaved tree species (N = 545) in a recently established, large-scale temperate tree diversity experiment using over 17,000 seedlings. Specifically, we tested whether increases in tree richness and phylogenetic diversity would increase fungal endophyte diversity (the “Diversity Begets Diversity” hypothesis), as well as alter community composition (the “Tree Diversity–Endophyte Community” hypothesis) and function (the “Tree Diversity–Endophyte Function” hypothesis) at different spatial scales. We demonstrated that increasing tree richness and phylogenetic diversity decreased fungal species and functional guild richness and diversity, including pathogens, saprotrophs, and parasites, within the first three years of a forest diversity experiment. These patterns were consistent at the neighborhood and tree plot scale. Our results suggest that fungal endophytes, unlike other trophic levels (e.g., herbivores as well as epiphytic bacteria), respond negatively to increasing plant diversity.

scholarly journals How global extinctions impact regional biodiversity in mammals

2011 ◽  
Vol 8 (2) ◽  
pp. 222-225 ◽  
Author(s):  
Shan Huang ◽  
T. Jonathan Davies ◽  
John L. Gittleman
Keyword(s):  
Evolutionary History ◽  
Phylogenetic Diversity ◽  
Spatial Scales ◽  
Spatial Location ◽  
Ecosystem Processes ◽  
Biodiversity Hotspots ◽  
Species Assemblage ◽  
Species Extinction ◽  
History Of ◽  
And Function

Phylogenetic diversity (PD) represents the evolutionary history of a species assemblage and is a valuable measure of biodiversity because it captures not only species richness but potentially also genetic and functional diversity. Preserving PD could be critical for maintaining the functional integrity of the world's ecosystems, and species extinction will have a large impact on ecosystems in areas where the ecosystem cost per species extinction is high. Here, we show that impacts from global extinctions are linked to spatial location. Using a phylogeny of all mammals, we compare regional losses of PD against a model of random extinction. At regional scales, losses differ dramatically: several biodiversity hotspots in southern Asia and Amazonia will lose an unexpectedly large proportion of PD. Global analyses may therefore underestimate the impacts of extinction on ecosystem processes and function because they occur at finer spatial scales within the context of natural biogeography.

scholarly journals Fine-scale spatial patterns in bacterial community composition and function within freshwater ponds

2014 ◽  
Vol 8 (8) ◽  
pp. 1715-1726 ◽  
Author(s):  
Gavin Lear ◽  
Julia Bellamy ◽  
Bradley S Case ◽  
Jack E Lee ◽  
Hannah L Buckley
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Spatial Patterns ◽  
Bacterial Community Composition ◽  
Fine Scale ◽  
Freshwater Ponds ◽  
And Function

scholarly journals Global-scale patterns of observed sea surface salinity intensified since the 1870s

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
W. John Gould ◽  
Stuart A. Cunningham
Keyword(s):  
Hydrological Cycle ◽  
Global Scale ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Salinity Change ◽  
Surface Salinity ◽  
Salinity Changes ◽  
Change Pattern ◽  
The World ◽  
Global Mean

AbstractSea surface salinity patterns have intensified between the mid-20th century and present day, with saline areas becoming saltier and fresher areas fresher. This change has been linked to a human-induced strengthening of the global hydrological cycle as global mean surface temperatures rose. Here we analyse salinity observations from the round-the-world voyages of HMS Challenger and SMS Gazelle in the 1870s, early in the industrial era, to reconstruct surface salinity changes since that decade. We find that the amplification of the salinity change pattern between the 1870s and the 1950s was at a rate that was 54 ± 10% lower than the post-1950s rate. The acceleration in salinity pattern amplification over almost 150 years implies that the hydrological cycle would have similarly accelerated over this period.

scholarly journals Low shifts in salinity determined assembly processes and network stability of microeukaryotic plankton communities in a subtropical urban reservoir

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Yuanyuan Mo ◽  
Feng Peng ◽  
Xiaofei Gao ◽  
Peng Xiao ◽  
Ramiro Logares ◽  
...  
Keyword(s):  
Community Composition ◽  
Community Assembly ◽  
Network Architecture ◽  
Community Dynamics ◽  
Microbial Community Composition ◽  
Plankton Community ◽  
Network Stability ◽  
Salinity Change ◽  
Salinity Levels ◽  
Plankton Diversity

Abstract Background Freshwater salinization may result in significant changes of microbial community composition and diversity, with implications for ecosystem processes and function. Earlier research has revealed the importance of large shifts in salinity on microbial physiology and ecology, whereas studies on the effects of smaller or narrower shifts in salinity on the microeukaryotic community in inland waters are scarce. Our aim was to unveil community assembly mechanisms and the stability of microeukaryotic plankton networks at low shifts in salinity. Results Here, we analyzed a high-resolution time series of plankton data from an urban reservoir in subtropical China over 13 consecutive months following one periodic salinity change ranging from 0 to 6.1‰. We found that (1) salinity increase altered the community composition and led to a significant decrease of plankton diversity, (2) salinity change influenced microeukaryotic plankton community assembly primarily by regulating the deterministic-stochastic balance, with deterministic processes becoming more important with increased salinity, and (3) core plankton subnetwork robustness was higher at low-salinity levels, while the satellite subnetworks had greater robustness at the medium-/high-salinity levels. Our results suggest that the influence of salinity, rather than successional time, is an important driving force for shaping microeukaryotic plankton community dynamics. Conclusions Our findings demonstrate that at low salinities, even small increases in salinity are sufficient to exert a selective pressure to reduce the microeukaryotic plankton diversity and alter community assembly mechanism and network stability. Our results provide new insights into plankton ecology of inland urban waters and the impacts of salinity change in the assembly of microbiotas and network architecture.

scholarly journals EFFECT OF SALINITY CHANGES ON METHIONINE CONTENT IN TIGER GROUPER JUVENILE (Epinephelus fuscoguttatus)

2018 ◽  
Vol 12 (4) ◽  
Author(s):  
Muhammadar Abdullah Abbas ◽  
Muchlisin Zainal Abidin ◽  
Dedi Fazriansyah Putra ◽  
Firdus Firdus ◽  
Agung Setia Batubara ◽  
...  
Keyword(s):  
Analysis Data ◽  
Control Group ◽  
Treatment Groups ◽  
Salinity Changes ◽  
Methionine Deficiency ◽  
Salinity Levels ◽  
Epinephelus Fuscoguttatus ◽  
Tiger Grouper ◽  
Methionine Content ◽  
Methionine Level

This study was conducted to determine the effect of water salinity changes on methionine content in tiger grouper juvenile (Epinephelus fuscoguttatus). A total of 2,560 tiger grouper juveniles were used and divided into five groups consist of 1 control group (without exposed to salinity changes) and 4 treatment groups. The salinity was changed every 2, 3, 4, and 6 hours in treatment A, B, C, and D, respectively. Salinity levels were changed during 24 hours by lowering salinity level from 32 psu to 22 psu. Twenty five of fish were collected from each treatment for methionine content analysis. Data were analysed using one way analysis of variance (ANOVA). The results showed that there was a decrease in methionine content in all treatments. A significant decrease (P0.05) of methionine content in treatment A, B, and C were observed after 20 hours (1.15%), 18 hours (1.27%), and 16 hours (1.24%), respectively. While at 0 hours (control), the methionine content was 2.02%. Methionine level in treatment D was not significantly different (P0.05) compared to control group. As conclusion, rearing the tiger grouper juvenile with salinity fluctuations every 6 hours did not lead to methionine deficiency.

scholarly journals Salinity and its variability in the Lagoon of Venice, 2000–2009

2014 ◽  
Vol 5 (1) ◽  
pp. 41 ◽  
Author(s):  
Alberto Zirino ◽  
Hany Elwany ◽  
Carlos Neira ◽  
Francesco Maicu ◽  
Guillermo Mendoza ◽  
...  
Keyword(s):  
Steady State ◽  
Venice Lagoon ◽  
Intermediate Zone ◽  
Lagoon Of Venice ◽  
Salinity Change ◽  
Salinity Distribution ◽  
Rainfall Events ◽  
Salinity Changes ◽  
Salinity Data

Yearly averages computed from monthly and bimonthly salinity data collected between 2000 and 2009 from 13 broadly spaced stations in the Venice Lagoon were analysed in view of 30 min data collected semi-continuously during 2009 at nine similarly located stations. Data from all stations and all years indicate that, based on yearly averages, the lagoon may be divided along its major (long) axis into three areas: 1) a northern, freshwater impacted area (S = 32 PSU of low, tidally-caused, variability, and 3) an intermediate zone. Salinity changes are closely associated with rainfall events, and the incoming freshwater is consistently distributed throughout the lagoon by tidal action. Much variability is simply a result of the forward and backward motion of the tides and is not caused by a salinity change in the water itself. The consistency of the 2000–2009 data and the historical (to 1961) watershed record support the hypothesis that the Venice Lagoon has been and is currently at steady-state with respect to its salinity distribution. As such, it is conducive to the development of (at least) three separate ecosystems.

scholarly journals Hemocyte Responses of the Oyster Crassostrea hongkongensis Exposed to Diel-Cycling Hypoxia and Salinity Change

2021 ◽  
Vol 8 ◽  
Author(s):  
Zhe Xie ◽  
Shuaishuai Wei ◽  
Haomiao Dong ◽  
Hui Chen ◽  
Qianqian Zhang ◽  
...  
Keyword(s):  
Hong Kong ◽  
Immune Function ◽  
Summer Season ◽  
Mass Mortality ◽  
Combined Stress ◽  
Salinity Change ◽  
Salinity Fluctuation ◽  
Crassostrea Hongkongensis ◽  
Low Salinity ◽  
Salinity Changes

Marine hypoxia caused by nutrient enrichment in coastal waters has become a global problem for decades, especially diel-cycling hypoxia that occurs frequently in the summer season. On the contrary, sudden rainstorms, and freshwater discharge make salinity in estuarine and coastal ecosystems variable, which often occurs with hypoxia. We found mass mortality of the Hong Kong oyster Crassostrea hongkongensis in the field where hypoxia and salinity fluctuation co-occur in the summer season during the past several years. To investigate the effects of diel-cycling hypoxia and salinity changes on the hemocyte immune function of C. hongkongensis, oysters were exposed to a combined effect of two dissolved oxygen (DO) concentrations (24 h normal oxygen 6 mg/L, 12 h normal oxygen 6 mg/L, and 12 h hypoxia 2 mg/L) and three salinities (10, 25, and 35‰) for 14 days. Subsequently, all treatments were restored to constant normal oxygen (6 mg/L) and salinity under 25‰ for 3 days to study the recovery of hemocyte immune function from the combined stress. Hemocyte parameters were analyzed by flow cytometry, including hemocyte mortality (HM), total hemocyte count (THC), phagocytosis (PHA), esterase (EST) activity, reactive oxygen species (ROS), lysosomal content (LYSO), and mitochondrial number (MN). The experimental results showed that diel-cycling hypoxia and salinity changes have obvious interactive effects on various immune parameters. In detail, diel-cycling hypoxia and decreases in salinity led to increased HM, and low salinity caused heavier impacts. In addition, low salinity, and diel-cycling hypoxia also led to decreases in LYSO, EST, and THC, while the decrease of PHA only occurs in the early stage. On the contrary, ROS production increased significantly under low salinity and hypoxic conditions. After 3-day recovery, THC, PHA, EST, LYSO, and MN were basically restored to normal, while HM and ROS were still significantly affected by diel-cycling hypoxia and salinity change, indicating that the combined stress of diel-cycling hypoxia and salinity changes had latent effects on the immune function of C. hongkongensis. Our results highlight that diel-cycling hypoxia and salinity change may impair the health and survival of the Hong Kong oyster C. hongkongensis and may be the key factors for the mass mortality of this oyster in the field.

Responses of freshwater biota to rising salinity levels and implications for saline water management: a review

2003 ◽  
Vol 51 (6) ◽  
pp. 703 ◽  
Author(s):  
Kimberley R. James ◽  
Belinda Cant ◽  
Tom Ryan
Keyword(s):  
Water Management ◽  
Species Interactions ◽  
Sublethal Effects ◽  
Saline Water ◽  
Assessment Tools ◽  
Aquatic Communities ◽  
Elevated Salinity ◽  
Freshwater Biota ◽  
Salinity Levels ◽  
Complex Ecosystem

All of the plants and animals that make up freshwater aquatic communities are affected by salinity. Many taxa possess morphological, physiological and life-history characteristics that provide some capacity for tolerance, acclimatisation or avoidance. These characteristics impart a level of resilience to freshwater communities.To maintain biodiversity in aquatic systems it is important to manage the rate, timing, pattern, frequency and duration of increases in salinity in terms of lethal and sublethal effects, sensitive life stages, the capacity of freshwater biota to acclimatise to salinity and long-term impacts on community structure.We have limited understanding of the impacts of saline water management on species interactions, food-web structures and how elevated salinity levels affect the integrity of communities. Little is known about the effect of salinity on complex ecosystem processes involving microbes and microalgae, or the salinity thresholds that prevent semi-aquatic and terrestrial species from using aquatic resources. Compounding effects of salinity and other stressors are also poorly understood.Our current understanding needs to be reinterpreted in a form that is accessible and useful for water managers. Because of their complexity, many of the remaining knowledge gaps can only be addressed through a multidisciplinary approach carried out in an adaptive management framework, utilising decision-making and ecological risk assessment tools.

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