scholarly journals Influence of Estuarine Water on the Microbial Community Structure of Patagonian Fjords

2021 ◽  
Vol 8 ◽  
Author(s):  
Javier Tamayo-Leiva ◽  
Jerónimo Cifuentes-Anticevic ◽  
Pilar Aparicio-Rizzo ◽  
José Ignacio Arroyo ◽  
Italo Masotti ◽  
...  
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
Linear Span ◽  
Salinity Gradient ◽  
Estuarine Water ◽  
Eukaryotic Phytoplankton ◽  
Patagonian Fjords ◽  
Sar11 Clade

Fjords are sensitive areas affected by climate change and can act as a natural laboratory to study microbial ecological processes. The Chilean Patagonian fjords (41–56°S), belonging to the Subantarctic ecosystem (46–60°S), make up one of the world’s largest fjord systems. In this region, Estuarine Water (EW) strongly influences oceanographic conditions, generating sharp gradients of oxygen, salinity and nutrients, the effects of which on the microbial community structure are poorly understood. During the spring of 2017 we studied the ecological patterns (dispersal and oceanographic factors) underlying the microbial community distribution in a linear span of 450 km along the estuarine-influenced Chilean Patagonian fjords. Our results show that widespread microbial dispersion existed along the fjords where bacterioplankton exhibited dependence on the eukaryotic phytoplankton community composition. This dependence was particularly observed under the low chlorophyll-a conditions of the Baker Channel area, in which a significant relationship was revealed between SAR11 Clade III and the eukaryotic families Pyrenomonadaceae (Cryptophyte) and Coccomyxaceae (Chlorophyta). Furthermore, dissolved oxygen and salinity were revealed as the main drivers influencing the surface marine microbial communities in these fjords. A strong salinity gradient resulted in the segregation of the Baker Channel prokaryotic communities from the rest of the Patagonian fjords. Likewise, Microbacteriaceae, Burkholderiaceae and SAR11 Clade III, commonly found in freshwater, were strongly associated with EW conditions in these fjords. The direct effect of EW on the microbial community structure and diversity of the fjords exemplifies the significance that climate change and, in particular, deglaciation have on this marine region and its productivity.

scholarly journals Plant genotype controls wetland soil microbial functioning in response to sea-level rise

2021 ◽  
Vol 18 (23) ◽  
pp. 6133-6146
Author(s):  
Hao Tang ◽  
Susanne Liebner ◽  
Svenja Reents ◽  
Stefanie Nolte ◽  
Kai Jensen ◽  
...  
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Microbial Community ◽  
Sea Level Rise ◽  
Sea Level ◽  
Microbial Community Structure ◽  
Soil Microbial Communities ◽  
Litter Breakdown ◽  
Plant Genotype ◽  
Soil Microbial

Abstract. Climate change can strongly alter soil microbial functioning via plant–microbe interactions, often with important consequences for ecosystem carbon and nutrient cycling. Given the high degree of intraspecific trait variability in plants, it has been hypothesized that genetic shifts within plant species yield a large potential to control the response of plant–microbe interactions to climate change. Here we examined if sea-level rise and plant genotype interact to affect soil microbial communities in an experimental coastal wetland system, using two known genotypes of the dominant salt-marsh grass Elymus athericus characterized by differences in their sensitivity to flooding stress – i.e., a tolerant genotype from low-marsh environments and an intolerant genotype from high-marsh environments. Plants were exposed to a large range of flooding frequencies in a factorial mesocosm experiment, and soil microbial activity parameters (exo-enzyme activity and litter breakdown) and microbial community structure were assessed. Plant genotype mediated the effect of flooding on soil microbial community structure and determined the presence of flooding effects on exo-enzyme activities and belowground litter breakdown. Larger variability in microbial community structure, enzyme activities, and litter breakdown in soils planted with the intolerant plant genotype supported our general hypothesis that effects of climate change on soil microbial activity and community structure can depend on plant intraspecific genetic variation. In conclusion, our data suggest that adaptive genetic variation in plants could suppress or facilitate the effects of sea-level rise on soil microbial communities. If this finding applies more generally to coastal wetlands, it yields important implications for our understanding of ecosystem–climate feedbacks in the coastal zone.

scholarly journals Functional plasticity in oyster gut microbiomes along a eutrophication gradient in an urbanized estuary

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Rebecca J. Stevick ◽  
Anton F. Post ◽  
Marta Gómez-Chiarri
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Ecosystem Services ◽  
Microbial Community ◽  
Bacterial Community ◽  
Microbial Community Structure ◽  
Environmental Conditions ◽  
Eastern Oyster ◽  
Coastal Pollution ◽  
And Function

Abstract Background Oysters in coastal environments are subject to fluctuating environmental conditions that may impact the ecosystem services they provide. Oyster-associated microbiomes are responsible for some of these services, particularly nutrient cycling in benthic habitats. The effects of climate change on host-associated microbiome composition are well-known, but functional changes and how they may impact host physiology and ecosystem functioning are poorly characterized. We investigated how environmental parameters affect oyster-associated microbial community structure and function along a trophic gradient in Narragansett Bay, Rhode Island, USA. Adult eastern oyster, Crassostrea virginica, gut and seawater samples were collected at 5 sites along this estuarine nutrient gradient in August 2017. Samples were analyzed by 16S rRNA gene sequencing to characterize bacterial community structures and metatranscriptomes were sequenced to determine oyster gut microbiome responses to local environments. Results There were significant differences in bacterial community structure between the eastern oyster gut and water samples, suggesting selection of certain taxa by the oyster host. Increasing salinity, pH, and dissolved oxygen, and decreasing nitrate, nitrite and phosphate concentrations were observed along the North to South gradient. Transcriptionally active bacterial taxa were similar for the different sites, but expression of oyster-associated microbial genes involved in nutrient (nitrogen and phosphorus) cycling varied throughout the Bay, reflecting the local nutrient regimes and prevailing environmental conditions. Conclusions The observed shifts in microbial community composition and function inform how estuarine conditions affect host-associated microbiomes and their ecosystem services. As the effects of estuarine acidification are expected to increase due to the combined effects of eutrophication, coastal pollution, and climate change, it is important to determine relationships between host health, microbial community structure, and environmental conditions in benthic communities.

scholarly journals Seasonal dynamics of cyanobacteria and eukaryotic phytoplankton in a multiple-reservoir recycling irrigation system

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Ping Kong ◽  
Patricia Richardson ◽  
Chuanxue Hong
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Water Temperature ◽  
Microbial Community Structure ◽  
Seasonal Dynamics ◽  
Irrigation System ◽  
Seasonal Pattern ◽  
Agricultural Runoff ◽  
Eukaryotic Phytoplankton ◽  
Ammonium Level

Abstract Background Agricultural runoff recycling systems are manmade aquatic ecosystems of growing significance to global water sustainability, crop health, and production. This study investigated the seasonal dynamics of microbial community in a three-reservoir recycling irrigation system with a stepwise water flow and compared with that of an adjacent runoff-free stream. Runoff water from all production areas was captured in a sedimentation reservoir which overflowed to a transition reservoir then retention reservoir through a culvert. Stream water was pumped to replenish the reservoirs as needed during growing seasons. Results 16S rDNA PCR clone libraries of quarterly water samples from three reservoirs and one stream were sequenced, and 575 operational taxonomic units (OTUs) were identified and assigned to cyanobacteria, eukaryotic phytoplankton, and other bacteria. When compared to the stream, three reservoirs consistently had low microbial diversity. A distinct seasonal pattern of microbial community structure was observed for each reservoir and the stream. Stream was consistently dominated by other bacteria. Retention reservoir was dominated by cyanobacteria during the summer and fall and eukaryotic phytoplankton during the winter and spring. Sedimentation reservoir was dominated by cyanobacteria beginning in the spring but that dominance was altered when water was pumped from the stream from early spring to fall seasons. Transition reservoir had the greatest shift of microbial community structure, being dominated by other bacteria in the summer, cyanobacteria in the fall, and eukaryotic phytoplankton in the winter and spring. Water temperature and ammonium level were the two most important contributing factors to the seasonality of microbial community in these reservoirs. Conclusions The three recycling irrigation reservoirs consistently had lower microbial diversity and distinct community structure when compared to the stream. These reservoirs were typically dominated by cyanobacteria during warm seasons and eukaryotic phytoplankton during cool seasons. This seasonal pattern was altered when water was pumped from the stream. The cyanobacteria dominance was associated with rising water temperature and ammonium level. These results highlight the importance of preventing agricultural runoff from entering natural waterways and water resources and provide a useful framework for further investigations into the ecological processes of this emerging ecosystem.

scholarly journals Plant genotype controls wetland soil microbial functioning in response to sea-level rise 

2021 ◽  
Author(s):  
Hao Tang ◽  
Susanne Liebner ◽  
Svenja Reents ◽  
Stefanie Nolte ◽  
Kai Jensen ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Matter ◽  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
Soil Microbial Communities ◽  
Soil Microbial Activity ◽  
Litter Breakdown ◽  
Plant Genotype ◽  
Soil Microbial

Abstract. Climate change induced shifts in plant community composition affect the decomposition of soil organic matter via plant-microbe interactions, often with important consequences for ecosystem carbon and nutrient cycling. Given the high degree of intraspecific trait variability in plants, it has been hypothesized that genetic shifts within species yield a similar potential to affect soil microbial functioning.We examined if sea-level rise and plant genotype interact to affect soil microbial communities in an experimental coastal wetland system, using two known genotypes of the dominant salt-marsh grass Elymus athericus characterized by differences in their sensitivity to flooding stress – i.e. an adapted genotype from low-marsh environments and an unadapted genotype from high-marsh environments. Plants were exposed to a large range of flooding frequencies in a factorial mesocosm experiment, and soil microbial-activity parameters (exo-enzyme activity and litter breakdown) and microbial community structure were assessed.Plant genotype mediated the effect of flooding on soil microbial community structure and determined the presence of flooding effects on exo-enzyme activities and belowground litter breakdown. Larger variability in microbial community structure, enzyme activities, and litter breakdown in soils planted with the unadapted plant genotype supported our general hypothesis that effects of climate change on soil microbial activity and community structure can depend on plant intraspecific adaptations. We conclude that adaptive genetic variation in plants can suppress or facilitate the effects of climate change on soil microbial communities. If this finding applies more generally to wetland ecosystems and beyond, it yields important implications for experimental climate change research and models of soil organic matter accumulation.

scholarly journals Effects of Climate Change on Microbial Community Structure and Function in the Antarctic Glacier Lagoon

2010 ◽  
Vol 17 (1) ◽  
Author(s):  
Aleksander Świątecki ◽  
Dorota Górniak ◽  
Katarzyna Jankowska ◽  
Marek K. Zdanowski ◽  
Piotr Borsuk ◽  
...  
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
Structure And Function ◽  
And Function ◽  
The Antarctic

scholarly journals Experimental drought induces short-term changes in soil functionality and microbial community structure after fire in a Mediterranean shrubland

2014 ◽  
Vol 11 (10) ◽  
pp. 15251-15287 ◽  
Author(s):  
M. B. Hinojosa ◽  
A. Parra ◽  
V. A. Laudicina ◽  
J. M. Moreno
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Microbial Community ◽  
Soil Nutrients ◽  
Nutrient Availability ◽  
Microbial Community Structure ◽  
Fire Severity ◽  
Historical Control ◽  
Fire Intensity ◽  
Severe Drought

Abstract. Fire is a major ecosystem driver, causing significant changes in soil nutrients and microbial community structure and functionality. Post-fire soil dynamics can vary depending on rainfall patterns, although variations in response to drought are poorly known. This is particularly important in areas with poor soils and limited rainfall, like arid and semiarid ones. Furthermore, climate change projections in many such areas anticipate reduced precipitation and longer drought, together with an increase in fire severity. The effects of experimental drought and fire were studied on soils in a Mediterranean Cistus-Erica shrubland in Central Spain. A replicated (n = 4) field experiment was carried out in which four levels of rainfall pattern were implemented by means of a rain-out shelters and irrigation system. The treatments were: environmental control (natural rainfall), historical control (long-term average rainfall, 2 months drought), moderate drought (25% reduction of historical control, 5 months drought) and severe drought (45% reduction, 7 months drought). After one growing season, the plots were burned with high fire intensity, except a set of unburned plots that served as control. Soils were collected seasonally during one year and variables related to soil nutrient availability and microbial community structure and functionality were studied. Burned soils increased nutrient availability (P, N, K) with respect to unburned ones, but drought reduced such an increase in P, while it further increased N and K. Such changes in available soil nutrients were short-lived. Drought caused a further decrease of enzyme activities, carbon mineralization rate and microbial biomass. Fire decreased the relative abundance of fungi and actinomycetes. However, fire and drought caused a further reduction in fungi, with bacteria becoming relatively more abundant. Arguably, increasing drought and fires due to climate change will likely shift soil recovery after fire.

The First Use of Biofilm Microbial Community Structure as an Indicator of Impact of Two Dams on the Elwha River (Washington)

2009 ◽  
Vol 27 (4) ◽  
pp. 385-387
Author(s):  
W. D. Eaton ◽  
B. Wilmot ◽  
E. Epler ◽  
S. Mangiamelli ◽  
D. Barry
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
Elwha River
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