scholarly journals Biological and environmental drivers of deep-sea benthic ecosystem functioning in Canada’s Laurentian Channel Area of Interest (AOI)

2018 ◽  
Author(s):  
Marta Miatta ◽  
Paul V Snelgrove
Keyword(s):  
Deep Sea ◽  
Ecosystem Functioning ◽  
Environmental Variables ◽  
Environmental Changes ◽  
Marine Ecosystem ◽  
Environmental Drivers ◽  
Biological Traits ◽  
Area Of Interest ◽  
Prokaryotic Abundance

Ongoing environmental changes and accelerating biodiversity loss raise concern and interest about the role of environmental factors and biodiversity in determining marine ecosystem functioning. This study aims to identify the main drivers of benthic ecosystem functioning in deep-sea sedimentary habitats in the Laurentian Channel Area of Interest (AOI), and in particular the role of sea pens (Pennatulacea) as potential keystone species in the area. Using the ROV ROPOS we collected sediment cores and measured environmental variables from 6 stations inside the AOI (depths 348–445m) in September 2017. Through 48-hours incubations and flux measurements (oxygen, inorganic nutrients), we estimated organic matter remineralization, a key benthic function. Preliminary analyses show no significant variation in fluxes among stations, despite significant differences in environmental variables However, the presence/absence of Pennatulacea inside the cores indicated some capability to enhance remineralization and particularly nitrification. Ongoing analyses will address sediment properties, macrofaunal biodiversity, prokaryotic abundance, and biological traits as drivers of remineralization. Shedding new light on the primary drivers of ecosystem functioning in the area will inform the design or monitoring strategies proposed for this AOI and offer new perspectives and tools for MPA design.

scholarly journals Biological and environmental drivers of deep-sea benthic ecosystem functioning in Canada’s Laurentian Channel Area of Interest (AOI)

2018 ◽  
Author(s):  
Marta Miatta ◽  
Paul V Snelgrove
Keyword(s):  
Deep Sea ◽  
Ecosystem Functioning ◽  
Environmental Variables ◽  
Environmental Changes ◽  
Marine Ecosystem ◽  
Environmental Drivers ◽  
Biological Traits ◽  
Area Of Interest ◽  
Prokaryotic Abundance

Ongoing environmental changes and accelerating biodiversity loss raise concern and interest about the role of environmental factors and biodiversity in determining marine ecosystem functioning. This study aims to identify the main drivers of benthic ecosystem functioning in deep-sea sedimentary habitats in the Laurentian Channel Area of Interest (AOI), and in particular the role of sea pens (Pennatulacea) as potential keystone species in the area. Using the ROV ROPOS we collected sediment cores and measured environmental variables from 6 stations inside the AOI (depths 348–445m) in September 2017. Through 48-hours incubations and flux measurements (oxygen, inorganic nutrients), we estimated organic matter remineralization, a key benthic function. Preliminary analyses show no significant variation in fluxes among stations, despite significant differences in environmental variables However, the presence/absence of Pennatulacea inside the cores indicated some capability to enhance remineralization and particularly nitrification. Ongoing analyses will address sediment properties, macrofaunal biodiversity, prokaryotic abundance, and biological traits as drivers of remineralization. Shedding new light on the primary drivers of ecosystem functioning in the area will inform the design or monitoring strategies proposed for this AOI and offer new perspectives and tools for MPA design.

scholarly journals Monitoring studies should consider temporal variability to reveal relations between cyanobacterial abundance and environmental variables

2015 ◽  
Vol 87 (3) ◽  
pp. 1717-1726 ◽  
Author(s):  
JULIANA WOJCIECHOWSKI ◽  
ANDRÉ A. PADIAL
Keyword(s):  
Temporal Variability ◽  
Environmental Variables ◽  
Environmental Changes ◽  
Environmental Variability ◽  
Time Lag ◽  
Cyanobacteria Blooms ◽  
Environment Variables ◽  
Sampling Points ◽  
The Relationship

One of the main goals of monitoring cyanobacteria blooms in aquatic environments is to reveal the relationship between cyanobacterial abundance and environmental variables. Studies typically correlate data that were simultaneously sampled. However, samplings occur sparsely over time and may not reveal the short-term responses of cyanobacterial abundance to environmental changes. In this study, we tested the hypothesis that stronger cyanobacteria x environment relationships in monitoring are found when the temporal variability of sampling points is incorporated in the statistical analyses. To this end, we investigated relationships between cyanobacteria and seven environmental variables that were sampled twice yearly for three years across 11 reservoirs, and data from an intensive monitoring in one of these reservoirs. Poor correlations were obtained when correlating data simultaneously sampled. In fact, the 'highly recurrent' role of phosphorus in cyanobacteria blooms is not properly observed in all sampling periods. On the other hand, the strongest correlation values for the total phosphorus x cyanobacteria relationship were observed when we used the variation of sampling points. We have also shown that environment variables better explain cyanobacteria when a time lag is considered. We conclude that, in cyanobacteria monitoring, the best approach to reveal determinants of cyanobacteria blooms is to consider environmental variability.

scholarly journals How vadose zone mass and energy transfer physics affects the ecohydrological dynamics of a Tibetan meadow?

2020 ◽  
Author(s):  
Lianyu Yu ◽  
Yijian Zeng ◽  
Simone Fatichi ◽  
Zhongbo Su
Keyword(s):  
Vadose Zone ◽  
Land Surface ◽  
Ecosystem Functioning ◽  
Vegetation Dynamics ◽  
Process Model ◽  
Environmental Changes ◽  
Model Performance ◽  
Frozen Soil ◽  
The Tibetan Plateau

Abstract. The vadose zone is a sensitive region to environmental changes and exerts a crucial control in ecosystem functioning. While the way in representing the underlying process of vadose zone differs among models, the effect of such differences on ecosystem functioning is seldomly reported. Here, the detailed vadose zone process model STEMMUS was coupled with the ecohydrological model T&C to investigate the role of solving influential physical processes, considering different soil water and heat transfer parameterizations including frozen soils. We tested model performance with the aid of a comprehensive observation dataset collected at a typical meadow ecosystem on the Tibetan Plateau. Results indicated that: i) explicitly considering the frozen soil process significantly improved the soil moisture/temperature (SM/ST) profile simulations and facilitated our understanding of the water transfer processes within the soil-plant-atmosphere continuum; ii) the difference among various complexity of vadose zone physics have an impact on the vegetation dynamics mainly at the beginning of the growing season; iii) models with different vadose zone physics can predict similar interannual vegetation dynamics, and energy, water and carbon exchanges at the land-surface. This research highlights the role of vadose zone models and their underlying physics, in ecosystem functioning and can guide the development and applications of future earth system models.

scholarly journals Environmental Factors Are Stronger Predictors of Primate Species’ Distributions Than Basic Biological Traits

2021 ◽  
Author(s):  
Katherine A. Williams ◽  
Helen D. Slater ◽  
Phillipa Gillingham ◽  
Amanda H. Korstjens
Keyword(s):  
Environmental Conditions ◽  
Environmental Variables ◽  
Large Scale ◽  
Species Distributions ◽  
Sub Saharan Africa ◽  
Primate Species ◽  
Biological Traits ◽  
Data Set ◽  
Environmental Processes

AbstractUnderstanding the neutral, biological, and environmental processes driving species distributions is valuable in informing conservation efforts because it will help us predict how species will respond to changes in environmental conditions. Environmental processes affect species differently according to their biological traits, which determine how they interact with their environment. Therefore, functional, trait-based modeling approaches are considered important for predicting distributions and species responses to change but even for data-rich primate communities our understanding of the relationships between traits and environmental conditions is limited. Here we use a large-scale, high-resolution data set of African diurnal primate distributions, biological traits, and environmental conditions to investigate the role of biological traits and environmental trait filtering in primate distributions. We collected data from published sources for 354 sites and 14 genera with 57 species across sub-Saharan Africa. We then combined a three-table ordination method, RLQ, with the fourth-corner approach to test relationships between environmental variables and biological traits and used a mapping approach to visually assess patterning in primate genus and species’ distributions. We found no significant relationships between any groups of environmental variables and biological traits, despite a clear role of environmental filtering in driving genus and species’ distributions. The most important environmental driver of species distributions was temperature seasonality, followed by rainfall. We conclude that the relative flexibility of many primate genera means that not any one particular set of traits drives their species–environment associations, despite the clear role of such associations in their distribution patterns.

scholarly journals Role of phylogenetic structure in the dynamics of coastal viral assemblages

2021 ◽  
Author(s):  
Julia A. Gustavsen ◽  
Curtis A. Suttle
Keyword(s):  
High Throughput Sequencing ◽  
Environmental Changes ◽  
Marine Ecosystem ◽  
Marker Genes ◽  
Marine Microbes ◽  
Phylogenetic Structure ◽  
Genes Encoding ◽  
One Year ◽  
Rna And Dna

Marine microbes, including viruses, are an essential part of the marine ecosystem, forming the base of the foodweb and driving biogeochemical cycles. Within this system, the composition of viral assemblages changes markedly with time, with some of these changes being repeatable through time; however, the extent to which these dynamics are reflected within versus among evolutionarily-related groups of viruses is largely unexplored. To examine these dynamics, changes in the composition of two groups of ecologically important viruses and communities of their potential hosts were sampled every two weeks for 13 months at a coastal site in British Columbia, Canada. We sequenced two marker genes for viruses, the major capsid protein (gp23) of T4-like phages and their relatives, and the RNA-dependent RNA polymerase (RdRp) of marnavirus-like RNA viruses, as well as their bacterial and eukaryotic host communities, the genes encoding 16S and 18S ribosomal RNA (rRNA). There were strong lagged correlations between viral diversity and community similarity of putative hosts implying that the viruses influenced the composition of the host communities. The results showed that for both viral assemblages, the dominant clusters of phylogenetically-related viruses shifted over time and this was correlated with environmental changes. Viral clusters contained many ephemeral taxa and few persistent taxa, but within a viral assemblage the ephemeral and persistent taxa were closely related implying ecological dynamics within these clusters. Furthermore, these dynamics occurred in both the RNA and DNA viral assemblages surveyed, implying that this structure is common in natural viral assemblages. Importance Viruses are major agents of microbial mortality in marine systems; yet, little is known about changes in the composition of viral assemblages in relation to that of the microbial communities that they infect. Here, we sampled coastal seawater every two weeks for one year and used high-throughput sequencing of marker genes to follow changes in the composition of two groups of ecologically important viruses, as well as the communities of bacteria and protists that serve as their respective hosts. Different subsets of genetically related viruses dominated at different times. These results demonstrate that although the genetic composition of viral genotypes is highly dynamic temporally, for the most part the shuffling of genotypes occurs within a few clusters of phylogenetically related viruses. Thus, it appears that even in temperate coastal waters with large seasonal changes the highly dynamic shuffling of viral genotypes largely occurs within a few subsets of related individuals.

scholarly journals Diversity, Ecological Role and Biotechnological Potential of Antarctic Marine Fungi

2021 ◽  
Vol 7 (5) ◽  
pp. 391
Author(s):  
Stefano Varrella ◽  
Giulio Barone ◽  
Michael Tangherlini ◽  
Eugenio Rastelli ◽  
Antonio Dell’Anno ◽  
...  
Keyword(s):  
Deep Sea ◽  
Ecosystem Functioning ◽  
Marine Fungi ◽  
Marine Ecosystem ◽  
Bioactive Molecules ◽  
Ecological Role ◽  
Biotechnological Potential ◽  
Morphological Adaptations ◽  
Antarctic Marine ◽  
The Antarctic

The Antarctic Ocean is one of the most remote and inaccessible environments on our planet and hosts potentially high biodiversity, being largely unexplored and undescribed. Fungi have key functions and unique physiological and morphological adaptations even in extreme conditions, from shallow habitats to deep-sea sediments. Here, we summarized information on diversity, the ecological role, and biotechnological potential of marine fungi in the coldest biome on Earth. This review also discloses the importance of boosting research on Antarctic fungi as hidden treasures of biodiversity and bioactive molecules to better understand their role in marine ecosystem functioning and their applications in different biotechnological fields.

scholarly journals Metabarcoding Reveals Lacustrine Picocyanobacteria Respond to Environmental Change Through Adaptive Community Structuring

2021 ◽  
Vol 12 ◽  
Author(s):  
Lena A. Schallenberg ◽  
John K. Pearman ◽  
Carolyn W. Burns ◽  
Susanna A. Wood
Keyword(s):  
Environmental Change ◽  
Environmental Variables ◽  
Community Dynamics ◽  
Environmental Changes ◽  
Epifluorescence Microscopy ◽  
Environmental Drivers ◽  
Rrna Gene ◽  
Community Adaptation ◽  
Phylogenetic Studies ◽  
Community Data

Picocyanobacteria (Pcy) are important yet understudied components of lake foodwebs. While phylogenetic studies of isolated strains reveal a high diversity of freshwater genotypes, little is known about abiotic drivers associated with Pcy in different lakes. Due to methodological limitations, most previous studies assess potential drivers using total cell abundances as a response, with often conflicting and inconsistent results. In the present study, we explored how picocyanobacterial communities respond to environmental change using a combination of epifluorescence microscopy and community data determined using 16S rRNA gene metabarcoding. Temporal shifts in picocyanobacterial abundance, diversity and community dynamics were assessed in relation to potential environmental drivers in five contrasting lakes over 1year. Cell abundances alone were not consistently related to environmental variables across lakes. However, the addition of metabarcoding data revealed diverse picocyanobacterial communities that differed significantly between lakes, driven by environmental variables related to trophic state. Within each lake, communities were temporally dynamic and certain amplicon sequence variants (ASVs) were strongly associated with specific environmental drivers. Rapid shifts in community structure and composition were often related to environmental changes, indicating that lacustrine Pcy can persist at high abundances through collective community adaptation. These results demonstrate that a combination of microscopy and metabarcoding enables an in-depth characterisation of picocyanobacterial communities and reveals strain-specific drivers. We recommend that future studies cease referring to picocyanobacterial as one functional group and take strain specific variability into consideration.

scholarly journals Theoretical basis for predicting climate-induced abrupt shifts in the oceans

2015 ◽  
Vol 370 (1659) ◽  
pp. 20130264 ◽  
Author(s):  
Gregory Beaugrand
Keyword(s):  
Ecosystem Functioning ◽  
Theoretical Basis ◽  
Environmental Changes ◽  
Marine Ecosystem ◽  
Marine Species ◽  
Present Theory ◽  
Community Shifts ◽  
Underlying Mechanisms ◽  
Abrupt Shifts ◽  
Taxonomic Groups

Among the responses of marine species and their ecosystems to climate change, abrupt community shifts (ACSs), also called regime shifts, have often been observed. However, despite their effects for ecosystem functioning and both provisioning and regulating services, our understanding of the underlying mechanisms involved remains elusive. This paper proposes a theory showing that some ACSs originate from the interaction between climate-induced environmental changes and the species ecological niche. The theory predicts that a substantial stepwise shift in the thermal regime of a marine ecosystem leads indubitably to an ACS and explains why some species do not change during the phenomenon. It also explicates why the timing of ACSs may differ or why some studies may detect or not detect a shift in the same ecosystem, independently of the statistical method of detection and simply because they focus on different species or taxonomic groups. The present theory offers a way to predict future climate-induced community shifts and their potential associated trophic cascades and amplifications.

scholarly journals Resilience and stability of a pelagic marine ecosystem

2016 ◽  
Vol 283 (1822) ◽  
pp. 20151931 ◽  
Author(s):  
Martin Lindegren ◽  
David M. Checkley ◽  
Mark D. Ohman ◽  
J. Anthony Koslow ◽  
Ralf Goericke
Keyword(s):  
Ecosystem Functioning ◽  
Decadal Variability ◽  
Current System ◽  
Marine Ecosystem ◽  
Experimental Studies ◽  
Trophic Levels ◽  
Environmental Drivers ◽  
California Current System ◽  
Functional Complementarity ◽  
Key Species

The accelerating loss of biodiversity and ecosystem services worldwide has accentuated a long-standing debate on the role of diversity in stabilizing ecological communities and has given rise to a field of research on biodiversity and ecosystem functioning (BEF). Although broad consensus has been reached regarding the positive BEF relationship, a number of important challenges remain unanswered. These primarily concern the underlying mechanisms by which diversity increases resilience and community stability, particularly the relative importance of statistical averaging and functional complementarity. Our understanding of these mechanisms relies heavily on theoretical and experimental studies, yet the degree to which theory adequately explains the dynamics and stability of natural ecosystems is largely unknown, especially in marine ecosystems. Using modelling and a unique 60-year dataset covering multiple trophic levels, we show that the pronounced multi-decadal variability of the Southern California Current System (SCCS) does not represent fundamental changes in ecosystem functioning, but a linear response to key environmental drivers channelled through bottom-up and physical control. Furthermore, we show strong temporal asynchrony between key species or functional groups within multiple trophic levels caused by opposite responses to these drivers. We argue that functional complementarity is the primary mechanism reducing community variability and promoting resilience and stability in the SCCS.

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