scholarly journals Diatoms structure the plankton community based on selective segregation in the world’s ocean

2019 ◽  
Author(s):  
Flora Vincent ◽  
Chris Bowler

ABSTRACTDiatoms are a major component of phytoplankton, believed to be responsible for around 20% of the annual primary production on Earth. As abundant and ubiquitous organisms, they are known to establish biotic interactions with many other members of the plankton. Through analysis of co-occurrence networks derived from the Tara Oceans expedition that take into account the importance of both biotic and abiotic factors in shaping the spatial distributions of species, we show that only 13% of diatom pairwise associations are driven by environmental conditions, whereas the vast majority are independent of abiotic factors. In contrast to most other plankton groups, at a global scale diatoms display a much higher proportion of negative correlations with other organisms, particularly towards potential predators and parasites, suggesting that their biogeography is constrained by top down pressure. Genus level analyses indicate that abundant diatoms are not necessarily the most connected, and that species-specific abundance distribution patterns lead to negative associations with other organisms. In order to move forward in the biological interpretation of co-occurrence networks, an open access extensive literature survey of diatom biotic interactions was compiled, of which 18.5% were recovered in the computed network. This result reveals the extent of what likely remains to be discovered in the field of planktonic biotic interactions, even for one of the best known organismal groups.ImportanceDiatoms are key phytoplankton in the modern ocean involved in numerous biotic interactions, ranging from symbiosis to predation and viral infection, which have considerable effects on global biogeochemical cycles. However, despite recent large-scale studies of plankton, we are still lacking a comprehensive picture of the diversity of diatom biotic interactions in the marine microbial community. Through the ecological interpretation of both inferred microbial association networks and available knowledge on diatom interactions compiled in an open access database, we propose an eco-systems level understanding of diatom interactions in the ocean.

mSystems ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Flora Vincent ◽  
Chris Bowler

ABSTRACT Diatoms are a major component of phytoplankton, believed to be responsible for around 20% of the annual primary production on Earth. As abundant and ubiquitous organisms, they are known to establish biotic interactions with many other members of plankton. Through analyses of cooccurrence networks derived from the Tara Oceans expedition that take into account both biotic and abiotic factors in shaping the spatial distributions of species, we show that only 13% of diatom pairwise associations are driven by environmental conditions; the vast majority are independent of abiotic factors. In contrast to most other plankton groups, on a global scale, diatoms display a much higher proportion of negative correlations with other organisms, particularly toward potential predators and parasites, suggesting that their biogeography is constrained by top-down pressure. Genus-level analyses indicate that abundant diatoms are not necessarily the most connected and that species-specific abundance distribution patterns lead to negative associations with other organisms. In order to move forward in the biological interpretation of cooccurrence networks, an open-access extensive literature survey of diatom biotic interactions was compiled, of which 18.5% were recovered in the computed network. This result reveals the extent of what likely remains to be discovered in the field of planktonic biotic interactions, even for one of the best-known organismal groups. IMPORTANCE Diatoms are key phytoplankton in the modern ocean that are involved in numerous biotic interactions, ranging from symbiosis to predation and viral infection, which have considerable effects on global biogeochemical cycles. However, despite recent large-scale studies of plankton, we are still lacking a comprehensive picture of the diversity of diatom biotic interactions in the marine microbial community. Through the ecological interpretation of both inferred microbial association networks and available knowledge on diatom interactions compiled in an open-access database, we propose an ecosystems approach for exploring diatom interactions in the ocean.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259004
Author(s):  
Facheng Ye ◽  
G. R. Shi ◽  
Maria Aleksandra Bitner

The global distribution patterns of 14918 geo-referenced occurrences from 394 living brachiopod species were mapped in 5° grid cells, which enabled the visualization and delineation of distinct bioregions and biodiversity hotspots. Further investigation using cluster and network analyses allowed us to propose the first systematically and quantitatively recognized global bioregionalization framework for living brachiopods, consisting of five bioregions and thirteen bioprovinces. No single environmental or ecological variable is accountable for the newly proposed global bioregionalization patterns of living brachiopods. Instead, the combined effects of large-scale ocean gyres, climatic zonation as well as some geohistorical factors (e.g., formation of land bridges and geological recent closure of ancient seaways) are considered as the main drivers at the global scale. At the regional scale, however, the faunal composition, diversity and biogeographical differentiation appear to be mainly controlled by seawater temperature variation, regional ocean currents and coastal upwelling systems.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Hsiang-Yu Tsai ◽  
Dustin R Rubenstein ◽  
Bo-Fei Chen ◽  
Mark Liu ◽  
Shih-Fan Chan ◽  
...  

Understanding how climate-mediated biotic interactions shape thermal niche width is critical in an era of global change. Yet, most previous work on thermal niches has ignored detailed mechanistic information about the relationship between temperature and organismal performance, which can be described by a thermal performance curve. Here, we develop a model that predicts the width of thermal performance curves will be narrower in the presence of interspecific competitors, causing a species’ optimal breeding temperature to diverge from that of its competitor. We test this prediction in the Asian burying beetle Nicrophorus nepalensis, confirming that the divergence in actual and optimal breeding temperatures is the result of competition with their primary competitor, blowflies. However, we further show that intraspecific cooperation enables beetles to outcompete blowflies by recovering their optimal breeding temperature. Ultimately, linking abiotic factors and biotic interactions on niche width will be critical for understanding species-specific responses to climate change.


1992 ◽  
Vol 6 ◽  
pp. 113-113
Author(s):  
David R. Greenwood ◽  
Margaret E. Collinson

Modern plant communities define global Biomes by their structure, floristics and physiognomy. The modern distribution and character of plant communities is determined by climate, large-scale biotic interactions and abiotic factors such as fire and other disturbance history. Biogeographic patterns also reflect past continental movements, dispersal, extinction and speciation events. The past distribution and history of the principal modern plant communities can be traced using key taxa and associations of taxa, and the foliar physiognomy of the biomal communities.The antecedents of many modern types of vegetation can be found in the mixed plant communities of the Cretaceous and earlier. Late Cretaceous angiosperm radiation and K/T extinctions substantially altered these plant communities, setting preconditions for subsequent evolution and the floristic character of terrestrial plant communities. Paleocene vegetation appears intermediate, and the main phase of floristic modernisation appears to have been during the Eocene.Tropical rainforests and deciduous forests of a modern aspect are well represented in Eocene macrofloras at middle and higher palaeolatitudes respectively, in North America, Europe and Australia. These forests partly reflected present day phytogeographic provincialism but many taxa exhibited past cosmopolitanism, having much reduced modern ranges. The presence of “tropical” forests at middle latitudes, well outside their present day latitudinal extent, reflects the Early to Middle Eocene thermal maximum with widespread equable, humid and subhumid climates. At higher latitudes macrofloras reflect deciduous angiosperm vegetation of lower diversity than the middle latitude rainforests. Deciduousness in these forests was probably an adaptation to seasonal darkness beyond the palaeo-Arctic circle, but at intermediate latitudes may have reflected adaptation to greater temperature seasonality. Coniferous forests are represented in Eocene macrofloras from high latitudes and from uplands in the middle latitudes. Grasses are present in some Eocene macrofloras, but grasslands do not appear in the fossil record until the Oligocene or later. They seem to be a response to climatic deterioration and an evolving mammalian biota. Forested and herbaceous wetland communities may have been more diverse and latitudinally more uniform in the Palaeogene than today, but are otherwise quite modern. Post Oligocene history of most plant communities is that of climate altered distribution and floristic extinction.


1999 ◽  
Vol 56 (8) ◽  
pp. 1437-1451 ◽  
Author(s):  
Bernadette Pinel-Alloul ◽  
Catherine Guay ◽  
Nadine Angeli ◽  
Pierre Legendre ◽  
Pierre Dutilleul ◽  
...  

Spatial distribution of macrozooplankton was studied during spring in Lake of Geneva to evaluate the influence of abiotic (water temperature and stability, nutrients) and biotic (bacteria, chlorophyll a, fish biomass) factors on macrozooplankton distribution. Mapping and spatial analyses revealed that abiotic factors, as well as crustacean abundances, were structured along a gradient in the great lake basin. Chlorophyll a biomass, bacteria density, cyclopoid abundance, and fish biomass showed more patchy or inshore-offshore distribution patterns. Using canonical analyses, we determined the relative contribution of the spatial and environmental factors to the distribution of macrozooplankton species and of trophic groups based on herbivory and omnivory/carnivory. The distribution of macrozooplankton can be explained by small-scale variations and lake gradients in abiotic and biotic factors, with a dominant contribution of the abiotic factors. Water temperature and stability, as well as ammonium, are the main factors related to macrozooplankton distribution in Lake of Geneva during spring. Chlorophyll a biomass was also related to the distribution of cyclopoids. The canonical models explained 35-72% of the variance in the distribution of total crustaceans, species, and trophic groups. However, 28-65% of the macrozooplankton variance remained unexplained, which may be due to fine-scale variations in other environmental factors.


2006 ◽  
Vol 72 (7) ◽  
pp. 4704-4712 ◽  
Author(s):  
Michael Schauer ◽  
Jing Jiang ◽  
Martin W. Hahn

ABSTRACT The spatial and temporal variation of SOL cluster bacteria was assessed in oligomesotrophic Lake Mondsee and adjacent lakes by fluorescence in situ hybridization over two annual cycles. The filamentous SOL bacteria were present in Lake Mondsee throughout the study period, and the seasonal dynamics of the SOL community were remarkably similar with respect to both abundance and composition in the two consecutive years. Only two of the three SOL subclusters were detected in Lake Mondsee and four connected lakes. These two populations significantly differed in size distribution and demonstrated pronounced but recurrent differences in seasonality and length of period of appearance in Lake Mondsee. Extensive sampling of the lakes in September 2003 revealed low horizontal variation in the composition of the SOL community within Lake Mondsee but marked variations with depth. Between connected habitats pronounced differences in the composition and abundance of the SOL community were detected. The interaction of SOL bacteria with bacterivorous protists, mesozooplankton, and phytoplankton was investigated in order to reveal variables controlling the structure and dynamics of SOL communities. No strong indication for a bottom-up influence of phytoplankton was found, while the estimated community grazing rates of mesozooplankton on SOL bacteria indicated a top-down control of SOL abundance during mesozooplankton peaks in spring and early autumn. Furthermore, species-specific differences in grazing of mesozooplankton on SOL bacteria were observed. In general, the overall composition of SOL communities was controlled by abiotic factors (water chemistry), while their dynamics seemed to be controlled by abiotic and biotic interactions.


2021 ◽  
Vol 7 (1) ◽  
pp. 66
Author(s):  
Anusha Telagathoti ◽  
Maraike Probst ◽  
Iuliia Khomenko ◽  
Franco Biasioli ◽  
Ursula Peintner

In ecology, Volatile Organic Compounds (VOCs) have a high bioactive and signaling potential. VOCs are not only metabolic products, but are also relevant in microbial cross talk and plant interaction. Here, we report the first large-scale VOC study of 13 different species of Mortierella sensu lato (s.l.) isolated from a range of different alpine environments. Proton Transfer Reaction–Time-of-Flight Mass Spectrometry (PTR–ToF–MS) was applied for a rapid, high-throughput and non-invasive VOC fingerprinting of 72 Mortierella s.l. isolates growing under standardized conditions. Overall, we detected 139 mass peaks in the headspaces of all 13 Mortierella s.l. species studied here. Thus, Mortierellas.l. species generally produce a high number of different VOCs. Mortierella species could clearly be discriminated based on their volatilomes, even if only high-concentration mass peaks were considered. The volatilomes were partially phylogenetically conserved. There were no VOCs produced by only one species, but the relative concentrations of VOCs differed between species. From a univariate perspective, we detected mass peaks with distinctively high concentrations in single species. Here, we provide initial evidence that VOCs may provide a competitive advantage and modulate Mortierella s.l. species distribution on a global scale.


2019 ◽  
Author(s):  
Antton Alberdi ◽  
Orly Razgour ◽  
Ostaizka Aizpurua ◽  
Roberto Novella-Fernandez ◽  
Joxerra Aihartza ◽  
...  

AbstractLarge-scale species’ distributions have been traditionally attributed to physiological traits related to abiotic factors, while behavioural features linked to biotic interactions have received little attention. We tested the relationship between trophic and spatial niche breadths through combining species distribution modelling with dietary DNA metabarcoding of over 400 bats sampled across Europe belonging to seven species. Our results point to a causality cascade between hunting plasticity, trophic niche breadth and spatial niche breadth, and thus indicate that behavioral plasticity and dietary diversification can contribute to shaping broad-scale species distributions.


Author(s):  
Kai Geschuhn ◽  
Andreas Vogler

Abstract This paper makes the strong, fact-based case for a large-scale transformation of the current corpus of scientific subscription journals to an open access business model. The existing journals, with their well-tested functionalities, should be retained and developed to meet the demands of 21st-century research, while the underlying payment streams undergo a major restructuring. There is sufficient momentum for this decisive push toward open access publishing. The diverse existing initiatives must be coordinated so as to converge on this clear goal. The international nature of research implies that this transformation will be achieved on a truly global scale only through a consensus of the world’s most eminent research organizations. All the indications are that the money already invested in the research publishing system is sufficient to enable a transformation that will be sustainable for the future. There needs to be a shared understanding that the money currently locked in the journal subscription system must be withdrawn and re-purposed for open access publishing services. The current library acquisition budgets are the ultimate reservoir for enabling the transformation without financial or other risks. The goal is to preserve the established service levels provided by publishers that are still requested by researchers, while redefining and reorganizing the necessary payment streams. By disrupting the underlying business model, the viability of journal publishing can be preserved and put on a solid footing for the scholarly developments of the future.


2015 ◽  
Vol 282 (1802) ◽  
pp. 20142925 ◽  
Author(s):  
Kristian Trøjelsgaard ◽  
Pedro Jordano ◽  
Daniel W. Carstensen ◽  
Jens M. Olesen

Although species and their interactions in unison represent biodiversity and all the ecological and evolutionary processes associated with life, biotic interactions have, contrary to species, rarely been integrated into the concepts of spatial β-diversity. Here, we examine β-diversity of ecological networks by using pollination networks sampled across the Canary Islands. We show that adjacent and distant communities are more and less similar, respectively, in their composition of plants, pollinators and interactions than expected from random distributions. We further show that replacement of species is the major driver of interaction turnover and that this contribution increases with distance. Finally, we quantify that species-specific partner compositions (here called partner fidelity) deviate from random partner use, but vary as a result of ecological and geographical variables. In particular, breakdown of partner fidelity was facilitated by increasing geographical distance, changing abundances and changing linkage levels, but was not related to the geographical distribution of the species. This highlights the importance of space when comparing communities of interacting species and may stimulate a rethinking of the spatial interpretation of interaction networks. Moreover, geographical interaction dynamics and its causes are important in our efforts to anticipate effects of large-scale changes, such as anthropogenic disturbances.


Sign in / Sign up

Export Citation Format

Share Document