Within outlying mean indexes: refining the OMI analysis for the realized niche decomposition

Karasiewicz, Stéphane; Dolédec, Sylvain; Lefebvre, Sébastien

doi:10.7717/peerj.3364

Cited by 44 publications

(72 citation statements)

References 26 publications

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“…Only the significant species identified by the BV step analysis above were used further in the study. The subniche estimations within the subsets H and L (see below) were calculated with the Within Outlying Mean Indexes calculations (WitOMI) (Karasiewicz et al, 2017). Species' subniche dynamics were estimated by comparing the subniche parameters (marginality and tolerance) to the origin G (WitOMIG and Tol), which is the representation of a uniformly distributed theoretical species that would occur at all available habitat conditions (i.e.…”

Section: Niche and Subniche Analysismentioning

confidence: 99%

“…ubiquitous) (Dolédec et al,2000). Second, the estimation of the subniche parameters to the subset origin G K (WitOMIG K and Tol), which is the representation of the subset mean habitat conditions used by a hypothetical species (Karasiewicz et al, 2017), revealing the species distribution within the subset habitat conditions. The statistical significance of marginality was tested using a Monte Carlo permutation procedure (Manly, 1997) with 10000 permutations.…”

Section: Niche and Subniche Analysismentioning

confidence: 99%

“…Calenge et al, 2005;Ter Braak, 1987), Hernández-Fariñas et al (2015) used the niche through using the Outlying Mean Index (OMI) (Dolédec et al, 2000), assessing the niche of 35 phytoplankton species, including diatoms, along the French coast. Recently, the Within Outlying Mean Indexes calculations (WitOMI;Karasiewicz et al, 2017) was developed as a refinement of the OMI analysis and provides estimations of niche shift and/or conservatism of a community under different subsets of habitat conditions (temporal and/or spatial). The WitOMI calculates the species' realized subniche dynamics (species' niche occupation within subset habitat conditions)…”

Section: Introductionmentioning

confidence: 99%

“…The unused part of the existing fundamental subniche is considered as the subset's biological constraints (e.g. competition, predation, mutualism, dispersal and colonization) (Karasiewicz et al, 2017). This last method deciphers the effect of selected environmental factors from unknown biotic factors and is fully adapted to explore the phytoplankton community response to climate change along with HABs.…”

Section: Introductionmentioning

confidence: 99%

“…The study aim was to use the Within Outlying Mean Indexes calculations (Karasiewicz et al, 2017) to understand how the environment influences harmful species realized niches. The method should reveal how the phytoplankton community before and/or during HABs, can influence the harmful algae realized niche.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Realized niche analysis of phytoplankton communities involving HAB: Phaeocystis spp. as a case study

et al. 2018

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The link between harmful algal blooms, phytoplankton community dynamics and global environmental change is not well understood. To tackle this challenging question, a new method was used to reveal how phytoplankton communities responded to environmental change with the occurrence of an harmful algae, using the coastal waters of the eastern English Channel as a case study. The great interannual variability in the magnitude and intensity of Phaeocystis spp. blooms, along with diatoms, compared to the ongoing gradual decrease in anthropogenic nutrient concentration and rebalancing of nutrient ratios; suggests that other factors, such as competition for resources, may also play an important role. A realized niche approach was used with the Outlying Mean Index analysis and the dynamics of the species' realized subniches were estimated using the Within Outlying Mean Indexes calculations under low (L) and high (H) contrasting Phaeocystis spp. abundance. The Within Outlying Mean Indexes allows the decomposition of the realized niche into realized subniches, found within the subset of habitat conditions and constrained by a subset of a biotic factor. The two contrasting scenarios were characterized by significantly different subsets of environmental conditions and diatom species (BV-step analysis), and different seasonality in salinity, turbidity, and nutrients. The subset L environmental conditions were potentially favorable for Phaeocystis spp. but it suffered from competitive exclusion by key diatom species such as Skeletonema spp., Thalassiosira gravida, Thalassionema nitzschioides and the Pseudo-nitzchia seriata complex. Accordingly, these diatoms species occupied 81% of Phaeocystis spp.'s existing fundamental subniche. In contrast, the greater number of diatoms, correlated with the community trend, within subset H exerted a weaker biological constraint and favored Phaeocystis spp. realized subniche expansion. In conclusion, the results strongly suggest that both abiotic and biotic interactions should be considered to understand Phaeocystis spp. blooms with greater consideration of the preceeding diatoms. HABs needs must therefore be studied as part of the total phytoplankton community.

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Section: Niche and Subniche Analysismentioning

confidence: 99%

Section: Niche and Subniche Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Realized niche analysis of phytoplankton communities involving HAB: Phaeocystis spp. as a case study

et al. 2018

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Seasonal niche and spatial distribution modelling of the loggerhead (Caretta caretta) in the Adriatic and Ionian seas

Zampollo

Arcangeli

Costantino

et al. 2022

Aquatic Conservation

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Although Caretta caretta is the most common turtle in the eastern Mediterranean Sea, its distribution is relatively difficult to assess due to the lack of data in offshore waters. The ecological niches in the central‐southern Adriatic Sea and the north‐eastern Ionian Sea were investigated for loggerhead turtles with body sizes ≥20 cm during two periods: winter (W), which includes months from October to March, and breeding–nesting (BN), from April to September. Differences in the spatial distribution of loggerheads were explored between periods, and the environmental predictors driving habitat selection were examined. Loggerheads mainly select habitats within the continental shelf (<200 m) differently, and exhibit: (i) a generalist behaviour in the Adriatic subregion during BN and a specific selection of environmental conditions during W; and (ii) a specialist behaviour in the Ionian Sea. The Adriatic niche appeared as an important foraging ground year‐round, whereas the distribution of suitable areas in the Ionian Sea is patchy and limited to specific habitats close to shore. Extreme values of sea surface temperatures (SSTs) from October to March (W) influenced loggerhead distribution differently in the subregions: areas experiencing cold and warm SST peaks were selected, respectively, in the Adriatic and Ionian subregions. Moreover, SST in April largely contributed to defining the habitat suitability in BN for both subregions This study further confirms the importance of the Adriatic and Ionian seas for the conservation of loggerhead sea turtles and the need for seasonal investigations to establish effective conservation measures. Here, the use of a cost‐effective method (fixed line transects from ferries) to inform the distribution of sea turtles in offshore waters is a valuable methodology for long‐term seasonal investigations of the habitat use of sea turtles.

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Stygofaunal community trends along varied rainfall conditions: Deciphering ecological niche dynamics of a shallow calcrete in Western Australia

et al. 2019

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Groundwaters host highly adapted fauna, known as stygofauna, which play a key role in maintaining the functional integrity of subterranean ecosystems. Stygofaunal niche studies provide insights into the ecological dynamics shaping the delicate balance between the hydrological conditions and community diversity patterns. This work aims to unravel the ecological trends of a calcrete stygofaunal community, with special focus on niche dynamics through the Outlying Mean Index analysis (OMI) and additional calculation of Within Outlying Mean Indexes (WitOMI), under three rainfall regimes. Temperature and pH changed significantly among different rainfall conditions (P < .001), and together with salinity were the most influential drivers in shaping stygofaunal assemblages. These environmental conditions, linked with nutrient fluctuations in the groundwater, constrained changes in niche occupation for water mites, two species of beetles and juvenile amphipods (OMI analysis, P < .05). The WitOMI analysis revealed differential subniche breadths linked with taxa-specific adaptations after different rainfall conditions. Our results indicate that stygofaunal niches are closely linked to the hydrodynamic conditions influenced by different rainfall regimes. Further long-term investigations, incorporating broader ecological perspectives, Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site. will help to understand the impacts associated with climate change and anthropogenic pressures on one of the most threatened ecosystems in the world.

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Within outlying mean indexes: refining the OMI analysis for the realized niche decomposition

Cited by 44 publications

References 26 publications

Realized niche analysis of phytoplankton communities involving HAB: Phaeocystis spp. as a case study

Realized niche analysis of phytoplankton communities involving HAB: Phaeocystis spp. as a case study

Seasonal niche and spatial distribution modelling of the loggerhead (Caretta caretta) in the Adriatic and Ionian seas

Stygofaunal community trends along varied rainfall conditions: Deciphering ecological niche dynamics of a shallow calcrete in Western Australia

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