Loss of benthic macrofauna functional traits correlates with changes in sediment biogeochemistry along an extreme salinity gradient in the Coorong lagoon, Australia

We evaluated tolerances to salinity (10–2000 mM NaCl) in three halophytic succulent Tecticornia species that are differentially distributed along a salinity gradient at an ephemeral salt lake. The three species showed similar relative shoot and root growth rates at 10–1200 mM NaCl; at 2000 mM NaCl, T. indica subsp. bidens (Nees) K.A.Sheph and P.G.Wilson died, but T. medusa (K.A.Sheph and S.J.van Leeuwen) and T. auriculata (P.G.Wilson) K.A.Sheph and P.G.Wilson survived but showed highly diminished growth rates and were at incipient water stress. The mechanisms of salinity tolerance did not differ among the three species and involved the osmotic adjustment of succulent shoot tissues by the accumulation of Na+, Cl– and the compatible solute glycinebetaine, and the maintenance of high net K+ to Na+ selectivity to the shoot. Growth at extreme salinity was presumably limited by the capacity for vacuolar Na+ and Cl– uptake to provide sufficiently low tissue osmotic potentials for turgor-driven growth. Tissue sugar concentrations were not reduced at high salinity, suggesting that declines in growth would not have been caused by inadequate photosynthesis and substrate limitation compared with plants at low salinity. Equable salt tolerance among the three species up to 1200 mM NaCl means that other factors are likely to contribute to species composition at sites with salinities below this level. The lower NaCl tolerance threshold for survival in T. indica suggests that this species would be competitively inferior to T. medusa and T. auriculata in extremely saline soils.

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Taxonomic and Functional Patterns of Benthic Communities in Southern Temperate Tidal Flats

Frontiers in Marine Science ◽

10.3389/fmars.2021.723749 ◽

2021 ◽

Vol 8 ◽

Author(s):

Orlando Lam-Gordillo ◽

Ryan Baring ◽

Sabine Dittmann

Keyword(s):

Functional Diversity ◽

Functional Traits ◽

Environmental Conditions ◽

Ecosystem Functioning ◽

Latent Variable ◽

Benthic Communities ◽

Benthic Macrofauna ◽

Temporal Differences ◽

Holistic Understanding ◽

Functional Patterns

Coastal ecosystems are vulnerable to anthropogenic disturbances which can cause loss of benthic macrofauna and their ecosystem functioning. Despite the importance of functional assessments for conservation and management, knowledge gaps persist on the generality of how the diversity and functional traits of benthic communities influence ecosystem functioning. We investigated eight sites in three different habitats across ~1,260 km of coastline, to evaluate patterns between taxonomic and functional diversity of benthic macrofauna, and the relationship between benthic macrofauna, functional traits and environmental conditions. A total of 74 benthic macrofauna taxa were identified. Significant differences across sites and season were found for metrics based on taxonomic and functional traits. Multivariate analysis revealed spatial-temporal differences, which were more evident based on taxa than functional traits. Functional diversity also showed spatial and temporal differences and was positively correlated with the number of taxa. The dominant functional traits modalities were deposit feeders, with large (>20 mm) body size, burrowers, bioirrigators, deeper than 3 cm in sediments, and irregular morphology. Novel Generalized Linear Latent Variable Models (GLLVM) uncovered several site-dependent relationships between taxa, traits and environmental conditions. Functional redundancy was lowest in a highly modified lagoon, and highest in a more pristine embayment. The outcomes from this study showed site-dependent patterns of benthic communities based on either taxonomic or functional metrics, highlighting that both perspectives are complementary to obtain a holistic understanding of the functioning in marine sediments under environmental change.

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Dependency of Air Heating and Cooling for Karbala Buildings on a Salinity Gradient Solar Pond Area

10.33329/aus.2019.n26.4.29 ◽

2019 ◽

Vol 26 (4) ◽

pp. 206-214

Keyword(s):

Salinity Gradient ◽

Heating And Cooling ◽

Solar Pond ◽

Air Heating

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Environmental controls on estuarine nitrifying communities along a salinity gradient

Aquatic Microbial Ecology ◽

10.3354/ame01847 ◽

2017 ◽

Vol 80 (2) ◽

pp. 167-180 ◽

Cited By ~ 3

Author(s):

M Monteiro ◽

J Séneca ◽

L Torgo ◽

DFR Cleary ◽

NCM Gomes ◽

...

Keyword(s):

Salinity Gradient ◽

Environmental Controls

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Ecology and biogeography in the introduction to “De bestiis marinis” by Georg Wilhelm Steller

Archives of Natural History ◽

10.3366/anh.2019.0554 ◽

2019 ◽

Vol 46 (1) ◽

pp. 63-74

Author(s):

Stefano Mattioli

Keyword(s):

Body Size ◽

Phenotypic Plasticity ◽

Geographical Distribution ◽

Functional Traits ◽

Marine Mammals ◽

Main Part ◽

Wide Distribution ◽

Restricted Range ◽

Direct Influence ◽

Modern Biology

The rediscovery of the original, unedited Latin manuscript of Georg Wilhelm Steller's “De bestiis marinis” (“On marine mammals”), first published in 1751, calls for a new translation into English. The main part of the treatise contains detailed descriptions of four marine mammals, but the introduction is devoted to more general issues, including innovative speculation on morphology, ecology and biogeography, anticipating arguments and concepts of modern biology. Steller noted early that climate and food have a direct influence on body size, pelage and functional traits of mammals, potentially affecting reversible changes (phenotypic plasticity). Feeding and other behavioural habits have an impact on the geographical distribution of mammals. Species with a broad diet tend to have a wide distribution, whereas animals with a narrow diet more likely have only a restricted range. According to Steller, both sea and land then still concealed countless animals unknown to science.

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