A Taxonomic and ecological study of diatoms from freshwater habitats in the Falkland Islands

The diatom flora of the Falkland Islands was investigated by sampling twenty-eight representative lake, pond and stream habitats. Diatom assemblages were moderately diverse and dominated by benthic taxa characteristic of oligotrophic soft waters. Particularly the Fragilarioid and Achnanthoid taxa possessed unusually small valves and this condition is thought to be favoured by the prevailing harsh environmental conditions. Eleven new diatom taxa are described and several new combinations are proposed but it is likely that further research will show that at least some of the new taxa will co-occur, in Patagonia and elsewhere, rather than be endemic in the Falklands archipelago. Taxon richness varied strongly between sites but only weak trends were indicated between total number of taxa, number of regional endemic taxa, or rare taxa and habitat complexity, habitat size or water pH (diversity models were not used because dispersal and immigration rate data are lacking). Cosmopolitan taxa were most common but a significant portion (approximately one third) of the assessed flora was attributed to taxa with regionally restricted distributions. Southern South American, Subantarctic and North American elements were present but probably very few taxa are entirely restricted to the Falkland Islands. Macro- and microecological factors determine both the composition and numbers of taxa in a diatom sample. The species assemblages recorded are thought to reflect near pristine aquatic conditions at all the Falkland sites (palaeolimnogical techniques are nevertheless required to test hypotheses about native and non-native taxa). Irrespective of difficulties in fitting diatom data to species diversity models, the occurrence and abundance of diatom taxa in these representative samples provide a unique site-specific biological signature that reflects water quality and physical habitat as well as regional flora attributes. Routine diatom analysis for ecological purposes requires accurate taxonomy and consistency is of paramount importance but, compared with biogeographic and systematic studies, a lower level of precision is probably adequate. 8. Monitoring diatom communities offers one way of perceiving environmental change and global warming is thought to pose the greatest threat to the biological integrity of the inland waters of the Falkland Islands.

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Additional Info

Field Value
Last Updated April 14, 2022, 04:56 (PDT)
Created April 14, 2022, 03:46 (PDT)
Region Falkland Islands
Language eng
Topic Category Biota; flora and/or fauna in natural environment
Temporal Extent Start 2002-02-21
Temporal Extent End 2002-03-12
Dataset Reference Date 2005
Lineage Habitat details as well as water and diatom samples were taken at each of the 28 sites visited. The methodology for collecting diatoms involved collecting surface sediment from an inflatable boat. Surface sediment samples were collected using a Glew corer; at sites with high sandy or peaty sediment an Ekman grab was used. Where the open water depths were less than 50cm surface, sediment was collected by hand. Sediment samples from lentic habitats were usually taken from the central area of the site, aiming to collect from the deepest or open areas, while samples from lotic habitats were collected from between 5 and 10 bryophyte free stones and removing epilithon with a brush. Samples were preserved in alcohol and sent to the UK for analysis.
West Longitude -52.05948
South Latitude -60.45126
East Longitude -51.435973
North Latitude -57.93763
Spatial Reference System WGS84
Responsible Organisation Name Hidden (personal data protection)
Contact Mail Address Hidden (personal data protection)
Responsible Party Role Hidden (personal data protection)
Access Limitations Restricted, send data request to data owner
Use Constraints Open, but copyright and/or Intellectual Property Rights apply
Resource Reference Flower, R.J., 2005. A taxonomic and ecological study of diatoms from freshwater habitats in the Falkland Islands, South Atlantic. Diatom research, 20(1), pp.23-96.
Data Format pdf, csv
Update Frequency Survey Completed
Accuracy N/A
Resource Type Dataset, Report
Original Title Hidden (internal use only)
Metadata Date 2021-01-28
Metadata Point of Contact datamanager@saeri.ac.fk
Contact Consent Contact details hidden

Dataset extent

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