Research Article |
Corresponding author: Loren Bahls ( eemahtuskie@gmail.com ) Academic editor: Kalina Manoylov
© 2018 Loren Bahls, Tara Luna.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Bahls L, Luna T (2018) Diatoms from Wrangell-St. Elias National Park, Alaska, USA. PhytoKeys 113: 33-57. https://doi.org/10.3897/phytokeys.113.29456
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As a contribution to our knowledge of diatom biodiversity and biogeography in the United States, high resolution light microscope images are provided for 139 diatom taxa recorded from lake, stream, spring and glacier habitats in Wrangell-St. Elias National Park, Alaska. The spring had the highest taxa richness of the four habitats that were sampled, likely owing to the relative stability of this habitat compared to the others. Most of the taxa were described from northern and alpine locations in Europe and North America and are typical of habitats in the northern Rocky Mountains, with two notable exceptions. Surirella arctica had been reported previously only from locations in the High Arctic of North America, north of 68°N latitude. Gomphonema caperatum has a disjunct distribution in montane regions of the eastern and far western contiguous United States. This may be the first record of this taxon from Alaska.
diatoms, Alaska, diatom biodiversity, diatom biogeography, glacier diatoms
For a land area as large as Alaska (1,717,856 km2), there are relatively few published articles on freshwater diatom taxonomy and biodiversity (
Wrangell-St. Elias National Park and Preserve (WRST) is located in the southeast corner of Alaska (Fig.
Although diatoms have been used to assess water quality and climate change within and near WRST (
Samples of benthic diatoms were collected from four sites in WRST (Table
Samples collected on 29 June 2018 from WRST, Alaska. Sample numbers are for the Montana Diatom Collection and database. Slide numbers are for slides in the diatom collection at the University of Montana Herbarium, Missoula (
Sample number | Site name | Latitude (°N) | Longitude (°W) | Slide number | WRST |
---|---|---|---|---|---|
6955 | Donoho Lake | 61.5275, -142.9580 | 50–31 | 22949 | |
6956 | Jumbo Creek | 61.5030, -142.8972 | 50–32 | 22950 | |
6957 | McCarthy Spring | 61.4344, -142.9278 | 50–33 | 22951 | |
6958 | Root Glacier (pools) | 61.5098, -142.9265 | 50–34 | 22952 | |
6959 | Root Glacier (rock glacier) | 61.5122, -142.9211 | 50–35 | 22953 |
Substrata that were sampled at WRST collection sites were cobbles (Jumbo Creek), sediment (all sites) and peat (moulins). As there were very few diatom cells in the samples from Root Glacier pools, they were combined for the purpose of sample processing and reporting. The pools appeared to extend to the bottom of the glacier, so diatoms in the pool samples may have originated from greater depth. The Root Glacier Ice Field is up to 213 m thick at this location, which is near its confluence with the Kennicott Glacier. Collection sites on the glacier were 6 km below the massive 2,133 m Staircase Ice Fall, at the head the valley, which is the largest icefall outside the Himalayas.
Sediment samples were collected with a large-bore pipette (5 mm diameter) with a suction bulb. The pipette was rinsed with ambient water twice between collection sites. Approximately 7.5 cm3 of water and sediment was pulled from the upper 1 cm of sediment at each sample site and stored in collection bottles. At Jumbo Creek, the surface film on several cobbles was scraped into the sample bottle and some peat material was included in the moulin samples. Iodine was added to each sample within 12 hours of collection. In the laboratory, samples were treated with 30% hydrogen peroxide (H2O2) and heated gently for several days to remove organic matter. After several rinses in distilled water, cleaned diatom material was dried on cover slips and mounted permanently on glass slides using Naphrax.
One slide per sample was examined under light microscopy (LM) with differential interference contrast optics and images were captured using a Leica DM LB2 research microscope and a Spot Insight monochrome digital camera (Model 14.0). Slides examined for this study will be deposited in the University of Montana Herbarium, Missoula (
Each slide was systematically scanned at 100 magnifications to locate very large taxa that might otherwise be missed while scanning at higher magnifications. After these large taxa were identified, listed and photographed, slides were examined under oil immersion at 630 and 1,000 magnifications in order to find, identify and photograph smaller taxa. A “random walk” was taken around each slide and additional taxa were listed and photographed until no additional taxa were found after 20 minutes of scanning. The number of images that were captured of each taxon is roughly proportional to the relative abundance of that taxon in a sample.
A total of 139 taxa were identified at the genus or subgenus level (Table
Taxa | Plate | Donoho Lake | Jumbo Creek | McCarthy Spring | Root Glacier | Type Locality |
---|---|---|---|---|---|---|
Achnanthidium gracillimum (Meister) Lange-Bertalot | 4 | × | Japan | |||
Achnanthidium minutissimum (Kützing) Czarnecki | 4 | × | × | × | Germany | |
Amphora Ehrenberg in Kützing | 10 | × | Europe | |||
Amphora copulata (Kützing) Schoeman & Archibald | 10 | × | Germany | |||
Amphora inariensis Krammer | 10 | × | × | Finnish Lapland | ||
Amphora pediculus (Kützing) Grunow | 10 | × | Germany | |||
Brachysira microcephala (Grunow) Compére | 6 | × | Austria | |||
Caloneis alpestris (Grunow) Cleve | 7 | × | × | Austria | ||
Caloneis falcifera Lange-Bertalot, Genkal & Vekhov | 7 | × | Russia | |||
Caloneis silicula (Ehrenberg) Cleve | 7 | × | New England, USA | |||
Caloneis tenuis (Gregory) Krammer | 7 | × | Scotland | |||
Caloneis thermalis (Grunow) Krammer | 7 | × | Germany | |||
Cocconeis placentula Ehrenberg | 4 | × | × | × | Germany | |
Cymatopleura solea (Brébisson) W. Smith | 13 | × | France | |||
Cymbella alpestris Krammer | 9 | × | × | Switzerland | ||
Cymbella cleve-eulerae Krammer | 9 | × | Sweden | |||
Cymbella cosleyi Bahls | 9 | × | Montana, USA | |||
Cymbella excisiformis Krammer | 9 | × | Germany | |||
Cymbella neocistula var. neocistula Krammer | 9 | × | × | Germany | ||
Cymbella neocistula var. islandica Krammer | 9 | × | Iceland | |||
Cymbopleura angustata (W. Smith) Krammer | 9 | × | × | Scotland | ||
Cymbopleura austriaca (Grunow) Krammer | 9 | × | Austria | |||
Cymbopleura incerta (Grunow) Krammer | 9 | × | × | Norway | ||
Cymbopleura lapponica (Grunow) Krammer | 9 | × | × | Swedish Lapland | ||
Cymbopleura naviculiformis (Auerswald) Krammer | 9 | × | Germany | |||
Cymbopleura oblongata Krammer | 9 | × | × | Spitsbergen | ||
Cymbopleura subaequalis (Grunow) Krammer | 9 | × | Belgium | |||
Delicata Krammer | 10 | × | France | |||
Delicata alpestris (Krammer) Bahls | 10 | × | Austria | |||
Delicata delicatula (Kützing) Krammer | 10 | × | France | |||
Denticula kuetzingii Grunow | 11 | × | × | × | Austria | |
Denticula tenuis Kützing | 11 | × | Germany | |||
Diatoma tenuis Agardh | 1 | × | Scandinavia | |||
Diatoma vulgaris Bory de Saint-Vincent | 1 | × | France | |||
Diploneis krammeri Lange-Bertalot & Reichardt | 6 | × | Austria | |||
Encyonema neogracile Krammer | 10 | × | Finnish Lapland | |||
Encyonema perminutum Krammer | 10 | × | Spitsbergen | |||
Encyonema silesiacum (Bleisch) Mann | 10 | × | × | Germany | ||
Encyonopsis alpina Krammer & Lange-Bertalot | 10 | × | Germany | |||
Encyonopsis cesatii (Rabenhorst) Krammer | 10 | × | Italy | |||
Encyonopsis czarneckii Bahls | 10 | × | Montana, USA | |||
Encyonopsis montana Bahls | 10 | × | Montana, USA | |||
Encyonopsis stafsholtii Bahls | 10 | × | Montana, USA | |||
Encyonopsis subminuta Krammer & Reichardt | 10 | × | Switzerland | |||
Eucocconeis alpestris (Brun) Lange-Bertalot | 4 | × | × | Switzerland | ||
Eucocconeis flexella (Kützing) Meister | 4 | × | × | Switzerland | ||
Eucocconeis laevis (Østrup) Lange-Bertalot | 4 | × | × | Denmark | ||
Eunotia arcus Ehrenberg | 4 | × | Sweden | |||
Eunotia valida Hustedt | 4 | × | Switzerland | |||
Fragilaria Lyngbye | 2 | × | × | Russia? | ||
Fragilaria amphicephala Ehrenberg | 2 | × | Oregon, USA | |||
Fragilaria sepes Ehrenberg | 2 | × | Russia | |||
Fragilaria tenera (W. Smith) Lange-Bertalot | 2 | × | Ireland | |||
Fragilaria vaucheriae (Kützing) Petersen | 2 | × | Germany | |||
Frustulia amosseana Lange-Bertalot in Rumrich et al. | 2 | × | Scotland | |||
Gomphonema Agardh | 8 | × | × | Germany | ||
Gomphonema bozenae Lange-Bertalot & Reichardt | 8 | × | Finland | |||
Gomphonema caperatum Ponader & Potapova | 8 | × | Virginia, USA | |||
Gomphonema lateripunctatum Reichardt & Lange-Bertalot | 8 | × | Germany | |||
Gomphonema minusculum Krasske | 8 | × | Tristan da Cunha | |||
Gomphonema olivaceoides Hustedt | 8 | × | Germany | |||
Gomphonema pseudobohemicum Lange-Bertalot & Reichardt | 8 | × | Germany | |||
Gomphonema pumilum (Grunow) Reichardt & Lange-Bertalot | 8 | × | Belgium | |||
Gyrosigma Hassall | 6 | × | Germany | |||
Hannaea arcus (Ehrenberg) Patrick | 2 | × | Germany | |||
Hantzschia Grunow | 12 | × | × | USA | ||
Hantzschia abundans Lange-Bertalot | 12 | × | Germany | |||
Hantzschia amphioxys (Ehrenberg) Grunow | 12 | × | × | USA | ||
Hantzschia elongata (Hantzsch) Grunow | 12 | × | Germany | |||
Hantzschia hyperborea (Grunow) Lange-Bertalot | 12 | × | Russia | |||
Hygropetra balfouriana (Grunow) Krammer | 7 | × | Scotland | |||
Kurtkrammeria aequalis (W. Smith) Bahls | 10 | × | Scotland | |||
Lindavia antiqua (W. Smith) Nakov et al. | 1 | × | Ireland | |||
Luticola mutica (Kützing) Mann | 6 | × | Germany | |||
Luticola ventricosa (Kützing) Mann | 6 | × | Germany | |||
Meridion circulare (Greville) Agardh | 1 | × | Scotland | |||
Muelleria gibbula (Cleve) Spaulding & Stoermer | 5 | × | Norway | |||
Navicula angusta Grunow | 7 | × | × | Austria | ||
Navicula cryptocephala Kützing | 7 | × | Germany | |||
Navicula cryptotenella Lange-Bertalot | 7 | × | Belgium | |||
Navicula lanceolata (Agardh) Ehrenberg | 7 | × | Germany | |||
Navicula libonensis Schoeman | 7 | × | Lesotho | |||
Navicula radiosa Kützing | 7 | × | Germany | |||
Navicula seibigiana Lange-Bertalot | 7 | × | Switzerland | |||
Navicula subconcentrica Lange-Bertalot | 7 | × | × | Germany | ||
Navicula vulpina Kützing | 7 | × | × | Germany | ||
Neidiomorpha binodiformis (Krammer) Cantonati et al. | 5 | × | Germany | |||
Neidium Pfitzer | 5 | × | Germany | |||
Neidium bergii (Cleve-Euler) Krammer | 5 | × | Scandinavia | |||
Neidium bisulcatum (Lagerstedt) Cleve | 5 | × | Spitsbergen | |||
Neidium bobmarshallensis Bahls | 5 | × | Montana, USA | |||
Neidium distinctepunctatum Hustedt | 5 | × | Austria | |||
Neidium fogedii Bahls | 5 | × | × | Alaska, USA | ||
Neidium kozlowii var. ellipticum Mereschkowsky | 5 | × | × | Tibet | ||
Nitzschia alpina Hustedt | 11 | × | Switzerland | |||
Nitzschia amphibia Grunow | 11 | × | Austria | |||
Nitzschia angustata (W. Smith) Grunow | 11 | × | Sussex, UK | |||
Nitzschia dissipata (Kützing) Rabenhorst | 11 | × | Germany | |||
Nitzschia dissipata var. oligotraphenta Lange-Bertalot | 11 | × | Austria | |||
Nitzschia exilis Sovereign | 11 | × | Oregon, USA | |||
Nitzschia fonticola (Grunow) Grunow | 11 | × | Belgium | |||
Nitzschia homburgiensis Lange-Bertalot | 11 | × | Germany | |||
Nitzschia inconspicua Grunow | 11 | × | Austria | |||
Nitzschia lacuum Lange-Bertalot | 11 | × | Germany | |||
Nitzschia linearis W. Smith | 11 | × | UK | |||
Nitzschia palea (Kützing) W. Smith | 11 | × | Germany | |||
Nitzschia perminuta Grunow | 11 | × | unknown | |||
Nitzschia pura Hustedt | 11 | × | Germany | |||
Nitzschia pusilla (Kützing) Grunow | 11 | × | Germany | |||
Nitzschia sublinearis Hustedt | 11 | × | × | Austria | ||
Odontidium hyemale Kützing | 1 | × | × | × | Germany | |
Odontidium mesodon (Ehrenberg) Kützing | 1 | × | Germany | |||
Pinnularia Ehrenberg | 8 | × | Germany | |||
Pinnularia krammeri Metzeltin | 8 | × | Finland | |||
Pinnularia permicrostauron Krammer & Metzeltin | 8 | × | Finland | |||
Pinnularia sinistra Krammer | 8 | × | Germany | |||
Pinnularia subanglica Krammer | 8 | × | Sweden | |||
Pinnularia subcommutata Krammer | 8 | × | Belgium | |||
Pinnularia viridis (Nitzsch) Ehrenberg | 8 | × | Germany | |||
Placoneis abiskoensis Hustedt | 6 | × | Sweden | |||
Planothidium lanceolatum (Brébisson) Lange-Bertalot | 4 | × | France | |||
Psammothidium helveticum (Hustedt) Bukhtiyarova & Round | 4 | × | Switzerland | |||
Pseudostaurosira robusta (Fusey) Williams & Round | 3 | × | France | |||
Rhopalodia gibba (Ehrenberg) O. Müller | 14 | × | Siberia | |||
Sellaphora laevissima (Kützing) Mann | 6 | × | Italy | |||
Sellaphora pupula (Kützing) Mereschkowsky | 6 | × | Germany | |||
Stauroneis amphicephala Kützing | 6 | × | Germany | |||
Stauroneis gracilis Ehrenberg | 6 | × | French Guiana | |||
Stauroneis reichardtii Lange-Bertalot et al. | 6 | × | Italy | |||
Stauroneis vandevijveri Bahls | 6 | × | Montana, USA | |||
Staurosira Ehrenberg | 3 | × | Connecticut, USA | |||
Staurosira construens Ehrenberg | 3 | × | Connecticut, USA | |||
Staurosira construens var. venter (Ehrenberg) Hamilton | 3 | × | Germany | |||
Staurosirella lapponica (Grunow) Williams & Round | 3 | × | Sweden | |||
Staurosirella leptostauron (Ehrenberg) Williams & Round | 3 | × | Germany | |||
Staurosirella pinnata (Ehrenberg) Williams & Round | 3 | × | USA | |||
Surirella arctica (Patrick & Freese) Veselá & Potapova | 14 | × | Alaska, USA | |||
Surirella minuta Brèbisson | 14 | × | France | |||
Ulnaria ulna (Nitzsch) Compère | 2 | × | Germany | |||
Total taxa | 39 | 41 | 61 | 29 |
Most taxa were described from type material collected in Europe (117 taxa), mostly northern Europe (Table
Except for McCarthy Spring, diatom cells were scarce in all of the samples, as may be expected for such austere habitats. Glacial sediment (rock flour) dominated all but the McCarthy Spring sample and often obscured specimens for photography. Capturing quality images of voucher specimens was further hindered by diatom frustules that were often broken, eroded or encrusted with lime.
1–4 Achnanthidium minutissimum (6955, 6956, 6957) 5 Planothidium lanceolatum (6958) 6, 7 Psammothidium helveticum (6959) 8 Eucocconeis laevis (6956) 9 Eucocconeis alpestris (6956) 10, 11 Achnanthidium gracillimum (6956) 12 Eunotia valida (6956) 13, 14 Eucocconeis flexella (6957) 15–19 Cocconeis placentula var.? (6956, 6957, 6958) 20–26 Eunotia arcus or Eunotia arcubus Nörpel-Schempp & Lange-Bertalot (6957). Scale bar: 10 µm.
1–6 Muelleria gibbula (6955) 7, 8 Neidium bergii (6955) 9, 10 Neidium sp. cf. N. bisulcatum (6955) 11 Neidium sp. cf. Neidium boreale Foged (6955) 12–15Neidium kozlowii var. ellipticum (6955) 16–18 Neidium sp. (6955, 6957) 19 Neidiopsis binodiformis (6957) 20 Neidium fogedii (6955) 21 Neidium distinctepunctatum (6955) 22–24 Neidium bobmarshallensis (6955). Scale bar: 10 µm.
1 Placoneis abiskoensis Hustedt (6957) 2 Frustulia amosseana (6955) 3 Sellaphora pupula (6957) 4 Sellaphora laevissima (6957) 5 Brachysira microcephala (6956) 6 Luticola ventricosa (6957) 7 Luticola mutica (6957) 8–10 Diploneis krammeri (6957) 11, 12 Stauroneis gracilis (6955) 13 Stauroneis amphicephala or Stauroneis ancepsfallax Bahls) (6955) 14, 15 Stauroneis vandevijveri (S. “arctic-anceps” Van de Vijver et al.) (6955) 16, 17 Stauroneis reichardtii (?) (6955) 18 Gyrosigma sp. (6955). Scale bar: 10 µm.
1, 2 Navicula cryptocephala (6955) 3 Navicula seibigiana (6956) 4 Navicula cryptotenella (6955) 5, 6 Navicula angusta (6957, 6958) 7 Navicula libonensis (6955) 8 Caloneis silicula (6957) 9, 10 Caloneis falcifera (6955) 11 Caloneis tenuis (6957) 12–15 Hygropetra balfouriana (6957) 16 Navicula vulpina (6957) 17 Navicula radiosa (6957) 18 Navicula lanceolata (6958) 19–21 Navicula subconcentrica (6955, 6956) 22, 23 Caloneis thermalis (6955) 24, 25 Caloneis alpestris (6955, 6957). Scale bar: 10 µm.
1 Gomphonema sp. (6957, 6959) 2 Gomphonema olivaceoides (6958) 3 Gomphonema minusculum Krasske (6958) 4 Gomphonema lateripunctatum (6956) 5 Gomphonema pumilum? (6956) 6 Gomphonema bozenae (6957) 7 Gomphonema pseudobohemicum (6958) 8–12 Gomphonema caperatum (6958) 13 Pinnularia krammeri (6955) 14 Pinnularia sinistra (6956) 15 Pinnularia subanglica (6958) 16 Pinnularia sp. (6957) 17, 18 Pinnularia subcommutata (6957) 19 Pinnularia permicrostauron (6955) 20 Pinnularia viridis (6955). Scale bar: 10 µm.
1 Cymbopleura austriaca (6957) 2 Cymbopleura lapponica (6956) 3 Cymbopleura angustata (6958) 4 Cymbopleura naviculiformis (6959) 5 Cymbopleura oblongata (6956) 6 Cymbopleura incerta (6956) 7 Cymbopleura subaequalis (6958) 8, 9 Cymbella excisiformis (6958) 10, 11 Cymbella alpestris (6957) 12–15 Cymbella neocistula (6956, 6957) 16 Cymbella cosleyi (6956) 17 Cymbella cleve-eulerae (6956) 18Cymbella neocistula var. islandica (6956). Scale bar: 10 µm.
1 Encyonema neogracile (6958) 2–4 Encyonema silesiacum (6957) 5–7 Encyonema perminutum (6956) 8 Delicata delicatula (6956) 9, 10 Delicata alpestris (6956) 11 Delicata sp. (6956) 12 Encyonopsis czarneckii (6956) 13 Encyonopsis subminuta (6956) 14 Encyonopsis alpina (6956) 15, 16 Amphora sp. (6955) 17 Amphora pediculus (6957) 18 Amphora copulata (6956) 19, 20 Amphora inariensis (6957) 21–23 Encyonopsis stafsholtii (6956) 24 Encyonopsis cesatii (6957) 25 Kurtkrammeria aequalis (6958) 26, 27 Encyonopsis montana (6956). Scale bar: 10 µm.
1 Nitzschia lacuum (6956) 2–7 Nitzschia fonticola (6957) 8 Nitzschia perminuta (6957) 9–11 Nitzschia alpina (6957) 12 Nitzschia inconspicua (6957) 13 Nitzschia pusilla (6956) 14 Nitzschia pura (6956) 15 Nitzschia palea (6955) 16–19 Nitzschia homburgiensis (6957) 20 Nitzschia dissipata (6957) 21Nitzschia dissipata var. oligotraphenta (6958) 22 Nitzschia linearis (6957) 23, 24 Nitzschia sublinearis (6956, 6957) 25 Nitzschia exilis (6955) 26–28 Nitzschia amphibia (6955) 29, 30 Nitzschia angustata (6957) 31–33 Denticula kuetzingii (6955, 6957) 34, 35 Denticula tenuis (6957). Scale bar: 10 µm.
McCarthy Spring had the highest species richness of the four habitats that were sampled, likely owing to the relative stability of this habitat compared to the lake, stream and glacier habitats. That most of the type localities for these taxa are in Europe is not surprising for two reasons: 1) Most of the early work in diatom taxonomy was conducted in Europe and 2) The existence of a Holarctic or circumboreal kingdom of diatoms has been well established (
Most of the 139 taxa documented from WRST are typical elements of diatom associations in the Northern Rocky Mountains of Alberta, Canada and Montana, USA (Bahls, unpublished data). Two notable exceptions from the Rocky Mountain flora are Surirella arctica and Gomphonema caperatum.
Surirella arctica is a rare Arctic species that had been recorded previously only from localities in the high Arctic (
Gomphonema caperatum, collected from a moulin on the Root Glacier, has a disjunct distribution in montane regions of the eastern and far western United States (
The four samples reported here provide just a hint of the diatom biodiversity in this wild and immense national park. Samples from other lakes, springs, streams and glaciers and samples from other habitats (e.g. seeps and wetlands) will likely produce hundreds more taxa and provide more clues to the origins and geographic and ecological affinities of the WRST diatom flora. Elsewhere in Alaska, there are vast areas and countless diverse habitats that remain to be explored for diatoms.
The authors would like to thank the following WRST personnel for their assistance with this study: Peter Frank, Morgan Gantz, Caroline Ketron, Mark Miller and Desiree Ramirez.