New Floristic Discoveries and Biodiversity of the Western Canadian Arctic Vascular Plant Flora

Jeffery M. Saarela, Lynn J. Gillespie, Laurie L. Consaul and Roger D. Bull

The Panarctic Flora comprises two to three thousand vascular plant taxa (species, subspecies), less than 1% of the world’s vascular plant flora. Some 1450 taxa occur in Arctic North America, and 1256 taxa (965 species) occur in the Canadian Arctic (Elven et al., Panarctic Flora, 2011).

Despite two centuries of collecting, substantial gaps remain in our floristic understanding

of the large and remote Canadian Arctic. Arctic vegetation and floristic diversity are

expected to change dramatically in the coming century as a result of climate change.

Floristic inventories provide detailed information on species diversity and distribution,

and can be useful for investigating the effects of global warming on Arctic ecosystems by

providing baseline data for future monitoring of potential floristic changes.

We are compiling baseline floristic data based on new field collections and

existing herbarium specimens to better understand the distribution and

diversity of the Arctic flora.

Geographical limit of the Arctic in Canada and the North Slope of Alaska

(Western Alaskan Arctic not included here)

“It can be fairly stated that botanical studies in this large area ... are still only in their beginnings. Certainly floras, annotated lists and checklists have been written or are being written, but each new collecting expedition results in some added knowledge.” -W.J. Cody (1971. Le Naturaliste canadien 98:145-158)

Arctic Flora of Canada and Alaska – A new flora project based at the Canadian Museum of Nature. See:http://arcticplants.myspecies.info/

This geographical boundary is based on: Circumpolar Arctic

Vegetation Team. 2003. Circumpolar Arctic Vegetation

Map. (1:7,500,000 scale), Conservation of Arctic Flora

and Fauna (CAFF) Map No. 1. U.S. Fish and Wildlife Service,

Anchorage, Alaska. See also Walker et al. 2005. J. Veg. Sci.

16:267-282.

Drying plants on the Arctic tundra, mainland Northwest Territories, Canada

A sedge meadow dominated by species of Eriophorum and Carex on northwestern Victoria Island, Northwest Territories

Creative Commons: Attribution-NonCommercial-ShareAlike licencePresented at XVIII International Botanical Congress (IBC2011) in Melbourne, Australia, 17-29 July 2011

Based on our field collections:

Some seven taxa are new to the flora of the Canadian Arctic Archipelago, including Draba pilosa, Silene uralensis subsp. uralensis, and taxa to the right.

Some eight taxa are new to the western Canadian Arctic Archipelago.

Many species are new to the flora of Victoria Island, and many collections represent range extensions for multiple species on Victoria Island.

We have increased the known flora of Victoria Island from 231 species to at least 261 species – an increase of some 11%.

Floristic discoveries on Victoria Island, Northwest Territories and Nunavut, Canada

Eriophorum brachyantherum

Cyperaceae

Pinguicula vulgarisLentibulariaceae

Major northern range extension

Salix arctophilaSalicaceae

Corallorhiza trifidaOrchidaceae

Second Arctic Island collection. Reported from Baffin Island by Gould (1997. Can Field Nat 111:471-472)

Carex bicolorCyperaceae

Species New to the Western Arctic Archipelago and Victoria Island

Victoria Island, the largest island in the western Canadian Arctic Archipelago, may be among the first of the Arctic Islands to experience floristic changes associated with a warmer climate given its proximity to the more species rich continental Arctic. New field collections have revealed a surprising number of floristic novelties in this botanically under-studied region.

Species New to the Canadian Arctic Archipelago

Suaeda maritimaChenopodiaceae

Elymus alaskanus

subsp. alaskanusPoaceae

Andromedapolifolia

Ericaceae

Stuckenia cf.subretusa

Potamogetonaceae

Photo credits: R.D. Bull, J.M. Saarela, L.J. Gillespie, G.W. Argus

We made over 2000 new

collections (numbers) on

Victoria Island in 2008 and 2010 in

the western Canadian Arctic

Archipelago.

Potentially new to Canada

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Festucabrachyphylla

Poaceae

Mertensia maritima subsp. tenellaBoraginaceae

CarexholostomaCyperaceae

Carexlachenalii

Cyperaceae

Kobresia sibiricaCyperaceae

Species New to Tuktut Nogait National Park and Vicinity

Carex garberiCyperaceae

Calamagrostisstricta

subsp. strictaPoaceae

Botrychium lunaria

Ophioglossaceae

Carexconcinna

Cyperaceae

Range Extensions into NE Continental Northwest TerritoriesFloristic discoveries in Tuktut Nogait National Park and vicinity, Northwest Territories, Canada

The continental Arctic in northeastern Northwest Territories is close to the treeline, and its flora includes boreal and arctic species. The diversity of boreal species will likely increase as the climate warms, and tundra species may eventually disappear. We have compiled existing and new baseline floristic data, which should be useful in tracking such changes in the future.

We collected plants in Paulatuk, along the Hornaday River in Tuktut Nogait National Park, and northwest of the Park. Our collections document many major range extensions and first records for the region, and build on the first study of the flora of the region (Cody et al. 1992. Can. Field Nat.). Many of our collections represent floristic novelties.

Based on study of all collections made in the area from ca. 1940 to 2009, the vascular flora of the region comprises 268 species, of which 214 are in the National Park (Saarela et al., in ms.). Photo credits: J.M. Saarela, R.D. Bull, L.J. Gillespie

We made some 1000 new Mainland Arctic collections

in 2009

Known vascular plant collection sites in Tuktut Nogait National Park and

vicinity. Squares represent our 2009 collections housed at CAN, triangles represent specimens in DAO (mostly

from an earlier study), and circles represent specimens at the Parks Canada Western Arctic Field Unit

office, Inuvik, Northwest Territories.

Draba oligospermaBrassicaceae

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Balsam poplar (Populus balsamifera; Salicaceae) beyond the treeline in the western Canadian continental Arctic (Northwest Territories)

Extralimital balsam poplar in Tuktut Nogait National Park and vicinity extends the geographical and ecological range of the tree species fully into continental Arctic Canada.

Balsam poplar is the northernmost tree species in North America, with a range that extends generally to the treeline. Extralimital stands growing beyond the treeline in Arctic ecosystems on the North Slope of Alaska have been well-documented and studied demographically. Extralimital balsam poplar is poorly known in the Canadian Arctic.

In 2009 we found two Arctic stands of balsam poplar in the northeastern continental Northwest Territories. We discovered subsequently that balsam poplar was first collected in the region over 50 years ago, but until now these records have essentially been ignored by scientists. Closer study of these Arctic populations may help scientists understand how this northern tree species may respond to a warming climate.

Balsam poplar range in Northwest Territories and Nunavut, Canada, as documented by herbarium specimens.

Extralimital Arctic balsam poplar in continental Northwest Territories, Canada

Saarela et al.,in press, Arctic

Photo credits: J.M. Saarela, R.D. Bull

Range of balsam poplar in North America, as typically reported (Farrar, 1995, Trees in Canada). Arctic stands are reported in Alaska, but not in continental Arctic Canada in the Northwest Territories.

A grove of scraggly balsam poplar growing on a terrace near the Hornaday River in Tuktut Nogait National Park., Northwest Territories, Canada. Four discrete stands occur along theterrace.

A grove of balsam poplar growing along the Brock River, Northwest Territories. Trees are larger in this stand compared with trees in the stand shown above.

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