Monday, 27 August 2018

Plant species at Alex

Alexandra Fiord is over three degrees of latitude further south than Lake Hazen where I have conducted Arctic plant phenology research in previous years. I have been surprised that the plant diversity at Alex is actually lower than at Lake Hazen. There have been about 120 plant species recorded in the Lake Hazen vicinity but only about 90 in the Alexandra Fiord vicinity. There are quite a number of plants that are commonly found at Lake Hazen that are rare or not present at Alex. Lake Hazen is a little higher in elevation and further north and has a harsher environment but that also means that there is discontinuous vegetation and less competition. Maybe this could be a reason why some plants are found at Lake Hazen but not at Alexandra Fiord where the vegetation is much more lush and competition from Arctic willow (Salix arctica) is greater.

Tufted saxifrage (Saxifraga cespitosa) is rarely seen near
Alexandra Fiord. It is more common on the mountain tops
surrounding the fiord but one of the most robust plants I saw
was by the boat leaning up against the toolshed in camp.
Arctic willow (Salix arctica) senescing its leaves in early August
ready for winter. The willow is a dominant and expanding
species at Alexandra Fiord, out competing other species.
One species that I really like and is much more prevalent at Alex than Lake Hazen is the moss campion (Silene acaulis). Interestingly at Alex, these cushion plants start flowering on the southern side of the cushion first then the flowers on the top open and then finally those on the north side open. I am conducting some preliminary investigations to gauge whether I can use this phenology progression across the cushion to study the relationship between time of flowering and reproductive success.

Moss campion (Silene acaulis) with flowers open on the top of the
cushion and flower buds still to open on the north side of the cushion.
One of the cool plants I have seen at Alex are white poppies. The taxonomy of the poppies in the Arctic is not fully resolved. The species most likely found at Alex is Papaver radicatum and my thought is that the white poppies are just an albino form of this species. Although, I have seen these white poppies with both white and yellow stigmatic hairs. I have seen albino forms of other Arctic species such as Pedicularis arctica and Parya arctica so albino flowers is not unheard of in the Arctic.
Arctic poppy (possibly an albino form of Papaver radicatum) near
Twin Glacier, Alex. Fiord with white petals and white stigmatic hairs.
Arctic poppy (possibly an albino form of
Papaver radicatum) on East Ridge with
white petals and yellow stigmatic hairs.

I have taken the time this summer to get to know the Arctic grasses and sedges a little better. They are more difficult groups of plants to identify and I have studiously avoided them for that reason. Sedges and grasses are also not the best for flower phenology studies because it is difficult to see when they are actually in flower and the period of anthesis when pollen is released is very short and often missed.

Foxtail grass (Alopecurus magellanicus), one of the easier grasses
to identify with its bushy foxtail shaped flowering inflorescence.
Three sedges commonly found at Alexandra Fiord.
Left to right: Carex misandra, C. nardina and C. scirpoidae.

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