Article published in Arctic Science journal

My first journal article on how climate change is impacting the flowering and fruiting times in the Arctic has just been published in the new on line, open access journal Arctic Science. The article is based on weather station and International Tundra Experiment (ITEX) flowering and fruiting time data that Parks Canada has been recording for the past 20 years at Tanquary Fiord, Quttinripaaq National Park. Tanquary Fiord is just a short 1/2hr flight from my field site at Lake Hazen, Quttinirpaaq National Park.

Head of Tanquary Fiord looking east from the Twin Otter flight out in August 2013. The orange square is Parks Canada's warden station (enlarged on right) and the green circle is the location of the ITEX site where there are 25  purple saxifrage (Saxifraga oppositifolia) and 25 mountain avens (Dryas integrifolia) plants tagged. The number of open flowers and number of mature fruits on these plants have been counted every 3 days every summer for the past 20 years. 

In a nutshell, annual temperatures have been rising over the past 25 years by 1.2C/decade at Tanquary Fiord, the flowering and fruiting times of the early spring flowering purple saxifrage has not significantly changed over the 20 year period but the mid-summer flowering mountain avens is trending towards earlier flowering and fruiting times.

Read a blog post I wrote about my article for Canadian Science Publishing NRC Research Press: http://www.cdnsciencepub.com/blog/studying-plant-responses-to-climate-change-in-the-arctic.aspx

Read the full article at: http://www.nrcresearchpress.com/doi/abs/10.1139/as-2015-0016#.VlR8QDddFdg

Wrapping Up Field Work

My field work at Lake Hazen is now complete and I write this as we wait at Lake Hazen to fly south. Resolute is fogged in and has been for 2 days now so the charter Twin Otter plane is unable to come to pick us up. 
Over the short Arctic summer at Lake Hazen we monitored 35 plant species and over 1800 individual plants! We visited each site twice per week and recorded the number of flowers open and the number of dispersing fruits on each tagged plant. I can use this data to determine the start peak and finish of flowering and the start and end of seed dispersal of each species.


Counting purple saxifrage (Saxifraga oppositifolia)      Photographing a tagged beautiful leaved bitter cress

flowers at my highest site on McGill Mountain             (Cardamine bellidifolia) in a mossy gully, McGill Mtn

with Lake Hazen in the background.                                with Snow Goose Valley below.

Photos by Carly Casey my field assistant for the summer. 



Nodding saxifrage (Saxifraga cernua)
one of the last species to flower.

On our last two days in the field, we counted all the undispersed fruits remaining on each of the tagged plants to estimate how near to completion the plants’ reproductive cycle was. All the species we were monitoring had finished flowering except the nodding saxifrage (Saxifraga cernua) and many species had substantially completed the seed dispersal stage. The majority of species here at Lake Hazen are flowering, fruiting and dispersing their seed all within less than 2 months.

 

Prickly saxifrage (Saxifraga tricuspidata) with
undispersed fruit that we counted at the end of the
field season. Some plants had as many as 500 fruits.

At some of my sites I set up a volumetric soil moisture probe to record the soil moisture. My data shows that there was a steady downward trend in soil moisture through the growing season. The moisture level rose a little at the start of the season at sites where snow was still melting (sites 20, 21 and 24) and there was also a slight rise in soil moisture after we had a little rain (<5mm) on a couple of days at the end of July. The slight rise at the end of the season could also be due to the active layer of the permafrost melting. Lake Hazen is a polar desert and receives very little precipitation (<50mm/yr compared to Ottawa that gets 800mm/yr). The main source of water for plants here is from snow melt in the spring and the active layer thawing from mid-July to early-August. The few plants that grow by the rivers and in the river deltas also get some water from glacial melt.


Soil moisture generally reduced through the growing season. Soil moisture initially rose a little at sites 19, 20 and 21 as the final snow patches melted at these sites. There was also a slight rise in soil moisture at the middle and end of July due to small rain events and the active layer of the permafrost thawing.



One thousand flowers

The plants at Lake Hazen have almost finished flowering now and there is an early morning chill to the air, hinting at autumn being just around the corner. The late flowering dwarf fireweed (Paunnat, Chamerion latifolium) and prickly saxifrage (Kakillarnat, Saxifraga tricuspidata) are at the peak of their flowering. The Arctic willow (Suputiit, Salix arctica), mountain avens (Malikkaat, Dryas integrifolia) and purple saxifrage (Aupilattunnguat, Saxifraga oppositifolia) have already started to disperse their fruit.

Dwarf fireweed (Paunnat, Chamerion latifolium) (top) and 

prickly saxifrage (Kakillarnat, Saxifraga tricuspidata) 

(bottom) are now in peak flower at Lake Hazen.

Mountain avens (Malikkaat, Dryas integrifilia) with the
fruit twisting (left) and ready to disperse seed (right).

We have had some amazing warm weather for the past two weeks - beautiful blue skies, no clouds and no wind. The water is roaring down the glacial fed Blister Creek, Abbe River and Snow Goose River that bound the Camp Hazen area. The water level in Lake Hazen is rising fast because of the warm temperatures melting the glacial ice faster than the last two years. My temperature sensors have been registering temperatures as high as 29°C at plant height (5cm above ground) and the temperature 10cm below ground has reached as high as 20°C. The landscape is looking much greener than I remember in the past two years.

Arrow Glacier (top) and Bridge Glacier (bottom) at the head of Blister Creek. The warm weather is producing high amounts of melt water from the glaciers this summer (top right). The water from the Arrow glacier runs underneath the Bridge Glacier (bottom left). Zoe at the snout of Bridge Glacier (bottom right).

The flowers have not lasted as long as last year probably because of the warm weather but there have been a lot more flowers to make up for it. The Arctic white heather (Itsutit, Cassiope tetragona) is a prime example. At my site close to camp last year the most flowers on any heather plant was 200 flowers, this year one plant had 1400 flowers at peak flowering!

An Arctic heather (Itsutit, Cassiope tetragona) plant we are
monitoring in full bloom high up on McGill Mountain on 8^th July.