Scouring coastal Alaskan forests : a journey through the past (Part 2)

Two wonderful weeks of hard work on the Kodiak Archipelago resulted in a truck loaded with 350 silica-dried needle samples and about as many tree cores from Sitka spruce forests. Happy and satisfied with the amount and spatial distribution of these tree samples, I embark on the ferry full of confidence about the second part of the trip: Sampling on the Kenai Peninsula.

Kodiak Island from the ferry

Bye-bye Kodiak!

Back on the continent, my main objective is to find old-growth forests of Sitka spruce and apply the same sampling design. By doing so, I will be able to compare the genetic make-up of a long-established forest to the young forests of the Kodiak Archipelago. I chose the Kenai Peninsula because it is the most likely origin of the trees that established on Afognak and Kodiak Island.


Just to remind you the general direction of Sitka spruce expansion.

This second chapter to the Alaska journey will provide the essential baseline data for my project and will help answering the following questions:


To what extent is population expansion linked to a drop in genetic diversity?

Are trees at the front of expansion experiencing higher levels of inbreeding than trees in core populations? Are they subject to lower levels of selective pressure?

Do deleterious / advantageous mutations spread more easily during population expansion?

Team number 2 is waiting for me in Anchorage: Jon and Vincent, fresh out of the plane. Two highly motivated Aitken Lab members. Two masters of tree-spotting, mushroom-picking, blueberry-gathering, and wild-cooking. Already on the first day I am tempted to re-name them Witty and Cheeky. But they ended up being “Yonathaaan” (with the strongest German accent you can adopt) and “Young Padawan”.

Jon and Vincent.

The crème de la crème of mushroom pickers.

While the difficulty on Kodiak was to get to big trees before the loggers, the difficulty on the Kenai was to get to big trees before the bark beetle. A devastating outbreak in the 1990s left very little of the pristine, old-growth spruce forest I was looking for. A lot of remaining old-growth lies in a thin strip of wet lowland crunched between the sea and the gigantic Harding Icefield, an impossible target for us and Bean, who likes roads more than glaciers and waves.

But thanks to the help of Ed Berg, bark beetle expert, John Morton, wildlife biologist, and our flawless determination, we finally manage to find beautiful, road-accessible stands of pure Sitka or mixed Sitka spruce-western hemlock forests around the Seward Inlet.

Kenai sampling areas

Sampling locations around Seward

After stalling a few times due to excessive scenic landscapes, we’re back in the coring-trunks-and-snipping-twigs business! We keep the same sampling scheme as on the Kodiak Archipelago: collecting equal numbers of tree needle and tree cores among 4 levels of forest structure (see previous post for details) in several locations, and keeping a distance of at least 50 m between sampled trees. The most striking difference in forest structure with Kodiak Island is that there is no “proper” tree of level 5. For sure there are very large trees (winning DBH: 138cm!), but none of them shows signs of open-growth (large lower branches). To me, this confirms that the canopy on the Kenai is way older than the oldest trees, unlike the canopy of Kodiak Island.


On the left, a Kodiak #5. On the right, a Kenai #5. Note: the scale on both pictures is represented by a normal-sized human being.

Although finding stands with no sign of recent disturbances was a real challenge on this part of the field trip, we managed to find four suitable sampling areas around the Seward inlet and added 197 trees to the collection. Early August, more than six weeks after having left from Vancouver with Ian, Bean and Jethro, it is time to return home. With a few kilometers added to Bean’s odometer, new or reinforced friendship bounds, beautiful memories of wild landscapes, a total of 550 tree samples and exciting prospects for my PhD research, I can’t wait to process all the data…. and go back on more adventures!


A last evening up North, somewhere on the Alaska highway


The Aitken lab goes to Saturna

What does a group of scientists and tree enthusiasts do when they go on a retreat? They go on hikes (or runs, paddles or swims), they look at trees, plants, landscape features  and wildlife. They cook and eat good food, and play board games at night. They also discuss trees, politics, philosophy and everything in between. In short, they have fun!

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Warm Kale Salad with Lemon Parmesan Dressing:

Warm Kale Salad with Lemon Parmesan Dressing

Thai dragon bowl soup:

This soup recipe comes from the Rebar modern food cookbook, by Audrey Alsterberg and Wanda Urbanowicz (2001), page 145. Since I don’t own copyrights to this book, I can’t just post the recipe, but I encourage you to find this book in your library, or go eat the soup in the Rebar restaurant in Victoria, BC. I will tantalize your tastebuds by mentioning some of the ingredients I used (I don’t follow recipes exactly): ginger, chili pepper, garlic, soy sauce, fish sauce, lemon, sugar, coconut milk, tofu, rice noodles, snow peas, tomatoes, scallions, bok choy, cilantro, basil, oyster mushrooms. Spinach would also work really well.


Welcome to the Internet Big Trees!

Registry committee member Ralf Kelman standing next to tree #320, the Wesbrook Ravine grand fir.

Registry committee member Ralf Kelman standing next to tree #320, the Wesbrook Ravine grand fir.

On September 25th, 2014, the BC Big Tree Registry was officially released to the world. Started in the 1980s by the infamous BC naturalist Randy Stoltmann (see article below), the registry contains the measurements and whereabouts of BCs most remarkable trees. Previous to the new online, publicly accessible database, the registry existed as a pile of difficult to navigate forms and pictures crammed into several banker’s boxes. Now, anyone with a computer and an internet connection can go online and nominate new trees or search out old ones. The bulk of this transformation was made possible through the hard work of Christine Chourmouzis and Bert terHart, with help from the registry committee and an Aitken lab member here and there.

The release party was held in the atrium of the Forestry building on the UBC Vancouver campus. The faculty of Forestry, and more specifically the Centre for Forest Conservation Genetics, is where the registry now calls home! A couple excited speeches preceded a sushi lunch, which was followed by a tree climbing demonstration.

Dr. Sally Aitken (left) helped bring the registry to the Faculty of Forestry. Christine Chourmouzis (right) was instrumental in the process of publicizing the registry.

Dr. Sally Aitken (left) helped bring the registry to the Faculty of Forestry. Christine Chourmouzis (right) was instrumental in the process of publicizing the registry.

The registry exists in order to identify, describe, monitor, and conserve the magnificent arboreal features of British Columbia. This is open source information for the public to access, go see the big trees for themselves, and find and nominate new trees so that others can do the same. The registry is always appreciative of new or updated information like tree health, photos, and growth. With the registry becoming completely digital, this sort of civilian maintenance should result in the most comprehensive Big Tree Registry to date.

Big tree climbing gear.

Big tree climbing gear.

Links to news articles and videos about the launch:





Don’t try this at home.

Don’t try this at home.


Randy Stoltmann: Father of the BC Big Tree Registry

Unlike many projects of this nature, the BC Big Tree Registry didn’t begin with a committee or organization, it began with one remarkable individual. Randy Stoltman compiled his first list of big trees in 1980 at the age of 18. An adventurous kid that loved the outdoors, Randy grew up playing in the forests on the north shore of Vancouver. His first list was a record of all the big trees in Stanley Park (the 1001 acre public park that borders downtown Vancouver) which he gave to the Vancouver Parks board. From then on Randy dedicated himself to conservation and public outreach, volunteering with the Western Canada Wilderness Committee to prevent old growth logging and building trails and signage to allow for people to get out into the wild and connect with nature.

The big tree godfather himself.

The big tree godfather himself.

On of the registry monsters.

One of the registry monsters.











From its humble beginnings in the hands of a nature-loving 18 year old, the formal registry was established in 1986 by the B.C. Forestry Association, which became Forest Education B.C. and most recently FORED BC. Sadly, in May 1994, Randy lost his life while ski touring in the Kitilope area. After his death, FORED BC stopped maintaining the registry and much of the original files, maps, and photographs went missing. Fortunately, shortly before he passed, Randy copied most of the registry records into a report for the B.C. Conservation Data Centre (CDC). After swapping hands a couple more times, in the fall of 2010 the BC Big Tree Registry found its home in the Faculty of Forestry at the University of British Columbia.


Simulating climates in growth chambers – Choosing day length regimes

This post is part of the series Simulating Climates in Growth Chambers.

Day length for a given latitude can be obtained from online programs, such as the online photoperiod calculator at http://www.sci.fi/~benefon/sol.html Day length was reprogrammed weekly for convenience. Latitude can be chosen corresponding to a target location (e.g., Williams Lake, 52°07’N) or latitude representative of an area, e.g. the province of B.C. (54.5°N).

Some practical limitations may rise here. Until LED lights become cheaper still, any light source also generates heat. It may not be possible to program a sunrise while temperatures are still below 4°C. This depends on the hardware of the climate chamber. In this case, consider turning on the lights gradually, reducing light intensity, and leaving off any incandescent lights until later, as they generate a relatively high percentage of heat.

Next up on the list is simulating winter conditions, heat waves, stimulating germination and bud set. You can also go back through some of our older posts on simulating climates in growth chambers.

 Day length during the growing season at 54.5 °N.

Day length during the growing season at 54.5 °N.