Trees we liked this summer

Summer is wrapping up and the Aitken lab is getting back to classes and lab meetings and all the regular routine of fall term. We spent our summer watering trees in the greenhouse, presenting at conferences, trekking around the field, and taking quiet vacations. Where ever we went, we found trees that delighted and soothed us. Here are a few of our favourites –

Susannah –

While wandering around Eves Provincial Park near Duncan, I came across the biggest bigleaf maple I’ve ever seen. The sign claimed it was the biggest maple in all of Canada. I’m not sure about that, but it was very impressive. When trying to verify the claim, I found there are 4 giant bigleaf maples in Stanley Park – practically in my backyard. Guess I know what I’m going to be looking for on my Stanley Park walks this fall! One of the things I love about bigleaf maple are how many epiphytes they support – their bark is just covered with mosses, lichens, liverworts, and ferns.
Bigleaf maple


Beth –

Bristlecone pine: wilderness survival expert

This is a Great Basin bristlecone pine tree (Pinus longaeva) from the protected Ancient Bristlecone Pine Forest in the Inyo National Forest of California. The trees in this forest are some of the oldest on the planet; the oldest living tree is estimated to be over 5,000 years old. They achieve these great ages by growing extremely slowly; an inch of diameter growth can take up to 100 years. Their needles can persist for over 40 years (the longest lasting of any plant). As they age, portions of cambium die, leaving only narrow strips of active vascular tissue and bark, leading to their characteristically gnarled growth form.

GB bristlecone pine

Pia –

My favourite neighbourhood tree:  a large multi-stemmed pine on 14th and Trimble. It’s on my way to the swimming pool. Unfortunately, I don’t know the species.


ID anyone?

Sally –

European yew (Taxus baccata) on Mt. Olympus in Greece. Yews are rare in Greece as they are toxic to livestock and farmers cut them down, but this population survived because it is near a monastery.

Taxus baccata


Iain –

This summer took me from Waterton to Jasper and everywhere in between helping complete health surveys of permanent whitebark and limber pine plots. Whitebark and limber pine continue to decline throughout their ranges mainly due to the introduced pathogen Cronartium ribicola causing the disease white pine blister rust, but also from mountain pine beetle, fire suppression and subsequent encroachment of lower elevation species, and climate change. Started in 2003 by Parks Canada, these permanent plots are surveyed every 5 years to assess the condition of whitebark and limber pine in the Canadian Rocky and Columbia Mountains. Lucky for me, I was able to help with the 2019 surveys while working for Parks Canada and travel to remote parts of these mountains to assess the endangered trees. I can safely say it was the most physically exhausting road trip I have been on!

Whitebark pine by Iain Reid

Whitebark pine by Iain Reid

Rafa –

Saying goodbye to my little Douglas-fir babies – this was the last picture I took from my experiment at Totem Field before cutting the plants down two weeks ago for biomass measurements.

It was quite a close and intense interaction with these plants since they were sowed in May 2017. Many and many assessments for phenology, height and cold hardiness.

Doug fir growing at Totem Field


Sierra McLane and Sally Aitken in The Walrus

Aitken-ites in The Walrus talking whitebark pine and assisted migration.

[N]ear the end of McLane’s whitebark planting trip in BC, it started to snow. Parked in whiteout conditions on a mountaintop, with no views to admire, McLane pulled a fourth layer over her down coat, grabbed her fingerless gloves, and braced herself for the whipping wind. Each day, as the temperature dropped, her unplanted seedlings became less likely to make it through the winter, leaving them in as much danger as ever and us no wiser for it. Crawling through ankle-deep snow, McLane spent her days scraping out holes with a tent peg and pushing the sprouts into the frozen dirt with her bare, numb fingers. Then, as now, the experiments had to go on. “We’re in a race against time,” she said.


Garry Oak trial

The Garry oak trial was established by Colin Huebert. A range-wide collection of acorns (2007) was planted first in a greenhouse, then in a common garden in Totem field (2008).

Garry oak in 2008 (top) and 2010 (bottom).

Garry oak in 2008 (top) and 2010 (bottom). Bark chips and landscape cloth help control weed growth.

After a few years, with various people studying aspects of Garry oak, the planting density was  a bit tight. Some trees grew really well.

Garry Oak trial in March 2015

Garry Oak trial in March 2015

A decision was made to thin half of the 1900 trees. The better your trees grow, the more work they require! But, we are not dealing with poplars. Thinning required a chainsaw and a team of helpers. It was definitely a collaborative effort.

Thinning was a collaborative effort.

Thinning was a collaborative effort.

But we had fun nonetheless.

Hard work and fun, too.

Hard work and fun, too.

This work party provides a good opportunity to single out some demonstration trees to illustrate provenance variation.

from top left, clockwise: thinned trees waiting to be chipped; provenance variation; discussing past and future research

from top left, clockwise: thinned trees waiting to be chipped; provenance variation; discussing past and future research

Who knows which other studies will take place in this trial?


The last big push – wrapping up the phenotyping for AdapTree

One last experiment of the AdapTree project remained in the ground: the trial comparing natural and seed orchard seed lots. The roughly 6000 plants were kept for a third season to collect periodic height measurements for the pine, and cold hardiness data for the spruce. The spruce trees announced themselves ready for freeze testing by the end of August, so September was dedicated to needle chopping and conductivity measurements. Thousands of them. Three whole weeks. Those who stuck it out were by then thinking with fond memories of the days gone by when the AdapTree team was large and fresh. But we did it, and the resulting data were clean.

Fig 1: Pine heights, diameters, and harvesting for shoot dry mass

Fig. 1: Pine heights, diameters, data logging and harvesting for shoot dry mass

Nonetheless, it was the middle of October by the time we were performing the final height and diameter measurements on the pine, while simultaneously harvesting them for shoot dry weights. (Figure 1). Harvest time was preferred for diameter measurements because it gives us easy access to the stems. We had sun, we had fog, we had beautiful autumn days and we had rain. Now, we don’t exactly melt from a little rain. But shoving wet plants in wet paper bags which are marked with sticky labels of moderate stickiness is asking for trouble. And while the recording tablets are protected, raindrops beading on a screen are not ideal for visibility. So this became a long, drawn-out affair. Of course, we only take pictures on the nicest days!

Fig. 2: Gradual progress.

Fig. 2: Gradual progress

The ideal team consisted of three people, so we organized our schedules, waited for the rain to stop, and gradually made progress (Figure 2). We finished the pine and thought we’d just continue at the same speed with the spruce. (Figure 3). Not so. While the spruce plants were much smaller than the pine, the stems were thick and asymmetric, with multiple roots spreading horizontally almost before touching the ground. Individual diameter measurements were not very repeatable, so multiple measurements were taken. Rather than taking turns at measuring, recording and bagging, for consistency’s sake all twelve blocks were measured by the same person. The repetitive bending over proved fatiguing.

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Fig. 3 : Some large pine, and the first snowfall

If you wonder what I am holding up: it’s an old toothbrush, to clean the root collar of sand and mud before taking a diameter measurement.

Then we had frost and snow in November! And the frozen ground in combination with the frozen liverworts and moss did not make a good basis for reliable height measurements – who’d have thought frozen bryophytes could bring science to a halt? As the days got shorter and shorter, we completed the heights separately.

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Fig. 4: Dry weights – so many!

In the meantime, shoot dry weights were measured in the lab, to keep the accumulating boxes of dried plants under control. (Figure 4). We didn’t finish before Christmas as planned, and Ian had to wait and wait for his data. With mild weather in the first week of January, we made one last big push, and the last spruce tree was cut on January 9 (Figure 5), with the last dry weights gathered two weeks later.

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Fig. 5 : The last spruce tree is cut …

And now all the plants are gone and no more measurements can possibly be collected from them!!!

I am grateful to all those who helped out (you can see some of them in the pictures!), and for the hot tub in the swimming pool. Did I mention the guys who (re)built the raised beds in the first place (Figure 6) ? And the summer students who helped sowing, and the technicians and students who collected weekly height measurements (Figure 7) ?


Fig. 6 : Re-building the beds ...

Fig. 6 : Re-building the beds …


Fig. 7 : Sowing, observing, measuring, ...

Fig. 7 : Sowing, observing, DNA collection, measuring, …



Welcome to Beautiful Gavin Lake!

In early July, Tyler, Joanne, Ian, Sally, and I (the Aitken lab crew, a.k.a. the A-Team) were dispatched to the BC interior to liberate some pine and spruce tissue samples from the clutches of an army of berry-picking bear cubs.

The REAL A-Team.

The REAL A-Team.

The sneaky bear cubs defending their strawberry patch.

The sneaky bear cubs defending their strawberry patch.

Our destination was the Gavin Lake Forest Education Society camp (http://gavinlakecamp.wordpress.com/), which, among other things, serves as basecamp for many UBC research teams working in the UBC Alex Fraser Research Forest (AFRF) and an annual group of 4th year Forestry students participating in the education-veiled debauchery known as “Fall Camp” (one recent cohort saunaed so hard the sauna roof caught on fire).

The cut block where the two field trials were planted.

The cut block where the two field trials were planted.

Sampling the lodgepole pine seedlings.

Sampling the lodgepole pine seedlings.

Our elite squad of tissue wrangling researchers made the 8 hour trek north to collect lodegepole pine and interior spruce tissue samples from a field site in the AFRF. The field site was established on a recently harvested cut block in spring 2013, and contains two separate field trials, one of lodgepole pine (2200 seedlings) and one of interior spruce (3100 seedlings).  These two field trials are medium-term (10 – 15 year) validation studies for our current common garden experiment at Totem field on the UBC Vancouver campus that are part of the AdapTree project. Such validation studies allow for an understanding of how translatable our results are from a seedling trial conducted outside of both of the species natural ranges, to more realistic scenarios of reforestation in the BC interior. In other words, it will tell us if coddled seedlings in raised beds, experiencing mild Vancouver weather accurately represent the seedlings out there in the wild trying to make it on their own. In OTHER other words, it will tell our graduate students if they wasted the last 5 years of their life. Just kidding, but only just.

The cut block, now 18 months after being clear cut, was home to three black bear families that passed their time munching on the sea of wild strawberries that have since recolonized the site. They were very considerate creatures, always maintain a healthy I’m-not-going-to-eat-you distance.  We also saw several deer around the site.  This little guy was particularly handsome.

Handsome Jack.

Handsome Jack.

Mama and baby eating all the strawberries.

Mama and baby eating all the strawberries.

Seeing as the designated UBC research cabin had already been commandeered by another crack squad of UBC researchers, we were upgraded to the lakeside Prime Ministorial cabin, which was very nice, as you can see here. During our free time in the evening we took advantage of our gorgeous surroundings by swimming, canoeing, and hiking around the lake. I must admit, aside from the mild inconvenience of having to wake up at 7:00 in the morning, it felt like more of a vacation than work.

Work is so HARD sometimes.

Work is so HARD sometimes.

Our humble lodgings.

Our humble lodgings. Sally shows us how to assemble a ‘Glory Bowl’.