Campaign 3: Bariloche to Trevelin

Two Argentines, two Germans, two Frenchmen, and a United Statesian walk into a lenga forest…

Happily, there is no punchline. After a week of intensive field sampling, we all walked right back out again! However, it goes without saying that communication is critical in field work. When there’s a mile-high language barrier, more often than not the entire group doesn’t operate on the same page. Case in point, I’d struggled with the language barrier difficult on the previous campaign to Tierra del Fuego. But, it was ONE language barrier. On this campaign, everyone was suddenly surrounded by one to three language barriers. Of the two native Spanish speakers, one spoke English and a bit of French. Both of the French speakers knew some Spanish, but only one spoke some English. One of the German speakers knew fluent English, but neither had much Spanish. And, par for the course, the United Statesian mostly spoke slang-filled English, in addition to 517 German words, and about 20 Spanish ones. Whew.

Our extremely international team assembled in Bariloche, and we drove south past a chain of misty lakes and rugged mountains along the fabled Route 40. With a quick pit stop in Trevelin to pick up our seventh volunteer, who would also be our local field expert, we carried on to our first sampling location at Lago Guacho. A tiny crystalline lake squished between mountains, it’s so far off the beaten path that it isn’t even known to Google Maps. Nonetheless, official green road signs led us 100 kilometers down a dirt road, all the way from Trevelin. We arrived late and had just enough time to train the enormous crew, divide work tasks, and sample about 10 trees before darkness began to fall.

We’d decided to camp overnight on the shores of Lago Guacho, which we had entirely to ourselves. We’d brought along all the essentials: tents, sleeping bags, a parrilla, yerba mate, and a few giant chunks of beef. Our drinking water we pulled straight from the lake – the water was so pure we didn’t bother to filter or boil it. Once the sun had set and our work ground to a halt, one of the Argentines built up a fire, generating an endless supply of glowing coals to toss under the low-slung parrilla (grill). The coals slow-roasted the large chunks of meat over the course of a few hours until they were crispy on the outside and juicy on the inside, like the carnivore’s version of a caramelized marshmallow. Although I’d more or less stopped eating beef at the age of 15, I wasted no time grabbing a steaming chunk with my bare fingers and sinking my teeth into it. Like rakí in Turkey, haggis in Scotland, or meggyleves in Hungary, eating beef in Argentina was just something I refused to miss.

The temperature drops fast once the sun sets on the eastern edge of the Andes, a consequence of the sub-alpine location and dry air. We edged ever closer to the burning coals as the darkness became complete, each of us taking turns to visit the lakeshore and gaze up into the inky black sky. Unsullied by a single electric light, cloud, or even the moon, the flawless spread of unfamiliar constellations reflected in the mirror-flat lake. I shivered stubbornly at the edge of the lake until I saw a single shooting star briefly flare to the northwest, then turned tail and ran to my tent. The temperature hovered near freezing the entire night and I lie awake shivering for much of it, stuffing the lining of my sleeping bag with extra clothes in a futile attempt to gain some insulation. Finally the sun poked its eye up over the eastern horizon, signalling it was time to dive back into field work.

We’d ended up with so many field volunteers that the next day we split into 2.5 working groups to try to make the work go faster. Two teams of two selected and cored trees, which is one of the steps that takes the longest in the field. Our trusty Milwaukee drill was handled by an expert corer, a Frenchman who was involved with the Gentree project in Europe and who could hit the pith (heart) of the tree on the first try almost every time. One of my German project supervisors headed the other coring team with a manual borer, a process that takes significant time, patience, and strength. The remaining three of us swarmed among the selected trees like bees, taking morphological measurements, giving each specimen its fancy ID tag, and obtaining DNA samples.

Collecting DNA samples from trees is straightforward when there are low branches – a simple snip with the pruning scissors takes just a minute or two. However, sometimes the branches are hilariously out of reach, and for this we have a…well, I don’t even think we have a word for this contraption in English. Basically, it’s a bean bag tied to the end of a long string that you throw over the lowest-hanging branch. Much like headphones thrown into a pocket, this string will tangle itself into hopeless knots every time it gets put away, no matter how hard we try to stop it from happening. Also, there’s really just not a dignified way to throw a bean bag 10 meters up into a tree. My personal favorite is the “granny shot,” which involves rigging the string into a triangle and swinging it through your legs before launching it underhand into the canopy, hoping that your shot will actually snag a good branch and not a) hit one of your colleagues, b) hit the trunk and ricochet back at you, c) land in the wrong tree, d) wrap around itself and get stuck, or e) somehow miss every branch in the forest and fly off into space. Almost without fail, one of these things would happen at every tree. I think the record for DNA extraction is about 30 minutes from a single tree – and it just wouldn’t do to transcribe the various things that were said during the process.

In one day we managed to finish sampling at the lower site next to our camping spot, hike to the upper site on the other side of the lake, sample the entire upper site, break down camp, and drive back to Trevelin. The next morning we piled into two pickups and skidded and bumped our way 40 minutes up the mountainside from the regional INTA experimental station. Small herds of free-ranging cattle halted our progress every now and then, staring at us as they chewed their cud before finally bolting off into the wild. We hiked to the edge of the forest and were immediately swallowed by a monstrous patch of colihue, a brutally strong native species of bamboo. The colihue was so thick around the trees that the laser we use to measure the crown couldn’t penetrate all the way to the trunk. Bushwhacking even the requisite 30 meters between trees took five minutes of infinite patience. Even a machete did little to help. After sampling a mere four trees in the thick undergrowth, a quick consensus led us to walk further up the road to a less dense patch of colihue – where we were promptly swarmed by biting horseflies.

Although we had some issues on that first day with the insects and the colihue, it’s come to my attention that we should NEVER assume that the second day at a field site will be easier. According to our local field expert Victor, the place we were going on the second day was supposed to have little undergrowth and, most importantly, no colihue. There was even a clear path following the boundary fence that would lead us a kilometer up into the forest, directly to an ideal sampling site. Hoja!, we thought. An easy day!

Until we got actually got a kilometer up into the woods. The path was clear and the colihue was absent, as promised, but the lenga regeneration was staggering. Enormous patches of varying ages absolutely blanketed the understory, some no taller than my ankle and some that towered over my head. Because lenga is a hardy species that often has to survive deep snowpack, it has strong and flexible trunks that are almost more difficult to bushwhack through than colihue. The regeneration was good news for the future of the lenga forest (and potentially for our future research on gene flow), but not so great for ease of field work – or for finding each other in the forest, for that matter.

The worse struggle, though, came from a crossing of our quadrilingual wires. In a classic too-many-cooks-in-the-kitchen-who-all-speak-different-languages scenario, we had differing opinions on the interpretation of the research protocol, and couldn’t agree on where to sample. The path we’d been following was helpful for navigation but it was leading us up into a valley, and after a kilometer of walking, the forest still looked almost identical to the forest we’d sampled in the lower site. Eventually we just picked a site that was 200 meters higher than the first site (a distance that approximates a 1° C difference in average annual temperature). As we worked our way up the nearest slope, though, the forest became shorter. The trunks grew more twisted, often snaking along the ground for half a meter before abruptly turning skyward.

We’d found the krumholz, a characteristic wood morphology caused by extreme weather conditions like wind and deep snow that often occurs near the tree line. The trees grow slowly and agonizingly, stunted in height with fat and twisted trunks. We’d found a stressed forest – the ideal forest type we’d been looking for all along.

After we’d already sampled 17 of our 25 trees.

Well, nuts.

A hasty executive decision was made to increase our sampling size to 50 trees, creating two populations by taking 25 from the upper “krumholz” zone and 25 from the more normal zone. Although the populations are smack next to each other and probably have high gene flow, sampling two “populations” with such stark morphological differences might help elucidate whether the differences are caused by genotype, environmental conditions, or something else like phenotypic plasticity. An additional point of interest is the volcanic nature of the Andes range. Every few years, one of the regional volcanoes gets ornery and spews thick clouds of ash across the landscape. A Chilean volcano had erupted near Trevelin in 2008, and digging just a centimeter or so into the dark organic soil revealed a thin layer of fine silver ash. So another potential question we can ask is how these different populations have responded to eruptions.

Our final day took us to a small ski resort near Esquel called La Hoya (“the hole”), to sample one of two extreme eastern populations that have much less precipitation than the main range of lenga. Craggy barren peaks clawed at the sky all around us, rimming a bowl filled with clear ski pistes and forlorn chairlifts swinging in the wind. Loose rocky scree dominated the steep hillsides, but the lenga carried on growing anyways. Drought stress was evident in some trees whose leaves were already turning orange and red. Some trees lived a more horizontal than vertical life, with split trunks that crawled along the ground for a meter or more.

I’m not sure what it is about field work – the fresh air, the sun, the daily 10 hours spent hiking cross-country up loose-soiled mountain faces. All I do know is that it leaves you absolutely ravenous at the end of the day. With our final sampling site complete, we went out for a celebratory dinner and ordered so much food our waitress actually commented on it, counseling us to order less because we couldn’t possibly finish it all.

When the food arrived, we descended upon it like vultures. It took us maybe 10 minutes to polish off the entire spread, and at the end we hailed our waitress and asked for another round of everything. She may have judged us as we demolished absolutely everything a second time. She definitely judged us when we ordered dessert on top of it all.

Our work complete and our bellies full, our international team dissipated like lenga pollen on the wind: two headed west to Chile, one returned home to Trevelin, and the remaining four of us rambled back up Route 40 to Bariloche to enjoy some well-deserved time off.

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