From Arizona to the Amazon

I usually study population dynamics in the upper Sonoran Desert near Tucson, but since I am still entering data from last summer’s fieldwork and analyzing it, I took my laptop down to Brazil for nearly a month. While I’m here, I also get to climb massive trees and learn about the questions and methods used by Scott Saleska’s lab to better understand the future of the Amazon under climate change.

Climate models predict wildly different things about how the Amazon Rainforest will respond to a new climate, but all agree that whatever happens will have a big effect on the rest of the world’s climate. There is a lot of carbon stored in these trees, and if they release that to the atmosphere through dying or burning, it will accelerate global warming. On the other hand, if they grow bigger and faster, they might actually buffer the climate by taking up more carbon dioxide.

One problem is that no one really knows how these trees respond to changes in the climate. Our best understanding, captured in mathematical models, predict that drought would cause the forest to die back, looking barer and browner. Yet during recent droughts, the forest appeared to green up! Was it because the forest is light limited and fewer clouds meant more light for the plants to  grow? Would that response continue if the drought continue?

It turns out that in a very diverse forest like the Amazon, no one really knows how the leaves behave. Unlike in, say, New Hampshire, where trees all put out buds around the same time and then lose their leaves around the same time, this forest appears evergreen. Since leaves don’t live forever, we might assume trees replace their leaves. But how often? All at once, or on a sort of rolling basis? Regularly, or in response to some environmental signal? Tree species might behave very differently – after all, some grow fast in response to forest gaps, while others grow slowly in the shade of larger trees until they reach the canopy. So how similar are their leaf lifespans and replacement strategies? These answers are pretty difficult to answer, especially because walking up to a tree whose lowest branches are over 100 feet in the air makes it very difficult to look at their flowers – or even their leaves.

Fortunately, with improved arbor techniques, climbers can now safely access much more of the canopy to measure and tag individual leaves. Imaging and remote sensing might be calibrated to in the future provide an even faster way to measure leaf age and species identification. I’m enjoying learning both techniques for measuring leaf traits and leaf demography as well as for climbing into the canopies. And I’m especially enjoying thinking about a completely different set of scientific questions: questions about movement of water and carbon through a whole ecosystem, instead of competition, predation, and population dynamics.


Grad student Neill Prohaska shows the lab's newest member some equipment.
Grad student Neill Prohaska shows the lab’s newest member some equipment.
Alejandro learning to climb an access line into a 40m high canopy.
Alejandro learning to climb an access line into a 40m high canopy.


One instrument tower has stairs for easy access.
One instrument tower has stairs for easy access.
Neill at the top of the walk-up tower, looking out over the canopy of the Tapajos National Forest. I was surprised how diverse the canopy structure was.
Neill at the top of the walk-up tower, looking out over the canopy of the Tapajos National Forest. I was surprised how diverse the canopy structure was.
The other tower, which measures the carbon flux of the forest, must be climbed like a ladder, wearing a harness.
The other tower, which measures the carbon flux of the forest, must be climbed like a ladder, wearing a harness.

What does wilderness mean to you?

Where does the grassland end and the pinion-juniper forest begin? Looks simple from back here, but hike to the first juniper you find, and there is still an awful lot of grass....
Where does the grassland end and the pinion-juniper forest begin? Looks simple from back here, but hike to the first juniper you find, and there is still an awful lot of grass….

Drawing lines is hard. In a variable and idiosyncratic world, our tendency is to lump ideas or places into groups. We learn in preschool to categorize, to delineate, and later to characterize and describe those categories. This leaves us frustrated when we look closer at where those lines should be, and they become difficult to draw.

Very frustrated.

Last week, I posted about Dave Bertelsen, who has recorded flowering plants along a five mile section of trail ascending the Santa Catalina Mountains for nearly 30 years. The vegetation’s structure, species identity, and density looks very different at an elevation of 8,000 feet than at 5,000 feet, which looks different than plants at 3,000 feet. Biologists commonly recognize these as different “communities,” “biomes,” or “assemblages” of plants, but when you hike from 2,500 feet up to 6,000 feet, you realize it is hard to draw a line between them on the ground. It makes perfect sense when you think of each individual species responding to the temperature, moisture, soil, competition from other plants, and herbivory from animals, but it makes generalization more difficult.

Another line that becomes difficult to draw when you think about it too hard is which areas to ask the US Congress to designate “Wilderness.” That designation is the highest legal protection against housing developments, mining, and other activities that would change the character of a place. We probably each have an idea of what wilderness looks like, and what activities are compatible with wilderness. But those ideas may vary from person to person in ways that seem subtle when viewed as an abstract national policy, but can be very important when that line touches a place you love.

Earlier this week I attended a meeting of the Southern Arizona Climbers’ Coalition. I had been meaning to join them for nearly a year, when they first formed. After all, I didn’t just move to Arizona for grad school. My list of potential advisors was strictly within a few hours of decent rock climbing. At this meeting, I had been invited to give a short presentation on the ecology of the region, and I used it as an opportunity to ask what ecology should be included if you had only two pages in a guide book. Being down in the weeds, it can be hard to see the big picture of the desert and Sky Islands, even from the top of a six pitch crag. Thanks to the folks who responded to that question – if you have an opinion, especially if you’re new to the area – please email me or leave a comment on this post!

Almost more valuable than those comments were the conversations I had about ongoing land management issues. Climbers enjoy and value wilderness, I suspect more than much of the general public. The recent shift of land management agencies toward prohibiting safe and practical rock climbing in areas being managed for wilderness character changes the way the increasingly large segment of the public uses the land. It also puts the climbing community in the very awkward position of somehow opposing wilderness designations. Of course we want to protect the landscape from mines, off road vehicles, and other large impacts. But it seems ludicrous to lump rock climbing in with mining and road creating, especially when a majority of climbers practice Leave No Trace ethics (though not as many as I wish would). Many of us have worked or volunteered with, or for, or been members of organizations like The Wilderness Society, which are promoting more wilderness designations.

I definitely see rock climbing in the traditional style (trad climbing) being consistent with wilderness character. Typically (these days) anchors and gear are primarily removed, with the possible exception of webbing used to rappel off the top of the climb, which eventually fades and disintegrates – eventually, not fast, but still eventually. One of the earliest North American pioneers of rock climbing, John Muir, who was also a wilderness advocate and started the Sierra Club, would have agreed, I think, though he likely would be astounded at our safety technology today. Maybe, like many old climbing hardmen, he would be contemptuous, too, but I like to think his vision, compassion, attention to detail, and evidence based values would have won him over to the freedom of climbing having a place, even in wilderness. Judiciously, of course, and with climbing ethics firmly in mind.

But what about sport climbing, in which metal bolts are drilled into the rock, usually requiring a mechanized drill, and left for following climbers to use? Those bolts also need to be replaced periodically that practically for the safety of the climbers. These bolts are rarely visible except right next to a crag (and sometimes maddeningly invisible to a climber on the route), so they are unlikely to heavily impact the wilderness experience of nonclimbers. Rock climbers who want a pure experience, a true pathfinding adventure without metal cairns, may not appreciate their presence, although my understanding of climbing ethics is to not place bolts where finding alternative protection is actually possible. This is definitely not a cut and dried area – especially when you consider drilling in metal rap anchors at the top of a popular trad route to make the descent safer (or possible).

Should leaving any gear or drilling bolts be allowed in areas where we want to preserve wilderness character? Wilderness is, after all, an important legal protection for areas that we would like to keep climbing against threats like mining that would completely remove access. If even wheelbarrows are prohibited, can exceptions be made for mechanized equipment like drills? Actually – what about cameras and wristwatches and smartphones? Are only mechanized things that interact with the landscape prohibited? That touch something other than the person? Where do you draw that line?

Somewhere like Cochise Stronghold, a backcountry area whose rugged terrain practically protects itself from offroad vehicles and even off train mountain bikes, certainly includes rock climbing in its wilderness character. Anecdotal evidence from climbers there suggest that a few humans climbing the rocks slowly and awkwardly (okay, some of us more slowly and awkwardly than others) does little to strike fear into the hearts of nearby animals. Anecdotal, to be sure. And does the short term presence of a drill’s racket increase that disturbance? By how much? (I am currently writing a paper on how the ecology of fear affects biodiversity, and I would love to collect more rigorous empirical data on the effects of climbers.)

I had a good series of conversations with other members of SACC following the meeting about other access issues related to ecological and species specific concerns. One of my greatest frustrations as a recent college graduate back in D.C. dealing with gigantic policy concerns and disagreements between close allies in environmental issues was my lack of expertise. Besides the lack of climbing in the Washington area, that was a major factor in driving me to pursue a Ph.D. in a basic science department.

It’s been nearly five years to the day since I packed my mountain bike and clothes into a station wagon, and drove three days to Arizona and begin a Ph.D. in Ecology and Evolutionary Biology. Although I had spent the previous 18 months working on federal environmental policy, I chose a basic science department, rather than one dedicated to solving immediate and applied issues. This even despite the fact that the 6 months prior to my position in D.C., I had worked for BLM in Nevada, and before that for a lab studying the effects of an invasive plant. My entire post-college professional experience was in solving pressing environmental problems, and I walked into a department where that training was not particularly valued, and instead the focus was on what questions would move the state of human knowledge forward. Perhaps a naive choice, but perhaps wise. After all, I had been glad that as an undergraduate, I focused on a degree in Biology (Scripps being a small liberal arts college, we had no differentiation possible within that major at the time) rather than an attractive interdisciplinary major in Environment, Economics, and Politics.

I’m not done with my PhD yet. I’m still writing and revising drafts of papers for publication, some of which will eventually become my dissertation. It feels like a long slog sometimes. An exciting and endlessly fascinating slog, but nevertheless long.

I may be still slogging the long slog, slog by slog, but it felt good at that meeting to offer my background in ecological theory, local field work, and access to current scientific literature to contribute to the conversation between climbers and land managers. I came away with ideas for new topics I want to research in my spare time (ha).

I would say it felt spooky for my former world of negotiating differences in environmental allies to collide with my current research and climbing worlds in so personal a way, but I’m actually more surprised it hasn’t happened sooner.

Summer stress

What I'm placing behind my ear is no tropical flower: that is the rind of a saguaro fruit, burst open to reveal the deliciousness inside! Behind me, most shrubs like the ocotillo are leafless. Thanks to Elena Martin for the photo.
What I’m placing behind my ear is no tropical flower: that is the rind of a saguaro fruit, burst open to reveal the deliciousness inside! Behind me, most shrubs like the ocotillo are leafless. Thanks to Elena Martin for the photo.

The news (and some photos on Facebook) would have me believe the summer is all about sitting on the beach, enjoying a fast paced book. But my last three summers in the Sonoran Desert have been a race against time to census seedlings as they pop up and quickly die following the patchy monsoon thunderstorms. The seasons have been full of long days in the hundred degree plus heat, and dreaming of seedlings again in my sleep.

Actually, the monsoons that just began may have brought a silent sigh of relief from many dry and browning plants in the region. The long, arid early summer was finally over. June can be a miserable time of year, made bearable by the fact that candy falls out of the sky. Saguaro fruits (Carnegiea gigantea) ripen and split open during June, revealing the sugary flesh surrounding thousands of seeds the size of poppy seeds. Those the white winged doves fail to eat off the cactus fall to the ground, where, if we are lucky, we find them before the coyotes, javelinas, or ants. As they dry in the sun, they reach a sticky, chewy, very sweet consistency, broken by the bitter crunch of the seeds. A little like a date or a fig, maybe. Mostly it tastes like a saguaro.

A few species seemed to jump the gun on the monsoons. During a season when most stems are brown and the only leaves that dare show themselves whither reticently, the limberbush (Jatropha cardiophylla) in the Santa Catalinas started to put out small leaves and even to bloom, a full two weeks before the monsoon rains arrived! I observed them myself on a hike up the Finger Rock Trail with naturalist David Bertelsen and environmental science teacher Elena Martin on June 27. In this unpredictable region, with its patchy storms and fickle promise of rain, why spend the energy and the water to make flowers prior to the storms hitting? Where had the plant held on to this reserve of moisture? Was it to get the jump on all the other plants when the rain finally hit? Do limberbush in other canyons, and other mountain ranges have this same phenology? Do they always in the Catalinas?

Dave is one of the few people who could may actually be able to answer that final question, by checking his notes. Nearly 30 years ago, he set out to hike the Finger Rock Trail weekly for 20 years, all the way from Tucson to the top of Mount Kimball, and record all flowering species and which section of the trail they appeared in. The result is a rich data set of phenology (the seasonal timing of events) of the flowering plants along that trail, which climbs thousands of feet in elevation. He has published several papers on this data, along with Theresa Crimmins and Mike Crimmins. I was astounded that he had a vision right from the start of the degree of dedication and the amount of time he planned to continue. It was a bold vision, especially for someone who was working a full time job – and not a research job.

Speaking of working full time at a job outside of academia and even scientific research, we had a conversation along the way about the term “citizen scientist.” To me, that term evokes the National Guard’s advertising campaigns for “citizen soldiers,” individuals who have a high degree of training and professionalism in their military duties, even while not being full time employed as such. But Dave hears it differently: he wonders why the “citizen” need be there at all. It implies that scientists are a class apart, excluding the general public, instead of being accessible to anyone pursuing answers through rigorous use of the scientific method. Charles Darwin, for example, was not a professional scientist, but made great contributions to scientific fields. Albert Einstein was employed full time at a patent office while he developed much of the early theory of relativity. Dave suggested the term “naturalist” has a less diminutive connotation for people studying nature without an official posting to do so.

After our hike, I was reading through the final entries in the field journals kept by students on the field course I recently helped teach. One of the final questions posed by the main instructor was, “What research project would you want to go spend an additional three weeks studying?”

Forget three weeks, I thought. Be bold like the Jatropha. Start now, and in 20 years, you’ll have the jump on the others, you’ll have that data set.