Pay and support early career scientists

Graduate student workers remain on strike in the University of California system, although some news outlets are reporting that a tentative deal has been reached for postdocs and other academic researchers to end their strike, now in its third week.

Postdocs are considered early career in academic science, despite the usually 5+ years of research experience they bring as a graduate student, plus often experience before that. They bring a wealth of expertise to technical projects – and that knowledge and contribution should be fairly compensated!

I co-authored an editorial in the December issue of the journal Frontiers in Ecology and the Environment that went live online today titled “Action to support early career ecologists.” The other authors and I, all current or former chairs of the Early Career Ecologists section of the Ecological Society of America, outline four key points that the early career ecology workforce needs more of:

  • Equity and inclusion, including understanding of its important by more senior people
  • Funding, both for salary and benefits and also for development opportunities such as conference travel
  • Mentorship in targeted and individualized areas and development opportunities
  • Exposure to diverse career opportunities and paths

Also I want to point out that the December issue cover highlights glaciers and tardigrades – one of my favorites!

Girls On Rock is hiring!

Girls On Rock is hiring a temporary (9-month) part-time coordinator for ~10 hours/week at $20-28 per hour (depending on experience) to start ASAP – please spread the word!

Application closes October 2nd:

Because part of the coordinator’s responsibilities will be visiting schools and community events within Colorado to spread the word to eligible high schoolers, they should ideally be located in Colorado, but do not need to be based in the Front Range.

Girls On Rock is a tuition-FREE 2-week backcountry expedition for 16-18-year-old girls (including trans and non-binary youth) to explore the Rocky Mountains and challenge themselves through science, art, and rock climbing. Selection of participants is NOT based on grades, nor is prior experience with any of those skills required. Instead, we seek to serve high schoolers who are passionate about the opportunity to grow from these experiences and who would use it to become a leader in their community.

Why go to zero gravity? One reason is to study balance

A few months ago I won a contest on Instagram to go on a Zero-G flight with Space Hero, a new media company developing opportunities for civilians to explore space. While the flight was postponed due to Covid, over on LinkedIn they’re highlighting why I’m excited about research in space and microgravity – reposting here (post 1/3):

One challenge to future space exploration is the difficulty astronauts have with balance and orientation in changing between microgravity, Earth’s gravity, and someday Mars’ gravity.

I recently got to check out research on gravity and balance by scientists at the University of Colorado Boulder. For example, Dr. Jordan Dixon and his colleagues have rebuilt NASA’s Tilt Translation Sled that accelerates on tracks as subjects inside tilt and respond to visual cues to simulate hovering a spacecraft. They also have a Mars landing simulation that can be used to explore manual flying performance after exposure to altered gravity environments! Check out the video of me “landing” on Mars below 🙂

The research on balance and perception will help future astronauts stay safe, but could also improve safety here on Earth for pilots fighting disorientation, patients with fall-risk, or persons recovering from neural trauma.

I had my own experience with months of dizziness several years ago. Although I am well now, the experience made a lasting impact, and I hope the research into balance also helps future patients like me.

Me sitting in the rebuilt NASA Tilt Translation Sled used for studying disorientation and acceleration in helicopter pilots, while Dr. Jordan Dixon mans the controls outside.
“Landing” on Mars in the simulation

College reunion

I hadn’t been back to Scripps College since graduating 15 years ago – until last month! I had a great time re-visiting many of the places I loved, like the Motley Coffeehouse, and meeting old friends and making new friends. It was especially wonderful to see my research advisers from that time, Dr. Nina Karnovsky (Pomona) and Dr. Diane Thomson (Joint Science, now becoming Scripps-Pitzer Science).

Thanks to Scripps for the Outstanding Recent Alumna Award! My training and the community there built a strong foundation for pursuing my dreams – and starting to dream even bigger. I’ll make sure it’s not another 15 years before I go back again.

The cost of invasions

The catastrophic human cost of the military invasion is filling the news, but biological invasions also cause damage. A grass from Kenya was bred and planted in the southwestern US and northern Mexico for decades (and is still planted in some places) for cattle grazing, but has escaped cultivation in pastures and begun spreading across the landscape. You can see in these photos the way the bright yellow grass, called buffel grass, fills in the previously empty gaps between the iconic desert cacti and native trees like palo verde. It is already contributing to wildfires in the Sonoran Desert.


A research study I started about a decade ago was (finally!) published last week (, showing that buffel grass is reducing the establishment of native plants where it spreads, even without burning. It’s not just spreading into space that they have vacated.

This scientific article, which formed part of my doctoral dissertation, was the result of a decade of work by not just me, but by a truly tough field crew, advice and help from land managers, mentors official and unofficial who helped and encouraged me, and financial support from the Garden Club of America, Western National Parks Association, the National Science Foundation, the Tindall Conservation Bio Internship from UA EEB Dept, a UA GPSC research grant, the NASA Arizona Space Grant Fellowship, and more I probably forgot.



My colleagues and I just published a new study on what limits microscopic Antarctic life in the tiny oases found on glaciers (cryoconite holes): Unlike much of the Dry Valleys region, “cryo holes” aren’t limited by moisture – so what determines the upper limit of growth there?

Photosynthesis by algae and cyanobacteria forms the basis of the food web, and like primary producers everywhere, key macronutrients like nitrogen (N) and phosphorus (P) can limit their growth.

Multiple lines of evidence in this paper and in past studies show that P is the real limit on primary production and resulting growth cascading through the community, and that at least on some glaciers, N is likely being “fixed” into biologically usable forms from atmospheric N.

Why does any of this matter? It can seem small and insignificant in the face of current geopolitical conflicts. I am posting this on the day that Russia brazenly invaded Ukraine.

Alternatively, our human conflicts can seem small and insignificant in the face of the vast polar regions and the mysteries of nature.

The cryosphere makes up a significant part of our planet, even if we rarely think of it because it’s not so habitable for humans. That makes it globally important, and also an important “natural laboratory” for biology. A natural lab we are rapidly losing as it warms, however.

This paper highlights the need to conduct actual experiments, adding N and P to cryoconite ecosystems to see how they change as a result. I hope to receive funding to do just that in the future 🙂

79 N

I have previously worked in Antarctica’s McMurdo Dry Valleys, at about 79 degrees south. I have finally made it along with a team of colleagues to Svalbard, which is 79 degrees north! This project’s fieldwork has been delayed a year and we are excited to be here.

Some of the landscape feels very familiar from my time in Antarctica, like the bare, rocky mountains with glaciers cascading down through the passes. But there are some key differences! Svalbard is closer to more temperate land masses, only a two hour flight from mainland Norway. It is warmer, and has tundra with grasses and flowering plants growing.

And of course, rather than firearms being banned as they are in Antarctica, they are required in Svalbard for self defense in case of hungry polar bears!

Sledding or not, here we go. Are are headed for the dumps?

When was the last time you went sledding? Doesn’t that sound great right about now, as we’re roasting in summer?

Brandishing my new ice axe before the trip, before slicing my knee open with it sliding down the steep snow. (I’m okay)

I tried to sled – without a sled – over the 4th of July weekend, high in the mountains of Colorado (about 11,000 feet). Technically I was trying to glissade, to slide on my feet or bum down snow so steep I was carrying an ice axe to stop myself if I got out of control. I wasn’t very good at it. I need a sled.

As a kid, I preferred inflatable snow tubes to plastic sleds. My dad would build an epic tube run in the snow from the top of a hill in the backyard. It banked hard around a treacherous curve to avoid a steep drop into the neighbors’ fence, then bounced down a series of stone steps. We called that section “the dumps,” because it wasn’t uncommon to dump there. If you made it around the curve and down the dumps, you hoped the bushes at the end of the yard stopped you before you flew out into the street.

As I grew up, there seemed to be less and less snow. I guess things always seem bigger to littler kids than they do to adults. But I remember building entire cave systems out of the snow piled on the side of the driveway from the piled snow. Maybe I was just much smaller.

Actually, no. I mean, I was smaller, but when you look at the numbers, Salt Lake City (where I grew up) gets less snow. I’m a 90’s kid (born 1985) who definitely went to see the new Lion King already (and was really disappointed by the version of “Be Prepared”). When I was tubing in my backyard on snow days, Salt Lake got on average almost half again as much snow as it gets on average now. Booooo.

And it’s not just Salt Lake. Lots of mountain ranges receive less snow than they used to. My colleagues in Colorado, where I live now, have studied the effects of snowpack on the soil microbiome of the mountains here. Just like the bacteria of our microbiome in our intestines help us absorb and process nutrients, microbes in the soil affect things like water quality and plant growth by processing nutrients.

When our microbiome gets out of balance, it makes us sick (ever heard of “C. diff. infection?”). Our systems don’t function the way we want them to. Changes to the microbiome of soils due to lower snowpacks and other ways in which humans are affecting the planet could change how our ecosystems function. We might not like those changes.

I say “could” and “might” because just like your doctor can’t usually tell you with 100% certainty how your body will respond to, say, antibiotics for a C. diff. infection or exactly when you’ll suffer a heart attack if you don’t change your diet, we don’t understand our microbial ecosystems well enough yet to know how big a deal this will be. Here’s how I think about that:

If I am planning to swimming at my local pool, or at a scenic mountain reservoir, I check the weather forecast. If it’s 30% chance of rain, I’ll probably go anyway and just get out of the water if I hear thunder.

2007-11-17 11-45-22_0013
Rappelling and swimming down Zion’s Pine Creek Canyon in 2007.

But if I am going to rappel down a steep and narrow slot canyon into deep pools, a rainstorm could kill me in a flash flood. The sky might be blue when I start my hike, but a rainstorm even miles away could start a flood that would sweep down the canyon toward me, with walls too steep to climb out. When rain means unavoidable death, 30% chance is too high to even go there.

We don’t understand Earth’s microbiome well enough to know what works and what doesn’t. Heck, we’re only just starting to tweak our own microbiomes inside our bodies, and that’s just one of us at a time. It’s like we woke up sitting in water in the dark and not sure if we’re in a reservoir or slot canyon.  So we might want to treat it like a slot canyon, in case it is. Because sooner or later it’s going to rain.

A bunch of people who make it their jobs to way overthink these kind of numbers agree. I just signed on to the recently published scientific consensus statement called Scientists’ Warning to Humanity: Microorganisms and Climate Change, or “Microbiologists’ Warning” for short.

This statement echos a broader consensus statement I signed in 2017 called World Scientists’ Warning to Humanity: A Second Notice. It’s an update 25 years after a statement from 1992 signed by 1,700 scientists then laying out the problem that we might be sitting in a slot canyon.

The message now? (Signed by >21,000 scientists, including me.) People, we’ve been feeling around and we’re finding walls. This ain’t no reservoir.

It’s time to get out of the water.

A study from 2017 calculated the relative impact of actions you can take to get us up and out of here. Here are the top recommendations:

  • Eat a more plant-based diet (I wasn’t impressed with the much-hyped Beyond Burger, but there are some kick-butt black bean burgers out there…)
  • Avoid airplane travel (want an excuse not to go to that one wedding or meeting?)
  • Live car-free
  • Have one fewer child (fewer people = less impact)

Obviously some of these are a big deal or unrealistic (we can’t all afford to live where we work when that’s Boulder, CO). But every little bit is a start. Try subbing in beans and grilled veggies and mushrooms on burritos one night instead of carne asada.

And tell your stories of what you have seen change. Tell them here. Tell them to your representatives. Tell them over family dinner. Especially when the numbers recorded show that it’s not just you…. there really is less snow.

And thank you. Now let’s go find some snow this winter. Bring your snow tube.

How does hiding from a predator affect biological diversity?

Ecosystems, and the biological diversity they harbor, are complex things. Yet simple mathematical models can often capture important features and teach us about their dynamics.

You might once have learned about food chains in school. For example, plants producing energy from the sun are eaten by rodents which are preyed on by owls. That’s a food chain with three links. Because just about everything has some kind of predator or parasite or other natural enemy, and just about everything must compete for resources of some kind, let’s focus on the middle link in this chain.

To study how many species can be supported in a middle link of such a chain, think first of two species. If each one can invade the system with the other species present, they can coexist. A simple model proposed early in the 20th century by Alfred Lotka and Vito Volterra can be solved for when two species would coexist, increasing biodiversity.

But this model leaves out a major piece of how animals function in the world around them: behavior. What if both kinds of rodents learn to hide from the owls under plants? Does it make them more or less likely to coexist?

In research I did with my doctoral adviser, Peter Chesson, published online recently by The American Naturalist, we show that the answer depends on how much those animals overlap in their resource requirements, like the types of food they like to eat, and in their vulnerability to different predators. When both prey can avoid predators, if they need exactly the same types of plants to survive and ground to dig their burrows, one may drive the other extinct. But if they are more different ecologically in their resource use than in which owls prey on them, then avoiding owls could make them even better able to coexist. (In an appendix, we even show how this scales to more than two species.)

I started this research in 2009 as a brand new graduate student, and worked on it off-and-on for the last decade. Peter’s guidance on this project taught me how to do research, and how to present it and to write about it.

You can see a plain-language summary of article here, or download the paper itself with all the equations here. Feel free to email me for a copy if you don’t have a university hook-up to access it without paying an arm and a leg.