A Case of the (Missing) Mondays

Last month, when I boarded a plane to Canada for a math conference, I thought affectionately that I was glad that the last stamp in my passport, which expires in October, would be from my beloved Northern neighbor.

I didn't expect to be headed to New Zealand for another stamp before I sent my passport off for renewal. But, as those of you who saw me in my most frantic moments at the Ecological Society of America Annual Meeting this week know, sometimes surprises happen.

 This time, the surprise came on Monday: an email from a colleague who'd been kindly keeping an eye on my seedlings in New Zealand. "There's a fungus among us," he wrote -- or something of the sort. Or, to use another trite turn of phrase, "Houston, we have a problem."


His email was enough to have me scrambling to buy a last-minute (but fortuitously inexpensive!) plane ticket to New Zealand, leaving Sunday, a scant 48 hours after my return from the ESA meeting in Minneapolis. Hence, a Monday lost to the date line. (After a red-eye flight, I will arrive mid-afternoon on Monday, California time, but with the date change, it will be Tuesday in NZ.)

There is indeed a fungal problem, whose severity I don't yet know. Basically, when I left New Zealand last December, I'd just finished setting up a big greenhouse experiment to look at competition between the belowground fungi, ectomycorrhiae, that associate with Douglas-fir seedlings. In the "great swap," my fantastic helpers and I unpotted, sampled, and replanted literally hundreds of baby trees in a little over one week's time. We then had a "before" picture of the fungal community on the seedlings, and how it differed among the baby trees. By planting the seedlings in pairs in new pots, we then hoped to look at how those fungal communities battled it out with one another (yep, they sure do go to war, complete with chemical weapons!) and figure out who would "win" the root systems of our various seedlings. This gets at age-old questions in ecology about what traits make organisms more or less successful in different environments, how species diversity is maintained, and so on.

As is always the case in experimental work, it's important to keep things clean.

For example, we wanted to make sure that the only fungi present in our experiment were the ones that we had put there ourselves, rather than outside contaminants. For this reason, we do things like planting "negative controls." In this case, these are seedlings who were never exposed to any fungal colonists throughout their entire lifetimes. If their root systems stay clean (i.e., no fungi show up on them) over the course of the experiment, we know our greenhouse is pretty sterile, and it helps us to trust our results.

So, when there's any hint of contamination, the instinct of most experimental scientists is, well, to freak out.

My colleague's email suggests that we might have some contamination in our experiment. He saw mushrooms (the reproductive structures of the fungi that we study) in some of the seedling-containing pots. These mushrooms release tons of spores into the air, which means that the fungi can rapidly spread between pots in the greenhouse, contaminating the whole experiment in a matter of weeks -- even days.

And, if our worst fears are confirmed, the mushrooms we see might possibly indicate widespread contamination that has already taken place across the experiment -- but that's what our controls will tell us when I dig them up first-thing when I get to Landcare on Tuesday.

Greenhouse work in New Zealand, as those of you who have followed this blog know, has been fraught with ups and downs. But then, science is always that way. When I called my dad to cancel our scheduled vacation ("Umm, sorry, Dad, swimming with sharks sounds awesome but I've got to get to Christchurch."), he reminded me of the fretful days in undergrad when the failing cold room threatened to plunge my Antarctic phytoplankton into hot, humid New Jersey summer weather. And I still remember the ironically-titled poster I saw during my interview at Princeton: "My field site burned while I was gone, so now I study fire effects."

It's enough to turn a girl fully into a modeler...

It is also a good reminder to be grateful: for sufficient thesis data already collected, for sympathetic  conference roommates, for grant money, for attentive collaborators, for loopholes regarding departure dates and passport expiry, for scheduling flexibility, and for understanding friends and family.

I'm sure that's a list I'll be repeating to myself as I unpack those controls on Tuesday.

See you on the flip side (of the planet)!