Orion is upside down! (Anatomy of field sampling)

On Monday night, to celebrate the completion of the field survey, I stayed up long past sunset (working on this column, actually) in order to check out the Southern Hemisphere's stars.

One of many, many Douglas-fir seedlings we've collected in the past weeks.

It was a remarkably clear night up in Hanmer (location of the Hanmer Hot Springs, which we skipped, and one of the worst wasp infestations I've seen, which we sampled in), and the tiny town offered very little light pollution.  So I got my first look at an upside-down sky.

I only recognized one constellation, Orion (my "cellestial boyfriend").  And he was upside down.

"No, he's not!" K. said.  Though born and raised in Germany, she's been in NZ for more than a decade and a half, so this disconcerting reversal is normal for her.

"But his sword is pointing up instead of hanging down..."

Feeling troubled, I went back to my room in our rented Kiwi batch.  (We stayed overnight in someone's vacation home.  One wall of the living room was literally plastered with pictures, from which K. and I decided that the family had three children, one of whom was now married with a child of his own, and the parents loved taking pictures of themselves with statues.  And bathing in the... erm... nude.  Naughty bits safely underwater, fortunately.)  It was 10:30pm, way past my bedtime (yes, I am an old lady), and I was ready for bed.

After two and a half weeks interspersed with daytrips and this one overnight expedition, we'd collected literally hundreds of Douglas-fir seedlings from five sites across the Christchurch area, all of which now need to undergo processing in the lab.

Duane, Ian, and I have come up with a sampling scheme that balances two things: First, getting good science done.  Second, getting good science done in a reasonable time frame (read as: before Holly gets on a plane in just a few short weeks).

Our question: What ectomycorrhizal fungi are helping Douglas-fir seedlings establish under different canopy types?
Our method: Collect seedlings from three canopy types (grassland, native Beech forest, and Douglas-fir plantation), and identify the fungi colonizing their roots.

An example of one of our grassland sites.  Did I mention,
we work in paradise?

Under mountain beech canopy.

A clearing in the Douglas-fir plantation, chock
full of up-and-coming seedlings.

From a statistical perspective, it's important to have good replication in these studies.  That is, you want to sample multiple locations (here, we'll call each location a site) to make sure that what you see isn't just a phenomenon of a single site. 

Another expository food example: When Holly travels, she likes to treat herself to a McDonalds milkshake.  The last time she had one, though, was some time ago on Cape Cod.  This milkshake was served in a snazzy clear plastic cup, topped with whipped cream and a cherry, far classier than what Holly is used to -- and, frankly, less delicious.  There are two competing explanations: (1) McDonalds joints everywhere have upgraded, or (2) Cape Cod is fancier than other places.  But because Holly's sample size is one (one milkshake, at one McDonalds), she cannot determine whether her results are limited to that single site.

Bringing this back to research, that means we want to check out the roots of Douglas-fir seedlings that came from many different sites, which are theoretically independent of one another because they're far enough apart that both the seedlings and the fungi colonizing them come from different sources.

For our purposes, we've defined a site by its Douglas-fir planting history.  Each site has its own independent Douglas-fir plantation, and seeds from that plantation have resulted in the establishment of Douglas-fir babies under the plantation's canopy itself, under adjacent Beech canopy, and in adjacent grassland.

K. digging up one of the grassland seedlings.

A seedling coming up in the grassland.  Because of the greater
light intensity there (no tree cover), the seedlings tend to be bushier.

From each site, we collect at least fifteen Douglas-fir seedlings, which gives us a chance to encounter even the fungal species that are rare.  (Typically, a seedling will be colonized by only one or two dominant fungi, because its root system is so small.  So if you took only a single seedling, you'd likely find only a couple fungi, when in reality there can be many important species.)

From an armchair ecologist's perspective, we decided it would be great to sample three sites.  So 3 sites x 3 canopy types per site x 15 seedlings per canopy type gives 135 seedlings to analyze.

It's important to keep the seedling's root system
as intact as possible, so that we can look through all
the root tips for fungal infection.

 In reality, I've been able to visit 5 sites -- three with all three canopy types, and two with only Douglas-fir and Beech canopies -- and have collected closer to 25 seedlings under each canopy type.  Slowly I'm working my way through bags and bags and bags of seedlings...  More on this processing later (look for: Anatomy of laboratory work).

J. and I holding up some cut Douglas-fir.  When
we have the time, we cut down the older, reproductively
active trees in the Beech forest, doing what we can to
slow the invasion.

Shortly after hacking down some souvenir Christmas trees,
J. and I enjoyed photographing this Daddy Long Legs.

Paradise comes with snacks: sweet snowberry growing in the grassland.