Field Season Part 1

The first stage of the experiment having been successful - the trees that should have had mycorrhizae did, and the ones that shouldn't, didn't - it was time to take the trees to the great outdoors and let them grow there for a while. There are several reasons for doing the experiment this way, some of them practical and some of them related to the questions I am asking. Among the most pertinent:

• Chestnut trees get tall quickly. By the time they were planted in May, they had already gotten dangerously close to outgrowing their pots, and so the growth chamber was no longer a suitable environment for them. Because it'll take two years before we can say for sure whether or not the mycorrhizae are impacting their growth, they need to go somewhere where they can grow in peace.
• When the restoration of the chestnut begins in earnest, this is the likely protocol that the ecologists will use: take greenhouse-grown trees that are a few months old and plant them either in an orchard for further maturation, or directly into the field. Since this project was formed with their goals in mind, we want to follow their protocol, at least as much is as feasible.
• There's been a lot of debate over methods for testing mycorrhizal inoculation, but it seems like the researchers who have done their experiments entirely in pots have had much less success than those who take their plants into the field. Furthermore, as I said above, this is really the more applicable approach. It's probable that adding mycorrhizae to the potted tomatoes on your deck won't do much for them; mycorrhizae work best in natural ecosystems, and that's ultimately where we want to study them. Inoculation is merely a kick-start.

So to the field we go! In order to minimize the impact a specific site has on the growth of the trees, I, along with my mentees Austin and Mason, split the trees into three subsamples, which were taken to different field sites in upstate New York. We protected the seedlings with some tree tubes and left them to grow over the course of the summer. Fall tends to be the peak of mycorrhizal activity, so this September I will go out to take more growth measurements and to harvest more root tips to see if the lab fungi are still there or if they've been replaced by fungi out in the field.

Until the fun starts, however, it's back to reading papers in the office.