Biomass, Big Hairy Spiders, and the Beginning of the End

 

Time for some science!

Greetings backers, readers, members of the curious public!

One strange thing about this project is that between the bursts of activity and the long lulls of waiting for trees to grow (wherein many, many other things must be accomplished) is that it's really easy to lose track of time. Another strange thing is that even though I'm almost to the end of my program, much of the work remains to be done. This fall is going to be a pretty wild ride, and you're definitely going to be along for it. So let's get filled in on what's been happening so you're ready for the grand finale.

The end of the last growing season saw the chestnuts experiencing what's called "planting check." In technical terms, this is an inverse ratio between starting height and growth increment and in layman's terms it's the plants not doing much of anything. Essentially, what happens is when a plant is removed from the growth chamber and planted in the ground, it loses its nice, constant environment with few stressors and needs to get acclimated to the much more variable conditions of the great outdoors: no more regular waterings, no more constant humidity (although our growth chamber was pretty temperamental itself in that respect), and no more daily visits from a charismatic grad student. This combination of factors can put a plant in a grumpy mood, and it will take time to consolidate its root system -spreading laterally to anchor it down, vertically to secure reliable access to water and nutrients - rather than grow upward.

 

Fortunately, insect damage hasn't been an issue.

This is a problem for someone on a short time scale, because there's no way to tell if mycorrhizae are actually having an effect on growth if there isn't any growth, and so I had little choice but to hunker down over the winter and attempt to extract DNA from my first round of root tip samples (on which more later). The good news, however, is that if the plants successfully weather that first growing season, they're in prime position to take off in the next, and that's exactly what's been happening. Of the 84 chesnuts that were planted in the field, only four died, and only one of those was a victim of the groundhog that decided to move into one of my field sites last year. The remaining chestnuts have been growing like crazy, and some have even begun to escape from their four-foot shelters, having put on anywhere from 2 to 3 feet since May. Based on the quick and dirty statistics I've been running on measurements that I've taken so far this year, there's an indication that mycorrhizae are having a beneficial effect on growth, which is exactly what I was hoping to see. I'll have to sit down and do things properly once all the data are in, but this is an encouraging result.

 

So what now? I'll continue to bide my time and keep an eye on my trees until this autumn, probably around the second week in September, when mushrooms are at peak fruiting so I have nice, easy-to-work-with root tips and I can avoid a repeat of this spring. At that point, I'll go out and harvest my trees for biomass measurements and grab root samples for that DNA analysis I needed funding for. We'll be aiming to see what fungi are out there fueling that extra growth if it turns out there is some as well as if the fungi from the growth chamber hung out with the chestnuts. This will mean a bunch of busy days in the lab. See you all there!