Early Sunday morning (12:10 AM...) Trista and I rappelled out of NoPathy, a 130 foot white pine in the Lost 40 SNA. It was in the upper 20's, cloudy, with a brisk north wind. It was her third climb of the day, and my second. We were bushed. But we did get the numbers and the samples.

White pines (and a lot of other eastern trees) don't seem to grow as tall toward the north end of their range as they do toward the south. This could just be because the growing season is shorter to the north, or MAYBE there are cold-related physiological stresses as well. On of my grad students (Trista Little), an undergrad (Justin Lee) and I have been looking into this for half a year now. It gets us up into the trees under conditions that most people don't seek out for fun.

One of the things we need to keep track of is whether the needles are "awake" (able to do photosynthesis) or "cold-hardened" (shut down for the winter) in different parts of the canopy. Quickest way to do this is by measuring "chlorophyll fluorescence" - the amount of light that leaves give off a fraction of a second after a controlled flash of light. The fun part is that the easiest measurements to understand are taken at night.

So we have been climbing our study trees 2-3 hours after sundown.
At regular intervals.
Most of the winter.
Why are we doing this again?

There's some work to do over the summer too, and into next fall, and into next winter (this year was pretty wimpy by Bemidji standards).
Grueling, but I get to tree climb on the job some days...

Go Mark go!

Sounds awesome. Are you hearing/seeing great-horned owls on your night excursions? Also wondering if you've flushed any small birds roosting high in the pines. I've been surprised to find quantities of Juncos roosting much higher than I would've expected (for a bird that spends most of the day foraging on the ground) in winter conifers.

Also... is that piece of woods in timber wolf territory? If so, maybe some extra adrenaline for you, or at least some nice canine singing
-AJ

We heard a barred owl one night, and sometimes hear waterfowl that are out on a nearby wetland - coolest call last weekend was the first sandhill crane of the year (about a month earlier than usual).

We've never flushed any birds out of trees at night - a good thing, since they'd be pretty disoriented and might not re-settle safely. It helps that we're generally setting lines for a night climb in the late afternoon/early evening.

Pretty much all of northern Minnesota is in wolf territory, but the home range of a pack is dozens of miles across and wolves are pretty shy around here, so you don't hear them often. Nice thing about the Lost 40 is that it's many miles from any town in a very thinly inhabited part of the state. You often don't hear a single human-made sound other than your own breathing when you're up a tree at night.

Sounds amazing, I'll have to get there someday.
-AJ