Saturday, 16 September 2017

Everything's bigger in America

... or so my kids have told me. Andy and I have been having an amazing time scanning here in CA, with our NASA/UMD colleagues Laura Duncanson, David Lagomasino, and John Armston. We've managed to scan 8 x 0.25 ha plots as part of the NASA Carbon Monitoring System project, following Laura's protocol for the GEDI cal/val. The others have been measuring stems in 25 m fixed radius plots (i.e. single GEDI footprint-sized) overlapping within each 0.25 ha. Meanwhile, Andy and I have been doing the TLS - 1ha in two locations, and then in Armstrong Redwoods State National Reserve, using smaller 0.25 ha plots due to the constricted nature of the site (paths, valley, road).

These trees really are amazing. It's perhaps too easy to bandy around words like 'majestic' or 'spiritual' and so on, but there is something quite primal about being here. And amazing (and sad) to think that this whole area was covered with giants like this not much more than 100 years ago. Also incredible to think about the effort required to fell and remove one of these things, with nothing more than handsaws and some horse-powered carts and trucks. And a lot of labour of course.
"That's not a tree maayte, THIS is a tree"

"We're going to need a bigger DBH tape"
Some of these trees are HUGE - approaching 100m tall and 4m in diameter or more. They have amazing structures, roots, fire damage and I literally can't stop looking at them - my neck hurts from looking up.

Interestingly, the largest/tallest trees as noted on the maps and guides may be taller/shorter than measured - we're waiting on the TLS to find out for sure. The recorded sizes are from 20+ years ago in some cases so that may explain some of the differences, but we already think we may have found a taller tree than the apparently tallest one, just off the beaten track a little bit. We'll see!

Meanwhile, Dave was deploying his cool 14 GoPro 360 shape-from-motion-on-a-stick set-up. Here's a 360 picture of us in the plot from the system - but I'm really interested to see some of the point clouds from this. He's got some excellent results from mangroves, so this is a liiiiiittle different.

I've even managed to rope the kids into doing some work - it's educational! 
Roots. Or as I like to call them "someone elses' problem".

Andy in classic fieldwork with TLS mode.

Never let people who aren't *doing* the TLS lay out the grid. Precarious.

Strange fire history - possibly due to a large 19th C fire caused by an explosion from an illegal whisky still - but hard to see how (or if) that caused the scarring, other than the burn.
It's been a stunning field visit and I can't wait to see the data. It will be fascinating to see where these very large trees sit on the allometry line - how variable they are and then to think about some of the issues of density and hollowness.

One of the interesting things about working in a very public location like this has been the interest shown by people walking past. I've given the "Weighing trees with lasers! Carbon! NASA! Science!" spiel so often that the kids have started calling me Steven Spielberg. School groups, retirees, local cops & park volunteers, runners, walkers, cyclists - the response has been almost overwhelmingly positive. People have been interested, enthusiastic universally extremely supportive of what we're trying to do, particularly in view of the current political and funding climate. It's rare to get such instant, positive feedback on your research! People *are* interested in science, particularly if they can see it in action and you can explain why it's cool and important.

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