Some images from Nouragues

Here are a few images from our time at the CNRS station at Inselberg, Nouragues.

The type of large, buttressed trees that hold all the carbon. How on earth do you model that trunk??

Obligatory lidar in the canopy shot.

And and Blaise working hard.

Perhaps the biggest hazard in the whole place: HORRIFIC spikes on the palm stems, under their leaves, everywhere. These things are an absolute nightmare. Shouldn't be allowed.

Scan 242. The last one. Slightly blurry, but then that's how we felt I think.

Mission complet

So we spent an amazing 10 days or so at the Inselberg field station, Nouragues. The weather was a bit mixed - the so-called dry season seemed to be ending a bit early, and so some days we had to flee from unbelievable rain storms. But working dawn until dusk, and following Andy's new Stakhanovite sampling regime of a 10m grid, with 10 rolling targets - 5 ahead, 5 behind - we completed 242 scans in the 1 ha H20 plot, at a level of detail we've never even got close to before. We were indebted to Blaise (Tymen) who was our 3rd man and guide, and he helped made the task manageable. So far, the data look absolutely stunning. Our first visualisation is here:

The location of the station is stunning - deep in the dense Amazonian jungle. The helicopter ride in and out was worth the trip in its own right, even if it was cloudy on the way in. It wasn't on the way out!

Notes on scanning and lessons learned?
Scanning at this density (4 x what we've done before), ditching the waveform data and the photos, we managed to achieve 40-50 scans per day, even with the odd shower, as opposed to our previous best of 23 previously. We could do this on 2 batteries, and without filling the disk on the scanner so only needing to download in the rapidly fading light of the evening, enabling us to leave the scanner at the plot (in the case in a waterproof bag and under a tarp!).

Doing it this way also meant we only ever needed 10 poles and targets (so you could take 20 say, to leave spares). We just needed to do a little bit of judicious veg shifting & pruning for each new location; we never missed one. Finally, it meant that laying out targets was very, very much quicker and simpler than using the systematic schemes we've used in a 20m spacing in the past. So, swings and roundabouts.

Andy was able to download and register the new data each day, to make sure we could continuously update our chain from the start to the end of the plot. The multi-station adjustment obviously takes exponentially longer as the number of scans grows, but we were able at least to check we could register all scans together.

Off again! French Guiana here we come.

And so it's time to say goodbye to rainy England and head to hopefully not-so rainy French Guiana. We've been fortunate to get some funding via the French Government CNRS Nouragues Travel Grants Program, to visit the field site at Nouragues, and scan some existing tropical forests plots. Andy and I are ready to go, kit loaded on the plane and just hoping this isn't going to be too much of a problem:

Slightly foggy Orly airport.

We're looking forward to the helicopter ride to the forest site from Cayenne and getting to see a new patch of tropical forest. We're also excited to be able to visit some of the key tropical plots set up by Jerome Chave and colleagues. We know we're going to be seeing some lianas, and that ought to be interesting if challenging too.

UPDATE: arrived safe and sound in Cayenne, with all kit which is the important thing. Coldest flight I;ve ever been on, to 28C. Perfect. Spectacular forest on the way in - can't wait!

View from the taxi. Not too shabby!

Here's looking at Kew

Something slightly different this week, with some scanning at the Royal Botanic Gardens at Kew. I was contacted by a former UCL colleague and alumnus who now works in the GIS UNIT at Kew, where they are interested in capturing the structure of some of their oldest and more unusual trees. In part this may be to preserve them, if only virtually, for the record. But more immediately, the team there are exploring new ways to monitor and manage old trees for their own health and that of the visitors - large falling branches are potential hazard! We went out to Kew and scanned one of the oldest trees in the gardens, an oriental plane, ancestor of the London plane, planted in 1762 (or perhaps earlier) and now rather venerable, hollow, and listing in places. We also scanned the renowned stone pine, planted by Princess Augusta in 1846, and kept in essentially bonsai conditions. It's not little any more as you can see below and the odd shape is a result of the early pruning, but of course leaves it very prone to falling over and breakage.

Bonsai stone pine, with guy wires in the centre. 170 years old, 14m high and rather elegant.

Oriental plane, planted 1762 (perhaps earlier), before the sun came out.

Heavily downsampled point cloud from 3 scan locations, of the stone pine.

As above, but this time with Andy's defoliation algorithm applied, and the remaining wood-only parts coloured red.

Hopefully we'll be able to get back and scan the Plane leaf-off, after some remedial surgery has been carried out. We should then be able to see what the possible effects are on the remaining structure, if any.

A very civilised place to work: you can scan lovely trees, get a very good coffee and a cheeky croissant and even chat to some of the visitors! Fieldwork at its most genteel.

Nature's Greatest Survivor: the oak tree doc gets aired!

So the Oak tree documentary is finally going to get shown - looks like 1/10/2015. Here's the trailer - and you can see a quick snapshot of one of our scans about 35s in. Exciting!

There's also some of the drone footage shot while we were there, and it all looks beautiful - as it should I guess!

Some initial results from Kim's work at Wytham

Kim has been working hard on co-registering the 370+ scans we collected from Wytham over the summer. He's managed to pull together the scans and put them into some sort of order, along the LAI2000 and 2200 data and everything else - great job! The co-registration of the scans looks pretty good so far, but is likely to improve as we use the multi-station adjustment on it. But Kim's first fly-through already looks VERY impressive - this includes scans made from the Wytham walkway and so gives a great view up and around the canopy.

As far as I know I don't think anyone has ever scanned as large a chunk of forest as this in such detail so far. The next steps will be pulling out and reconstructing the individual trees, and comparing the resulting models with the inventory data, comparing the structural information with the other ground-based measurements (PAI, LAI, gap fraction), looking at clumping, and then building the canopy radiative transfer model that will allow us to look at fAPAR and satellite signals.

An interesting corollary is the density of targets the individual scan locations 'see' in the plot. Kim has plotted the scan locations with reflectors:

6 ha plot at Wytham Woods, with the scan locations (red) and the reflectors (crosses) marked.

Each reflector is seen from a minimum at least 2 scan locations minimum, and up to 25 maximum, but mostly between 5 and 6 scan locations. This is a useful way to think about how many reflectors we need, the density of scans and so on, as we do this in more locations.

NERC GREENHOUSE project Summer School

As part of my involvement in the NERC-funded GREENHOUSE consortium, led by Mat Williams at Edinburgh, Andy and I were scanning at Harwood Forest in Northumberland this week. The NERC GREENHOUSE initiative covers 3 different consortia, attempting to provdie robust estimates of GHG fluxes over the UK land surface and coastal and ocean regions, from top-down, bottom-up measurement and modelling schemes.

The Summer School brought together 25 or so NERC-funded early career scientists (Postdocs and PhD students) from across the broad area of GHG research (land, atmospheres, oceans), for a week of demos, tutorials, lectures and practical sessions to showcase @NERCScience across land, ocean and atmosphere. We were showing the students how we can use terrestrial laser scanning to estimate above ground biomass, and forest structure and function, in the Sitka plantations at Harwood, alongside FR colleagues, Mike Perks, James Morison et al. The sun shone for at least one day, we got some scan data (see below) and it's another environment to try out our TLS methods (slightly less challenging logistically than Brazil, and slightly more homogeneous. Slightly).  It was a bit of blast from the past for me, having worked there a fair bit as a NERC Postdoc myself during the old NERC Centre for Terrestrial Carbon Dynamics. It was good to be back in such a lovely landscape; the Cheviot Hills and surroundings really are a stunning and remote, wild landscape. I took my bike with me and went out for a couple of lovely spins through the hills, rabbit-related injuries notwithstanding (honestly: a rabbit ran through my bicycle front wheel, throwing me over the bars and leaving me with fractured clavicle, 2 chipped vertebrae and numerous other painful contusions. Pesky wabbit - RIP).

View from the bike: Coquetdale, early morning.

The students seemed to enjoy the opportunity to engage with the field measurements and asked a lot of interesting questions, even though for some of them we were quite a long way from the sea.

Looking along the stand at Harwood towards the flux tower.

Andy scanning from the road, with the 35-40 year aged stand we are measuring to the right.

Sunshine! And a well-earned lunch break for the summer school gang.

Initial results show we are able to pull out the trunks up to the crowns very well, scanning at a slightly higher resolution than previously (0.02 deg). But the rain on day 2 meant we could only scan at 6 locations, so the small area of plot meant we had less detail from the upper part of the crowns than we have had for other, larger plots.

Oblique view of scanned plot, with the individual trees pulled out and coloured by height up to max of ~30m. 

Looking down on the canopy showing the crowns, again coloured by height. The trees are very similar in height and so the general trend of higher to lower (red to green) from left to right is a function of the underlying topography.

See up-to-date details from @GHGProg on Twitter.