Destructive harvest data collected from four large tropical rainforest trees in Floresta Nacional de Caxiuanã

Title
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Destructive harvest data collected from four large tropical rainforest trees in Floresta Nacional de Caxiuanã

Authors
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A. Burt
M. Boni Vicari
A. C. L. da Costa
I. Coughlin
P. Meir
L. Rowland
M. Disney

Contact
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a.burt@ucl.ac.uk

License
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These data are distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC BY 4.0) - see the LICENSE file for details.

Overview
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We harvested four large tropical rainforest trees (diameter range: 0.6-1.2m, height range: 30-46m) in a natural closed forest stand in Floresta Nacional de Caxiuanã, Pará, Brazil (approx. coordinates in the WGS-84 datum: -1.798, -51.435 degrees), during August/October 2018.
The objective was to measure the green mass of each tree in its entirety, and to measure woody tissue green-to-dry mass and volume ratios, and basic/green/dry woody tissue density. 
A complete description of the four trees, these data, and the companion terrestrial lidar data (collected pre-harvest) can be found in our paper entitled: ‘New insights into large tropical tree mass and structure from direct harvest and terrestrial lidar’.

Acquisition
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Field measurements:

Neighbouring vegetation surrounding each tree was removed, including complete clearing of the felling area.
Stem diameter was measured using a circumference/diameter tape at either 1.3m above-ground, or 0.5m above-buttress.
Each tree was felled onto tarpaulin using a STIHL MS 650 chainsaw with a 20” bar length and 13/64” chain loop.
Tree height (incl. stump) was measured with a surveyor's tape measure, and GPS data were acquired from the centre of the stump using a Garmin GPSMAP 64st.
The stem (incl. stump) and crown were cut into manageable sections, and the mass of each section was measured via weighing using two Adam LHS 500 crane scales.
Mass measurements commenced immediately post-felling, requiring two, four, four and two days to complete measurement of CAX-H_T1 to CAX-H_T4 respectively.
Multiple discs (approx. 50mm thick) were also collected from each tree: at 1.3m and 25%, 50% and 75% the length of the stem, and up to 3x discs were taken from the mid-points of 1st, 2nd and 3rd order branches (totalling a minimum of 11 discs per tree).
Foliage/fruit samples were retained to confirm taxonomic identity at the Museu Paraense Emílio Goeldi, Belem, Pará, Brazil.

Laboratory measurements:

All discs were reduced to a set of subsamples using a consistent approach: for any particular disc, they were cut as guided by parallel chords straddling above and below the major axis, each with approximate dimensions of 150mm x 50mm x 50mm (i.e., each set included periderm, phloem, cambium, xylem and pith tissues).
Mass and volume measurements were made on each subsample in a green and dry state.
Subsamples were considered in a green state after soaking for 48 hours, and a dry state once a constant mass had been attained whilst drying in an oven at 105 degree Celsius.
Mass was measured using an Adam NBL4602i Nimbus Precision balance, and volume measurements were made on the same balance via Archimedes’ principle.

Processing
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Dry mass was estimated from measured green mass and an estimate of whole-tree woody tissue green-to-dry mass ratio. 
Whole-tree woody tissue green-to-dry mass ratio was estimated by weighting the mean value from subsamples in each pool (stem and crown), by the green mass in each pool.
This mass-weighted approach was also used for estimating whole-tree woody tissue green-to-dry volume ratio and whole-tree basic/green/dry woody tissue density. 

File and directory naming convention
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The four trees are identified: CAX-H_T1, CAX-H_T2, CAX-H_T3 and CAX-H_T4.
The various files and directories are described as follows: 

./CAXH-H/
├───overview/
│   ├───cal_cert/                    (Directory: contains balance calibration certificates)
│   ├───images/                        (Directory: various photographs illustrating the field and laboratory measurements)
│   ├───sentinel-2                    (Directory: contains RGB and NDVI images from Sentinel-2 data over the harvest site during the campaign dates)
│   ├───CAX-H.results.xlsx                    (File: top-level results)
├───CAX-H_T1/                        (Directory: tree-level directories)
├───CAX-H_T2/
├───CAX-H_T3/
├───CAX-H_T4/
│   ├───fieldsheets/
│   │   ├───CAX-H_T4.fieldsheets.pdf                (File: fieldsheets from the original campaign)
│   │   ├───CAX-H_T4.remeasurement.fieldsheets.pdf        (File: fieldsheets from the remeasurement campaign)
│   ├───gps/
│   │   ├───CAX-H_T4.gps.txt
│   ├───media/                        (Directory: contains various photographs and videos of the field measurements, and the discs and subsamples)
│   ├───CAX-H_T4.results.xlsx                    (File: tree-level results)