Deadwood decay and traits in the SAFE landscape

Deadwood decay and traits was measured across 20 SAFE Vegetation plots (17 existing plots and 3 new plots set up for this project). The plots form a gradient from no logging disturbance to salvage logged forest. See the 'PlotInfo' worksheet for plot descriptions.

'DeadwoodPieces_FieldData' worksheet: measurement of deadwood pieces in the forest.
In the initial campaign in 2017, deadwood pieces were chosen for sampling from four decay classes, from DC_1 to DC_4 (DC_5 was not included, as it was unlikely that these pieces could have been resampled in later campaigns) and from six diameter classes of 5-10 cm, 10-20 cm, 20-40 cm, 40-70 cm, 70-110 cm and >110 cm. The aim was to sample one deadwood piece in each decay class x diameter class combination inside the plot or in the immediate vicinity, but in practice, not all combinations were found in every plot.

Decay classes are based on a five-point scale following Harmon et al. (1995) Biotropica 27:
DC_1 - recently dead, bark cover extensive and leaves and fine twigs present;
DC_2 - some signs of decay, no leaves and few fine twigs, bark started to fall off, but wood is still firm;
DC_3 - clear signs of decay, bark has started to fall off and/or sapwood is softening;
DC_4 - wood is soft, typically no bark;
DC_5 - wood is very soft and typically lost its shape.

Each deadwood piece was given a unique tag and its lenght and diameter was measured. In addition, the penetration of the knife into the wood was measured and bark cover, moss cover, presence of fungal bodies and presence of insect holes was recorded. Soil moisture was measured near each deadwood piece. All pieces were mapped and photographed.

Small samples of wood and bark were taken from each deadwood piece for deadwood trait measurements. For standing deadwood, the sampling point was 1.3 above the ground and for fallen deadwood the sampling point was determined from a random number generator, as a random proportion of the lenght of the tree, measured from the base of the deadwood. Volumetric samples were take using an increment borer or cylindrical samplign ring (for soft pieces), and small bulk samples were collected with chisel to obtain enough material for chemical analyses.

The deadwood pieces were resampled in 2019, after two years of decay. In addition, the 5-10 cm diameter class pieces were resampled in 2018 after one year decay, as it was not certain how many of the small pieces could be found after two years. The dimensions and other characteristics were measured as in 2017, and new wood samples were take near the initial sampling point.

'Density_Moisture_LabData' worksheet:
The samples were stored in plastic bags and transported to the field laboratory. They were stored in a vrefrigerator and processed within two days. Fresh Volume was estimated either based on geometry (diameter and lenght of the samples collected using increment borer or sampling ring) or on water displacement method. Fresh mass was recorded. Samples were dried at 50°C until constant mass and dry weight was recored. Wood moisture was estimated from the fresh and dry mass and wood density was calculated using the different volume estimates and dry weight.

'WoodChemistry_LabData' worksheet:
After drying, all material from each deadwood piece was pooled for chemical analyses (2017 samples). The chemical analyses were carried out at Forest Research Centre, Sabah Forestry Department, Sepilok, Sabah, Malaysia, led by Dr. Noreen Majalap. The samples were analysed for wood pH, total phosphorus concentration, total nitrogen concentration and total carbon concentration.

Project: This dataset was collected as part of the following SAFE research project: Decomposition of deadwood debris left over from tropical rainforest logging operations

Funding: These data were collected as part of research funded by:

• NERC (Grant, NE/P002218/1)
• Sime Darby Foundation (Grant, SAFE Core data)

This dataset is released under the CC-BY 4.0 licence, requiring that you cite the dataset in any outputs, but has the additional condition that you acknowledge the contribution of these funders in any outputs.

Permits: These data were collected under permit from the following authorities:

• Sabah Biodiversity Council (Research licence JKM/MBS.1000-2/2 JLD.10 (104))

XML metadata: GEMINI compliant metadata for this dataset is available here

Files: This consists of 1 file: SAFE_WoodDecomposition_Data_SAFEdatabase_2021-06-04.xlsx

SAFE_WoodDecomposition_Data_SAFEdatabase_2021-06-04.xlsx

This file contains dataset metadata and 4 data tables:

1. Field measurements of deadwood pieces (described in worksheet DeadwoodPieces_FieldData)

   Description: Field measurements of deadwood pieces

   Number of fields: 28

   Number of data rows: 523

   Fields:

   • Block: SAFE Project Block code (Field type: id)
   • PlotNumber: Plot within Block (Field type: id)
   • Block_Plot: SAFE Project plot name (combination of Block and plot number/code) (Field type: location)
   • SamplingYear: Sampling year. 1st campaign in 2017 (all diameter classes - set up phase), 2nd campaign in 2018 (diameter class 5-10 cm only - resampling), 3rd campaign in 2019 (all diameter classes - resampling). (Field type: numeric)
   • SamplingCampaign: 1st campaign in 2017, 2nd campaign in 2018 (diameter class 5-10 cm only), 3rd campaign in 2019 (all diameter classes). (Field type: ordered categorical)
   • Date: Field data collection date in excel format (dd/mm/yyyy) (Field type: date)
   • RA: Observers (RA=reseach assistant) (Field type: comments)
   • DiameterClass_cm: Diameter class of the deadwood piece, categorised during the first (2017) measurement campaign and not changed in subsequent campaigns (Field type: ordered categorical)
   • Tag: Unique tag number given to deadwood pieces (Field type: id)
   • DecayClass: Decay class of the deadwood piece, assessed separately during each campaign (Field type: ordered categorical)
   • Fallen_Standing: Fallen (F) or Standing (S) deadwood (Field type: categorical)
   • GroundContact: The point where the wood samples were taken was touching the ground (On) or off the ground (Off) (Field type: categorical)
   • DBH1_base: Diameter of the deadwood piece, measured at the base end. Not measured for standing deadwood. (Field type: numeric)
   • DBH2_tip: Diameter of the deadwood piece, measured at the tip end. Not measured for standing deadwood. (Field type: numeric)
   • DBH3_SamplingPoint: Diameter of the deadwood piece, measured at the point where the wood samples were taken (1.3 from the ground for standing deadwood, randomly assigned point for fallen deadwood) (Field type: numeric)
   • Length_Total: Length from the base to the tip of the deadwood piece (Field type: numeric)
   • Length_PaintToPaint: Distance between the base and tip diameter measurement points, which is typically somewhat shorter than the total length of the deadwood piece (Field type: numeric)
   • Length_ToSamplingPoint: Length from the deadwood base to the sampling point (Field type: numeric)
   • Hollowness_Proportion: Proportion of the total diameter that was hollow (Field type: numeric)
   • KnifePenetration: Depth to which a pocket knife could be pushed into the deadwood, maximum was 7.7 cm. (Field type: numeric)
   • BarkCover: Percentage cover of bark (Field type: numeric)
   • BarkLoose: How loose is the bark: _0-no bark; _1-bark not loose; _2-bark slightly loose; _3-bark very loose and peeling (Field type: ordered categorical)
   • MossCover: Percentage cover of moss (not taking into accout the sections of the surface against the ground) (Field type: numeric)
   • Fungi_YN: Fungal bodies present (Y) or not (N) (Field type: categorical)
   • InsectHole_YN: Insect holes present (Y) or not (N) (Field type: categorical)
   • SoilMoisture: Volumetric soil water content in the top 12 cm of soil measured near the deadwood samplign point (Field type: numeric)
   • LivingTreeTag: Tag number used in the living tree census (not found for most of the deadwood pieces). (Field type: id)
   • Notes: Any notes in the field or at data entry stage (Field type: comments)

2. Wood density and wood moisture data (described in worksheet Density_Moisture_LabData)

   Description: Wood density and wood moisture data, measured in the field lab

   Number of fields: 23

   Number of data rows: 2906

   Fields:

   • SamplingYear: Sampling year. 1st campaign in 2017, 2nd campaign in 2018 (diameter class 5-10 cm only), 3rd campaign in 2019 (all diameter classes). (Field type: numeric)
   • SamplingCampaign: 1st campaign in 2017, 2nd campaign in 2018 (diameter class 5-10 cm only), 3rd campaign in 2019 (all diameter classes). (Field type: ordered categorical)
   • SamplingDate: Date when sample collected in the field, in excel format (dd/mm/yyyy). Samples were processed within two days of the collection. (Field type: date)
   • RA_Lab: Names of people processing the samples in the lab (RA = research assistant) (Field type: comments)
   • Block: SAFE Project Block code (Field type: id)
   • Plot: Plot within Block (Field type: id)
   • PlotCode: SAFE Project plot name (combination of Block and plot number/code) (Field type: location)
   • Tag: Unique tag number given to deadwood pieces (Field type: id)
   • Method: Method for collecting wood and bark samples. For most deadwood pieces, several methods were used. Samples with an increment borer ('Core') or cylindrical samplign ring ('SamplingRing') allowed for volumetric samples, while the 'Bulk' method allowed for enough material to be collected for chemical analyses. (Field type: categorical)
   • SampleType: Samples are either Wood or Bark. CombWood samples are pooled wood samples (see the Summary sheet for futher info) (Field type: categorical)
   • SampleReplicate: Replicates of the individually measured and weighed samples within one deadwood piece in each samplign campaign. These are not independent, e.g. one core can result into several independently measured segments, and bulk samples can yield individually measured pieces. All samples were taken within 15 cm of one another. (Field type: replicate)
   • SampleDiameter: Diameter of the samples taken either with an increment borer (5 mm) or a samping ring (50 mm); bulk sample have no diameter (Field type: numeric)
   • SampleLenght_Total: Depth of the coring hole, if sample taken with an increment borer, measured in the field (the resulting sample is often broken into several pieces, which are measured separately), or the depth into which the sampling ring was inserted (Field type: numeric)
   • SampleLenght_Segment: Length of the individual segments of the samples taken with an increment borer. Measured in the lab from fresh samples. (Field type: numeric)
   • BarkThickness: Thickeness of the bark. Measured fresh. 2019 samples only. (Field type: numeric)
   • FreshMass: Fresh mass of the deadwood piece. (Field type: numeric)
   • WaterDisplacementWeight: Volume estimate using a water displacement technique (Field type: numeric)
   • DryMass: Mass after drying at 50°C until constant mass (Field type: numeric)
   • MoistureContent: Gravimetric wood moisture content (Field type: numeric)
   • Notes: Notes at the lab or during data entry (Field type: comments)
   • Density_Geometry_TotalSample: Density based on the total core or samplign ring volume, calculated using diameter and length (Field type: numeric)
   • Density_Geometry_CoreSegment: Density based on volume of the core segment, calculated using diameter and length. (Field type: numeric)
   • Density_WaterDisplacement: Density based on the volume estimated with the water displacement method (Field type: numeric)

3. Wood chemical traits (described in worksheet WoodChemistry_LabData)

   Description: Wood chemical traits (pH, Phosphorus, Carbon, Nitrogen) measured at Forest Research Centre, Sabah Forestry Department

   Number of fields: 10

   Number of data rows: 228

   Fields:

   • SamplingYear: Sampling year (2017) (Field type: numeric)
   • SamplingCampaign: 1st campaign in 2017, 2nd campaign in 2018 (diameter class 5-10 cm only), 3rd campaign in 2019 (all diameter classes). (Field type: ordered categorical)
   • Block: SAFE Project Block code (Field type: id)
   • Plot: Plot within Block (Field type: id)
   • PlotCode: SAFE Project plot name (combination of Block and plot number/code) (Field type: location)
   • Tag: Unique tag number given to deadwood pieces (Field type: id)
   • pH: Wood pH in water (Field type: numeric)
   • P_total: Total Phosphorus concentration (Field type: numeric)
   • N_total: Total Nitrogen concentration (Field type: numeric)
   • C_total: Total Carbon concentration (Field type: numeric)

4. Plot information (described in worksheet PlotInfo)

   Description: List of plots, their forest type and basal area

   Number of fields: 7

   Number of data rows: 20

   Fields:

   • ForestType: Plots divided into Logged and Old-growth. There is a gradient, the logging intensity varies across the logged plots and some of the old-growth plots have experienced light loggign in the past (Field type: categorical)
   • Site: Sites located in or near the SAFE Project area, or within Maliau Basin (Field type: id)
   • Block: SAFE Project Block code (Field type: id)
   • Plot: Plot within Block (Field type: id)
   • PlotCode: SAFE Project plot name (combination of Block and plot number/code) (Field type: location)
   • BasalArea_PerPlot: Basal area of stems >10 cm diameter, based on tree census (Field type: numeric)
   • BasalArea_PerHectare: Basal area of stems >10 cm diameter, based on tree census, converted to a per hectare value (Field type: numeric)

Date range: 2017-01-01 to 2021-06-30

Latitudinal extent: 4.5000 to 5.0700

Longitudinal extent: 116.7500 to 117.8200