Last modified: August 24th 2017

Data and code, along with this ReadMe file (BradfordVeenLitDecompREADME.txt), were submitted to the Dryad data repository August 24th 2017 following acceptance of the following manuscript by the journal Nature Ecology and Evolution.

ÔBradford MA, Veen, G.F.C., Bonis, A., Bradford, E.M., Classen, A.T., Cornelissen, J.H.C., Crowther, T.W., De Long, J.R., Freschet, G.T., Kardol, P., Manrubia-Freixa, M., Maynard, D.S., Newman, G.S., van Logtestijn, R.S.P., Viketoft, M., Wardle, D.A., Wieder, W.R., Wood, S.A., van der Putten, W.H. Testing the hierarchical model of litter decomposition. Nature Ecology and Evolution, in press.Õ

The persons associated with the code and data have dedicated the work to the public domain by waiving all of their rights to the code and data worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, distribute and use the code and data, even for commercial purposes, all without asking permission.

If you have queries about the data or code please contact Mark A. Bradford at Yale University, USA (mark.bradford@yale.edu).

The code file is named ÔBradfordVeenLitDecompCODE.txtÕ and contains all R (the statistical freeware package) code used for data analysis in the accepted manuscript. Analytical steps are explained ahead of each section of code within the code file. 

The data file is named ÔBradfordVeenLitDecompDATA.csvÕ. A full description of the original purpose of these data, as well as the methods used to collect them, are described in the accepted manuscript listed above.

Data in the BradfordVeenLitDecompDATA.txt file are organized across 52 columns, and 336 rows of data, with a single header row with the column title.
Header row names, units and description are as follows:

Column #. Variable (Column header). Unit. Explanation

1. Site. City. Umea (Sweden), Uppsala(Sweden), Copenhag (Copenhagen, Denmark), Rennes (France), Montpell (Montpellier, France), Wagenin (Wageningen, Netherlands)
2. Site2. Numeric. Sites in number order from N to S to aid with plotting data by site
3. Transect. Number. Each of the six Sites has four transects along which the quadrats are arrayed, and the transects are numbered 1 to 28 (i.e. 6 Sites * 4 transects)
4. Quadrat. Number. Each site has 7 quadrats per transect, giving 168 quadrats total (6 Sites * 4 Transects * 7 Quadrats)
5. Litbag. Number. Unique litterbag number
6. Lit. unitless. Litter type: Holcus (Hol) lanatus or Festuca (Fes) rubra
7. LitNum. Number. Binary variable (1,0) to identify the higher quality litter as 1
8. Teabag. Number. Unique litterbag number
9. Tea. unitless. Tea type: Green or Red
10. TeaNum. Number. Binary variable (1,0) to identify the higher quality litter as 1
11. Julday1. JulianDay. Julian Day measuring period 1
12. Julday2. JulianDay. Julian Day measuring period 2
13. Julday3. JulianDay. Julian Day measuring period 3
14. Temp1. oC. Soil temperature (5 cm depth) measuring period 1 (measured using a frozen food thermometer
15. Temp2. oC. Soil temperature (5 cm depth) measuring period 2 (measured using a frozen food thermometer
16. Temp3. oC. Soil temperature (5 cm depth) measuring period 3 (measured using a frozen food thermometer
17. Moist1. %. Gravimetric soil moisture for measuring period 1 expressed on a dry mass basis (water mass/dry soil mass). Scale is 0 to infinity
18. Moist2. %. Gravimetric soil moisture for measuring period 2 expressed on a dry mass basis (water mass/dry soil mass). Scale is 0 to infinity
19. Moist3. %. Gravimetric soil moisture for measuring period 3 expressed on a dry mass basis (water mass/dry soil mass). Scale is 0 to infinity
20. VolMoist1. %. Volumetric moisture for measuring period 1 using a handheld TDR probe (Campbell with 12-cm rods, inserted diagonally to capture surface soil). Means of three spot measurse per quadrat
21. VolMoist2. %. Volumetric moisture for measuring period 2 using a handheld TDR probe (Campbell with 12-cm rods, inserted diagonally to capture surface soil). Means of three spot measurse per quadrat
22. VolMoist3. %. Volumetric moisture for measuring period 3 using a handheld TDR probe (Campbell with 12-cm rods, inserted diagonally to capture surface soil). Means of three spot measurse per quadrat
23. SOM. %. Soil Organic Matter content estimated via LOI (Loss on ignition)
24. percNsoil. %. percentage total soil N measured by elemental combustion
25. percCsoil. %. percentage total soil C measured by elemental combustion. Note that for the Montpellier soils the high values could be an artefact of inorganic C as the have basic pH
26. NOxinit. mg/kg. Initial soil NO3 + NO2 extracted at time zero (before lab incubation) - 2 July 2015. 10 g dw soil, 50 mL KCL
27. NH4init. mg/kg. Initial soil NH4 content at time zero (before lab incubation) - 2 July 2015. 10 g dw soil, 50 mL KCL
28. Nitrif. mg/kg/d. potential net nitrification rate (14 d incubation, 65% WHC, 20oC; followed by KCL extractions). Based on NO3 produced or consumed from initial
29. Nmin. mg/kg/d. potential net N mineralization rate (14 d incubation, 65% WHC, 20oC; followed by KCL extractions). Based on NH4 produced or consumed from initial
30. WHC. %. 100% water holding capacity expressed as gravimetric moisture on a dry mass basis
31. pH. unitless. pH in water 1:1 with soil
32. TpH. H+ ion concentration. back-transformed pH data using (10^((-pH)))*1000000
33. Cmin1. ug C-CO2 g soil-1 h-1. 24 h mineralization assay at 65% WHC (1 of 2)
34. Cmin2. ug C-CO2 g soil-1 h-1. 24 h mineralization assay at 65% WHC (2 of 2)
35. Cmin. ug C-CO2 g soil-1 h-1	mean of the two Cmin measures
36. SIR. ug C-CO2 g soil-1 h-1. 4 h yeast estimate of SIR microbial biomass
37. LitSIR. ug C-CO2 g litter-1 h-1. 4 h yeast estimate of SIR microbial biomass on the decomposed litter
38. IncTime. days. Days in the field (Julian Day 3 minus Julian Day 1)
39. TeaLoss. %. percentage mass loss during the field incubation
40. LitLoss. %. percentage mass loss during the field incubation
41. STeaLoss. %. percentage mass loss during the field incubation standardized to 90 days
42. SLitLoss. %. percentage mass loss during the field incubation standardized to 90 days
43. LitMoist. %. percentage moisture (water mass divided by total fresh mass) of the harvested leaf litter. Note that any soil ingress will influence these values, unless you assume that per mass soil holds as much moisture as the litter
44. mLitMoist. %. average of LitMoist for Holcus and Festuca litter per quadrat
45. LitCloss. %. percentage C loss during the field incubation
46. SLitCloss. %. percentage C loss during the field incubation stadardized to 90 days
47. LitNmin. fraction. gain (>1) or loss (<1) of N during the field incubation
48. SLitNmin. fraction. gain (>1) or loss (<1) of N during the field incubation standardized to 90 days
49. LitInitCN. ratio (unitless). mean initial C:N ratio of the holcus litter
50. LitFinCN. ratio (unitless). final C:N ratio of the festuca litter
51. LitinitN. %. Initial N content (%) of the litter. Random values pulled from the range of initial measures
52. TeainitN. %. Initial N content (%) of the tea. Random values pulled from the range of initial measures
		note: missing observations = NA

We use ÔNAÕ for missing data.

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