Supporting Information for Plant and Soil

Supporting Information for Plant and Soil

Article title:Soil aggregate stability in Mediterranean and tropical agro-ecosystems: effect of plant roots and soil characteristics

Authors: Yves Le Bissonnais, Ivan Prieto, Catherine Roumet, Jérôme Nespoulous, James Metayer, Sylvain Huon, Mario Villatoro, Alexia Stokes.

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Table S1. Description of land use types at the different sites and climates where roots were collected. Mean annualtemperature (MAT) and mean annual precipitation (MAP) are shown for each site.Land use abbreviations are as follows: CA, monocultures (one species); TA, trees alone (one species); TC, agroforestry systems (2 species); FA, fallow, regeneration after cultivation (multiple species); TV, trees with natural vegetation (multiple species, mostly herbs); FO, secondary forest and associated understory (multiple species, mostly trees and woody plants). The abundance of herbs (Herbs) and trees (Trees) is given as a percentage foliar cover. Age to last disturbance (Dist) is the time (in years) to the last disturbance (ploughing).

Climate / Site / MAT (ºC) - MAP (mm) / Land use type / Dominant species / Herbs
(% cover) / Trees
(% cover) / Dist
(years)
Tropical / Aquiares
(AQ) / 20.8 - 3014 / CA / CoffeaarabicaL. / 33 / 56 / 40
TC / C. arabicaL.
ErythrinapoeppigianaWalp. / 25 / 63 / 40
FO / Lozania sp.
SynechanthuswarscewiczianusH. Wendi
Pentagonia sp.
/ 26 / 66 / 100
Llano Bonito (LB) / 21-2500 / CA / C. arabicaL. / 25 / 50 / 40
TC / C.arabicaL.
E. poeppigianaWalp. / 33 / 50 / 40
FO / Quercus sp. L.
Clusia sp. L.
DrimysgranadensisL.F.
/ 12 / 80 / 100
HouayPano (HP) / 25.7 - 1300 / CA / OryzasativaL. / 100 / 0 / 1
TA / TectonagrandisL. / 100 / 0 / 15
TC / O. sativa L.
TectonagrandisL. / 80 / 20 / 1
TV / T. grandis / 20 / 80 / 15
FA / ChromolaenaodorataL.
CratoxylumformosumBenth. & Hook.
Calleryaatropurpurea Wall.
Saccharumspontaneum L. / 20 / 0 / 2
Mediterranean / Restinclières (RE) / 14.5 - 950 / CA / Triticumturgidum L. subsp. durum / 100 / 0 / 1
TC / T. turgidum L. subsp. durum
JuglansregiaL. / 50 / 50 / 1
TV / J. regia L.
Vicia luteaL.
Medicago sp. / 49 / 50 / 5
FO / Pinus sylvestrisL.
Quercus ilex L. / 18 / 70 / 20

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Table S2.Soil variable values in shallow and deep soil layers at the four different study sites (values are Mean ± SE, n=3-5). Model fitted was a general linear model with site and depth within site as fixed factors. A covariable matrix was used to account for non-independence between samples from the same trench and depth.Soil variables are defined as follows: Clay, Sand and Silt, percentage of clay, sand and silt, respectively; SOC, soil organic carbon; soil N, soil nitrogen; soil C:N, soil carbon to nitrogen ratio; soil P, soil phosphorus; CEC, cation exchange capacity; pH, soil pH; Fe CBD, citrate-bicarbonate-dithionite extracted Iron; Al CBD, citrate-bicarbonate-dithionite extracted aluminum. Shown are F-values with significance (***P<0.001, **P<0.01, *P<0.05) for site and soil depth effects. Degrees of freedom were 3,20 and 4,20 for site and depth(site) effects, respectively. †Statistical tests could not be run forthese soil variables since they were measured only in one trench per site.

Site / Soil depth (cm) / Clay
(g kg-1) / Silt
(g kg-1) / Sand
(g kg-1) / SOC
(g kg-1) / Soil N
(g kg-1) / Soil C:N / Soil P
(mg kg-1) / CEC
(meq 100 g-1) / pH / Fe CBD†
(g kg-1) / Al CBD†
(g kg-1)
Restinclières (RE) / Shallow / 178.5 ± 13.0 / 441.5 ± 33.0 / 337.5 ± 37.1 / 29.73 ± 3.64 / 2.77 ± 0.41 / 10.86 ± 0.51 / 10.2 ± 1.4 / 8.28 ± 0.95 / 8.0 ± 0.1 / 9.7 / 1.1
Deep / 266.0 ± 13.9 / 567.8 ± 15.6 / 144.8 ± 32.2 / 18.83 ± 5.38 / 2.23 ± 0.70 / 9.23 ± 0.23 / 3.0 ± 0.4 / 10.03 ± 1.17 / 8.2 ± 0.0 / 11.3 / 1.6
Llano Bonito (LB) / Shallow / 583.0 ± 36.7 / 287.3 ± 38.3 / 45.7 ± 8.5 / 49.96 ± 2.59 / 2.70 ± 0.42 / 19.66 ± 3.97 / 23.0 ± 8.1 / 18.20 ± 0.70 / 4.3 ± 0.1 / 52.3 / 12.6
Deep / 565.3 ± 27.7 / 348.0 ± 40.2 / 40.7 ± 20.8 / 3.46 ± 0.84 / 0.30 ± 0.06 / 11.28 ± 0.81 / 1.0 ± 0.0 / 15.23 ± 2.01 / 4.3 ± 0.0 / 41.4 / 8.0
HouayPano (HP) / Shallow / 460.2 ± 39.1 / 341.4 ± 32.4 / 169.2 ± 16.8 / 21.28 ± 1.50 / 1.66 ± 0.08 / 12.79 ± 0.49 / 3.0 ± 0.3 / 15.80 ± 1.04 / 5.5 ± 0.1 / - / -
Deep / 697.0 ± 16.3 / 163.5 ± 13.5 / 96.8 ± 14.6 / 6.15 ± 0.25 / 0.65 ± 0.03 / 9.55 ± 0.75 / 1.4 ± 0.2 / 22.46 ± 2.45 / 4.7 ± 0.1 / - / -
Aquiares (AQ) / Shallow / 158.7 ± 70.6 / 370.3 ± 70.8 / 314.7 ± 21.0 / 67.08 ± 6.84 / 5.40 ± 0.32 / 12.43 ± 1.13 / 37.0 ± 16.3 / 36.80 ± 2.69 / 5.1 ± 0.4 / 28.9 / 31.8
Deep / 184.0 ± 50.3 / 349.7 ± 38.7 / 355.7 ± 11.2 / 28.27 ± 8.21 / 1.56 ± 0.28 / 17.24 ± 2.83 / 8.0 ± 3.1 / 27.93 ± 2.79 / 5.4 ± 0.3 / 30.3 / 32.1
Site / 88.2*** / 25.67*** / 46.18*** / 14.08*** / 13.01*** / 5.53** / 4.11* / 40.83*** / 233.12*** / - / -
Depth(Site) / 10.80*** / 7.94*** / 10.24*** / 22.35*** / 18.54*** / 4.42* / 5.09** / 3.80* / 5.28** / - / -

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Table S3.Root trait values in shallow and deep soil layers at the four different study sites (values are Mean ± SE, n=3-5). Model fitted was a general linear model with site and depth within site as fixed factors. A covariable matrix was used to account for non-independence between samples from the same trench and depth.Root traits are defined as follows: RLD, root length density; RMD, root mass density; Dm, root diameter; RDMC, root dry matter content; SRL, specific root length; VFRL, proportion of very fine root length; MRL, proportion of medium root length; FRL, proportion of fine root length; root N, root nitrogen concentration; root C, root carbon concentration; C:N, root carbon to nitrogen ratio; Soluble, root water-soluble compounds concentration; Cellulose, root cellulose concentration; Hemicellulose, root hemicellulose concentration; Lignin, root lignin concentration. Shown are F-values with significance (***P<0.001, **P<0.01, *P<0.05) for site and soil depth effects, df=3, 20 and df=4, 20 for site and depth(site) effects, respectively.

Site / Soil depth / RLD
(cm cm-3) / RMD
(mg cm-3) / Dm
(mm) / RDMC
(mg g-1) / SRL
(%) / VFRL
(%) / MRL
(%) / FRL
(%) / N
(mg g-1) / C
(mg g-1) / C:N / Soluble
(mg g-1) / Cellulose
(mg g-1) / Hemicellulose
(mg g-1) / Lignin
(mg g-1)
Restinclières (RE) / Shallow / 0.98
± 0.61 / 20.46
± 5.04 / 0.52
± 0.04 / 251.8
± 46.8 / 24.74
± 8.93 / 20.59
± 1.71 / 4.11
± 0.56 / 75.31
± 1.53 / 12.12
± 2.75 / 376.3
± 25.2 / 37.79
± 11.25 / 359.5
± 36.6 / 265.7
± 12.1 / 215.5
± 0.03 / 112.9
± 31.6
Deep / 0.17
± 0.10 / 3.63
± 1.89 / 0.59
± 0.05 / 234.9
± 36.7 / 15.47
± 4.23 / 14.67
± 3.56 / 4.95
± 1.04 / 80.38
± 3.72 / 7.08
± 2.43 / 409.2
± 4.3 / 50.58
± 20.14 / 422.1
± 34.8 / 234.6
± 28.2 / 202.4
± 10.8 / 131.6
± 35.1
Llano Bonito (LB) / Shallow / 1.96
± 0.41 / 19.38
± 1.92 / 0.70
± 0.03 / 260.1
± 43.5 / 9.14
± 2.32 / 9.01
± 0.13 / 11.46
± 1.79 / 81.60
± 0.71 / 15.04
± 4.20 / 484.4
± 1.7 / 41.14
± 15.73 / 269.2
± 13.4 / 258.6
± 8.0 / 229.0
± 16.71 / 264.0
± 23.6
Deep / 0.24
± 0.00 / 3.14
± 0.82 / 0.84
± 0.06 / 273.7
± 56.9 / 10.43
± 4.75 / 8.85
± 1.76 / 9.84
± 1.77 / 81.31
± 1.06 / 11.23
± 1.93 / 494.2
± 5.9 / 47.4
± 9.09 / 238.5
± 2.4 / 288.6
± 3.5 / 252.0
± 32.05 / 283.1
± 9.2
HouayPano (HP) / Shallow / 0.77
± 0.15 / 16.85
± 3.69 / 0.68
± 0.22 / 237.2
± 14.8 / 31.55
± 12.45 / 17.85
± 5.24 / 8.08
± 2.34 / 74.07
± 3.80 / 9.03
± 1.24 / 435.4
± 8.4 / 52.42
± 7.47 / 199.8
± 12.0 / 328.98
± 13.7 / 189.8
± 3.7 / 219.2
± 34.2
Deep / 0.07
± 0.02 / 2.00
± 0.43 / 0.65
± 0.27 / 283.7
± 48.2 / 41.48
± 21.36 / 14.93
± 4.48 / 7.65
± 1.55 / 77.43
± 3.65 / 7.48
± 0.60 / 431.3
± 6.7 / 59.72
± 5.52 / 244.2
± 20.1 / 323.7
± 7.5 / 208.1
± 8.1 / 203.1
± 23.3
Aquiares (AQ) / Shallow / 0.93
± 0.34 / 11.42
± 3.13 / 0.89
± 0.12 / 274.5
± 38.2 / 6.04
± 1.67 / 9.80
± 2.61 / 14.12
± 3.1 / 78.72
± 1.12 / 15.87
± 0.71 / 479.6
± 15.6 / 30.42
± 0.50 / 269.0
± 3.3 / 269.7
± 6.9 / 211.7
± 42.31 / 258.9
± 6.1
Deep / 0.37
± 0.05 / 3.63
± 1.25 / 0.83
± 0.03 / 249.9
± 35.1 / 8.16
± 2.50 / 6.26
± 0.47 / 17.66
± 2.67 / 61.96
± 13.88 / 13.74
± 0.13 / 508.8
± 30.8 / 37.22
± 2.02 / 252.1
± 21.1 / 263.2
± 11.4 / 261.9
± 30.72 / 269.1
± 9.7
Site / 1.65 / 0.97 / 1.23 / 0.14 / 2.51 / 3.05+ / 8.67*** / 1.79 / 3.40* / 21.43*** / 1.08 / 20.98*** / 11.18*** / 0.98 / 9.87***
Depth(Site) / 5.35** / 10.60*** / 0.14 / 0.33 / 0.20 / 0.67 / 0.41 / 1.07 / 1.25 / 1.43 / 0.28 / 1.68 / 1.002 / 0.59 / 0.16

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