Supplementary Materials
Fine root biomass mediates soil fauna community in response to nitrogen addition in poplar plantations (Populus deltoids) on the east coast of China
Haixue Bian1, 2, Qinghong Geng1, 2, Hanran Xiao1, 2, Caiqin Shen3, Qian Li4, Xiaoli Cheng5, Yiqi Luo6, Honghua Ruan1, 2*, Xia Xu1, 2*
1 College of Biology and the Environment, Nanjing Forestry University, Nanjing, Jiangsu 210037, China；[email protected] (H.B.)； [email protected] (Q.G.)； [email protected] (H.X.)； [email protected] (H.R.)； [email protected] (X.X.) 2 Co-Innovation Centre for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China 3 Dongtai Forest Farm, Yancheng, Jiangsu 224200, China；[email protected] 4 Advanced Analysis and Testing Center, Nanjing Forestry University, Nanjing, Jiangsu 210037, China； [email protected] 5 Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, Hubei, 430074, China；[email protected] 6 Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona 86011, USA；[email protected]
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Table S1. Results of two-way ANOVA for the responses of each individual soil fauna’s proportion over total soil fauna to nitrogen (N) addition (0, 50, 100, 150, and
300 kg N ha-1 year-1) and soil depth (0 - 10, 10 - 25, and 25 - 40 cm). P levels are indicated beside the F values by the following: *<0.05, **: <0.01, ***: <0.001, and no asterisks indicate P> 0.05.
N addition (N) Soil depth (D) N×D df F, P df F, P df F, P Oligochaeta 4 1.00 2 1.00 8 1.00 Nematoda 4 1.62 2 4.64* 8 0.91 Isopoda 4 1.00 2 1.00 8 1.00 Symphyla 4 1.20 2 0.36 8 2.27 Araneae 4 1.00 2 1.00 8 1.00 Oribatida 4 1.76 2 5.35* 8 0.63 Prostigmata 4 2.44 2 16.76*** 8 1.00 Collembola 4 3.49* 2 6.24** 8 1.02 Diplura 4 0.21 2 1.84 8 1.55 Coleoptera 4 2.04 2 2.49 8 1.58 Coleoptera Larvae 4 0.72 2 2.59 8 1.19 Diptera larvae 4 2.66 2 8.61** 8 2.06 Hymenoptera 4 0.50 2 1.11 8 0.97 Macrofauna 4 0.65 2 6.43** 8 1.91 Mesofauna 4 2.09 2 6.60** 8 0.41 Microfauna 4 1.62 2 4.64* 8 0.91
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Figure legends
30 a
C) 25 o 20 15 N0 N1 10 N2 5 N3 Soil temperature ( N4 0 40
30
20 Soil moisture (%) b 10 Jul Apr Oct Jan Jun Feb Mar Nov Aug Sep Dec May
Figure S1 Variations in soil temperature (a) and moisture (b) from January to
December along the nitrogen (N) addition gradient in 2016. N0, N1, N2, N3, N4
-1 -1 -1 -1 indicate different N additions (N0: 0 kg N ha year ; N1: 50 kg N ha year ; N2: 100
-1 -1 -1 -1 -1 -1 kg N ha year ; N3: 150 kg N ha year ; N4: 300 kg N ha year ).
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1500 live root a 1200
900
600
300
250 dead root b 200 150 100 50 0
total root c 1250 1000 750 500 250 0 N0 N1 N2 N3 N4
Figure S2 The live (a), dead (b), and total (c) fine root biomass along the N addition gradient and the soil profile (red for 0 - 10 cm, green for 10 - 25 cm, and blue for 25 -
40 cm). See Figure S1 for abbreviations.
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5.6 a
5.2
4.8
4.4 2D Graph 2 4.0 )
-3 3.6 5.6 b 2
(ind m live root, r =0.33*** p 5.2 2 D dead root, r =0.20** 2 4.8 total root, r =0.40***
4.4
4.0
3.6 0123
Fine root biomass (g m-3)
Figure S3 Regulation of fine root biomass (a: live and dead root biomass; b: total root biomass) on the density of phytophagous soil fauna (Dp), without the very small
points (circled in the panels). **: P < 0.01，***: P < 0.001.
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5.6 a
5.2
4.8
4.4 2D Graph 2
4.0 ) -3 3.6 5.6 b 2 (ind m (ind live root, r =0.32*** 2 total 5.2 dead root, r =0.21** D total root, r2=0.39*** 4.8
4.4
4.0
3.6 0123
Fine root biomass (g m-3)
Figure S4 Regulation of fine root biomass (a: live and dead root biomass; b: total root biomass) on the density of total soil fauna (Dtotal), without the very small points
(circled in the panels). **: P < 0.01，***: P < 0.001.
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120 a 0-10 cm Oligochaeta 100 Nematoda Isopoda Symphyla 80 Araneae Oribatida 60 Prostigmata Collembola 40 Diplura coleoptera Coleoptera Larvae 20 Diptera larvae Hymenoptera 0 b 10-25 cm 100
80
60
40
20
Percent of each soil fauna (%) fauna soil each of Percent 0 c 25-40 cm 100
80
60
40
20
0 N0 N1 N2 N3 N4
Figure S5 The proportion of each individual soil fauna over total soil fauna along the nitrogen (N) addition gradient and the soil profile. See Figure S1 for abbreviations.
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120 Macrofauna Mesofauna Microfauna a 0-10 cm 100
80
60
40
20
0 b 10-25 cm 100
80
60
40
20 Percent of the soil fauna (%) 0 c 25-40 cm 100
80
60
40
20
0 N0 N1 N2 N3 N4
Figure S6 The proportions of macrofauna, mesofauna, and microfauna over total soil fauna along the nitrogen (N) addition gradient and the soil profile. See Figure S1 for abbreviations.
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