Electronic Supplementary Material 1 s1

Electronic Supplementary Material 1

Title: Contributions of soil properties to elevational diversity gradients of forest understory vegetation

PLANT ECOLOGY

Shigyo, N., Umeki, K., Ohashi, H., Kawada, K. and Hirao, T.

N. Shigyo (Corresponding author)

The University of Tokyo Chichibu Forest, Graduate School of Agricultural and Life

Sciences, The University of Tokyo, 1-1-49 Hinoda-machi, Chichibu, Saitama 368-0034

E-mail: [email protected]

1 Table S1 List of plant species and their functional group classifications.

ID Family Species Functional groups Actinidia arguta (Siebold et Zucc.) 1 Actinidiaceae Tree seedlings Planch. ex Miq. Actinidia kolomikta (Maxim. et 2 Actinidiaceae Tree seedlings Rupr.) Maxim. Actinidia polygama (Siebold et 3 Actinidiaceae Tree seedlings Zucc.) Planch. ex Maxim. 4 Adoxaceae Sambucus racemosa L. Tree seedlings 5 Adoxaceae Viburnum dilatatum Thunb. Tree seedlings 6 Anacardiaceae Rhus javanica L. Tree seedlings 7 Araliaceae Aralia elata (Miq.) Seem. Tree seedlings Chengiopanax sciadophylloides 8 Araliaceae (Franch. et Sav.) C.B.Shang et Tree seedlings J.Y.Huang Kalopanax septemlobus (Thunb.) 9 Araliaceae Tree seedlings Koidz. Maianthemum dilatatum 10 Asparagaceae Herbs (Alph.Wood) A.Nelson et J.F.Macbr. Maianthemum japonicum (A.Gray) 11 Asparagaceae Herbs LaFrankie Asteraceae/Comp 12 Ainsliaea acerifolia Sch.Bip. Herbs ositae Asteraceae/Comp 13 Nabalus acerifolius Maxim. Herbs ositae Asteraceae/Comp Parasenecio adenostyloides (Franch. 14 Herbs ositae et Sav. ex Maxim.) H.Koyama Athyrium vidalii (Franch. et Sav.) 15 Athyriaceae Ferns Nakai Athyrium yokoscense (Franch. et 16 Athyriaceae Ferns Sav.) H.Christ 17 Betulaceae Betula corylifolia Regel et Maxim. Tree seedlings 18 Betulaceae Betula ermanii Cham. Tree seedlings 19 Betulaceae Betula grossa Siebold et Zucc. Tree seedlings 20 Betulaceae Betula maximowicziana Regel Tree seedlings 21 Betulaceae Carpinus cordata Blume Tree seedlings Carpinus laxiflora (Siebold et Zucc.) 22 Betulaceae Tree seedlings Blume 23 Betulaceae Carpinus tschonoskii Maxim. Tree seedlings 24 Betulaceae Ostrya japonica Sarg. Tree seedlings

2 Blechnum niponicum (Kunze) 25 Blechnaceae Ferns Makino Adenophora remotiflora (Siebold et 26 Campanulaceae Herbs Zucc.) Miq. Peracarpa carnosa (Wall.) Hook.f. et 27 Campanulaceae Herbs Thomson 28 Caprifoliaceae Abelia spathulata Siebold et Zucc. Tree seedlings 29 Caprifoliaceae Weigela decora (Nakai) Nakai Tree seedlings 30 Celastraceae Celastrus orbiculatus Thunb. Tree seedlings Euonymus fortunei (Turcz.) Hand.- 31 Celastraceae Tree seedlings Mazz. 32 Celastraceae Euonymus oxyphyllus Miq. Tree seedlings Chloranthus serratus (Thunb.) Roem. 33 Chloranthaceae Herbs et Schult. 34 Clethraceae Clethra barbinervis Siebold et Zucc. Tree seedlings 35 Colchicaceae Disporum smilacinum A.Gray Herbs 36 Cornaceae Cornus controversa Hemsl. Tree seedlings 37 Cornaceae Cornus kousa Buerger ex Hance Tree seedlings 38 Cornaceae Cornus macrophylla Wall. Tree seedlings 39 Cyperaceae Carex leucochlora Bunge Herbs 40 Cyperaceae Carex reinii Franch. et Sav. Herbs 41 Cyperaceae Carex siderosticta Hance Herbs Arachniodes mutica (Franch. et Sav.) 42 Dryopteridaceae Ferns Ohwi Dryopteris expansa (C.Presl) Fraser- 43 Dryopteridaceae Ferns Jenk. et Jermy Dryopteris sabae (Franch. et Sav.) 44 Dryopteridaceae Ferns C.Chr. Enkianthus campanulatus (Miq.) 45 Ericaceae Tree seedlings G.Nicholson Pieris japonica (Thunb.) D.Don ex 46 Ericaceae Tree seedlings G.Don Rhododendron pentandrum (Maxim.) 47 Ericaceae Tree seedlings Craven 48 Fagaceae Castanea crenata Siebold et Zucc. Tree seedlings 49 Fagaceae Fagus crenata Blume Tree seedlings 50 Fagaceae Fagus japonica Maxim. Tree seedlings 51 Fagaceae Quercus crispula Blume Tree seedlings 52 Gentianaceae Gentiana zollingeri Fawc. Herbs

3 Hydrangea hirta (Thunb.) Siebold et 53 Hydrangeaceae Tree seedlings Zucc. 54 Hydrangeaceae Hydrangea paniculata Siebold Tree seedlings Hydrangea petiolaris Siebold et 55 Hydrangeaceae Tree seedlings Zucc. Schizophragma hydrangeoides 56 Hydrangeaceae Tree seedlings Siebold et Zucc. 57 Juglandaceae Pterocarya rhoifolia Siebold et Zucc. Tree seedlings 58 Juncaceae Juncus tenuis Willd. Herbs Lamiaceae/Labiat 59 Clerodendrum trichotomum Thunb. Tree seedlings ae 60 Lauraceae Lindera umbellata Thunb. Tree seedlings Streptopus streptopoides (Ledeb.) 61 Liliaceae Herbs Frye et Rigg 62 Liliaceae Tricyrtis affinis Makino Herbs 63 Magnoliaceae Magnolia obovata Thunb. Tree seedlings 64 Malvaceae Tilia japonica (Miq.) Simonk. Tree seedlings 65 Oleaceae Fraxinus apertisquamifera H.Hara Tree seedlings 66 Oleaceae Fraxinus lanuginosa Koidz. Tree seedlings 67 Oxalidaceae Oxalis acetosella L. Herbs Pteridophyllum racemosum Siebold 68 Papaveraceae Herbs et Zucc. 69 Pinaceae Abies firma Siebold et Zucc. Tree seedlings 70 Pinaceae Abies homolepis Siebold et Zucc. Tree seedlings 71 Pinaceae Tsuga diversifolia (Maxim.) Mast. Tree seedlings 72 Pinaceae Tsuga sieboldii Carrière Tree seedlings Poaceae/Gramine Calamagrostis hakonensis Franch. et 73 Herbs ae Sav. Poaceae/Gramine 74 Sasa borealis (Hack.) Makino Tree seedlings ae Poaceae/Gramine 75 Sasa hayatae Makino Tree seedlings ae 76 Ranunculaceae Clematis japonica Thunb. Herbs 77 Ranunculaceae Coptis japonica (Thunb.) Makino Herbs 78 Ranunculaceae Coptis quinquefolia Miq. Herbs 79 Rosaceae Neillia incisa (Thunb.) S.H.Oh Tree seedlings 80 Rosaceae Potentilla rosulifera H.Lév. Herbs 81 Rosaceae Prunus grayana Maxim. Tree seedlings

4 82 Rosaceae Prunus sargentii Rehder Tree seedlings 83 Rosaceae Prunus sp. Tree seedlings 84 Rosaceae Rubus crataegifolius Bunge Tree seedlings 85 Rosaceae Rubus phoenicolasius Maxim. Tree seedlings Rubus subcrataegifolius (H.Lév. et 86 Rosaceae Tree seedlings Vaniot) H.Lév. 87 Rosaceae Sorbus commixta Hedl. Tree seedlings 88 Rutaceae Phellodendron amurense Rupr. Tree seedlings 89 Rutaceae Zanthoxylum piperitum (L.) DC. Tree seedlings 90 Sabiaceae Meliosma myriantha Siebold et Zucc. Tree seedlings Acer australe (Momot.) Ohwi et 91 Sapindaceae Tree seedlings Momot. 92 Sapindaceae Acer diabolicum Blume ex K.Koch Tree seedlings 93 Sapindaceae Acer japonicum Thunb. Tree seedlings 94 Sapindaceae Acer micranthum Siebold et Zucc. Tree seedlings 95 Sapindaceae Acer palmatum Thunb. Tree seedlings 96 Sapindaceae Acer pictum Thunb. Tree seedlings 97 Sapindaceae Acer rufinerve Siebold et Zucc. Tree seedlings 98 Sapindaceae Acer shirasawanum Koidz. Tree seedlings 99 Sapindaceae Acer sieboldianum Miq. Tree seedlings 100 Sapindaceae Acer tenuifolium (Koidz.) Koidz. Tree seedlings Acer ukurunduense Trautv. et 101 Sapindaceae Tree seedlings C.A.Mey. Schisandra repanda (Siebold et 102 Schisandraceae Tree seedlings Zucc.) Radlk. 103 Stachyuraceae Stachyurus praecox Siebold et Zucc. Tree seedlings 104 Styracaceae Styrax obassia Siebold et Zucc. Tree seedlings 105 Theaceae Stewartia pseudocamellia Maxim. Tree seedlings Thelypteris phegopteris (L.) Sloss. ex 106 Thelypteridaceae Ferns Rydb. 107 Ulmaceae Zelkova serrata (Thunb.) Makino Tree seedlings 108 Urticaceae Boehmeria gracilis C.H.Wright Herbs 109 Urticaceae Pilea hamaoi Makino Herbs 110 Violaceae Viola eizanensis (Makino) Makino Herbs Ampelopsis glandulosa (Wall.) 111 Vitaceae Herbs Momiy.

5 (a) (b) (c)

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1000 1200 1400 1600 1800 1000 1200 1400 1600 1800 1000 1200 1400 1600 1800 Elevation (m) Elevation (m) Elevation (m) (d) (e) (f) 15 ) y

r 60 ) a % 1 d ( -

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1000 1200 1400 1600 1800 1000 1200 1400 1600 1800 1000 1200 1400 1600 1800 Elevation (m) Elevation (m) Elevation (m) (g)

) 30 º (

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1000 1200 1400 1600 1800 Elevation (m)

Fig. S1 Correlations between elevation and soil temperature (a), soil pH (b), soil CN ratio (c), forest type (d), basal area (e), canopy openness (f) and slope (g). A strong negative correlation between elevation and soil temperature (r = –0.96, P < 0.001; Fig.

S1a) was detected. Elevation had a significant negative relationship with soil pH (r = –

0.41, P < 0.001; Fig. S1b) and a positive relationship with soil CN ratio (r = 0.52, P <

0.001; Fig. S1c). Old-growth forests were located at significantly higher elevation than secondary forests (P < 0.001; Fig. S1d). A weak, but significant negative correlation

6 was also observed between elevation and slope (r = –0.19, P = 0.001; Fig. S1g).

Significant correlations are represented by gray regression lines.