SI Appendix 1 Supporting Information Methods S1-S3

SI Appendix Supporting Information Methods S1-S3; Tables S1-S6, and Figures S1-S9. Environmental filtering by pH and soil nutrients drives community assembly in fungi at fine spatial scales Sydney I. Glassman1,2,3*, Ian J. Wang1, and Thomas D. Bruns1,3 1

Department of Environmental Science Policy and Management, University of California, Berkeley, Berkeley, CA, 94720; 2 Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA, 92697; 3 Department of Plant & Microbial Biology, University of California, Berkeley, CA, USA, 94720 Methods S1. Filtering Ectomycorrhizal Fungal Taxa from the OTU table. Ectomycorrhizal fungi were separated from the OTU table based on genera determined to be ectomycorrhizal by Tedersoo et al (2010) following established methods from previous studies (Glassman et al. 2017; Glassman et al. 2015) using the QIIME commands in Methods S2. OTUs belonging to questionable genera, including Ramaria, Entoloma, Lyophyllum, Sistorema, Sebacina, among others, in which only part of the lineages are known to be ectomycorrhizal, were examined more closely via BLAST and included only if we could conclusively identify them as EM fungi (Tedersoo et al. 2010). OTUs in genera considered dark septate endophytes (DSE), such as Acephala, Meliniomyces, Cadophora, Phialocephala, were also examined more closely. DSE are a miscellaneous group of ascomycetous anamorphic fungi, that colonize root tissues intracellularly and intercellularly (Jumpponen 2001). While they are consistently and ubiquitously found in studies of ectomycorrhizal tree roots, they are not consistently considered mycorrhizal, and their exact biology remains unclear (Rinaldi et al. 2008; Tedersoo et al. 2010). We examined OTUs belonging to these genera more closely via BLAST and retained only the OTUs that we could conclusively identify as EMF such as Cadophora finlandica and Meliniomyces bicolor (Tedersoo et al. 2010). The specific QIIME command used to filter out OTUs that we conclusively identified as non-mycorrhizal can be found in Methods S3. Methods S2. QIIME command used to filter the putative ectomycorrhizal fungal taxa from the total fungal OTU table based on established knowledge of ectomycorrhizal fungal genera (Tedersoo et al 2010). filter_taxa_from_otu_table.py -i otu_taxonomy.biom -o otutable_EMF.biom -p g__Acephala,g__Afroboletus,g__Albatrellus,g__Alnicola,g__Alpova,g__Amanita,g__Amphinema,g__Am ylascus,g__Andebbia,g__Arcangeliella,g__Aroramyces,g__Astraeus,g__Aureoboletus,g__Austroboletus,g __Austrogautieria,g__Austropaxillus,g__Balsamia,g__Bankera,g__Barssia,g__Boletellus,g__Boletinus,g_ _Boletus,g__Bothia,g__Byssocorticium,g__Byssoporia,g__Calostoma,g__Cantharellus,g__Castoreum,g__ Catathelasma,g__Cazia,g__Cenococcum,g__Choiromyces,g__Chondrogaster,g__Clavariadelphus,g__Clav ulicium,g__Clavulina,g__Coltricia,g__Corditubera,g__Cortinarius,g__Craterellus,g__Craterellus,g__Cuph ocybe,g__Cystangium,g__Densospora,g__Dermocybe,g__Descolea,g__Descomyces,g__Dingleya,g__Dipl ocystis,g__Elaphomyces,g__Fischerula,g__Galactinia,g__Gallacea,g__Gastroboletus,g__Gautieria,g__Gea strum,g__Genabea,g__Genea,g__Geopora,g__Gilkeya,g__Glischroderma,g__Gloeocantharellus,g__Gomp



1

SI Appendix hogaster,g__Gomphus,g__Gummiglobus,g__Gymnohydnotrya,g__Gymnomyces,g__Gyrodon,g__Gyropor us,g__Hallingea,g__Hebeloma,g__Heimiella,g__Heimioporus,g__Helvella,g__Humaria,g__Hydnangium,g __Hydnellum,g__Hydnobolites,g__Hydnoplicata,g__Hydnotrya,g__Hydnotryopsis,g__Hydnum,g__Hygro phorus,g__Hysterangium,g__Inocybe,g__Labyrinthomyces,g__Laccaria,g__Lachnea,g__Lactarius,g__Lec cinum,g__Leucangium,g__Leucogaster,g__Leucophleps,g__Mackintoshia,g__Macowanites,g__Malajczuk ia,g__Melanogaster,g__Membranomyces,g__Mesophellia,g__Mycolevis,g__Nothocastoreum,g__Nothojaf nea,g__Otidea,g__Pachyphloeus,g__Paragyrodon,g__Phylloboletellus,g__Phylloporus,g__Picoa,g__Pilode rma,g__Pisolithus,g__Polyozellus,g__Polyporoletus,g__Porphyrellus,g__Protoglossum,g__Pseudoboletus, g__Pseudotomentella,g__Pseudotulostoma,g__Pterygellus,g__Pulveroboletus,g__Quadrispora,g__Reddell omyces,g__Retiboletus,g__Rhizopogon,g__Rhodactina,g__Richoniella,g__Riessia,g__Riessiella,g__Royo ungia,g__Rozites,g__Rubinoboletus,g__Ruhlandiella,g__Russula,g__Sarcosphaera,g__Scabropezia,g__Scl eroderma,g__Setchelliogaster,g__Sowerbyella,g__Sphaerosporella,g__Sphaerozone,g__Strobilomyces,g__ Suillus,g__Tarzetta,g__Terfezia,g__Thaxterogaster,g__Thelephora,g__Tirmania,g__Tomentellopsis,g__To mentella,g__Tremellodendron,g__Tremellogaster,g__Tricholoma,g__Trichophaea,g__Truncoclumella,g__ Tuber,g__Turbinellus,g__Tyloporus,g__Tylospora,g__Ulurua,g__Underwoodia,g__Wilcoxina,g__Wynnel la,g__Xanthoconium,g__Xerocomus,g__Zelleromyces,f__Rhizopogonaceae,f__Suillaceae,g__Acephala,g_ _Amarrendia,g__Athelia,g__Brauniellula,g__Cadophora,g__Calciporus,g__Ceratobasidium,g__Chromelos porium,g__Chroogomphus,g__Chloridium,g__Clavariadelphus,g__Endogone,g__Entoloma,g__Gomphidiu s,g__Hydnocystis,g__Lyophyllum,g__Meliniomyces,g__Octaviania,g__Peziza,g__Phialocephala,g__Protu bera,g__Pulvinula,g__Ramaria,g__Rhizoctonia,g__Sebacina,g__Sistotrema,g__Tricharina,g__Tulasnella

Methods S3. QIIME commands use to prune out taxa definitively identified as nonectomycorrhizal fungi from the ectomycorrhizal fungal OTU table after further investigations with BLAST. filter_taxa_from_otu_table.py -i otutable_EMF.biom -o otutable_EMF_pruned.biom -n s__Entoloma_chalybaeum_var_lazulinum,s__Lyophyllum_anthracophilum,s__Entoloma_vernum,s__Entol oma_clypeatum,s__Sebacina_allantoidea,s__Entoloma_chalybaeum_var_lazulinum,s__Entoloma_lividocy anulum,s__Entoloma_hebes,s__Entoloma_abortivum,g__Ramaria,g__Peziza,g__Chroogomphus,g__Rhizo ctonia,g__Athelia,g__Strobilomyces,g__Sebacina filter_taxa_from_otu_table.py -i otutable_EMF_pruned.biom -o otutable_EMF_pruned2.biom -n s__Cadophora_sp_ICMP_18087,s__Phialocephala_fluminis,Phialocephala_sp_C8

References for Methods S1-S3 Glassman SI, Lubetkin KC, Chung JA, Bruns TD (2017) The theory of island biogeography applies to ectomycorrhizal fungi in subalpine tree "islands" at a fine scale. Ecosphere 8. Glassman SI, Peay KG, Talbot JM, et al. (2015) A continental view of pine-associated ectomycorrhizal fungal spore banks: a quiescent functional guild with a strong biogeographic pattern. New Phytologist 205, 1619-1631. Jumpponen A (2001) Dark septate endophytes - are they mycorrhizal? Mycorrhiza 11, 207-211. Rinaldi AC, Comandini O, Kuyper TW (2008) Ectomycorrhizal fungal diversity: separating the wheat from the chaff. Fungal Diversity 33, 1-45. Tedersoo L, May TW, Smith ME (2010) Ectomycorrhizal lifestyle in fungi: global diversity, distribution, and evolution of phylogenetic lineages. Mycorrhiza 20, 217-263.



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SI Appendix Supplemental Tables S1-S6 Table S1. Summary information for 40 trees. Location of each tree in longitude latitude as measured from GPS unit (3 m accuracy), tree age (years), tree volume (m3), distance from nearest forest edge (m), and isolation (# of stems within 10m of focal tree). PA=Pinus albicaulis; PC = Pinus contorta. Tree Tree Tree Forest Tree latitude longitude Species Age Volume Distance Isolation PC1 PC2 PC3 PC4 PC5 PC6 PC7 PC8 PC9 PC10 PC11 PC12 PC13 PC14 PC15 PC16 PC17 PC18 PC19 PC20 PA21 PA22 PA23 PA24 PA25 PA26 PA27 PA28 PA29 PA30 PA31 PA32 PA33 PA34 PA35

37.91504094 37.91157377 37.91457692 37.91509341 37.91561645 37.9158705 37.91649344 37.9170547 37.91757647 37.91679787 37.91871021 37.91852807 37.92045431 37.92092814 37.92083359 37.91848473 37.91736181 37.91763774 37.91678832 37.91570622 37.91506835 37.91540707 37.91467658 37.9155115 37.91587058 37.91648313 37.91698588 37.91764772 37.91889603 37.91854416 37.92049924 37.92103752 37.92095865 37.92108069 37.91844894

-119.2677182 -119.2724906 -119.2673838 -119.2676559 -119.2677555 -119.2683259 -119.2684809 -119.2685027 -119.2686659 -119.2701459 -119.2718868 -119.2719137 -119.2727774 -119.2734129 -119.2742694 -119.2745595 -119.2743132 -119.2749845 -119.2754098 -119.2746102 -119.2675672 -119.2674707 -119.2673661 -119.267844 -119.2682379 -119.2682383 -119.2684565 -119.2688316 -119.2719977 -119.2719542 -119.2728992 -119.2733605 -119.2743394 -119.2745478 -119.2744214

PC PC PC PC PC PC PC PC PC PC PC PC PC PC PC PC PC PC PC PC PA PA PA PA PA PA PA PA PA PA PA PA PA PA PA

124 45 112 67 37 60 55 29 121 72 108 40 93 69 43 61 51 120 45 71 51 105 66 48 59 38 61 93 57 29 29 71 33 50 36

5.56 4.02 16.09 5.07 1.69 29.9 7.46 8.3 18.74 55.13 12.1 1.15 16.96 11.45 2.93 3.4 3.59 7.59 1.38 2.42 3.08 26.69 23.94 3.55 12.31 2.31 5.51 53.19 10.21 1.42 1.16 26.76 1.74 11.87 4.05

547.9393 308.3791 488.6511 550.5376 595.1057 651.8635 691.2395 721.7103 764.0841 826.2742 775.257 762.9011 826.1854 824.7833 768.4734 564.9252 515.4592 480.6796 400.2746 544.5077 428.575 563.9238 497.7317 598.7287 644.6132 671.5072 714.4124 780.6151 777.6563 760.7225 821.8314 836.9311 775.7463 775.8801 572.2108

1 33 14 3 4 7 0 11 14 0 1 3 2 4 1 10 0 0 3 0 5 0 11 0 5 10 4 0 14 1 0 0 0 0 0 3

SI Appendix PA36 PA37 PA38 PA39 PA40



37.91790663 37.91777261 37.917453 37.91711563 37.91177477

-119.274145 -119.2750485 -119.2742952 -119.274842 -119.2724431

PA PA PA PA PA

48 177 48 54 27

48.68 17.82 8.16 5.6 3.05

559.2551 483.9553 521.8701 461.5317 325.4637

0 0 0 0 0

4

SI Appendix Table S2. Soil chemistry associated with each of the 40 trees. Phosphorous (P), Potassium (K), Magnesium (Mg), Calcium (Ca), Sodium (Na), and Sulphur (S) are presented as ppm. Percent organic matter (OM), pH, C:N ratio, and cation exchange capacity (CEC). Percent Tree OM pH P K Mg Ca Na CEC S C:N ratio PC1 PC2 PC3 PC4 PC5 PC6 PC7 PC8 PC9 PC10 PC11 PC12 PC13 PC14 PC15 PC16 PC17 PC18 PC19 PC20 PA21 PA22 PA23 PA24 PA25 PA26 PA27 PA28 PA29 PA30 PA31 PA32 PA33 PA34 PA35 PA36 PA37

5.4 3.4 5.8 13.7 7.9 5.9 33.6 25.6 7.8 4.7 3.5 2.4 5.7 4.8 4.6 2.5 3.4 8.3 3.7 21.8 13.5 7.3 5.4 8.5 13 8.7 6.2 13.5 3.3 3.1 3.7 3.7 3 2.7 5.5 2.7 7.4

4.1 3.9 4.2 4.1 4.4 4.5 4.3 4.1 4.3 4.5 4.8 4.6 4.6 4.5 5.1 4.6 4.6 4.2 4.4 4.6 4.2 3.8 4.5 4.2 4.4 4.5 4.4 4 4.8 4.6 4.4 4.7 4.9 4.8 4.7 4.3 3.9

28 90 35 17 22 24 3 6 88 63 48 73 91 74 70 73 85 60 52 22 19 14 34 53 11 20 99 47 57 82 66 56 57 90 92 80 64

53.3 45.9 65 43 66.8 36.9 60.2 49.5 67.7 88 124.3 79.9 109.7 105.1 140.2 67.4 71.3 54.8 57.6 59.9 42.4 38.7 51.2 50.4 44.6 56.3 51.5 31.3 92.5 85.4 74.9 67.8 164.2 185.6 96.4 69.9 25.3

22.4 10 24.1 28.3 30.8 15.5 38.5 23.7 13.7 32.3 34.2 20.9 33.7 25.2 63.4 20.8 12.1 26.7 15.5 51.6 25.7 18.2 24 20.1 31.5 47 13.8 11.8 24.3 18.2 12.6 18.3 53.3 68.1 20 14.8 9.8

136 81.3 176.6 208.3 212 158.6 347.4 124.6 95.4 197.7 253.3 164.6 223.2 158.5 436.6 177.5 89.4 204.3 93.3 600.1 175 102.1 184.1 135 293.4 290.7 119.1 97.8 211 124.6 69 137.2 349.8 432 210.2 66.1 60.1

6.5 5.8 7.6 6.2 6.3 6.2 6.5 5.8 13 10.7 9.5 8.9 7.3 6.9 9.5 10.3 7 7 9.4 9.9 5.8 5.7 6.4 8.5 7.3 6.4 5.9 4.5 8.1 6.9 5.4 7.5 6.3 5.8 5.1 7.2 4.9

4 2.5 4.3 5.4 4 2.5 6.6 3.7 2.4 3.6 3.6 2.7 3.7 3.1 5 2.8 1.6 4.8 2.1 7.9 4.1 3.1 3 3.4 4.9 4.8 2.3 2.7 2.9 2.2 1.7 2.1 4.7 6.1 3 1.9 1.9

4.6 7.5 5.7 4.1 5.7 5.9 8.6 10.9 4.9 7.2 5.6 4 4.9 6.4 3.3 3.7 5.6 4.9 6 8.8 4.1 4.2 3.8 5.5 6.8 4.5 4.1 2.7 8.3 4.8 4.3 4.9 3.4 4.2 4 7.7 2.9

17 15 16 20 14 13 22 17 19 15 12 11 14 12 13 13 15 13 14 18 21 16 15 16 20 20 16 56 12 12 13 12 12 12 14 13 14 5

SI Appendix PA38 PA39 PA40



3.8 3.3 3.8

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58 72 66

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6

SI Appendix Table S3. Results of mantel test for ectomycorrhizal and fungal community composition as measured by either Jaccard or Bray-Curtis dissimilarity against pairwise geographic distance for both trees together and for each tree host separately. PA = Pinus albicaulis; PC = P. contorta.



Fungi

Trees

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p-value

Ectomycorrhizal fungi Ectomycorrhizal fungi Ectomycorrhizal fungi Ectomycorrhizal fungi Ectomycorrhizal fungi Ectomycorrhizal fungi All Fungi All Fungi All Fungi All Fungi

Both trees Both trees PA PA PC PC PA PC Both trees Both trees

Jaccard Bray-Curtis Jaccard Bray-Curtis Jaccard Bray-Curtis Bray-Curtis Bray-Curtis Jaccard Bray-Curtis

0.001 0.069 0.082 0.096 -0.036 0.247 0.371 0.279 0.420 0.335

0.476 0.081 0.128 0.101 0.642 0.020 0.001 0.001 0.001 0.001

7

SI Appendix Table S4. Results of Generalized Dissimilarity Modeling (GDM) on fungal community composition. Community composition was measured as Bray-Curtis community dissimilarity for either the total fungal or ectomycorrhizal fungal community composition. Only predictors that were retained as significant in the backward elimination model selection are included. Model was run including pH but excluding pairwise geographic distance, and excluding pH but including all pairwise geographic distance. Total fungal Community Deviance explained Predictor Organic matter pH Paired distance (geography) Phosphorous Tree Volume Cation Exchange Capacity Ectomycorrhizal fungi Deviance explained Predictor pH Cation Exchange Capacity Tree Age Phosphorous Tree Species Paired distance (geography)



0.70 Coefficients Best Model 0.38 0.34 0.11 0.11 0.11 0.07

0.26 Coefficients Best Model 0.61 0.46 0.33 0.32 0.17 N/A

0.68 Geography excluded 0.37 0.36 N/A 0.14 0.11 0.09

0.26 Geography excluded 0.61 0.46 0.33 0.32 0.17 0.00

0.53 pH excluded 0.41 N/A 0.20 0.07 0.10 0.09

0.16 pH excluded N/A 0.59 0.29 0.23 0.17 N/A

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SI Appendix Table S5. Results of distance based linear modeling (DistLM) on fungal community composition. Backward model selection was employed on the following predictor variables: identity, size, and age of tree host, forest distance, isolation index, pH, OM, P, S, C:N Ratio, Na, and CEC as potential predictor variables. Pairwise geographic distance cannot be accounted for with this test because it does not allow predictor variable to be matrices. All fungi Predictor pH Organic Matter (OM) Phosphorous (P) Tree Age (years) Cation Exchange Capacity (CEC) Forest distance C:N ratio Tree Species Sulphur (S) Sodium (Na) Isolation Ectomycorrhizal fungi Predictor Tree Species pH Sodium (Na) Isolation Phosphorous (P) Cation Exchange Capacity (CEC) Sulphur (S) Tree size (volume in m3) C:N ratio Tree Age (years) Organic Matter (OM) Forest distance



R2 = 0.43; adjusted R2 = 0.21 SS(trace) Pseudo-F 1.1787 0.85569 0.84375 0.7233 0.70158 0.60246 0.5494 0.44154 0.43598 0.39849 0.27221

4.3507 3.0622 3.0161 2.5565 2.4748 2.1058 1.911 1.5208 1.5009 1.3672 0.92339

R2 = 0.44; adjusted R2 = 0.24 SS(trace) Pseudo-F 10634 8659.8 6706.3 5452.5 5043.9 5010.8 3734 3187 2966.1 2606.7 2489.3 2103.6

3.5609 2.8445 2.162 1.7372 1.6009 1.5898 1.1708 0.99426 0.92347 0.80892 0.77164 0.6498

P 0.001 0.001 0.001 0.002 0.001 0.002 0.001 0.046 0.051 0.076 0.553

P 0.006 0.019 0.049 0.099 0.150 0.140 0.321 0.411 0.502 0.558 0.565 0.665

Proportion 10.27 7.46 7.35 6.30 6.11 5.25 4.79 3.85 3.80 3.47 2.37

Proportion 9.48 7.72 5.98 4.86 4.50 4.47 3.33 2.84 2.64 2.32 2.22 1.88

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SI Appendix Table S6. Results of Multiple Matrix Regression Randomization (MMRR) on total fungal community composition for A) Pinus albicaulis (PA) and B) Pinus contorta (PC). Community composition was measured as Bray-Curtis dissimilarity. Tests were run separately for each tree species (Pinus albicaulis PA and Pinus contorta PC). We used MMRR to quantify the relative contributions of paired geographic distance, soil chemistry dissimilarity, tree characteristics (age and volume) dissimilarity, and isolation (isolation index and forest distance) differences to explain fungal community dissimilarity between trees. Significant differences bolded. A. PA 2

R

coefficient p-value F-statistic p-value

0.32 Intercept 0.0000 0.0649 21.7000 0.0001

Total fungi Distance 0.1370 0.0511

Soil 0.5220 0.0001

Tree 0.1270 0.3155

Isolation 0.0040 0.9653

Tree 0.0730 0.3971

Isolation 0.1130 0.1949

B. PC R2 coefficient p-value F-statistic p-value



0.2200 Intercept Distance 0.0000 0.1570 0.0829 0.0532 12.6900 0.0004

Total fungi Soil 0.4290 0.0003

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SI Appendix Supplemental figures S1-S10 Figure S1. Map of 40 tree ‘islands’ (in green) with forest polygons (in pink) used to estimate distance to nearest forest edge located in Gaylor Lake Basin, near Tioga Pass, in Yosemite National Park, California, USA.



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SI Appendix Figure S2. Correlations among soil cations (Ca, Mg, Na, and K) and cation exchange capacity (CEC). B. 8

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0.0

0.2

0.4

0.6

0.8

1.0

1.2

Differences in pH between pairs of trees



14

SI Appendix Figure S4. Correlations among pH, Organic Matter (OM), and distance from forest edge (forest distance). A. B.

30

Pearson's r = 0.0088 P = 0.957

OM

3.8

5

4.0

10

4.2

15

4.4

pH

20

4.6

25

4.8

5.0

Pearson's r = 0.52 P = 0.000574

300

400

500

600

700

800

300

400

500

600

700

800

Distance from forest edge (m)

Distance from forest edge (m)

C.

20 15 5

10

Organic Matter

25

30

Pearson's r = −0.3 P = 0.0587

3.8

4.0

4.2

4.4

4.6

4.8

5.0

pH



15

SI Appendix Figure S5. The 40 tree “islands” of Pinus albicaulis and P. contorta mapped by their latitude (lat) and longitude (lon) and colored by pH. The pH range is from 3.8 to 5.1 and ranges from red and small (low pH) to blue and large (high pH).

●●

●

● ● ●●

37.920

● ● ● ●

●● 37.918

pH 3.9

●

●

●

●

● ●

●

4.2

●

4.5

●

●

●

●

4.8

lat

●●

37.916

●●

●

pH ●

●

●

●

●●

● ●

●

3.9

●

4.2

● 4.5

●

4.8

37.914

37.912 ● ●

−119.274

−119.272

−119.270

−119.268

lon



16

SI Appendix Figure S6. Non-metric multidimensional scaling (NMDS) visualizing the effect of seasonality on A) total fungal community B) total ectomycorrhizal fungal community composition as measured by Jaccard dissimilarity. Points represent the fungal community composition at each of the 40 trees in October (red) or June (blue). A.



B.

17

0

● ● ● ●

Tricholoma myomyces Rhizopogon variabilisporus Rhizopogon aff luteorubescens

●

Rhizopogon sp2

● ●

Cortinarius aff fulvescens Hebeloma crustuliniforme

● ● ●

Gautieria pterosperma

●

●

● ●

Meliniomyces sp. SM7−2

●

Meliniomyces vraolstadiae

PA PC

Suillus aff brevipes

●

Pseudotomentella atrofusca

●

Inocybe lacera

Number of Trees 15

Choiromyces sp

●

Otidea sp

●

Thelephora terrestris

●

Rhizopogon fuscorubens

●

Cortinarius aff olivaceofuscus

●

Rhizopogon sp1

●

Acephala aff macrosclerotiorum

●

Tomentellopsis sp

●

Cadophora finlandica 2

Suillus brevipes2

Rhizopogon aff evadens

Suillus brevipes1

●

Rhizopogon salebrosus

●

Rhizopogon subpurpurescens

Cadophora finlandica

0

Cadophora finlandica Rhizopogon salebrosus Rhizopogon subpurpurescens Tricholoma myomyces Rhizopogon variabilisporus Rhizopogon aff luteorubescens Suillus brevipes1 Rhizopogon aff evadens Suillus brevipes2 Cadophora finlandica 2 Tomentellopsis sp Rhizopogon sp2 Rhizopogon sp1 Acephala aff macrosclerotiorum Rhizopogon fuscorubens Cortinarius aff olivaceofuscus Cortinarius aff fulvescens Hebeloma crustuliniforme Otidea sp Thelephora terrestris Inocybe lacera Choiromyces sp Suillus aff brevipes Pseudotomentella atrofusca Gautieria pterosperma Meliniomyces sp. SM7−2 Meliniomyces vraolstadiae Suillus sp Rhizopogon brunneiniger Cortinarius cf helobius Cenococcum geophilum Cortinarius aff laetus Hygrophorus sp2 Suillus placidus Rhizopogon sp3 Russula pallidospora Hygrophorus sp3 Amanita sp2 Helvella lacunosa Lactarius deceptivus Descolea gunnii Cortinarius aff badiolaevis Tomentella sp EDM19 Suillus pseudobrevipes Amanita aff muscaria Cortinarius duracinus Acephala aff macrosclerotium Inocybe scabriuscula2 Tomentella badia Hygrophorus sp1 Cortinarius uraceus Sistotrema sp2 Cortinarius sp1 Leucophleps spinispora Amphinema sp Sistotrema sp1 Entoloma majaloides Hygrophorus russula Clavulina sp Inocybe aff lanuginosa Tylospora sp Helvella sp1 Hebeloma crustuliniforme2 Tuber sp2 Hebeloma sp Hygrophorus russula3 Hydnum sp Amphinema diadema Gautieria sp HS2305USA Hygrophorus russula2 Mesophellia glauca Cortinarius sp3 Tuber sp4 Alnicola tantilla Inocybe scabriuscula1 Gautieria pterosperma2

Number of Trees

SI Appendix

Figure S7 A) Rank abundance curve of frequency of ectomycorrhizal fungal OTUs occurring on at least 2 trees (top 27 most frequent) of Pinus albicaulis (PA; n=20) and P. contorta (PC; n=16). Symbols represent primary dispersal modes of taxa. B) Rank abundance curve of frequency of all EMF OTUs.

A.

20

wind soil animal animal + wind

10

5

B. 20 PA PC

15

10

5

18

SI Appendix Figure S8. Bray-Curtis community dissimilarity versus pairwise geographic distance in meters (paired distance) among trees for A) total fungal and b) ectomycorrhizal fungal communities. Pinus albicaulis (PA) trees are in red and P. contorta (PC) trees are in blue.

0.8 0.6 0.4

0.8 0.7 0.6

0.0

0.2

PA PC

EMF community dissimilarity

●

0.5

All fungi community dissimilarity

0.9

●

B

1.0

A

0

200

400

600

Paired distance



800

1000

0

200

400

600

800

1000

Paired distance

19

SI Appendix Figure S9. Non-metric multidimensional scaling (NMDS) of Bray-Curtis ectomycorrhizal fungal community dissimilarity colored by tree host (PA = Pinus albicaulis; PC=P. contorta). Circles represent the 95% confidence interval around the centroid of each group, which was calculated based on the standard error. Species driving the differences among trees were found as environmental factors fit onto the ordination.

●

1.0

●

PA PC

● ●

Suillus brevipes1 ● ● OTU_3187 OTU_166 ● ● ● ●

● ●

0.5

● ● ● ● ● ●

● ●

● ●

● ● ● ●

● ●

● ●

● ●

0.0

NMDS2

● ●

● ● ● ●

● ●

● ●

OTU_100

● ●

Rhizopogon salebrosus

● ●

● ●

● ● ● ●

● ●

● ●

● ●

OTU_2821 Helvella

lacunosa

−0.5

● ●

● ● ● ●

● ●

● ●

● ●

● ●

● ● Tricholoma myomyces

−1.0

OTU_11

−1.0

−0.5

0.0

0.5

1.0

NMDS1



20