Online Appendix

Figure S1. Gain, persistence, and loss in potential distribution of western redcedar under

the emission scenario A2A for two future time periods (2050s, 2080s)

compared to baseline extent (inset), based on degree of agreement among three

GCMs (CSIRO, CCCMA, HADCM3).

1

Figure S2. Gain, persistence, and loss in potential distribution of Sitka spruce under the

emission scenario A2A for two future time periods (2050s, 2080s) compared to

baseline extent (inset) based on degree of agreement among three GCMs

(CSIRO, CCCMA, HADCM3).

2

Figure S3. Gain, persistence, and loss in potential distribution of western hemlock under

the emission scenario A2A for two future time periods (2050s, 2080s)

compared to baseline extent (inset) based on degree of agreement among three

GCMs (CSIRO, CCCMA, HADCM3).

3

Figure S4. Gain, persistence, and loss in potential distribution of Pacific silver fir under

the emission scenario A2A for two future time periods (2050s, 2080s)

compared to baseline extent (inset) based on degree of agreement among three

GCMs (CSIRO, CCCMA, HADCM3).

4

Figure S5. Gain, persistence, and loss in potential distribution of grand fir under the

emission scenario A2A for two future time periods (2050s, 2080s) compared to

baseline extent (inset), based on degree of agreement among three GCMs

(CSIRO, CCCMA, HADCM3).

5

Figure S6. Gain, persistence, and loss in potential distribution of yellow-cedar

under the emission scenario A2A for two future time periods (2050s, 2080s)

compared to baseline extent (inset) based on degree of agreement among three

GCMs (CSIRO, CCCMA, HADCM3).

6

Figure S7. Gain, persistence, and loss in potential distribution of mountain hemlock under

the emission scenario A2A for two future time periods (2050s, 2080s)

compared to baseline extent (inset) based on degree of agreement among three

GCMs (CSIRO, CCCMA, HADCM3).

7 TABLE S1. Expected and modeled distributions of Pacific coastal focal rainforest species

based on species experts and the literature.

Species Range Habitat Climate Expected Modeled

preference envelope shift shift

Western Along coast 0-1500m Wet Retraction of High redcedar from Alaska elevation; climates riparian persistence

to California, Found on west of the populations throughout

also inland various Cascades, as runoff BC and

to Alberta, substrates, especially declines and coastal AK.

Idaho, and commonly on in BC and fires Expansion to

Montana. moist sites, in the Olympic intensify. higher

mixed Peninsula. Southern elevations

coniferous Dry interior contraction and latitudes.

forests. climates of coastal Contraction

restricted to range. in SE

riparian portions of

habitats the range.

west of the

Rocky

Mountain

divide.

Sitka spruce From Kodiak Usually found Encompasss Retraction of High levels

Island south growing on wide range range, of

to N. CA. well-drained of precip especially persistence

8 Generally acidic soils. and south of BC, throughout

within 20km Tolerant of temperature localized BC and AK

of coast or salt spray.2 2. Inability changes in with some

with the fog to tolerate response to expansion to

belt south of moisture changes in higher

B.C. Up to stress disturbance elevations

200km from during regimes. and latitudes.

the sea in growing Southern

B.C. and season. range

AK.1 contraction

along CA

and OR

coast, as well

as S.

Cascades.

Western Alberta and Coastal to Shade Expansion Southern hemlock BC, Canada, mid-montane tolerant. along parts of

Alaska, forests. Some elevational Coast Range

Washington, Dominant or evidence gradients experience

Idaho, found with that they especially greatest loss.

Montana, Sitka spruce grew well at along N. Higher

Oregon, and in coastal higher coastline, amounts of

California forests, elevations and through persistence

Douglas-fir in when the Prince in BC and

9 Cascades3 and climate was William Cascades.

with western warmer and Sound. Most

redcedar. drier.2 opportunity

for

expansion to

higher

elevations in

BC.

Pacific silver Western BC, Deep well- Maritime Loss of Heavy range fir Canada; SE drained soils climate with winter contraction

Alaska, W in cool, moist significant snowpack throughout

Washington coastal winter should result coastal and

and Oregon, forests, snowpack.4 in retraction southern

NW descending to Intolerant of of range in portions of

California sea level fire. low the range.

northward elevation Northward

from habitats expansion

Vancouver along and

Island. From northern expansion to

1000 m to coast.5 In its higher

treeline in southern elevations in

Oregon and range it BC.

further south. would be

Typically expected to

10 higher and increase its

wetter habitat elevational

than grand fir range with

and western other

redcedar. subalpine

Highly shade species.

tolerant.

Grand fir BC, Canada, Moist sites Areas Likely to Substantial

Washington, from 0- where continue to loss of

Idaho, 1500m; summer expand as climatic

Montana, Riparian drought and fire regimes niche

Oregon, and settings along fire are change in throughout

California streams and common interior southern

rivers in OR west of the regions. portions of

and WA. Cascade the range,

Above 1000m Crest; throughout

in CA2. relatively Cascades

Sensitive to moist and Coast

changes in habitats in range.

fire regimes. interior Extensive

regions. potential

expansion

northward.

11 Alaska West coast, Wet sites7, Limited to Retraction of Coastal and

Yellow- from the close to tree wet soils coastal southern cedar Kenai line in south, and high populations; portions of

peninsula to to sea level in elevations, restriction to range

the Klamath north. Often especially montane contracts.

Mountains of in high in the south, habitats due Distribution

Northern montane and but also at to snow pack becomes

California6 subalpine low requirements patchy

forests of the elevations throughout

Cascades. in the north. range. Little

Vulnerable expansion.

to fine-root

freezing.

Mountain BC, Canada, Found at Relatively Some Coastal and hemlock Alaska, increasing coastal, western southern

Washington, elevations with high expansion, portions of

Idaho, from AK to snowfall or but mostly range

Montana, CA.2 Upper rainfall. localized contracts.

Oregon, portion of Mean expansion in CA

California, subalpine annual temp elevation populations

and Nevada forest to of 3-4° C. upward and become

treeline. Cannot loss of lower disjunct.

Sometimes tolerate elevation Some

grows as frozen soils. populations. expansion

12 krummholz. east (to

higher

elevations)

and north.

Coast SW OR and Below 300m Foggy Retraction of Contraction redwood NW CA but coastlines1 southern throughout

within 60km occasionally range due to most of the

of the coast to 1000m. changes in range. Small

Alluvial soils. fog belt and patches of

Pure stands or some persistence

with Douglas- potential possible.

fir or Port expansion Little

Orford cedar northward. expansion

(Chamaecypa expected.

ris Extirpation

lawsoniana) 1 throughout

range

possible.

1 Thompson, R. S., Anderson, K. H., Bartlein, P. J., 1999. Atlas of Relations Between

Climatic Parameters and Distributions of Important Trees and Shrubs in North America.

USGS Professional Paper 1650 A&B. http://greenwood.cr.usgs.gov/pub/ppapers/p1650-

a/pages/conifers.html (accessed 27 June 2014).

2 The gymnosperm Database, Edited by Earle, C. J. http://www.conifers.org (accessed 27

June 2014). 13 3 Franklin, J. F. and Dyrness., C.T., 1988. Natural Vegetation of Oregon and Washington.

Corvallis, OR: Oregon State University Press.

4 Pojar, J., Mackinnon, A., 1994. Plants of the Pacific Northwest Coast. Vancouver, BC: Lone

Pine Publishing. http:// www.lonepinepublishing.com/cat/9781551055305 (accessed 27

June 2014)

5 Burns, R.M., Honkala, B.H., 1990. Silvics of North America, Vol. 1, Conifers. Washington

DC: U.S.D.A. Forest Service Agriculture Handbook 654.

http://www.na.fs.fed.us/pubs/silvics_manual/table_of_contents.shtm (accessed 27 June

2014)

6 USGS 1999. Digital representation of "Atlas of United States Trees" by Little, E. L.

http://geo-nsdi.er.usgs.gov/metadata/professional-paper/1650/metadata.faq.html (accessed

27 June 2014).

7 Peattie, D. C., 1950. A Natural History of Western Trees. New York: Bonanza.

14 TABLE S2. Shown Kappa values serve as measurement of agreement between baseline potential species distributions and future potential

distributions for all modeled species. Lower values indicate less accordance.

Species 2050s 2080s

CSIRO CCCMA HADCM3 CSIRO CCCMA HADCM3 Western redcedar 0.708 0.778 0.673 0.567 0.671 0.556 Sitka spruce 0.747 0.852 0.834 0.631 0.796 0.799 Western hemlock 0.806 0.863 0.803 0.668 0.777 0.71 Pacific silver fir 0.503 0.713 0.549 0.334 0.565 0.468 Grand fir 0.676 0.716 0.47 0.373 0.525 0.265 Alaska yellow-cedar 0.8 0.854 0.814 0.56 0.738 0.692 Mountain hemlock 0.696 0.78 0.743 0.541 0.638 0.619 Coast redwood 0.644 0.397 0.648 0.626 0.083 0.458

mean of scenario 0.698 0.744 0.692 0.538 0.599 0.571 mean of period 0.711 0.569

15

TABLE S3. AUC values for focal rainforest species based on training and test data averaged across 25 Maxent model runs. Thresholds used for

converting probability surfaces into presence/absence data are shown including values for sensitivity and specificity.

Species AUC[training] AUC[test] threshold sensitivity specificity

Western redcedar 0.85 0.85 0.35 0.88 0.95

Sitka spruce 0.90 0.90 0.20 0.88 0.93

Western hemlock 0.82 0.82 0.30 0.92 0.89

Pacific silver fir 0.89 0.88 0.43 0.88 0.96

Grand fir 0.88 0.88 0.28 0.96 0.93

Alaska yellow-cedar 0.92 0.92 0.22 0.92 0.90

Mountain hemlock 0.90 0.90 0.21 0.94 0.90

Coast redwood 0.94 0.93 0.20 0.95 0.83

16 TABLE S4. Overview of training gain values that were used as thresholds for WorldClim predictor selection for final climate envelope models,

based on preliminary model runs. Moreover, the contribution of selected predictors to final models derived from jackknife statistics is

shown. The overall rank of the two most important predictors is indicated below.

Species Gain Bio 1 Bio 2 Bio 3 Bio 4 Bio 5 Bio 6 Bio 7 Bio 8 Bio 9 Bio 10 Bio 11 Bio 12 Bio 13 Bio 14 Bio 15 Bio 16 Bio 17 Bio 18 Bio 19

[training]

Western redcedar 0.10 3.03 0.24 0.24 1.10 0.21 2.25 1.47 0.27 11.30 1.19 6.15 3.673 0.26 0.07 - 0.27 16.62 0.38 51.30

Sitka spruce 0.40 0.04 6.76 0.39 0.92 - 1.02 39.24 0.83 4.02 - 0.46 30.40 5.01 0.60 - 8.21 0.75 0.13 1.22

Western hemlock 0.15 1.70 1.19 0.30 0.97 - 0.92 0.77 0.58 0.46 0.26 3.05 41.76 0.32 0.10 - 0.82 3.20 0.48 43.14

Pacific silver fir 0.25 0.47 0.62 0.86 3.44 - 1.85 24.54 5.03 2.85 - 1.61 0.63 0.17 0.76 - 0.23 16.26 - 40.70

Grand fir 0.30 0.19 - 4.07 5.73 5.02 0.68 0.42 0.32 35.57 1.31 5.01 1.90 1.16 0.66 - 0.03 12.90 0.76 24.28

Alaska yellow-cedar 0.30 1.06 - 1.33 2.21 0.59 0.67 10.87 0.13 1.97 0.08 0.87 6.64 0.845 1.23 - 35.57 11.42 0.16 24.35

Mountain hemlock 0.25 2.81 0.98 0.55 11.52 - 2.86 1.70 0.49 6.53 4.59 2.68 5.75 1.05 0.57 0.92 0.92 0.55 0.04 55.51

Coast redwood 0.10 3.31 2.30 2.26 39.35 2.15 0.86 20.70 3.38 1.41 0.88 1.08 11.05 4.09 2.66 - 0.21 1.12 1.34 1.87

Variable belongs to the 2 most important predictors 0 0 0 2 0 0 3 0 3 0 0 3 0 0 0 2 5 0 6 overall rank 2 1

17 BIO1 - Annual Mean Temperature BIO8 - Mean Temperature of Wettest Quarter BIO15 - Precipitation Seasonality

BIO2 - Mean Diurnal Range BIO9 - Mean Temperature of Driest Quarter BIO16 - Precipitation of Wettest Quarter

BIO3 - Isothermality BIO10 - Mean Temperature of Warmest Quarter BIO17 - Precipitation of Driest Quarter

BIO4 - Temperature Seasonality BIO11 - Mean Temperature of Coldest Quarter BIO18 - Precipitation of Warmest Quarter

BIO5 - Max Temperature of Warmest Month BIO12 - Annual Precipitation BIO19 - Precipitation of Coldest Quarter

BIO6 - Min Temperature of Coldest Month BIO13 - Precipitation of Wettest Month

BIO7 - Temperature Annual Range BIO14 - Precipitation of Driest Month

18 TABLE S5. The 50 largest protected areas within the coastal temperate rainforests.

Protected areas were derived from the Protected Area Database and Global

Forest Watch Canada. Projected future vegetation stability was derived from

MC1 dynamic vegetation models for the 2080s under scenario A2A.

Protected Area (names from the database) Area (km2) Stable Vegetation (%) Semi-remote

Recreation 9150.01 44.75

Misty Fjords National Monument Wilderness 8360.84 43.27

Glacier Bay 5638.22 44.83

Tongass National Forest Old Growth Habitat 4469.57 35.46

Olympic National Park 3703.66 70.06

Chugach Backcountry Prescription 3698.46 20.56

Kootznoowoo Wilderness 3682.39 60.67

Tongass National Forest Remote Recreation 3650.27 50.88

Huchsduwachsdu Nuyem Jees / Kitlope

Heritage Conservancy 3027.08 84.70

Tongass National Forest Land Use

Designation Ii 2615.58 17.54

Sea to Sky LRMP - Wildland No Logging

Areas 2608.14 59.79

Strathcona Park 2476.28 18.44

Stephen Mather 2341.48 35.50

Chugach National Forest Recommended

Wilderness 2239.95 36.32

Garibaldi Park 1887.15 75.53

19 -Fords Terror Wilderness 1682.02 80.81

Cassiar Iskut/Stikine LRMP-No logging area 1622.41 65.45

Glacier Peak Wilderness 1579.65 74.89

Trinity Alps 1461.75 31.23

Gwaii Haanas National Park Reserve and

Haida Heritage Site 1439.84 43.38

Duu Guusd Conservancy 1356.21 66.19

South Baranof Wilderness 1213.57 41.41

Cascade-Sutslem Conservancy 1208.31 55.83

Stikine-LeConte Wilderness 1154.69 61.07

Haida Gwaii Queen Charlotte Islands

Conservancies/ILMB Vancouver Island

Service Centre 1072.76 48.74

Wrangell-Saint Elias 1069.12 29.58

Kenai Fjords 1022.24 13.40

Chugach National Forest Alaska National

Interest Lands Conservation Act 501(b)-1 989.85 52.06

Alpine Lakes Wilderness 965.73 47.91

Morice Land and Resource Management

Plan- No logging areas 917.72 58.11

Chugach National Forest Fish And Wildlife

Conservation Area 844.70 3.59

Copper River Delta Critical Habitat Area 834.06 15.98

Fiordland Conservancy 785.54 58.05

Siskiyou 727.67 76.21

20 Owikeno Conservancy 705.92 47.09

Naikoon Park 680.12 66.28

Tongass National Forest Special Interest Area 666.38 17.61

Kalmiopsis Wilderness 661.44 37.72

Golden Ears Park 616.35 35.98

Tongass National Forest Non-wilderness

Monument 612.31 12.50

Foch-Gilttoyees Park 604.98 72.19

Gitnadoiks River Park 577.46 84.05

Marble Mountain 558.83 25.55

Hunwadi/Ahnuhati-Bald Conservancy 553.36 28.18

Kachemak Bay State Wilderness Park 528.73 6.87

Ventana 510.14 38.14

Mount Rainier 496.29 5.49

Ellerslie-Roscoe Conservancy 490.24 67.71

Hakai Luxvbalis Conservancy 490.00 0.96

Mount Baker Wilderness 469.44 18.57

21