North Cascades conifer forests ecoregion

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North Cascades conifer forests

RESOLVE 358

The North Cascades conifer forests cover the deeply glaciated mountain country of northern Washington and the immediately-adjacent British Columbia interior. North America's southernmost extension of substantial alpine glaciation outside Alaska; over 300 glaciers remain. Forest banding from western hemlock + Douglas fir at low elevation through Pacific silver fir + mountain hemlock subalpine, with whitebark pine at treeline. The most species-rich conifer flora in Washington state.

Marker placed inside the RESOLVE 2017 polygon at 48.4°N, 120.9°W.

Climate snapshot for this ecoregion

°C

°F

USDA zone range (now)

6b-8b

USDA

What seed packets and nursery tags reference. Coldest-day survival semantics.

Plotwright projection (2041–2070)

8b-10b

Plotwright

Where CHELSA models say the typical winter month is heading.

Average warming this ecoregion is on track for: +4.5°F by mid-century. SSP3-7.0 (current trajectory) · CHELSA v2.1 bio06 sampled across 10 of 10 points within this ecoregion's bounding box.

• North Cascade glaciers have lost ~50% of their volume since the early 20th century; the loss is accelerating, and late-summer meltwater contribution to downstream rivers is on a measurable decline.

• Whitebark pine — keystone subalpine species — is in steep decline from white pine blister rust + warming-amplified mountain pine beetle outbreaks; loss propagates through Clark's nutcracker, grizzly bear, and other wildlife systems.

• Garden-relevant: high-elevation natives face habitat-island contraction; lower-elevation Cascade understory (sword fern, vine maple, Pacific rhododendron) carries forward strongly in PNW lowland gardens.

At a glance

States / provinces

Washington, British Columbia

Dominant biome

Temperate Conifer Forests

Realm

Nearctic

Approximate area

13,574 sq mi

Elevation range

500 – 10,781 ft

Climate type

Oceanic to alpine (Köppen Cfb / Dfb mid, ET above treeline)

Conservation tier

Nature Could Reach Half Protected (Dinerstein NNH 2)

About the temperate conifer forests biome

Temperate forests dominated by evergreen conifers, from coastal rainforests to montane pine and fir stands. Adapted to cool, moist or seasonally dry climates, they include some of the tallest and longest-lived trees on the planet.

National refinement sub-regions

Within this RESOLVE ecoregion, national agencies recognise finer-grained sub-regions. Plotwright assigns each sub-region polygon to its containing RESOLVE polygon by centroid.

EPA Level III (US-only) — 1 sub-region

77 · North Cascades

Source: USGS / EPA via Omernik (1987).

What's native here

Catalog plants whose Lady Bird Johnson Wildflower Center native-distribution range overlaps the 2-state/province roster for this ecoregion. Distinct from the “suited” section below — these are plants that belong here, not just plants that will grow here.

Grain caveat: native here means “native to at least one state / province this ecoregion crosses,” not necessarily native to this ecoregion's specific habitat. A plant tied to wet meadows that crosses Ontario will surface for any Ontario-spanning ecoregion. Finer per-ecoregion native-status data is a future arc.

Catalog plants suited to this ecoregion

Computed from each plant's stated USDA zone range against this ecoregion's USDA Plant Hardiness Zone Map 2023 (1991-2020 climatology) via ArcGIS FeatureServer published current zone range, with the CHELSA mid-century warming delta applied for the projection. Plants whose stated range falls outside both the current and projected zone end up dropped; the rest land in one of the three buckets below.

Climate-resilient picks · 265

These plants fit this ecoregion today AND remain in range under the mid-century SSP3-7.0 projection. Lead with these for a planting that holds up as the climate shifts.

American red raspberry

Bearberry (kinnikinnick)

Black tupelo (black gum)

Calendula (pot marigold)

Canadian serviceberry

Cantaloupe

Cardinal flower

Carolina allspice (sweetshrub)

Firecracker penstemon

Fragrant plantain lily

Maypop (purple passionflower)

Northern maidenhair fern

Short-toothed mountain mint

Summersweet (sweet pepperbush)

Tulip tree (yellow poplar)

Currently suited · 5

These plants fit the ecoregion as it is today, but the mid-century projection moves them outside their stated zone range — plan for them to struggle by 2070.

Newly possible by 2070 · 8

These plants don't fit the current zone range yet, but the mid-century projection brings them into reach. Long-horizon picks for the climate-adaptation wedge.

Wildlife your native plants here support

What this surface IS — and isn't

Inferred from the relationships catalog plants native to this region have with wildlife. We don't carry direct wildlife-range data per ecoregion — this lists what your native plant palette here can support, not a verified checklist of what occurs here. Cross-check the range note on each wildlife's detail page before treating a row as a presence claim.

Only plants with structured native-distribution data contribute here. Old World cultivars and most vegetables are excluded by design — this view shows “what your native palette supports,” not “what your whole garden does.” It will grow as more plants gain native-range data.

Larval hosts · 15

Plants that caterpillars and other larvae feed on while growing.

Butterfly

Eastern tiger swallowtail

Papilio glaucus

5 native plants here: Eastern cottonwood, Quaking aspen, Scarlet bee balm + 2 more

Butterfly

Common buckeye

Junonia coenia

4 native plants here: Blue vervain, Canada goldenrod, New England aster + 1 more

Moth

Hummingbird clearwing moth

Hemaris thysbe

4 native plants here: Chokecherry, Blue vervain, Scarlet bee balm + 1 more

Moth

Polyphemus moth

Antheraea polyphemus

4 native plants here: Chokecherry, Eastern cottonwood, Oregon white oak + 1 more

Moth

Io moth

Automeris io

3 native plants here: American red raspberry, Eastern cottonwood, Quaking aspen

Butterfly

Pearl crescent

Phyciodes tharos

3 native plants here: New England aster, Smooth blue aster, Canada goldenrod

Butterfly

Red-spotted purple

Limenitis arthemis astyanax

3 native plants here: Chokecherry, Eastern cottonwood, Quaking aspen

Butterfly

Spring azure

Celastrina ladon

3 native plants here: Blue elderberry, Chokecherry, Pacific dogwood

Moth

Hawkmoths

Sphingidae (family-level entry)

2 native plants here: Chokecherry, Wild bergamot

Butterfly

Mourning cloak

Nymphalis antiopa

2 native plants here: Eastern cottonwood, Quaking aspen

Butterfly · Specialist support

Skipper butterflies

Hesperiidae (family-level entry)

2 native plants here: Side-oats grama, Common yarrow

Butterfly

Viceroy

Limenitis archippus

2 native plants here: Eastern cottonwood, Quaking aspen

Moth

Cecropia moth

Hyalophora cecropia

1 native plant here: Chokecherry

Moth

Imperial moth

Eacles imperialis

1 native plant here: Vine maple

Butterfly

Silvery checkerspot

Chlosyne nycteis

1 native plant here: Cutleaf coneflower

Pollinators · 4

Wildlife that moves pollen between flowers as it forages.

Bee · Specialist support

Common eastern bumblebee

Bombus impatiens

21 native plants here: American red raspberry, Canada goldenrod, Common sunflower + 18 more

Bee

European honeybee

Apis mellifera

10 native plants here: Common sunflower, Anise hyssop, Blue vervain + 7 more

Bird

Ruby-throated hummingbird

Archilochus colubris

6 native plants here: Scarlet bee balm, Anise hyssop, Blue vervain + 3 more

Bee

Mason bees

Osmia spp.

2 native plants here: Chokecherry, Golden currant

Nectar foragers · 9

Wildlife drawing nectar from the plant.

Bee

Rusty-patched bumble bee

Bombus affinis

6 native plants here: Anise hyssop, New England aster, Scarlet bee balm + 3 more

Bee

Sweat bees

Lasioglossum spp.

6 native plants here: Anise hyssop, Blue vervain, California poppy + 3 more

Fly

Hover flies (flower flies)

Syrphidae

5 native plants here: Canada goldenrod, Common yarrow, New England aster + 2 more

Bee

American bumblebee

Bombus pensylvanicus

4 native plants here: Canada goldenrod, New England aster, Wild bergamot + 1 more

Butterfly

Monarch butterfly

Danaus plexippus

4 native plants here: Canada goldenrod, New England aster, Smooth blue aster + 1 more

Bee

Stem-nesting native bees

multiple genera (Ceratina, Hylaeus, Osmia, etc.)

3 native plants here: Common camas, Canada goldenrod, Wild bergamot

Butterfly

Great spangled fritillary

Speyeria cybele

2 native plants here: Anise hyssop, Blue vervain

Other

Green lacewings

Chrysopidae

2 native plants here: Anise hyssop, Common yarrow

Butterfly

Painted lady

Vanessa cardui

2 native plants here: Anise hyssop, New England aster

Pollen foragers · 3

Wildlife collecting pollen for food or provisioning.

Bee

Long-horned bees

Melissodes spp.

6 native plants here: Canada goldenrod, Common sunflower, Cutleaf coneflower + 3 more

Bee

Leafcutter bees

Megachile spp.

4 native plants here: Anise hyssop, Blue vervain, Scarlet bee balm + 1 more

Bee

Mining bees

Andrena spp.

3 native plants here: Chokecherry, Golden currant, Prairie smoke

Fruit foragers · 6

Wildlife eating the plant’s fruit.

Bird

Eastern songbirds (multi-species)

multiple species (Passeriformes)

16 native plants here: American red raspberry, Bearberry (kinnikinnick), Blue elderberry + 13 more

Bird

Downy woodpecker

Dryobates pubescens

7 native plants here: Blue elderberry, Golden currant, Anise hyssop + 4 more

Bird

American robin

Turdus migratorius

4 native plants here: Blue elderberry, Chokecherry, Golden currant + 1 more

Bird

Cedar waxwing

Bombycilla cedrorum

2 native plants here: Chokecherry, Pacific dogwood

Bird

Eastern bluebird

Sialia sialis

2 native plants here: Blue elderberry, Chokecherry

Bird

Baltimore oriole

Icterus galbula

1 native plant here: Chokecherry

Seed foragers · 3

Wildlife eating the plant’s seed.

Mammal

White-tailed deer

Odocoileus virginianus

5 native plants here: Oregon white oak, Blue elderberry, Chokecherry + 2 more

Bird · Specialist support

American goldfinch

Spinus tristis

4 native plants here: Common sunflower, Cutleaf coneflower, New England aster + 1 more

Mammal

Eastern gray squirrel

Sciurus carolinensis

1 native plant here: Oregon white oak

Shelter · 4

Wildlife nesting in or sheltered by the plant.

Bird

Black-capped chickadee

Poecile atricapillus

4 native plants here: Chokecherry, Eastern cottonwood, Oregon white oak + 1 more

Beetle

Lady beetles

Coccinellidae

3 native plants here: Anise hyssop, Canada goldenrod, Chokecherry

Beetle

Common eastern firefly

Photinus pyralis

2 native plants here: Oregon white oak, Quaking aspen

Bird

Eastern phoebe

Sayornis phoebe

2 native plants here: Eastern cottonwood, Red-osier dogwood

Collections for this ecoregion

Curated multi-plant collections whose members all fit this ecoregion's zone range — no won't-grow members smuggled in. Overall fit class shown per collection is the weakest link across its members.

Climate-resilient · 2 plants

Bright shade foundation

A part-shade starting point with shrub structure and low foliage contrast.

Annabelle hydrangea

Coral bells

Climate-resilient · 8 plants

Climate-resilient natives for warming zones (eastern NA)

A pollinator-supporting palette of eastern NA natives whose USDA zone range and broad continental distribution score high on the climate-resilience composite. Every plant tolerates 6-7 USDA zones and is native across 15+ US states + multiple Canadian provinces. Holds up under the SSP3-7.0 mid-century projection without the gardener trading wildlife value for resilience.

Switchgrass

Little bluestem

Common milkweed

Black-eyed Susan

Wild bergamot

Sweet Joe-Pye weed

Cutleaf coneflower

New England aster

Climate-resilient · 6 plants

Mediterranean drought-tolerant edible

A low-water edible palette of culinary herbs + a hardy grape for hot dry sunny sites. Mediterranean-origin plants thrive on neglect; their primary failure mode is overwatering, not underwatering.

English lavender

Rosemary

Garden sage

Oregano

Common thyme

Fox grape

Climate-resilient · 9 plants

Native pollinator border (eastern US)

A continuous-bloom native pollinator strip for eastern North America. Covers spring through frost with host + nectar plants spanning monarchs, native bees, hummingbirds, and specialist Lepidoptera. Little bluestem provides the matrix grass + Hesperiidae host.