Two Key Habitats in Acadia National Park: Rocky Shores and Acadian Forests

Acadia National Park (Mount Desert Island, Maine) protects a dramatic coast-to-summit gradient. Two foundational habitats define its ecology:

1. Rocky Shores & Intertidal Zone

• Geology: Glacially sculpted pink granite (Cadillac Mountain pluton), sheer cliffs, pocket beaches
• Zonation: Splash zone (lichens, periwinkles) → barnacle zone → mussel/rockweed zone → kelp zone (subtidal)
• Species: Barnacles (Semibalanus), blue mussels, dog whelks, sea urchins, sea stars, Jonah crabs, harbor seals, eiders, purple sandpipers
• Tides: 3–4 m range exposes vast intertidal — 12-hr cycle drives feeding, competition, predation

2. Acadian Forest (Transition Forest)

• Composition: Boreal (spruce, fir, paper birch) + Northern Hardwood (maple, beech, yellow birch, hemlock) mix
• Structure: Multi-aged, gap-driven regeneration, thick duff, coarse woody debris
• Fauna: White-tailed deer, red fox, raccoon, porcupine, snowshoe hare, bobcat, black bear; warblers, thrushes, owls, woodpeckers; salamanders (red-backed, spotted)
• Distinctive: Red spruce dominance at higher elevations; cedar swamps in hollows

Other Habitats

Freshwater lakes/ponds (Jordan Pond, Eagle Lake), subalpine heath (Cadillac summit), freshwater wetlands, carriage road corridors.

Climate Pressure

Warming → spruce/fir retreat upslope, hardwoods advance, phenology mismatches, invasive pests (hemlock woolly adelgid, winter moth). Acadia is a sentinel park for boreal-temperate transition.

Rocky shore meets spruce-fir forest: where the continent exhales into the Atlantic.