Altitudinal Gradients• An increase in altitude (elevation) mimics a

progression towards northern biomes

Altitudinal gradient on a tropical mountain

In Western Maine and New Hampshire…

• At the mountain base, northern hardwood species (sugar maple, American beech, yellow birch) or oak hardwood species

• Spruce and balsam fir forests further up• Krummholtz “sub alpine” zone - stunted, dwarf

trees, often flagged• Alpine zone - above treeline (grasses, lichens,

specialized plants)• Drastic changes in plant communities and

forest structure

Alpine Communities

• Very rare (<5% of terrestrial habitat on planet)• Very similar species to tundra biomes• Mount Washington biggest alpine zone east of

Mississippi (Mt. Katahdin is second).• Plants remenants of last glacial retreat (9000

years ago)• Very fragile (easily trampled by humans)• Endemic plant species present• Threated by warming trend (global warming)

Alpine Vegetation• Low lying (cushions) for protection against snow

• Have thick, waxy leaves to prevent wind/snow damage

• Alpine plants can tolerate extremes in environment (drying winds, acidic soils, scant water, ice coating)

• Evergreen leaves to save energy of foliation in spring

Moss Campion

Silene acaulis

Alpine Azalea

Diapensia lappocona

Cladina stellarisStar-tipped reindeer lichen

• Lichen - mutualism between algae and fungi

• Attaches to hard substrates (rocks, trees)

• Nutrients from air and photosythesis

• Bioindicator

• Cladina stellaris important food for caribou

Birds of the Alpine Zone

• American Pipit– Rare in the East

– Only nests on Katahdin and Presidentials

Mammals

• Caribou once roamed throughout New England’s alpine zones

• Extirpated by turn of century

• Reintroduction to Baxter State Park failed in 1980s

What we will do on Bald Face?• Measure canopy height• Measure % canopy cover and light intensity• Record tree species and diameter (dbh) in

10x10 meter plots• Collect a soil sample and measure horizons• Record height and % cover of forest layers

(herbacious, shrub, subcanopy, canopy)• Identify plant species (herbs, shrub, fern, etc)• Determine Stand Age• Incidental mammals, herps, birds