Biomes: Tundra, Taiga, Deciduous Forests

Tundra Background - General

Cold, treeless biome

Tundra Background - Between…

Polar ice caps and the taiga (boreal forest)

Tundra Background - Covers

Northern Canada, Alaska, Siberia, Greenland

Tundra Background - Key factors

Extreme cold, short growing season, permafrost, strong dry winds

Tundra - Temperature

Ground frozen year round

Tundra - Temperature: Permafrost…

prevents deep roots and trees

Tundra - Temperature: Summertime…

Thaws and creates bogs, ponds, shallow lakes

Tundra - Soil

Slow decomposition, acidic, often waterlogged

Tundra - Wind

Strong dry wind

Tundra - Strong dry wind

Plants grow low to the ground. Boundary layer (warmer, less wind)

Tundra - Growing season

Extremely short, long daylight during summer, slow maturity in plants.

Tundra Subtypes: Article Tundra

High latitude of NA, Europe, Asia. Circumpolar

Arctic Tundra - Growing season

Extremely short

Arctic Tundra - Low Precipitation

Frozen soil keeps soil waterlogged

Arctic Tundra - Almost ___ hours of sunlight in the summer

24 hours

Arctic Tundra - Vegetation

Growth forms of plants: Tussocks and mats, evergreen shrubs hairy stems and leaves, shallow roots

Arctic Tundra - Tussocks and mats

Protect from wind and conserve warmth

Arctic Tundra - Evergreen shrubs

Keep leaves year-round

Arctic Tundra - Dominant vegetation species

Arctic willow, sedges, grasses, moss, lichens. Low to the ground, flexible.

Arctic Tundra - Animal Adaptations: Numbers

Few residents-large numbers.

Arctic Tundra - Animal Adaptations: Food Chains

Short, simple food chains. One grazer can support multiple carnivore species

Arctic Tundra - Animal Adaptations

No hibernation. Fat layers, stocky bodies, double fur layers. Seasonal color change.

Arctic Tundra - Include both…

Resident and migratory species.

Arctic Tundra Animals - Summer

Insect explosions: mosquitos and flies

Arctic Tundra Animals - Residents

Snowy owls, lemmings, ptarmigans, Arctic fox, polar bear

Arctic Tundra Animals - Migrators

Caribou, snow geese, wolves, waterfowl

Antartica Tundra - Locatoin

Many please on Antarctic Peninsular

Antartica Tundra - Extremely…

Cold, dry, and windy

Antartica Tundra - Few ice-free areas

Not areas are covered in ice year round. Some barren areas (no growth).

Antartica Tundra - Plants

Lichens, moss, grass, two flowering plants. Extremely short growing season

Antartica Tundra - Animals

Springtails, mites, nematodes, tardigrades, no large land animals, penguins, seals, whales

Alpine Tundra - Location

Anywhere on earth: high elevations. Rockies, Andes, Alps, Himalayas, Kilmanjaro

Alpine Tundra - Climate

Varies seasonally and daily

Alpine Tundra has ____ UV and solar radiation exposure.

Intense

Alpine Tundra - Short Growing Season

Extreme temperature swings daily, freeze and thaw within 24 hours

Alpine Tundra - Plants resemble…

Arctic tundra species

Alpine Tundra - Plants

Mosses, lichens, grasses, often dense mats, deep roots, red pigmentation (uv protection)

Alpine Tundra - Plants contain…

Antifreeze components in tissues

Alpine Tundra - Animals are…

Herbivores that shelter in rocks, hibernate

Alpine Tundra - Animals

Pikas, marmots, alpacas, mountain goats, snow finches, pipits, raptors (seasonally)

High Altitude Tropical Environments

Above tree line but below snow line in tropical mountains

High Altitude Tropical Environments - Tropical version of ____

Alpine tundra

Tropical version of alpine tundra:

Cold nights, intense sun, thin air

High Altitude Tropical Environments - Regions

Paramo (northern Andes), Afro-Alpine (Kilimanjaro, Mt. Kenya), Himalayan highlands, New Guinea Highlands

High Altitude Tropical Environment - Plants evolved from…

Lowland tropical ancestors, not tundra

High Altitude Tropical Environment - Plants

Wet grasslands, shrubs, dwarf bamboo, giant groundsels (daisies)

High Altitude Tropical Environment - Animals

Few vertebrates, mountain viscachas, Andean condor, cold-tolerant invertebrates.

Taiga (conifer or boreal forest) is the …

Largest continuous biome

Taiga - Where

South of tundra: Canada, Alaska, Scandinavia, Siberia

Taiga - Key Factors

Cold, long winders. Cool, short summers. Low species diversity. Large carbon storage (soil). Coniferous trees.

Taiga - Soils are…

Thin, nutrient-poor, and acidic. Low soil fertility. pH of ~4. Large amounts of leaching.

Taiga Soils - Water retention

Permafrost and peat slow percolation (standing water and bogs), sandy permeable soil, water is a limiting factor here

Taiga Climate - Winters

Extremely cold, ~40C common

Taiga Climate - Precipitation

Moderate, 15-20 in (half snow), sudden thaw leads to high runoff.

Taiga climate - Growing season

3-4 months

Taiga Climate - Permafrost

Year round in northern regions

Taiga - Plant Ecology

Water stress, Dark green color allows earlier photosynthesis

Taiga - Water stress

Trees shaped to shed snow. Needles to conserve water. Keep leaves year round

Taiga Understory Zones - North

Transition to tundra. Spruces, mosses, lichens.

Taiga Understory Zones - Central

Dense shrubs, moss cover

Taiga Understory Zones - South

Closed canopy. Tall trees, few ground plants.

Taiga Understory Zones- Fire

Dominant ecological driver, restarting succession. Deciduous trees often pioneers (birch, willow)

Taiga Understory Zones - Nitrogen

Scarce, lichens and mosses may outcompete trees

Common Taiga Plants

Vary depending on local environment

Common Taiga Plants - Wet areas

muskeg, peat moss

Common Taiga Plants - Bogs and fens

Willow, poplar

Common Taiga Plants - Dry uplands

Conifers. Spruce, fir, pine.

Taiga Animals

Few animals can digest conifer needles. 90% of birds in the taiga migrate.

Taiga Animals - Mammals

moose, elk, caribou, wolf, lynx, fox, grizzly bear, voles

Taiga Animals - Birds

Owls, crossbills, grouse

Taiga Animals - Insects

Mosquitoes and flies intense in summer

Taiga - Regional Variations

North America (Canada, Alaska), Appalachians, Eurasia (Siberia, Scandinavia)

Taiga - North America - Where

Canada, Alaska, Northern U.S. mountains

Taiga - North America - Dominant species

black spruce, white spruce, balsam fir, jack pine

Taiga - North America - Notable Features

extensive permafrost, peatlands, fire and insect outbreaks

Taiga - Appalachian - Where

Eastern US mountain zones

Taiga - Appalachian - Dominant trees

red spruce, Fraser fir, balsam fir

Taiga - Appalachian - Notable features

found at high elevations “islands”. Host relict species of last glaciation

Taiga - Eurasian - Where

Scandinavia, Russia, Siberia

Taiga - Eurasian - Dominant trees

Norway spruce, Scots pine, Dahurian larch

Taiga - Eurasian, Notable features

Siberian taiga is the largest terrestrial biome. Supports large mammals (brown bear, lynx, moose, wolverine). Extremely nutrient poor soil

Importance of Taiga

Carbon storage, climate regulation, vulnerability

Taiga - Carbon storage

Soil stores more carbon than tropical forests. Slow decomposition

Taiga - Climate regulation

Snow and conifer canopies affect albedo and carbon cycle

Taiga - Vulnerability

Permafrost thaw, Increase in fire frequency

Deciduous Forest

Mid-latitude regions. Distinct seasons. Moderate precipitation. Broadleaf, seasonally shedding trees.

Deciduous Forest - Location

Eastern NA, Europe East Asia, New Zealand

Deciduous Forest Climate - Precipitation

20-100 in/year. Evenly distributed.

Deciduous Forest Climate - Temperature

Distinct seasonal changes. Warm summer. Cold winter (below freezing is common). Trees shed leaves

Deciduous Forest Climate - Growing Season

6 months (longest of the lecture)

Deciduous Forest - Soil

Soils vary greatly. Alfisols, utlisols primarily. Some are extremely fertile. Less acidic than taiga (less leaching). Richest in NE USA (cool, moist areas).

Deciduous Forest - Plant Ecology

Closed canopy, multi-layered forest. Canopy, sapling layer, shrub layer, ground layer

Deciduous Forest - Canopy

Tall, deciduous trees. Oak, maple, beech.

Deciduous Forest - Ground layer

Well developed. More light reaches floor. Canopy is less dense. Spring plants bloom earlier. Longer growing season

Deciduous Forest - USA subtypes - Beech-Maple

North Central USA. Lush ferns, dense under

Deciduous Forest - USA subtypes - Maple-Basswood

Upper Midwest (WI)

Deciduous Forest - USA subtypes - Oak-Hickory

West and South (dryer)

Deciduous Forest - USA subtypes - Oak-Chestnut

Appalachians. Now mostly oak

Deciduous Forest - USA subtype - Mixed Mesophytic

Appalachians. Highly divers. Oaks, hickory, poplar.