Biomes summary flashcards

Tropical rainforest: climate type

Af climate, no dry season, average monthly T > 18°C

Tropical rainforest: rainfall

2000 mm, dry season < 2 months

Tropical rainforest: location

10°N – 10°S, below 1000m. Congo, SE-Asia, tropical America

Tropical rainforest: key vegetation traits

Buttresses, drip tips, cauliflory, aerial roots, thin smooth bark

Tropical rainforest: species coexistence

Intraspecific clustering, many rare species, independent placement of individuals

Tropical rainforest: main threat

Deforestation; nutrient-poor soils left behind, erosion, hardens like cement

Tropical montane forest: key traits

Shorter trees, more epiphytes, less lianas, moisture from condensation

Tropical montane forest: other name

Elfin forest or cloud forest

Tropical dry forest: climate type

Aw climate, 1–2 dry periods of 2–6 months, rainfall 250–2400mm

Tropical dry forest: vegetation subtypes

Tropical deciduous forest, thorn forest, tropical woodland

Tropical dry forest: main threat

Soils are better for farming, so rapidly converted to agricultural land

Tropical savanna: climate

Aw climate, dry season 3–9 months, rainfall 500–1500mm, warm year round

Tropical savanna: location

10°–30° latitude, mostly Africa, Australia, South America

Tropical savanna: vegetation traits

Tall perennial C4 grasses, drought- and fire-resistant trees, leathery leaves, deep taproots

Tropical savanna: non-climate factors

Poor soil drainage, soil infertility, grazing, frequent fire

Tropical savanna: animal diversity

World's largest diversity of hoofed animals in African savanna

Hot desert: rainfall

< 400mm; true desert < 120mm, extreme desert < 70mm

Hot desert: causes

Subtropical high pressure (~30°), rainshadow, interior continental location, cold coastal winds

Hot desert: vegetation adaptations

Succulents, annuals, bulbs, halophytes, window plants, tillandsias

Hot desert: animal adaptations

Nocturnal, long appendages, small bodies, concentrate urine, light colour

Cold desert: difference from hot desert

Same low rainfall but prolonged periods below 0°C, hot summers above 40°C

Cold desert: examples

Great Basin (USA), Gobi (Mongolia), Patagonia (Argentina)

Cold desert: vegetation

Shrubs, subshrubs, bulbs, halophytes, cushion plants; fewer succulents than hot desert

Temperate grassland: climate

Bsk climate, semi-arid continental, rainfall 250–750mm, cold winters, warm summers

Temperate grassland: location

Interior of N-America and Eurasia, rainshadows in S-America and S-Africa

Temperate grassland: vegetation types

Shortgrass prairie, mixed grass prairie, tallgrass prairie

Temperate grassland: soil

Most fertile soils on earth, thick humus layer, high in nutrients and organic matter

Temperate grassland: threats

Loss of fire, cattle replacing wild grazers, non-native species, conversion to cropland

Mediterranean woodland: climate

Cs climate, cool wet winters, hot dry summers, rainfall 380–1000mm

Mediterranean woodland: 5 regions

California, Cape (S-Africa), Mediterranean basin, SW Australia, Central Chile

Mediterranean woodland: vegetation traits

Evergreen sclerophyllous shrubs, leathery leaves, sunken stomata, long taproots, bulbs

Mediterranean woodland: fire adaptations

Resprout from root crown, serotiny, aromatic oils promote fire, seeds stimulated by fire

Temperate deciduous forest: climate

Cfa/Cfb or Dfa, rainfall 750–1250mm, cold winters, warm to hot summers

Temperate deciduous forest: location

E North-America, E-Asia, Europe

Temperate deciduous forest: structure

Multi-layered: tall canopy, lower canopy, shrub layer, herb layer

Temperate deciduous forest: tree examples

Oak, maple, beech, chestnut, elm, linden, walnut

Temperate deciduous forest: threats

Deforestation, air pollution, introduced diseases (e.g. chestnut fungal infection)

Temperate rainforest: climate

Maritime influence, cool temperatures, abundant rainfall

Temperate rainforest: vegetation

Conifers in N-America; broad-leaved trees in Chile, NZ, Australia; some of tallest trees on earth

Temperate rainforest: threats

Clear-cut logging, low-diversity plantations; disappeared faster than tropical rainforest until recently

Boreal forest: climate

Dfc/Dfd/Dwd, long cold winters, short cool summers, 400–500mm rainfall

Boreal forest: other names

Taiga, evergreen needle-leaf forest, northern coniferous forest

Boreal forest: coverage

1/3 of all forested area on earth

Boreal forest: tree examples

Spruce, fir, pine, larch, alder, aspen, birch

Boreal forest: vegetation adaptations

Conical shape, dark needles, sunken stomata, thick cuticle, frost hardening in autumn

Boreal forest: succession

Birch/aspen → spruce → N decrease → spruce disappears → birch/aspen → …

Boreal forest: threats

Commercial lumbering; climate change causing wildfires and CO2 feedback loop

Tundra: climate

ET climate, mean annual T < 0°C, growing season < 50 days, 200–500mm precipitation

Tundra: location

Northern N-America and Eurasia; small areas on Antarctic peninsula

Tundra: vegetation traits

Mosses, lichens, graminoids, dwarf shrubs; grow close to ground for warmth

Tundra: plant adaptations

Slow growth, vegetative reproduction, underground energy storage, hairs for insulation

Tundra: animal adaptations

Thick fat, small surface/volume ratio, short limbs and ears, double fur, seasonal colour change

Tundra: soil

Shallow, nutrient-poor, continuous permafrost