BIOMES What determines a terrestrial biome Climate Temperature

BIOMES

What determines a terrestrial biome? • Climate – Temperature – Precipitation • Similarly adapted plants & animals • Can vary depending on external forces- human disturbance • Fire important to many… – Controls tree pop. – Adds nutrients to soil – Plant seeds germinate

TUNDRA • Extreme northern hemisphere • Long cold winters, short cool summers; very little precip. called “arctic desert” • Permafrost- soil frozen • Short plants, lichen, mossno trees (too windy, thin soil) • Reindeer, polar bears, arctic fox, insects, birds • Threats: fragile food webs, oil spills, global warming

TAIGA • Below tundra • Long cold winters, summer 3 -4 months; more precip than tundra (snow) • Soil acidic due to evergreen needles. • Mostly coniferous treesplant biodiversity low due to acidic soil. • Grizzlies, wolverines, moose, cougars • Threats- deforestation

TEMPERATE DECIDUOUS FOREST • Mid-latitudes • Moderate winters & summers; moderate precip. • Soil rich in humusdecaying matter. • Deciduous trees- drop leaves in winter to conserve water. • Deer, rabbits, rodents, raptors, • Threats: Deforestation

TROPICAL RAINFOREST • • • Located around equator- most biodiverse place on planet. Warm & wet all year- 250 cm rain/year, no distinct seasons. Soil- low nutrients due to high # of decomposers Diverse Plant life – Forest floor- moss, ferns – Understory- saplings, shrubs – Canopy- most trees – Emergent Layer- a few taller trees Monkeys, jaguars, sloths, raptors, insects, tapirs Threats: deforestation, farming

DESERT • Arid regions – can be hot or cold deserts. • Receives 10 -25 cm of rain each year. Hot days/cold nights (no clouds to hold heat in) • Soil high in minerals, low in organic matterslow decomposition • Plants adapted to dry conditions • Thick stems to store water • Thorns to deter herbivores & conserve water • Shallow roots- infrequent rains • Rodents, reptiles, raptors, camels, jackrabbits, coyote • Nocturnal • Large ears to dissipate heat • Threats- ATV’s, only growing biome

CHAPPARAL • Edges of deserts • Mild rainy winter, long hot summers • Soil- more nutrients due to higher rain • Shrubs, cacti- adapted to frequent fires- seed germination, soil nutrients • Seed eating birds, rodents, deer, rodents • Threats- land development

TEMPERATE GRASSLANDS • Eastern side of mountains • Cold winters, hot summerslittle rainfall • Soil- rich in nutrients • Grasses dominant plantthick mat-like roots; increased rainfall = taller grasses • Bison, antelope, prairie dogs, burrowing animals • Threats: desertification; misuse by ranchers/farmers

SAVANNAS • Most of Africa, some of S. America & Australia • Receive a little more rainfall than prairie. • Soil- rich in nutrients • More trees here due to increased rain- Acacia trees • Cheetah, giraffes, zebras, lions, etc. • Threats: habitat destruction, poaching

What determines water biomes? • Salinity – Animals must be adapted to varying levels • Light availability – Photic zone- light penetrates – Aphotic zone- no/very little light

AQUATIC BIOME • Less than 3% salt • Moving waters – – Rivers, streams Fast, highly oxygenated Colder, clear Algae attached to rocks, some streamlined plants – Insect larvae, trout • Standing waters – – – Lakes, ponds Slow, low oxygen Warmer, murky Algae, cattails, lily pads, etc. Catfish, frogs, snakes, salamanders

Zones of Lakes • Littoral- closest to shore • Limnetic/pelagicopen water; well lit; plankton • Profundal- deep water; colder; lower oxygen; less light so fewer plants/algae which means fewer animals.

Transitional Aquatic Ecosystems • Wetlands- soil is saturated with water – Swamps- dominated by trees – Marshes- dominated by grasses – Bogs- nitrogen poor soil; carnivorous plants – All are important to prevent flooding, provide habitat for numerous species, filter pollutants • Estuaries- where freshwater rivers dump into oceans – Almost as biodiverse as coral reefs or rainforests – Organisms adapted to changes in salinity

MARINE BIOME • 3% Salt Zones of Ocean: • Intertidal zone- flooded by high tides, dry during low tides • Pelagic zone- open water; most of phytoplankton lives here • Benthic zone- bottom of oceanlittle/no light, limits life. • Abyssal zone- deepest trenches; organisms feed on food that drifts down; may find hydrothermal vents with invertebrates.