Location: tropical forest occurs in equatorial & subequatorial region

Precipitation: rainfall is relatively constant, about 200-400 cm annually ( in tropical dry forest precipitation is highly seasonal about 150-200 cm annually w/ 6 to 7 months of dry season)

temperature: high year-round, averaging 25-29 degrees Celsius with little seasonal variation

Dominant organisms: trees, shrubs & herbs ( small, non-woody plants), insects, spiders, & arthropods, amphibians , birds & other reptiles, & mammals

location: deserts occur in bands near 30 degrees north & south latitude or at other latitudes in the interior of continents

precipitation: It is low and highly variable, generally less than 30 cm per year

temperature: is variable seasonally & daily; maximum air temperature in hot desert may exceed 50 degrees Celsius; cold desert temp. may fall below -30 degrees Celsius

Dominant organisms: low, widely scattered vegetation; cacti or euphorbs, deeply rooted shrubs, also snakes, lizards, scorpions, ants, beetles, birds,& seed eating rodents

precipitation: seasonal rainfall averages 30-50 cm per year; dry season can last up to 8 or 9 months

temperature: warm year around; averaging 24-29 degrees Celsius, but with somewhat more seasonal variation that in tropical forest

Dominant organisms: scattered trees, different densities often thorny & have small leaves, forbs, large plant-eating mammals (zebra, wildebeests) & insects; also large predators like lions& hyenas

precipitation: highly seasonal, w/ rainy winters & dry summers; annual precipitation generally falls within the range of 30- 50 cm

temperatures: fall, winter, & spring are cool averaging 10-12 degrees Celsius ; average summer can reach 30 degrees Celsius

Dominant organisms: shrubs, small trees, variety of grasses & herbs, adapted woody plants; mammals such as dear, goats, amphibians, birds & other reptiles, & insects

Location: veldts of south Africa, the puszta of Hungary, pampas of Argentina & Uruguay , & North America are all example of temperate grassland

precipitation: often highly seasonal, w/ relatively dry winters & wet summers annual precipitation generally average 30- 100 cm ; droughts are also common

temperature: winters generally cold , average temp. falling below -10 degrees Celsius; summers average approach 30 degrees Celsius

Dominant organisms: grasses & forbs; which vary in height from few cm to 2 m in tallgrass prairie ; large grazers such as bison & wild horses, burrowing mammals, such as prairie dogs in north america

Location: extending in a broad band across northern North America & Eurasia to the edge of the arctic tundra; largest biome on Earth

precipitation: annual precipitation ranges from 30-70 cm, droughts are common; (some coastal coniferous forest are temperate rain forest & may receive over 300 cm annually of precipitation)

temperature: winters are usually cold; summer may be hot; some areas of coniferous forest in Siberia typically range from -50 degrees Celsius in winter & over 20 degrees Celsius in summer

Dominant organisms: cone-bearing trees( pine, spruce, fir, & hemlock) , shrubs& herb layers; moose, brown bears, & Siberian tigers

location: found mainly at midlatitudes in the Northern Hemisphere, w/ smaller areas in Chile, South Africa, Australia, & New Zeland

Precipitation: it can average from 70 to over 200 cm annually, significant amounts fall during all seasons, including summer rain & some forest winter snow

temperature: Winter temp. average 0 degrees Celsius; temp. up to 35 degrees Celsius ( hot & humid)

Dominant Organisms: closed canopy, one or two strata of understory trees, a shrub layer, 7 a herb layer; many mammals, & birds, insects

Location: covers expansive areas of the arctic, amounting to 20% OF Earth land surface, Very high mountaintops at all latitudes, including the tropics

Precipitation: precipitation averages from 20-60 cm annually in arctic tundra but may exceed 100 cm in alpine tundra

Temperature: Winters are cold, w/ averages in some areas below -30 degrees Celsius ; Summer temp. are generally average less than 10 degrees Celsius

Dominant Organisms: Mostly herbaceous , mixture of mosses, grasses, & forbs along with some dwarf shrubs & tree & lichens; oxen, bears, wolves, & foxes, birds migrate

light decreases with depth, creating stratification temperate lake may have a seasonal thermocline

Standing bodies of water ranges from ponds a few square meters in areas to lake covering thousands of square kilometers

Oligotrphic lakes tend to be nutrient poor & generally oxygen-rich

high rates of decomposition in deeper layers of eutrophic lakes cause periodic oxygen depletion; the amount of disposable organic matter in bottom sediments is low in oligotrophic lakes & high in eutrophic lakes

wetland is a habitat that is inundated by water at least some of the time & that support plants adapted to water-saturated soil

some wetlands are inundated at all times, whereas other flood infrequently

both the water & the soil are periodically low in dissolved oxygen

Wetland have a high capacity to filter dissolved nutrients & chemical pollutants

most prominent characteristic is speed & volume of their flow; streams & rivers are stratified into vertical zones

Streams are generally cold, clear, swift, & turbulent; father downstream tributaries join forming a river which are warmer & more turbid

Salt & nutrients content of streams & rivers increase from the headwaters to the mouth

headwaters are generally rich in oxygen, downstream water may also contain substantial oxygen except where there has been organic enrichment

large fraction of the organic matter in rivers consists of dissolved or highly fragmented material

estuary is a transition area between river & sea; seawater may flow up or down during different tides

Ofton higher-density seawater occupies the bottom of the channel & mixes little w/ the lowest-density river water at the surface

salinity varies spatially within estuaries, from nearly that of fresh water to the of seawater

Nutrients from the river make estuaries, like wetland, among the most productive biomes

Intertidal zones is periodically submerged & exposed by the tides, twice daily on most marine shores

Upper zones experience longer exposures to air & greater variation in temp. & salinity

Changes in physical conditions from the upper to the lower intertidal zones limit the distribution of many organisms to particular strata

Oxygen & nutrient levels are generally high & are renewed w/ each turn of the tides

Oceanic pelagic zone is a vast realm of open blue water, constantly mixed by wind driven oceanic current

because of higher water clarity, the photic zone extend to greater depth than in coastal marine water

Oxygen levels are generally high; nutrients concentration are generally lower that in coastal waters

because they are thermally stratified year-around, some tropical zones have lower nutrient concentrations than temp. oceans

coral reefs are formed largely from the calcium carbonate skeletons of corals. shollow reef-building corals live in the photic zone of relatively stable tropical marine environment w/ high water clarity

Sensitive to temp. below about 18-20 degrees Celsius & above 30 degrees Celsius; Deep coral reefs are found between 200 & 1500 m deep

Coral requires high oxygen levels & are excluded by high inputs of fresh water & nutrients

Marine benth Zone consist of the seafloor below the surface waters of the coastal, or neritic, zone & the offshore pelagic zone

Except in areas of organic enrichment, oxygen is usually present at sufficient concentration to support divers animal life

since the Earth is tilted on its axis (23.5 degrees) the intensity of the solar radiation can vary seasonally

21st of June/ December is when the tilt is direct or further from the sun

when tilts is perpendicular to the sun on 21st of March/ September

step 3. less moisture is left in the air reaching the leeward side, which therefore has little precipitation, the rain shadow can create a desert on the back side of the mountain