Earth has different physical regions {ecosystem}|, closely related to climate. Ecosystems include broadleaf forest, coniferous forest, desert, savanna, prairie, sclerophyll woodland and shrub, swamp, tropical forest, tropical rain forest, steppe, and tundra. Biological systems have climates, inorganic matter, organic matter, producers, and consumers. Cities are warmer, less humid, cloudier, foggier, rainier, snowier, and less sunshiny, and have less ultraviolet light, than countryside.
Ecosystems have regions {biogeographic realm}. Palearctic includes Europe, Russia, north China, Japan, and Iceland. Nearctic includes Greenland, Canada, and USA. Palearctic and Nearctic together are Holarctic. Neotropical includes Mexico, Central America, South America, and West Indies. Ethiopian includes Africa south of Sahara Desert. Oriental includes India, Indochina, Malay Peninsula, south China, and East Indies. Australian includes Australia, New Zealand, New Guinea, and East Indies.
Vertebrate species typically have ranges {biogeography} smaller than large USA states. Common birds, such as cowbirds, grackles, and cardinals, have larger ranges. Only species with large ranges are not rare. Most vertebrate species are rare.
State-size regions can have few, medium, or many species, depending on climate and resources. Tropical areas have 100 times more species than arctic areas. Areas with many species have species with large ranges. Areas with few species have species with small ranges.
The world {biosphere}| includes many different environments for living things.
Species can have gradual anatomy and physiology changes throughout gradually changing geographic areas {cline}|.
Species have roles {ecological niche}| {niche, ecology} in ecosystems.
Species inhabit environments {habitat}|.
rivers and coasts {limnology}|.
Different communities live in different geographic zones {bione}|.
forest
Forest biones include broad-leaved evergreen subtropical forest, chaparral, coniferous forest, deciduous forest, and tropical rain forest.
ocean
Sea biones include neritic zone, littoral zone, continental shelf below low tide, oceanic zone, euphotic zone, bathyal zone, and abyssal zone.
other
Other biones include desert, grassland, tundra, snow and ice, estuary, marsh, running water, littoral, limnetic zone, standing water, and deep water.
changes
Biones gradually change or cycle. Sahara desert expands and contracts in a 30-year cycle.
More species and higher population densities are at bione boundaries {ecotone}.
dry bushy plains {prairie}|.
wide dry grassy plains {savanna}|.
Animals can live between low-tide and high-tide lines {tide pool}|: sea anemone, sculpin fish, hermit crab, chiton, ochre star, barnacle, limpet, mussel, and turban snail. Algae and other plants are in tide pools. Sea urchin, abalone, sunflower star, bat star, and giant sea anemone live below low-tide line.
In ocean, animal masses {deep scattering layer} (DSL) rise at night and fall by day, in vertical migration.
Ocean zones {oceanic zone} include bathyal and abyssal zones.
Oceanic zones {abyssal zone} can be below 2000 meters.
Oceanic zones {bathyal zone} can be from surface down to 2000 meters.
Oceanic zones {euphotic zone} can have light.
ocean coasts and river mouths {limnetic zone}.
Continental shelf {littoral zone} can be between tides.
Continental shelf {neritic zone} can be above high tide.
vegetation-rich still water {swamp}|.
Swamps can have phosphorescent light {ignis fatuus}| {will of the wisp} {friar's lantern}, from spontaneous methane combustion.
Nutrients undergo recurring use and storage {ecological cycle}. Carbon atoms circulate between organism organic molecules and environment carbon dioxide and calcium carbonate {carbon cycle, ecology}. Nitrogen atoms circulate between organism proteins and environment nitrogen gas, nitrates, and nitrites {nitrogen cycle, ecology}. Phosphorus atoms circulate between organism organic phosphates and environment mineral phosphates {phosphorus cycle}. Water molecules circulate between organism cells and intracellular fluids and environment oceans, clouds, and fresh water {water cycle, ecology}.
Nutrients leave and return {cycling pool} {exchange pool} from and to reservoir pools. Detritus and excrement recycle nutrients.
Nutrients are in ocean, atmosphere, and crust {reservoir pool}.
Energy circulates between organism organic-molecule bonds and environment heat and sunlight {energy cycle, ecology}. Ecosystems have energy flows.
If energy and material inflow balances energy and material outflow, the minimal material limits species-organism number or size {Liebig's law of the minimum} {Liebig law of the minimum}.
Physical factors {environmental factor} can directly affect organism growth: temperature, light, water, dissolved gases, trace elements, water flow, soil acidity, soil porosity, soil depth, fire hazard, and organic nutrients. Tropical plants have high carbohydrate percentage.
land
Light, temperature, and rainfall are important land environmental factors.
water
Light, temperature, and salinity are important ocean environmental factors. Oxygen content is important environmental factor in fresh water.
temperature
Growth is typically faster with varying temperature. Water has less temperature variation than land or air.
light
Ultraviolet light kills unprotected cells, so organisms must filter light. Sunlight inhibits protein synthesis.
Organism absence from environments or failure to live in new environments depends on limiting environmental factors organism can tolerate {Shelford's law of tolerance} {Shelford law of tolerance}.
Species occupy geographic areas {range, species} {range of tolerance} {tolerance range} with temperature, elevation, water supply, and sunlight extremes. Range is lower for embryonic and immature life stages and during adult reproductive periods.
Range can be wide {eury range}. Eury-organisms have wider distribution than steno-organisms.
Range can be narrow {steno range}.
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Date Modified: 2022.0225