Chapter 2: Abiotic Factors of Land Environments

climate; soil; water; human influences

the four abiotic factors of land environments

climate/atmosphere

how solar radiation varies with latitude; differences in temperature and rainfall; involves geography and topography

equator (0 degrees)

the region which sunlight strikes most directly

north and south pole (60 degrees)

the region which receives the least amount of sunlight due to low angle

tropic of cancer

the region 30 degrees north

tropic capricorn

the region 30 degrees south

atmospheric circulation

caused by the uneven heating of the Earth's surface; descending dry air absorbs moisture and ascending moist air releases moisture

trade winds

permanent east-to-west prevailing winds that flow in Earth's equatorial region

doldrums/intertropical convergence zone (ITCZ)

a dynamic, low-pressure band of clouds and thunderstorms encircling the Earth near the equator; it forms where Northeast and Southeast trade winds converge, causing intense solar heating, moist air to rise, and heavy, seasonal rainfall

coriolis effect

an apparent deflection of moving objects, such as air currents, water, or projectiles, to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, caused by the Earth's rotation

global water cycle

the continuous movement of water between the atmosphere, land, and oceans, driven by solar energy and gravity

climatogram/graph

a graphical representation of a location's average monthly temperature and precipitation, typically displayed over a 12-month period

polar; temperate; arid; tropical; mediterranean; mountains

6 world climatic zones

polar

climatic zone that is very cold and dry all year

temperature

climatic zone that has cold winters and mild summers

arid

climatic zone that is dry and hot all year

tropical

climatic zone that is hot and wet all year

mediterranean

climatic zone that has mild winters and dry, hot summers

mountains (tundra)

climatic zone that is very cold all year

albedo effect

measures a surface's ability to reflect sunlight

greenhouse effect

a natural process where atmospheric gases, such as carbon dioxide, methane, and water vapor, trap heat near the Earth's surface, keeping the planet warm enough to sustain life

global warming

a long-term rise in Earth's average temperature, driven primarily by human activities like burning fossil fuels, which release heat-trapping greenhouse gases

rain-shadow effect

a dry region on the leeward (downwind) side of a mountain range that receives significantly less rainfall than the windward side; moist air is forced upward by mountains, cools, and releases moisture as rain; the dry air then descends, warms, and causes arid conditions

topography

the detailed study and mapping of the land's surface features, including natural forms like mountains and rivers, and man-made structures like roads

global; regional; local; microclimate

four climatic regimes

global climate

the long-term, planetary-scale average of weather patterns, driven by the atmosphere, oceans, ice, land, and ecosystems

regional climate

the long-term weather patterns (temperature, precipitation, humidity, wind) of a specific geographic area, typically averaged over 30 or more years

local climate

refers to the unique, small-scale atmospheric conditions distinct from surrounding areas, spanning from a few city blocks to kilometers

microclimates

a small, localized atmospheric zone where the climate differs from the surrounding area, typically spanning from a few meters to a kilometer

relative humidity

the percentage of moisture currently in the air compared to the maximum amount it can hold at a specific temperature

amihan

Philippine trade winds; northeastern monsoon; brings cool, dry winds; November to April

habagat

Philippine trade winds; southwestern monsoon; warm, humid; May to October

typhoon

a tropical storm in the region of the Indian or western Pacific oceans

ground; crown

2 types of forest fires

ground fire

also called root fire; a wildfire caused by the burning of tree roots; underground burns generally triggered by off-trail camping or other causes

crown fire

fire activity in the forest or shrub canopy

bushfire/wildfire/forest fire

an unplanned and uncontrolled fire in an area of combustible vegetation

soil

the foundation for terrestrial life

parent material

original material before soil development begins

regosol/young soil

thin solum, organic matter accumulation in A horizon, from which carbonates have been leached; minimal weather and eluviation

brunizem/mature soil

organic matter content is at a maximum level; has moderate clay accumulation in the B horizon and the solum is acid; stage of maximum productivity

planosol/old soil

very acid in reaction, severely weathered and less organic matter than nature stage; clay accumulation in B horizon has formed a clay pan; an A2 horizon exists

O horizon

solum/true soil; topsoil; loose and partly decayed organic matter

A horizon

solum/true soil; topsoil; zone of eluviation; mineral matter mixed with some humus

E horizon

solum/true soil; light colored mineral particles; zone of eluviation and leaching

B horizon

solum/true soil; subsoil: zone of illuviation; accumulation of clay transported from above

C horizon

partially altered parent material

humus

a dark, organic component of soil formed by the decomposition of plant and animal matter, acting as a vital, nutrient-rich soil conditioner

eluviation

the removal of dissolved or suspended organic matter, clay, and minerals from upper soil horizons (layers) by the downward or lateral movement of water

illuviation

the introduction of salts or colloids into one soil horizon from another by percolating water

climate; organisms; relief; parent material; time

five factors affecting soil development

soil=f(clorpt)

Hans Jenny's soil equation

edaphic factors

the physical, chemical, and biological properties of soil that directly influence the growth, distribution, and health of plants and soil organisms

Munsell soil color chart

a quick and affordable way to assess soil types in any given area

entisol

recent; a soil order with a dominance of mineral soil materials; absence of distinct horizons; found on floodplains

vertisol

inverted; a soil order with dark clay soils that exhibit wide, deep cracks when dry; grumusols

inceptisol

beginning; a soil order with texture finer than loamy sand; little translocation of clay; often shallow; moderate development of horizons

aridisol

arid; a soil order that is dry for extended periods; low in humus, high in base content; may have carbonate, gypsum, and clay horizons

mollisol

soft; a soil order that has surface horizons dark brown to black with soft consistency; rich in bases; soils of semihumid regions

spodosol

ashy; a soil order that is light gray, whitish A2 horizon on top of a black and reddish B horizon high in extractable iron and aluminum; podzol, brown podzolic soils

alfisol

coined from Al and Fe; a soil order that has a shallow penetration of humus, translocation of clay, and well-developed horizons

ultisol

last; a soil order that is intensely leached; strong clay translocation, low base content; humid, warm climate

oxisol

oxidized; a soil order that has highly weathered soils; red yellow, or gray; rich in kalinite, iron oxides, and often humus; in tropics and subtropics

histosol

organic; high content of organic matter

Rhizobium

Gram-negative nitrogen-fixing soil bacteria found within roots of legumes and other flowering plants

mycorrhiza

the role of the fungus in the plant's rhizosphere, the plant root system, and its surroundings