Ecology- Terrestrial adaptations

soil

layer of chemically and biologically altered material that overlies bedrock or other unaltered material at earths surface

soil profile

vertical layering of soil materials

soil horizon

distinct layer of soil

parental material

the layer of bedrock that underlies soil and plays a major role in determining the type of soil that will form from it

O horizon

layer composed of dead organic matter

A horizon

layer rich in humus, consisting of partly decomposed organic material mixed with mineral soil

E horizon

layer that has been leached of its minerals

B horizon

layer with chemical composition that resembles the underlying parent material; clay and minerals leached from E horizon are deposited here

C horizon

layer composed of large rocks of broken parent material

R horizon

unaltered parent material; bedrock

leaching

a process in which groundwater removes nutrients by dissolving them and moving them through lower soil layers

permeability

the ability of water to flow through a soil

porosity

the amount of space between sediments

weathering

the physical and chemical alteration of rock material that breaks them into smaller particles

clay

smallest particles; very small pore spaces, holds water and nutrients tightly but drains slowly

silt

medium sized particles

Loam

soil don dominated by any of the particle sizes

Sand

large-sized particles; large pore spaces, drains quickly and holds little water or nutrients

turgor pressure

provides stiffness to plant tissues, affects the opening and closing of stomata, and influences leaf movements

stomata

tiny openings on leaf and stem surfaces used for gas exchange

transpiration

the process by which leaves can generate water potential as water evaporates from the surfaces of leaf cells into the air spaces within the laves

cohesion

the mutual attraction of water molecules; allows water to move up through empty remains of xylem cells

root pressure

when osmotic potential in the roots of a plant draws in water from the soil and forces it into xylem

cohesion-tension theory

the explanation of the mechanism of water movement from roots to leaves due to water cohesion and water tension

radiation

transfer of heat via electromagnetic waves

conduction

direct transfer of heat between objects in physical contact

convection

the transfer of heat by movement of liquids and gases; molecules next to a warm surface gain energy and move away

evaporation

conversion of liquid water to vapor, requiring energy input; removes heat from a surface

shuttling

moving between sun and shade to control heat gain

perpendicular position

maximizes exposure to radiation

parallel position

minimizes exposure to radiation

sprawled posture

heat. gain via contact with a warm surface

extended posture

reduced contact with ground to limit heat gain

body shape adjustments

spreading ribs or coiling to change surface area exposure

blood shunting

an adaptation that allows specific blood vessels to warm blood flows to the cold extremities

ectotherms

body temperature is strongly influenced by external environmental conditions

endotherms

replace heat lost by generating metabolic heat or by gaining heat through other means