Topic 3: Importance of Water for Life Flashcards
adaptation
an evolutionary process that changes anatomy, physiology, or behaviour, resulting in a population’s increased ability to live in a particular environment; the term is also applied to the anatomical, physiological, or behavioural characteristics produced by this process
ecotone
spatial transitions from one type of ecosystem to another: for instance, the transition from a woodland to a grassland
evaporative water loss
reduction in the quantity of water due to the process of evaporation
evapotranspiration (ET)
combined evaporation of water from soil and leaf surfaces
hydrologic cycle
the sun driven cycle of water through the biosphere through evaporation, transpiration, condensation, precipitation, and run off
interceptions
refers to all the processes that prevent rainfall from immediately reaching the soil
metabolic water
water released during oxidation of organic molecules
potential evapotranspiration (PET)
ET assuming no limit to water supply - “a well-watered lawn”
relative humidity
a measure of the water content of air relative to its content at saturation; relative humidity = water vapour density/saturation water vapour density x 100
saturation water vapour pressure
the pressure exerted by the water vapour in the air that is saturated with water vapour
stand water balance
the flow of water in and out and changes of a surface water system, groundwater system, catchment or specified area over a defined period of time
stemflow
the flow of intercepted water down the trunk or stem of a plant.
throughfall
is that portion of rainfall that reaches the soil or litter by falling through spaces in the canopy or by leaf drip
transpiration
the exhalation of water vapour through the stomata
vapour pressure deficit (VPD)
the difference between the actual water vapour pressure and the saturation water vapour pressure at a particular temperature
