Stocking rates are expressed as the number of animal unit months (AUM) supplied by one acre of land. The greater the difference between current forage production and the potential forage production of a pasture, the greater the difference will be between carrying capacity and recommended stocking rate.
The fundamental frequency of a wave is the lowest frequency (longest wavelength) that can be used to define its period. The easiest way to understand it is via a musical analogy: The fundamental frequency is the root tone of the overtone or harmonic series.
Hum derives from the fundamental frequency of the AC power line, which in the USA is 60 Hz. However, most hum also contains harmonics of that fundamental frequency: 120 Hz., 180 Hz., and so forth.