Ground flow resistivity is far lower in forests than in grassland.

Evidence

Sutherland and Daigle (1997) report effective flow resistivity values of 200–400 kN s m4 for grass-covered ground, compared to values for forest ranging from 20 to 80. … For acoustic pulses propagating near the ground, the lower flow resistivity tends to cause waveform distortion and reduction of higher frequency components. — Donald G. Albert, Michelle E. Swearingen, Frank E. Perron, and David L. Carbee, Low Frequency Acoustic Pulse…, 25

Categorization

• XREF: Relevant to acoustic propagation modeling and to sensor placement in forest vs. field environments.