The Forest as a Biological Semiconductor: planting geometry as programming, resistance wave as clock, and a forest computer solving optimisation problems

This paper is the fifth in the series on forest bioelectric systems. We propose the concept of a forest as a biological semiconductor device in which planting geometry plays the role of circuit topology. The boundary between two tree species with different bioelectric impedances forms a biological p-n junction with asymmetric conductivity — a biological diode. Three species in n-p-n or p-n-p geometry form a biological transistor. From transistors, logic elements are built (AND, OR, NOT). The oscillating stomatal resistance wave (Paper 4) serves as the clock generator of the computing system. The horizontal ladder network (Paper 4) is the data bus between logic elements. Mycelial memory is implemented through Hebbian strengthening of active paths. We also analyse an extended catalogue of planting geometries: Star of David (twelve-tree six-phase generator), crescent (directed loop antenna with variable cross-section), Fibonacci spiral (self-consistent isotropic system), and double spiral (bidirectional rotational torque transmission). The considered computing machine is slow (clock frequency ~0.5–3 mHz) but optimal for distributed real-time optimisation tasks over large areas.