Influence of lunisolar tides on plants. Parametric resonance induced by periodic variations of gravity

TL;DR

This paper explores how periodic lunisolar gravitational variations induce parametric resonances in plants, affecting their growth and fluid dynamics, with experiments conducted in space and a mathematical model explaining these effects.

Contribution

It introduces a mathematical model linking lunisolar tidal forces to plant fluid instabilities, supported by space experiments and analysis of lunar orbit eccentricity effects.

Findings

Lunisolar tides can induce parametric resonances in plant fluids.

Space experiments show periodic leaf oscillations linked to lunar cycles.

The model explains pressure impulses and sap movements caused by tidal forces.

Abstract

Recent experiments conducted in the International Space Station highlight the apparent periodicity of leaf oscillations and other biological phenomena associated with rhythmic variations of lunisolar forces. These events are similar to those occurring on Earth, but with greater effects over a shorter period of time. Among the possible disturbances, other than forced or self-existing oscillations, parametric resonances appear caused by a small periodic term; such is the case of fluids subjected to small periodic variations in gravitational forces in microscopic or mesoscopic plant channels filled with sap and air-vapor. The interface instabilities verify a Mathieu's second order differential equation resulting from a Rayleigh-Taylor stability model. These instabilities appear during the Moon's rotation around the Earth and during the revolution of the International Space Station. They create impulses of pressure and sap movements in the network of roots, stems and leaves. The model can explain the effects of the lunar tide on plant growth. The eccentricity of the lunar orbit around the Earth creates an important difference between the apogee and perigee of the Moon's trajectory and therefore the tidal effects can depend on the distance between the Moon and the Earth.