Initial Phases of Antarctic Ramalina terebrata Hook f. & Taylor Thalli Rehydration Observed by Proton Relaxometry

Hydration kinetics, sorption isotherm, and proton free induction decays are measured for Ramalina terebrata thalli rehydrated from gaseous phase. Very tightly, tightly, and loosely bound water fractions are distinguished. Sorption isotherm is sigmoidal in form with the mass of water saturating primary water binding sites equal to Δ m/$m_0$ = 0.046. Proton free induction decays show the presence of immobilized water fraction ($T_{2 L_1}$* ≈ 100 μs) and mobile water pool ($T_{2 L_2}$* ≈ 330 μs). Sorption isotherm fitted to the NMR data shows the absence of water fraction "sealed" in pores of dry thallus.