mathematical description of the effect of resaturation on net photosynthesis in the lichen, Parmelia praesignis Nyl

Resaturation respiration occurs in Parmelia praesignis Nyl., although it is not strongly developed as in other lichens. Less than 2 h was required for full recovery of photosynthetic ability after having been dry for at least 5 weeks. After three daily, 4 h soaking periods the time for recovery was reduced to 11 min. The resaturation phenomenon is mathematically described for the first time as a negative exponential from which parameters can be derived for maximal net photosynthetic rate, maximal velocity and the velocity at the half-time for recovery. Net photosynthetic rate was independent of the period of drought. The velocity at the half-time for recovery increased by 81% after one soaking period and by 990% after two.