Which preposition to use with transpirations

in Occurrences 1%

But if the trees are so scattered as not materially to reduce evaporation from the ground, the effect of transpiration in diminishing the moisture of the soil is readily shown.

of Occurrences 1%

It may seem, however, at a period so long subsequent to the actual transpiration of events herein recorded, that little could be said to throw light or interest upon the history, and even less upon the character, or in extenuation of the follies or the frailties of the unfortunate subject of the following pages, and upon which public opinion had long ago rendered its verdict and sealed it for a higher tribunal.

Which preposition to use with  transpirations