My rhizotron flooding experiment with Nordmann and Fraser firs has been interesting, but so far it has provided more questions than answers. On the side I carried out a small flooding recovery experiment, testing to see if there were differences between the fir species in root regeneration after a period of flooding. I expected Nordmann fir to be better at regenerating roots than Fraser fir.
I tested a one week flooding event and a two week flooding event. Today marked three weeks since the one week flooding event ceased. The last two weeks there were differences between species, but as of today they have equaled out. This really surprised me. What?!?!
The plants that were flooded for two weeks are now showing indications of new root tip formation. This was not what I expected to see.
I’m left trying to explain why the foliage of Nordmann firs looks so much better than that of Fraser firs in flooded conditions. If the roots are responding the same, why are the shoots so different?