Alder and ash - probability of root growth in flooded soils.

[Gary Prentice]

In an attempt to establish RPAs for a proposed development I'm hoping that the collective arbtalk mind might point me to some literature.

 

There's a row of semi-mature alder and ash growing on a narrow belt of land (around 2 m wide) between a canal and a pond/flood-plain. In the summer the pond was dry, just really soft mud with no vegetation, but is now filling up from precipitation. So, during an average summer I'm assuming that some water remains in the 'pond' almost all year. Some roots are visible that head towards the pond bank before being truncated and appear to be dead (from alder) 

 

I know that alder have special vessels that supply oxygen to the roots and that they can grow in water, but can/will they if the area is underwater for 80/90 % of the time? 

Searching for tolerance to flooding reveals that ash has either a high or intermediate to flooding, but I don't think that information is that relevant to a site which is mostly flooded/water-logged/under water.

 

The TO suggested that root-spread was probably restricted to the belt of land between the two bodies of water and I'm not sure that I can agree or disagree. 

Thoughts?

[Watercourse management]

Hi Gary interesting question, alder roots on hard bottomed water courses always seem to push towards the central channel where the water will normally always flows. On the bank of a chalk bed river which normally flows brim full the roots don’t spread to much into the main channel, if you need any photos of alder roots in water courses let me know and I will ping some over cheers Simon