Alder coppice dieback

Has anyone experienced dieback of alder (Alnus glutinosa) coppice? This year I have had several stumps which have significant regrowth dieback together with small bracket fungi on the trunk.



Last year I did lose a tree in the same area, (posted here) although did not see any fungi associated with it. I've lost several small birch in the same general region over the years which I'd put down to root rot, but perhaps there's something else going on....

Advice invited please.

What time of year/season are you cutting it?

Are you cleaning/disinfecting your tools?

I cut them back in late winter - Jan / Feb usually.

I must admit I'm not disinfecting my tools, which would be a risk of spreading a problem. I use a reciprocating electric saw for most of my larger cuts. The blade is double toothed, (flat on outside with teeth angled both ways to centre) so rather tricky to clean :(

I see. May be you can try cutting at an angle to allow water to drain quicker.

The Japanese hand saw brand 'samurai' and 'silky' are good alternative although the blades are rather complicated; a wire brush will clean them and then some alcohol.

I always cut at a slight angle, and try to leave a smooth cut - Taking a wedge from one side and then joining up from the other before a cleaning cut on the stump if neccessary.
My gut feeling (having had a bit more apparent dieback over the summer) is that these stumps are too shaded by adjacent spruce trees - It is the ones closest to the spruce that have suffered the most. From observation: normally as the new growth comes there are lots of stems on the alder, but some of the new twigs and lower twigs and branches die back naturally, I assume from lack of light. I think in this case there is also a tendency for fungal disease (my climate is cool and damp) which has exacerbated the problem.

Could the sprouts have been girdled by voles? It's interesting to see the discoloration a few inches up from the base of each sprout. The shading could have an effect but it seems strange to see such a consistent pattern along the base of the stems.

Alder is so wet tolerant that I wouldn't think excessive moisture would be the cause.

Mark Krawczyk wrote:Could the sprouts have been girdled by voles? It's interesting to see the discoloration a few inches up from the base of each sprout. The shading could have an effect but it seems strange to see such a consistent pattern along the base of the stems.

Alder is so wet tolerant that I wouldn't think excessive moisture would be the cause.

I don't think it is voles. When we planted the trees it was noticable that alder is one of the ones that voles don't particularly like. I can't see any loss of bark and I think the discolouration is due to the fungus. I'll try and find a more detailed picture and post it later