Roger Gilbert's picture

Lichen on Hawthorn

Observed: 6th April 2011 By: Roger GilbertRoger Gilbert’s reputation in Fungi and LichensRoger Gilbert’s reputation in Fungi and LichensRoger Gilbert’s reputation in Fungi and Lichens
Lichen
Description:
Identifications

Caution: Do NOT use iSpot to identify fungi to eat!

Some fungi are very poisonous so a mistaken ID could have serious consequences.

Species interactions

No interactions present.

Comments

AlanS's picture

Jenny just beat me to the ID

Roger Gilbert's picture

Thanks for comments, the location ..

Howardian Local Nature Reserve is a relatively small (32 acres) urban reserve mostly on an old landfill site. It is bounded to the North by the main road M status into Cardiff, to the East by a feeder from that road to the Cardiff docks, to the West by a housing estate and the South by an industrial estate. I presume the ammonia would be from exhaust fumes and not from the industrial estate.

Howardian Local Nature Reserve
http://www.howardianlnr.org.uk

AlanS's picture

ammonia deposition

Yes, I agree - exhaust fumes (initially as oxides of nitrogen) are a major source (as is drift of agrochemicals in rural areas). It's all very insidious, but the spread of nitrophilous Physcia and Xanthoria species may be as great threat to our lichen flora as was sulphur dioxide.

Alan

Roger Gilbert's picture

I have heard it said ...

that blanket weed in ponds from nutrient rich waters is fixing the extra nitrogen and thus preventing possible greater harm to the system, could this be so for Physcia and Xanthoria.

Howardian Local Nature Reserve
http://www.howardianlnr.org.uk

AlanS's picture

Frankly I doubt it.

The spread of Physcia and Xanthoria will make negligible difference to amounts of nitrogen oxides/ammonia in the atmosphere.

What is not clear, so far as I know, is whether the spread of Xanthoria and Physcia species is actually displacing other lichens, or whether they are merely occupying space that has already been vacated by more sensitive species.

I find the swathes of countryside with very little but Xanthoria and Physcia very dispiriting, though I admit to liking the tiny Lecania species that can occur in their company.

Alan