Klebsormidium near Langcliffe Locks

I took these three photos on 16 Oct, just over a week ago. This wall is close to the River Ribble, in the second fiedl above the Locks at Langcliffe. You can see Langclffe Qarry and Scar in the background. It surprised me how much Klebsormidium crenulatum there is on the rocks.

This velvetty filamentous alga is spreading and grows because of nitrogen compounds in the air.

Why is there so much here?

Here are four reasons

1) This field does have cow muck applied in winter

2) On the other side of the river is a large field leading up to a farm that still has dairy cattle. (All the other farms higher up int the valley now only have beef). Perhaps ammonia and nitrogen compounds come from the farm.

3) Most of the walls around here are made of limestone which does not let Klebsormidium grow on it.

but in the soil of the valley floor lots of rocks of the Yoredale series rocks  have been deposited, so the walls have quite a lot of sandstone rocks in them.

4) We are having an amazingly warm autumn - in that we have not had a frost yet. so plants and algae are continuing to grow.