Nitrogen pollution, tree stress and susceptibility to disease

[HCR]

This is copied from a post on LinkedIn, not made by me. It's an interesting thought, and I wondered if anyone here had any thoughts on the matter:

 

For some time now I have been wondering if there is any link between an increase in nitrogen pollution predisposing trees to an increase in their susceptibility to disease.

 

Through an amateur interest in lichenology, particularly what they can tell us about air quality, the potential effects of nitrogen pollution has intrigued me. Most noteworthy is the apparent (and I suspect) increasing dominance of lichen communities favoring nitrogen rich conditions. Obviously much has already been written about this, but nonetheless fascinating to observe for one's self.

 

Essentially my thoughts are that an increase in nitrogen pollution is predisposing trees to increased stress, thereby weakening their immunity and making them more susceptible to disease. To coin a phrase, 'too much of a good thing'.

 

Whether this is a direct or indirect effect, I do not know, but I can't help but suspect that it is the rather insidious effect upon the trees symbiotic mycorrhizal relations, the 'good' fungal associations, essential to the trees health?

 

I won't go on any further as I realize I have already made a number of assumptions and I would really appreciate hearing what your thoughts may be on this?

[JonnyVine]

For anyone interested in the efects of Nitrogen saturation, Shigo explains this best in modern arboriculture, unfortunately I learned by bitter experience.

 

Jonny

[likeitorlumpit]

balanced diet is best- now where have we heard this? applied to humans

Farmers soon realised that the increasing returns from additional N applications suddenly dropped off. As you say, too much of a good thing.....

[Tony Croft aka hamadryad]

ive been telling you all this for ages, the nitrogen tolerant lichens are now thriving because of it.

[HCR]

For anyone interested in the efects of Nitrogen saturation, Shigo explains this best in modern arboriculture, unfortunately I learned by bitter experience.

 

Jonny

 

So, what exactly have you learned, and it did it tally completely with Shigo's text?