Does mushroom picking damage or encourage the Mycelium?

[Lorelei Norvell]

On Sat, 11 Nov 1995, Marck D. Pearlstone wrote:

> I have long believed that collecting the fruiting bodies of a fungus
> would (for many species) encourage the mycelium to fruit more stringly
> in future years.
> 
> Can anyone confirm or deny this scientifically speaking?
	

	There are numerous field studies attempting to ascertain the 
answer to this question.  European studies -- particularly those in the 
Netherlands and Norway -- have investigated this, particularly with 
respect to forest management.  Eef Arnolds has found that some 
ectomycorrhizal fungi appear to respond beneficially to a MODERATE amount 
of disturbance.  In Switzerland, Egli, Ayer & Chatelain have monitored an 
area since 1976 and found that there seems to be no deleterious response 
to mushroom harvesting with respect to future productivity.  
	In Oregon the Oregon Mycological Society has been investigating 
whether picking chanterelles has any effect on future productivity -- our 
study was begun in 1986 (with three years for procurement of baseline 
data, and harvesting begun on the experimental plots -- and no harvesting 
on the control plots -- in 1989).  Preliminary data indicate that there 
appears to be no deleterious effect on mushroom fruiting OVER THE SHORT 
TERM.  We shall statistically analyze our data after we have obtained ten 
years of harvesting data.  (The study will be discussed more fully in the 
1995 issue of McIlvainea -- journal of the NOrth AMerican Mycological 
Association -- currently in press.  The article will also contain full 
references of similar studies in Mexico and Europe).
	However, as you know, an ecosystem is a complicated entity, and 
the health of the whole must be considered as well.  The variables 
accompanying any field study -- weather variability is a major problem -- 
make interpretation of data extraordinarily complicated.  But studies are 
underway attempting to answer the impact of harvesting on fungi 
throughout the world.

Lorelei Norvell