Jim wrote ...
I know there are many knowledgable people on these two lists. I am looking
for a hint on the cause of a circle of dead grass that is very well
defined on my lawn and extends, faintly, into the adjoining lawn.
I recall that a cherry tree once existed in this general area in the
neighboring lawn. I had a maple in my yard that was damaged by a wind
storm and removed. However, neither of these was near the center of the
circle. I have heard that maple roots can cause problems in grass, but no
previously-existing root circle matches what I now observe.
Anyone got a suggestion?
These are also sometimes called "fairy circles".
They are caused by fungi ( usually the kinds people call "mushrooms" or
"toadstools") which grow in the soil. Mostly these might be saprobic, living
on waste material left when grass etc roots die. Others might also be
mycorrhizal, living in a mutually beneficial relationship with the green plants
above. These soil fungi have no chlorophyll, so depend, one way or another,
on green plants which do.
So, a fungal spore blows in on the wind and germinates at one spot in the
soil (just as they do in our lenses) and with a bit of luck, against huge odds,
thrives. The mycelia ( the thread-like body of the fungus) spreads out. In all
directions. And so a circle forms.
Sometimes, as in Jim's example, the grass is temporarily killed during the
expansion. But notice, on the inside of Jim's circle, in one patch it has grown
even higher than the grass outside. This is not uncommon.
In New Zealand, in the autumn, people look for these circles because some
fungi which have delicious mushrooms create these circles, and in the
autumn they fruit. From the thread-like mycelia, a miracle of nature causes a
re-organisation for fruiting. Mushrooms pop up out of the turf as the weather
cools and rains start again. The mushrooms plan to liberate billions of
spores; but if it is a good mushroom species such as Horse Mushroom, field
mushroom, giant puffball, or Lepiota rhacodes (forget the common name -
oh yes, Shaggy Parasol), then I eat them first.
And there is no agricultural subsidy either !!
Warning !! It is ESSENTIAL to know what species it is and if it is edible,
prior to culinary use. Lethal species also create these fairly rings.
I have no idea what species caused Jim's circle.
Brian Swale.
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|