10
Boletus and Amanita fungi which were found in the churchyard on September 3rd 1994
are all mycorrhizal and thus depend opon the existence of the trees. They were
Boletus regius - broad leaved trees
Boletus moravicus - broad leaved trees
Boletus queletii - Beech, Oak and Lime
Amanita echinocephala - broad leaved trees
The grid reference is TL822285 and the church lies between the 60 and 70 metre
contours. My calculations place it on an outcrop glacial till as shown on the surface
geology map in Jermyn's "Flora of Essex". On searching for sub-soil dug up from graves
some pebbles of chalk were found. However in the surface soil no chalk pebbles or
fragments were noticed. The soil was dark in colour.
The pH was measured at five scattered points using a Rapitest pH meter. A square of turf
(3 inches x 3 inches was removed with a trowel and the soil immediately beneath was
mixed with rainwater to form a mud. The probe behind the tip was shone with the pad
provided, and then inserted into the mud for 60 seconds, and twisted two or three times.
It was then removed and wiped clean with a paper towel. As the pH readings were below
7 the probe did not have to be reshone. (Reshone if 7 or higher). It was reinserted in a
new position, twisted and read after 60 seconds (thirty seconds if it had been 7 or higher).
The following readings were obtained:
6.5 : 6.6 : 6.0 : 6.5 : 6.7
Therefore the top-soil was acid in pH despite the existence of chalk in the sub-soil. This
suggests that the boulder clay was leached.
Geoffrey Kibby states that these four rare fungi all prefer alkaline conditions. In order to
obtain such conditions the fungal mycelium must extend below the top 4-6 inches, which,
if they are to form mycorrhizae with the tree roots they presumably do. These fungi were
the only species found on this occasion.
In my current survey of Essex churchyards around Chelmsford preliminary observations
suggest a correlation between soil acidity and fungal diversity. I have measured the pH of
the soil in the following churchyards in the same manner and related it to the number of
species identified from September 1994 to the end of November 1995. Lignicolous
species were excluded. The results are shown below:
Great Leighs 7.5 6.8 6.2 6.6 6.3 27 species 14 visits acid
Broomfield 6.2 7.2 6.6 6.7 6.8 24 species 18 visits acid
Fryerning 6.6 6.5 6.7 6.5 6.0 24 species 7 visits acid
Sandon 6.2 6.6 6.5 6.5 6.5 23 species 8 visits acid
Danbury 6.5 6.0 5.6 5.8 6.5 22 species 8 visits acid
Terling 7.1 6.7 6.6 6.6 6.7 18 species 9 visits acid
Little Waltham 6.6 6.5 6.6 5.9 6.6 16 species 9 visits acid
Little Baddow 6.4 5.8 6.3 5.9 5.7 11 species 6 visits acid
Margaretting 7.3 6.1 6.1 6.7 6.6 9 species 7 visits acid
Boreham 6.5 6.0 6.0 6.3 6.0 6 species 5 visits acid
Fairstead 7.2 6.3 6.4 6.4 6.2 5 species 4 visits acid
Good Easter 7.5 7.1 7.5 6.5 7.2 4 species 6 visits alkaline
Pleshey 7.3 6.0 7.0 7.4 7.3 1 species 5 visits alkaline
High Easter 7.9 7.5 7.5 7.5 7.4 0 species 5 visits alkaline