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Sampling arable bryophytes
Richard Fisk's method of sampling arable fields:
Materials:
Collecting tin (tobacco tin 11cm x 8cm x 2.5 cm or similar)
Plastic sieve (15 cm diameter with mesh of 1-1.5 mm, e.g. a flour sieve)
Plastic container (e.g. 2 litre ice cream container)
Jam jar or similar with screw-top lid
At the collecting site fill tin with sample of bryophytes. Avoid too much
soil and discard large tufts of Barbula unguiculata and Tortula
acaulon - select more interesting tufts of Bryum and Dicranella.
As soon as convenient on returning home, empty soil sample into sieve
and suspend in a container filled with water. Leave to soak for a short
while so that soil softens (this can take up to two hours if soil is hard
or of sticky clay). Then gently break up soil by squeezing between fingers,
and the soil particles will fall through the sieve. This will need to
be repeated two or three times with clean water (this step can be carried
out under running water but it is a bit messy).
When sample is reasonably clean, squeeze out the excess water and transfer
to a jam jar filled two-thirds with water, screw on the lid firmly and
shake for a minute. Tip the sample into the sieve, refill the jamjar and
repeat until the water remains fairly clear. It will probably be cloudy
but not muddy.
You will now have a wad of bryophyte material about the size of a walnut.
Take a small piece(about 5-8 mm diameter) from this, place in a petri
dish of water, agitate to disperse individual plants and examine under
a stereo binocular dissecting microscope. Repeat until all of the sample
is examined. Plants will be thoroughly mixed by this method and most species
present will be seen in the first sample, but it is worth examining all
of the wad because single stems of some species, such as Ephemerum
serratum, may be found which were not observed in the field.