Conservation importance of ‘waxcaps
Waxcaps are amongst the most visible components of UK grassland
soil biota (associated with unimproved meadows). Conservation
of waxcap grasslands is a priority for SNH, CCW, EN, DENI
(genus includes two Red Data List species)
1. To investigate the distribution of FBs (fruiting bodies)
of Hygrocybe spp. at Sourhope and to examine in detail the
nutritional behaviour of the commoner species.
2. To determine differences in the acquisition of litter
and root derived nutrients between species by addition of
15N and 13C enriched substrates.
Hypotheses to be tested:
1. Plot treatments such as N or liming application, which
increase nutrient cycling by other soil organisms, will increase
the rate of decomposition of more recalcitrant plant polymers
and thus inhibit growth and FB production by Hygrocybe spp.
2. Mycelia of species (e.g. H. pratensis) with higher levels
of natural abundance 15N isotope are active in the deeper
litter layers compared to spp. (e.g. H. conica), whose FBs
show lower levels of enrichment.
1. Fortnightly surveying over two fruiting seasons (01-02)
and accurate marking of FB location. Correlate FB location
with plot treatments and variations in soil characteristics
across the site.
2. Mapping of genetic individuals (genets), using AFLP. Use
of specific PCR probes to localise mycelia within the soil/litter
3. Natural abundance 13C and 15N isotope ratios from FBs
and adjacent soil/litter will also be measured for FB in rings
away from the isotope enriched treatments.
4. 15N-enriched litter (Agrostis capillaris) has been prepared
for burial in bags in the field. 13C enrichment in FBs produced
near sites of 13CO2 pulses will be analysed.
Stable isotope analysis:
15N and 13C stable isotopes (measured using isotope ratio
mass spectrometry) are now widely used in ecology as markers
to follow nutrient flows.
The natural abundance of these isotopes can provide clues
about the nutritional behaviour of fungi.
15N and 13C pulse labelling during 2002
Use of PCR probes to locate mycelia in soil
Long-term mapping to measure ring growth rates
Examination of other ‘waxcap grassland’ spp. for stable isotope
Our work with stable isotopes of carbon and nitrogen indicate
that these fungi are feeding on recalcitrant organic material
in the soil, possibly recycling nitogen from these sources
back into the soil system.