WALK Report Halifax Scientific Society
LOCATION: Shibden Park, leader Steve Blacksmith
WEATHER: windy and light rain in the morning. Heavy rain came after group disbanded at 13.00.
Number attending 4 inc. leader
Target species: Ferns, also listening to resident bird song to learn to survey by ear, whilst no migrant songbirds are complicating the soundscape.
(We were also interested to see the area where many Rhododendron ponticum had been cut and burnt on site to try and stop the spread of a Phytophthera sp. tree and shrub disease which has recently been identified in the park. I had checked with the Estate Manager,Deborah Comyn-Platt,that it was safe to visit.)
Dryopteris dilatata- broad buckler Dryopteris filix-mas, male fern
Polystichum setiferum- soft shield fern (2 "wild"plants) Blechnum spicant- hard fern
Asplenium sclopendrium, hart's-tongue (planted) P.setiferum (planted)
P.aculeatum - hard shield fern (planted)
Some planted ferns in winter brown foliage were assumed to be Athyrium filix-femina, lady fern.
The typical ferns of the woodland are D.dilatata and D. Filix-mas, with Blechnum sparsley on exposed mudstones banks. Polystichum spp.remain rare though a spreading population in Elland Park Wood is on the coal measures as here. The 2 found along the woodland path below the A58 were well seperated.
Common ferns in other local areas which were absent were Pteridium (bracken), Polypodium spp, and various wall-dwelling small Aspleniums.
The ecology of ferns was discussed briefly: They grow in shade where many flowering plants don't; they grow on nutrient-poor mudstone outcrops; also in moss on fallen logs. They are opportunists (empty niche fillers) in the first two cases; early colonists in the second. They are browsed by deer. That is what we saw on the day.
They must be an important carbon sink. The old root-stocks of clump formers, and the underground rhizome-systems of creeping species must lock up carbon for huge lengths of time. Anyone who has tried to compost a rootstock will attest to their resistance to rot.
They are important hydrologically, storing rain in their tissues and on their filligree structures. They make woodlands humid, affecting other plant and insect, and therefore bird life. They retain deciduous tree debris around them again effecting slow water run-off and carbon-rich humus soil building .
I have heard of one insect only that specialises on them, a beetle on Pteridium. Perhaps there are more.
An endangered bird in England, the twite, important locally, sometimes nests among bracken foliage on the high Pennines.
I have been told about a fungus that colonises dead fern stems.
About 40 black-headed gulls Moorhens 5
Mallards - far fewer than gulls Mistle Thrushes 4 inc one singing on and off all day
Robins 4-5 Long Tailed Tits 10
Male Great Spotted Woodpecker visiting a feeder
Rookery - SE107257 - not reported in 2009 rookery survey - about 14-15 nests. Just above the playground.
MAMMALS: only two grey squirrels seen, but several dreys. A little browsing of ferns probably by a small deer.
PLANTS OTHER THAN FERNS: A bird-sown yew among many young hollies colonising recently regrown woodland (20 -30 years); next to A58 Whitehall Road. Both species are increasing as an understorey shrub in other parts of Calderdale. Only one plant was seen in flower - a planted Wych Hazel, Hamamelis mollis from N. America.
FUNGI: All logs were of deciduous trees. An old puffball group on a log, possibly common puffball, Lycoperdon. Another log below the Caldervale railway was spectacularly covered in a pale crust which showed only a little of its reverse side of mahogany brown. Above the playground on a collection of massive logs was a display of about 8 fungi, and at least one slime mould. Among them were a jelly ear, Auricularia; a bright orange toughshank with black stems, Collybia sp.; King Alfred's Cakes, Daldinia; candlesnuff, Xylaria and what looked like a wood blewit, Lepista. Further up the track on a stump was a white fungus like a ball of hard chewed gum growing out of the wood, but as we had no mycologist with us, its identity is a mystery.
COMMENT ON PARK MANAGEMENT: There are not many areas of unshaded long grass. These would increase biodiversity spectacularly by attracting butterflies.