Seed Bank Species If you can’t find it …

is it lost for ever?

Or is it merely asleep, dormant underground?

Judy WebbFebruary 2015

All photos copyright J Webb

Port Meadow, SSSI, SAC – rare seed bank species

Creeping marshwort Apium repens, mud wort, Limosella aquatica, marsh dock,Rumex palustris

Short-lived seed plants

Seed of Bee Orchid (above) - like dust - viable for just a few days. All orchids rely on seed dispersal to spread to new sites. BUT a tuber-bank may remain in the soil for some years.

Quaking grass, Briza media

Meadow thistle, Cirsium dissectum, and seeds

Woodlands have seed bank plants that wait

for a tree to fall

Temporary shallow pools have species that wait for bare mud to be exposed

FoxgloveGrass Poly, Lythrum hyssopifolia, at Cholsey

Marston Meadows SSSI, meadow 50A

Autumn 2009

Ditch cleaned, spoil spread on meadow

May 2011

• Massive flowering of ragged robin

• Good numbers of tasteless water pepper, fig- leaved goosefoot, bifid hemp nettle

Three rare calcareous fen plants - Bog Pimpernel, Marsh Lousewort, Grass of Parnassus. Which of them could you get back from the seed bank when renovating a fen taken over by scrub?

Fen plants and seed banks

General thoughts• Long-lived perennials tend not to have long-lived seed

(oak acorns live only 1-2 years) - so no significant seed bank.Like most meadow species they

o rely a lot on vegetative reproduction o live in constant, long-surviving, habitats that don’t change

erratically.

• Annuals/biennials tend to have long-lived seed and a significant seed bank. They are opportunists whose habitat tends to change erratically and unpredictably – arable weeds e.g. poppies, fat hen.

Conserving both types of plant can present problems, but different ones.

Keeping a plant species after getting it back from the seed bank

More difficult than you might think!

• Management is now crucial. If you can’t replicate historic traditional management/hydrology, the species will be ‘lost’ again.

• Creeping marshwort restored in Walthamstow marshes, but lost again due to changes in hydrology

• Restoring a significant gene pool or relevant mating types is also important – one plant resurrected may be insufficient.

• If you have a group, there may be only one mating type, e.g. for dioecious species a lone male or female is no good - Marsh Valerian is an example.

Long-lived soil propagules in other taxa? Liverworts, charophytes

Riccia beyrichiana and R. sorocarpa thickened spores

Oospores of Tolypella and Chara

Riccia sp.