Seed Bank Species

If you can’t find it … is it lost for ever?

Or is it merely asleep, dormant underground?

Judy Webb February 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

Quaking grass, Briza media 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.

Meadow thistle, Cirsium dissectum, and seeds

Woodlands have seed bank plants that wait for a tree to fall

Foxglove

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

Grass 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

Fen plants and seed banks

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?

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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 Riccia sp.

Oospores of

Tolypella

and Chara