Possible significance of changes in the light requirement of <em>Cirsium palustre</em> seeds after dispersal in ash coppice.

Pons, T. L.

It is demonstrated that after the felling of as coppice Cirsium palustre becomes established from seed that was produced during the previous coppice cycle and has lain underground for several years. These seeds are light-requiring and it is probable that their germination is triggered by exposure to light during coppicing in winter. It is assumed that the seeds become light-requiring because phytochrome in the far-red absorbing form (Pfr) disappears rapidly when the soil temperature is high. This facilitates their incorporation in the seed bank in summer. However, the disappearance of Pfr in inhibited at low temperatures; this means that the seeds can store the light stimulus in winter and will not germinate until they experience higher temperatures in spring. The significance of the inhibition of seed germination under a leaf canopy is that it enhances the seeds' chance of being incorporated in the soil seed bank.

CIRSIUM; COPPICE forests; GERMINATION; SEEDS; PHYTOCHROMES; SUNSHINE

Plant, Cell & Environment, 1984, Vol 7, Issue 4, p263

0140-7791

Academic Journal

10.1111/1365-3040.ep11589456