© 2003 Kluwer Academic Publishers. Printed in the Netherlands. 97 Spontaneous revegetation of mined peatlands: An useful restoration tool?

spontaneous revegetation The recent development of peatland restoration activities indicates that modern peat mining techniques seriously hamper the natural capacity of bog ecosystems to regenerate after a disturbance. However, some plants have the ability to colonize dry peat deposits, and seem to help stabilize the soil surface and facilitate the establishment of other plant species. In this paper, we review studies regarding the spontaneous regeneration of ombrotrophic peatlands. There are numerous examples throughout North America and Europe showing that spontaneous reve-getation of mined peatlands by typical bog plants, and particularly by Sphagnum species, is possible. However, this phenomenon is much more common in block-cut peatlands than in vacuum-mined sites. The slow recovery of vacuum-mined peatlands compared to block-cut sites is probably related to intense drainage necessary for the use of tractor-drawn vacuum machines. There are some cases, however, where the spontaneous revegetation of vacuum-mined sites is successful, particularly for vascular plants. These sites are mainly dominated by cotton-grass (Eriophorum vaginatum L.). It seems that the microclimatic conditions created by cotton-grass tussocks improve establishment conditions for other vascular and non-vascular plants. Restoration activities should be minimal in mined peatlands already invaded by cotton-grass, and spontaneous revegetation processes could and should be integrated into peatland restoration programs