RESERVES OF BURIED SEEDS IN BEAVER PONDS

Reserves of buried seeds are known to have an important role in the dy namics of plant communities. This is particularly so in wetlands, wher e periodic low water events are essential for plants to reestablish fr om seeds. In spite of the growing literature on reserves of buried see ds, little is known about this resource in beaver ponds. This study wa s designed to 1) document species found in beaver pond seed banks, 2) estimate their relative abundance, and 3) test whether the abundance a nd richness of seeds differ between young and old beaver ponds. Soil s amples were collected from 14 beaver ponds in Gatineau Park (Quebec) i n May 1995. Samples were spread out in plastic trays containing a sand and peat substrate and were placed in a growth chamber with fluctuati ng light and temperature regimes to stimulate germination. More than 2 000 seedlings representing 42 species germinated from the various soil samples, yielding an estimated density of 2300 seedlings/m(2). Juncus effusus (426 seeds/m(2)), Leersia oryzoides (390 seeds/m(2)), Scirpus cyperinus (246seeds/m(2)), Juncus brevicaudatus (170 seeds/m2), and L udwiga palustris (98 seeds/m(2)) were the 5 most abundant species. The abundance and richness of germinating seeds did not differ significan tly between young and old beaver ponds.