Geniiiimíioii of siibiiierged seeds froni floodplains 
by a water column of approximately 5 cm. Evaporated water was 
replaced daily. Germination was calculated as the number of seeds 
that germinated after 7 weeks in relation to the total initial seed number 
(in percent). The form of germination was differentiated as seed 
swelling (after absoiption of water), radicle growth, and shoot growth. 
A statistical analysis (ANOVA) of the differences in germination 
defined as number of radicle emergence between non-submerged and 
SLibmerged seeds was performed with SYSTAT. 
RESULTS 
In the unsLibmerged conditions, 30 to 100 % of the seeds of all 
species geiminated (at least radicle emergence) after seven weeks (Figure 
1). Of the SLibmerged seeds, seven species opened after swelling (10 - 
100% of the planted seeds), but in five they remained unchanged. Only 
foLir SLibmerged species showed radicle emergence, and no seeds of any 
species exhibited germination of the shoot (Figure 1). The statistical 
analysis showed highly significant differences in germination, defined 
as radicle emergence, between non-submerged and submerged seeds 
in nine species (P < 0.05) (Table 2). 
Seeds were flooded between 6 and 33 days in the plastic basins 
prior to initiation of the experiment. The seeds of Cnidia amazônica and 
Tahehiiia barbata were viable at least for a month, but most of the seeds 
of these two species started to rot thercafter. In the other ten species, 
seeds remained visually sound at least for 63-76 days (datanot shown). 
DISCUSSION 
The present experiment showed that seed germination of 
Amazonian floodplain trees occurs mainly in non-floodcd seeds. 
Submerged seeds of some species may initiate germination, which is 
shown by the emergence of a radicle, but no species was able to produce 
a shoot as long as it was submerged. The seeds of the floodplain trees 
32.5 
