96/04394 Hot gas desulfurization using zinc-ferrite regenerable sorbents

Abstract

Some aspects of the hydrochoric, endozoochoric and epizoochoric dispersal of seeds of Nymphaea alba L., Nuphar lutea (L.) Sm. and Nymphoides peltata (Gmel.) O. Kuntze were studied by examining their buoyancy, their passage through the intestinal tract of waterfowl and fish, and their tolerance towards desiccation.Buoyancy of Nuphar lutea carpels was found to be poor compared with that of released Nymphoides peltata and Nymphaea alba seeds.Mallard duck (Anas platyrhynchos L.) and coot (Fulica atra L.) digested all seeds of Nymphoea alba, Nuphar lutea and Nymphoides peltata completely, in contrast to seeds of Potamogeton natans L., Potamogeton obtusifolius Mert. et Kock and Potamogeton pectinatus L. Similar results were obtained when the seeds were fed to common carp (Cyprinus carpio (L.). Because of the complete digestion of the seeds of the nymphaeid waterplants by coot, duck and carp, endozoochory will hardly contribute to a successful dispersal between isolated water bodies.Unlike Nymphoides peltata seeds, the seeds of Nymphaea alba and Nuphar lutea are killed by desiccation. In view of these properties and the morphology of the seeds it is concluded that epizoochory can be an important factor in the seed dispersal between isolated water bodies of Nymphoides peltata, but not of Nymphaea alba and Nuphar lutea. It is also concluded that within one water body hydrochory is the main dispersal mode of the three nymphaeisd species studied.