PHENOLOGICAL STUDIES OF SELECTED SAVANNA MOSSES OF SOUTH-WESTERN NIGERIA

It was established that there is little diversity of bryophytes in the derived savanna. Mosses were found in the sampling sites, whereas liv erworts were rarely observed. The reproductive methods of four dominan t sexually reproducing savanna mosses - Archidium ohioense, Bryum coro natum, Fissidens minutifolius and Trachycarpidium tisserantii were mon itored over two consecutive rainy seasons. Protonemal and gametophyte production were noticed in the field in March/April, and capsule dehis cence and spore dispersal occurred in September/October. The sequentia l stages of development, starting with gametangial production and endi ng with the falling of the dehisced capsules, occurred within the rain y season. However, A. ohioense and T. tisserantii did not discharge th eir spores easily (cleistocarpous), unlike the stegocarpous species B. coronatum and F. minutifolius. Water availability and possibly high h umidity may have contributed to growth. The short period between sex o rgan formation and dehiscence of capsule seen in these studies, compar ed with the longer period in some temperate mosses, may be an advantag e for bryophytes in a savanna environment.