The reproductive phenology of three mistletoe species in the Loskop Dam Nature Reserve, South Africa

Abstract

In order to gain a clearer understanding of the mistletoe fruit/avian disperser interacting system the flowering and fruiting phenologies of Tapinanthus leendertziae (Sprague) Wiens. T. natalitius ssp zeyheri (Harv.) Wiens, and Viscum combreticola Engl. were studied in the Loskop Dam Nature Reserve. South Africa. Both Tapinanthus species produced flowers and fruit seasonally but followed quite different patterns. T. natalitius showed rapid flower production but subsequently slow fruit production, resulting in a low number of ripe fruit simultaneously available on a plant. T. leendertziae showed a slower flower production followed by a quick mass production of fruit. The peaks of the different phonological stages tended to be separate in T. natalitius but overlapped greatly in T. leendertziae. In the latter species peak flower production was reached later than in T. natalitius, but peak fruit production earlier, presumably resulting in less competition for pollinating and dispersal agents. Open, nectar-producing flowers were available for 12 weeks in T. natalitius compared with 21 weeks in T. leendertziae; a total period of Tapinanthus nectar availability of 22 weeks. Ripe fruits were available for 11 weeks in T. leendertziae compared with 20 weeks in T. natalitius; a total period of Tapinanthus fruit availability of 26 weeks. The mean period of the whole reproductive cycle in individual plants was 22 weeks in T. leendertziae compared with 40 weeks in T. natalitius. Viscum combreticola differed completely from both Tapinanthus species, producing flowers and fruit throughout the year.