| Krasylenko, Y; Kinge, TR; Sosnovsky, Y; Atamas, N; Tofel, KH; Horielov, O; Rambold, G: Consuming and consumed: Biotic interactions of African mistletoes across different trophic levels, Biotropica, 54(4), 1103–1119 (2022), doi:10.1111/btp.13130 | |
| Abstract: Mistletoes, as perennial hemiparasitic angiosperms that parasitize woody plants, are an important component of the highly diverse, endemically rich and mosaic African flora, which is attributed to the Holarctic, Paleotropical, and Cape Floristic kingdoms. The richness of African mistletoes from the Loranthaceae and Viscaceae, along with many aspects of their biology and ecology, was covered in the comprehensive monograph of Polhill and Wiens (1998, Mistletoes of Africa, Royal Botanic Gardens). The present review is devoted to the taxonomic and functional diversity of symbionts associated with mistletoes in Africa and adjacent islands that contribute to the major biological functions of mistletoes, such as establishment and growth, nutrition and fitness, resistance to external stresses, as well as pollination and dispersal. These functions are favored by more or less distinct sets of associated bionts, including host plants, animal herbivores, frugivorous birds, nectar- and pollen-feeding insects, and endophytic microorganisms. A separate section is devoted to mistletoe epiparasitism as a special case of host selection. All these organisms, which are components of the mistletoe-associated community and multitrophic network, define the role of mistletoes as keystone species. Some aspects of the symbiont communities are compared here with patterns reported for mistletoes from other continents, particularly to identify potential relationships that remain to be explored for the African species. In addition, properties of endophytic mistletoe associates that contribute to the plant's communication with coexisting organisms are considered. We also highlight the important gaps of knowledge of the functioning of mistletoe-associated communities in Africa and indicate some applied issues that need future attention. |
