Ecological importance of sedges: a survey of the Australasian Cyperaceae genus Lepidosperma

Abstract

Lepidosperma species are long-lived perennials with significant abundance and persistence in the landscape. Speciation patterns in the genus are of considerable interest due to complex biogeographical patterns and a high degree of habitat specificity. Potential benefits exist for medicinal products identified from several Lepidosperma species. Over 178 organisms, including 26 mammals, 42 birds, six reptiles, five amphibians, eight arachnids, 75 insects, three crustaceans and 13 fungi, are found to be dependent on, or making use of, Lepidosperma species. A significant relationship exists between Lepidosperma species and the moth genus Elachista. Implications for the conservation and ecology of both sedges and associated species are discussed.

Contrasting patterns of clonality and fine-scale genetic structure in two rare sedges with differing geographic distributions

“…There have been no empirical studies of their ecology or mating systems to date, and we did not observe any viable seed set in the two years of this study to enable our own investigations. However, Lepidosperma are considered to be primarily outcrossing via windpollination and their andromonoecious arrangement of unisexual and bisexual flowers with dichogamous development presumably limits selfing (Barrett, 2013). Finally, the presence of elaiosomes suggests that seed dispersal may be facilitated by ants and birds.…”

“…Geological stability across this ancient landscape, coupled with Pleistocene climatic fluctuations and complex soil mosaics (Hopper, 1979), have led to an array of common and rare species that show complex evolutionary patterns of fragmentation and structuring . Lepidosperma is one of the five largest genera in this region, consisting of many rare species with narrow geographic ranges that are associated with specific geologies (Barrett, 2013). Lepidosperma are known to exhibit rhizomatous propagation (Barrett, 2013), which in conjunction with rarity, suggest that fine-scale processes are likely to be important determinants of genetic diversity and structure in these species; however, no investigation of clonality has been published to date for this ecologically important genus.…”

“…Lepidosperma is one of the five largest genera in this region, consisting of many rare species with narrow geographic ranges that are associated with specific geologies (Barrett, 2013). Lepidosperma are known to exhibit rhizomatous propagation (Barrett, 2013), which in conjunction with rarity, suggest that fine-scale processes are likely to be important determinants of genetic diversity and structure in these species; however, no investigation of clonality has been published to date for this ecologically important genus.…”

“…Previous work confirms that both are outcrossing, although observations of poor seed set over recent years indicates that sexual reproduction is not regular for either species. Two consecutive seasons of good rainfall are required for flowering and seed development in Lepidosperma (Barrett, 2013) and this is likely to be the major limiting factor to sexual reproduction for both study species given that they co-occur in a low rainfall zone (Hopper, 1979). Their resilience in this landscape is thought to be attributed to a mixed strategy of sexual and asexual reproduction, which is consistent with geometric growth patterns, shared multilocus genotypes (MLGs) and high F IS values (Binks et al, 2015), although the extent of clonality in these species is unknown.…”

Ironplant (Astrotricha hamptonii, Araliaceae): an enigmatic species with a rich history in bioprospecting

“…Barrett unpubl. data), Lepidosperma ferricola R.L.Barrett (Barrett 2007(Barrett , 2013, Lindernia cleistandra W.R.Barker, L. eremophiloides W.R.Barker (Barker 1990 (Barrett et al 2005). Specialisation to growing on cliff faces requires a number of specific physiological adaptations to survive these extreme conditions (Larson et al 2000).…”