Rhizoidal tuber production in a non-native, male-biased population of Gemmabryum klinggraeffii (Schimper) J.R.Spence & H.P.Ramsay

ABSTRACT Introduction. It is unusual to encounter male-biased populations of dioicous mosses. We report a case of a non-native (to the USA) dioicous moss, Gemmabryum klinggraeffii, in male-biased populations established through tuber recruitment from the soil propagule bank in an urban park in the context of an invasive plant removal experiment. Methods. The mosses in this study originated from soil samples taken from an urban park in the Midwestern USA. Within the park, soils were taken from plots that underwent invasive species removal and control plots that did not undergo species removal. Mosses emerging from the soil samples were propagated and grown for 1 year, after which the density of Gemmabryum klinggraeffii plants per pot and the mean numbers of tubers and gametophores were computed. Key results. Gemmabryum klinggraeffii was more likely to occur in soil from control sites where invasive species had not been removed. The number of tubers per stem was dependent on the abundance of G. klinggraeffii in the pot, such that pots with more G. klinggraeffii produced more tubers per stem on average. Plants with and without gametophores produced similar numbers of tubers, and the only sex organs detected in the populations were antheridia. Conclusions. Gemmabryum klinggraeffii depends on rhizoidal tubers that persist in soil propagule banks and are important to local population persistence in the urban park studied. Potentially other populations in North America are also male, single-sex populations that deserve further attention.