caa a22 4500 469095954 CHVBK 20180323133030.0 cr unu---uuuuu 170328e19921201xx s 000 0 eng 10.1007/BF00317455 doi (NATIONALLICENCE)springer-10.1007/BF00317455 Hestmark Geir Division of Botany, Department of Biology, University of Oslo, P. b. 1045, N-0316, Oslo 3, Norway aut Sex, size, competition and escape—strategies of reproduction and dispersal in Lasallia pustulata (Umbilicariaceae, Ascomycetes) [Elektronische Daten] [Geir Hestmark] The lichen Lasallia pustulata has a mixed strategy of asexual and sexual reproduction. Close-dispersed, asexual, symbiotic isidia are produced early, when the thalli are small. The asexual propagules are subsequently supplemented by far-dispersed, sexually generated ascospores when the thalli grow larger. This observation is consistent with evolutionary stable strategy (ESS) models of dispersal allocations in heterocarpic plants accordin to which the production of far-dispersed propagules should increase as clutch size and sibcompetition in the local habitat increases. The observation is also consistent with the "tangled bank” or "elbow room” hypothesis for the maintenance of sexuality, according to which sex, by generating genetic variation, represents an escape from competition in biologically saturated environments. Thus the advantage of sex is density dependent. L. pustulata grows in densely packed populations where intraspecific competition results in self-thining and the development of distinct sizehierarchies. Springer-Verlag, 1992 Ecology of sex nationallicence Tangled bank nationallicence Heterocarpy nationallicence Dispersal nationallicence Lasallia pustulata nationallicence Oecologia Springer-Verlag 92/3(1992-12-01), 305-312 0029-8549 92:3<305 1992 92 442 https://doi.org/10.1007/BF00317455 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00317455 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Hestmark Geir Division of Botany, Department of Biology, University of Oslo, P. b. 1045, N-0316, Oslo 3, Norway aut NATIONALLICENCE 773 0- Oecologia Springer-Verlag 92/3(1992-12-01), 305-312 0029-8549 92:3<305 1992 92 442 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer