Jungermanniales

Abstract: Aim To explore species richness patterns in liverworts and mosses along a central Himalayan altitudinal gradient in Nepal (100-5500 m a.s.l.) and to compare these patterns with patterns observed for ferns and flowering plants. We also evaluate the potential importance of Rapoport's elevational rule in explaining the observed richness patterns for liverworts and mosses.Location Nepal, Central Himalaya.Methods We used published data on the altitudinal ranges of over 840 Nepalese mosses and liverworts to interpolate presence between maximum and minimum recorded elevations, thereby giving estimates of species richness for 100-m altitudinal bands. These were compared with previously published patterns for ferns and flowering plants, derived in the same way. Rapoport's elevational rule was assessed by correlation analyses and the statistical significance of the observed correlations was evaluated by Monte Carlo simulations.Results There are strong correlations between richness of the four groups of plants. A humped, unimodal relationship between species richness and altitude was observed for both liverworts and mosses, with maximum richness at 2800 m and 2500 m, respectively. These peaks contrast with the richness peak of ferns at 1900 m and of vascular plants, which have a plateau in species richness between 1500 and 2500 m. Endemic liverworts have their maximum richness at 3300 m, whereas non-endemic liverworts show their maximum richness at 2700 m. The proportion of endemic species is highest at about 4250 m. There is no support from Nepalese mosses for Rapoport's elevational rule. Despite a high correlation between altitude and elevational range for Nepalese liverworts, results from null simulation models suggest that no clear conclusions can be made about whether liverworts support Rapoport's elevational rule.Main conclusions Different demands for climatic variables such as available energy and water may be the main reason for the differences between the observed patterns for the four plant groups. The mid-domain effect may explain part of the observed pattern in moss and liverwort richness but it probably only works as a modifier of the main underlying relationship between climate and species richness.

Abstract: Preface Acknowledgements Introduction 1. Examination of material 2. Measurements 3. Use of keys 4. Nomenclature and taxonomy 5. Taxonomic categories 6. Frequency and distribution 7. Illustrations and descriptions 8. Conspectus of classification 9. Hepaticae: Artificial key to orders (including Anthocerotae), Calobryales, Jungermanniales 10. Artificial key to families of Jungermanniales, Metzgeriales 11. Artificial key to families of Metzgeriales, Sphaerocarpales, Marchantiales 12. Artificial key to families of Marchantiales 13. Anthocerotae Glossary Bibliography Index.

Abstract: Based on chloroplast DNA sequences we develop a phylogenetic hypothesis of the diversification of liverworts (Marchantiophyta) with an extant diversity of about 6,000 species. Divergence time estimates obtained using penalized likelihood with integrated fossil evidence suggest a Late Ordovician origin of Marchantiophyta, a separation ofHaplomitriopsida from the remainder of liverworts in the Early Devonian, a split of Jungermanniopsida and Marchantiopsida in the Late Devonian, and a separation of Metzgeriidae and Jungermanniidae in the Late Carboniferous. Leafy liverworts (Jungermanniidae) with an extant diversity of ca. 4,500 species split into Porellales and Jungermanniales in the Early-Middle Permian. Our data provide evidence for a diversification of Jungermanniidae in the Triassic-perhaps coinciding with the recovery of terrestrial vegetation from the Perm/Trias extinction-and an enhanced diversification in the Cretaceous and Early Tertiary. The latter diversification events may coincide with the establishment of modern rainforests in the Late Cretaceous to Early Tertiary that were dominated by derived groups ofangiosperms. In addition, the Late Mesozoic and Early Tertiary diversification of leafy liverworts may have also been influenced by drastic changes in the geographical structure of the land masses and the global climate.