|Thursday, July 08|
Centres of bryophyte endemism in southern Africa
* Nonkululo Phephu, Tshwane University of Technology, South Africa
Ed Witkowski, University of the Witwatersrand
Jacques van Rooy, South African National Biodiversity Institute
Manuela Sim-Sim, Universidade de Lisboa
Endemic and rare species are more prone to extinction than common species because they are habitat- specific and most of them present specific life strategies. In recent years the efforts to preserve rare organisms and seek out and protect areas of high endemism have acquired increased urgency in the light of the accelerating natural habitat and biodiversity losses through impacts of human action and climate change among others. In recent checklists of the mosses and liverworts of southern Africa (FSA region), 190 species, 23 genera and 14 families were identified as endemic to the region. The Cape fold mountains and the Drakensberg Mountains along the Great Escarpment of South Africa have recently been determined as centres of moss diversity in southern Africa. The Cape Floristic, Succulent Karoo and Maputaland-Pondoland Regions are recognized as the three regions of vascular plant diversity and endemism for South Africa. The aim of this study is to describe the centres of bryophyte endemism according to the number of endemic species per 1?2° grid square. The cells will then be grouped according to intervals, 0, 1 5, 6 10, 11 15, 16 20, 2125, 2630, 3135, 3640, 4145 species per grid. These groups will be mapped to determine the centres of bryophyte endemism. The centres will then be compared with rainfall, altitude, phytogeographic regions, centres of moss diversity and ecoregions in southern Africa. The centres of bryophyte endemism will also be compared with centres of vascular plant endemism in southern Africa.
Continental drift originated the E African - S Indian disjunction of Lewinskya firma (Orthotrichaceae, Bryopsida): fact or fiction?
* Raúl D. San Román, Autonomous University of Madrid, Spain
Pablo Aguado, Autonomous University of Madrid
Isabel Draper, Autonomous University of Madrid
Ricardo Garilleti, Autonomous University of Madrid
Francisco Lara, Autonomous University of Madrid
Disjunct distributions at specific level are common among bryophytes. When studied from a phylogeographic point of view, long-distance dispersal seems to be the most plausible mechanism for explaining most of such disjunctions. Even though, in some particular situations the contribution of other processes, such as continental drift or stepping-stone migration, cannot be ruled out. On the other hand, current taxonomical studies often show that apparently disjunct distribution patterns of bryophyte species actually correspond to complexes of cryptic species with much narrower distribution ranges and which not necessarily are closely related species. We analyse the apparently disjunct distribution of Lewinskya firma, a widespread species in the Afromontane forests of East Africa. Only one population of this species is knownoutside Africa, located in the Nilgiri Mountains in southeast India. Since this distribution is consistent with the drift of the Indian subcontinent since the Late Cretaceous, it is suggestive that this disjunction could in fact correspond to a process of vicariance. To verify this, an integrative taxonomy study has been undertaken, combining morphological and molecular analyses. The results of the morphological study support the existence of three well-defined morphotypes within the current Lewinskya firma concept. Two of them are mosses spread in Africa, while the third one corresponds to the population from the Indian subcontinent. The distinction of the two African morphotypes is also supported on the basis of the molecular data and could date from the Oligocene. Surprisingly, the Indian morphotype is molecularly closely related to one of the African morphotypes, pointing to a recent diversification. Further analysis including additional molecular data are needed in order to fully understand the evolutionary history within Lewinskya.
Targeted sequencing supports morphology and embryo features in resolving the classification of Cyperaceae tribe Fuireneae s.l.
* Julian Starr, University of Ottawa, Canada
Pedro Jiménez-Mejías, Universidad Autónoma de Madrid
Alexandre Zuntini, Royal Botanic Gardens, Kew
Étienne Léveillé-Bourret, Université de Montréal
Ilias Semmouri , University of Ottawa
Muthama Muasya , University of Cape Town
William Baker , Royal Botanic Gardens, Kew
Grace Brewer, Royal Botanic Gardens, Kew
Niroshini Epitawalage, Royal Botanic Gardens, Kew
Isabel Fairlie, Royal Botanic Gardens, Kew
Félix Forest, Royal Botanic Gardens, Kew
Izai Kikuchi, Royal Botanic Gardens, Kew
Lisa Pokorny, University of Ottawa
Isabel Larridon , Royal Botanic Gardens, Kew
Molecular phylogenetic studies based on Sanger sequences have shown that Cyperaceae tribe Fuireneae s.l. is paraphyletic. However, taxonomic sampling in these studies has been poor, topologies have been inconsistent, and support for the backbone of trees has been weak. Moreover, uncertainty still surrounds the morphological limits of Schoenoplectiella, a genus of mainly small, amphicarpic annuals that was recently segregated from Schoenoplectus. Consequently, despite ample evidence from molecular analyses that Fuireneae s.l. might consist of two to four tribal lineages, no taxonomic changes have yet been made. Here, we use the Angiosperms353 enrichment panel for targeted sequencing in order to: (1) clarify the relationships of Fuireneae s.l. with the related tribes Abildgaardieae, Eleocharideae and Cypereae; (2) define the limits of Fuireneae s.s., and (3) test the monophyly of Fuireneae s.l. genera with emphasis on Schoenoplectus and Schoenoplectiella. Using more than a third of Fuireneae s.l. diversity, our phylogenomic analyses strongly support six genera and four major Fuireneae s.l. clades that we recognise as tribes: Bolboschoeneae stat.nov., Fuireneae s.s., Schoenoplecteae, and Pseudoschoeneae tr.nov. These results are consistent with morphological, micromorphological (nutlet epidermal cell shape), and embryo differences detected for each tribe. At the generic level, most sub-Saharan African perennials currently treated in Schoenoplectus are transferred to Schoenoplectiella. Our targeted sequencing results show that these species are nested in Schoenoplectiella, and their treatment here is consistent with micromorphological and embryo characters shared by all Schoenoplectiella species.
Integrative taxonomic study disclosed a hidden diversity in hygrophilous species of the genus Pseudohygrohypnum
Vladimir Fedosov, Lomonosov Moscow State University, Biological Faculty
* Anna Shkurko, Tsitsin Main Botanical Garden, Russian Academy of Sciences, Russian Federation
Alina Fedorova, Tsitsin Main Botanical Garden, Russian Academy of Sciences
Elena Ignatova, Lomonosov Moscow State University, Faculty of Biology
Michael Ignatov, Lomonosov Moscow State University, Faculty of Biology
Molecular and morphological study of the hygrophilous species of Pseudohygrohypnum, P. eugyrium and P. subeugyrium, revealed their severe heterogeneity. Plants referred hiterto to P. eugyrium comprise three allopatric species occurring in Europe, North America and East Asia, and those of P. subeugyrium belong to five species. Distributions of the latter lineages are partly overlapped. Pseudohygrohypnum subeugyrium s.str. is a North Atlantic species, while East Asian populations are referred to P. purpurascens, that is thus resurrected. In addition, three exclusively or predominantly North Asian lineages from harsh continental climates were revealed. Results of Maxent distribution modeling and niche identity & similarity tests indicate remarkable divergence of niches of all lineages excepting East Asian “P. eugyrium” and P. purpurascens, which actually are not related. Considerable nucleotide distances and results of the ASAP test suggest a need of split two hygrophilous Pseudohygrohypnum species into eight. Our work was supported by RSF grant # 18-14-00121
Spatial phylogenetics of the North American moss flora
* Benjamin Carter, San Jose State University, United States
Tracy Misiewicz, University of Oklahoma
Brent Mishler, UC Berkeley
Spatial phylogenetics is a relatively new and important approach that adds an evolutionary dimension to traditional measures of biodiversity based on species richness and endemism, using measures such as Phylogenetic Diversity (PD - the phylogenetic relatedness of lineages within areas), Relative Phylogenetic Diversity (RPD - the distribution of phylogenetic branch lengths across a landscape), and CANAPE (Categorical Analysis of Neo-and Paleo-Endemism). In this study we aimed to identify the important regions within North America north of Mexico for PD, RPD, and CANAPE and to examine climatic patterns that may help explain these measures. The dataset included occurrence data and a phylogeny for 971 mosses (70.1% of the flora). PD peaks in the Pacific Northwest, and is bimodally distributed between the east and west coasts of the continent. PD and RPD are both significantly higher than expected (based on a spatial randomization test) in the eastern US, indicating phylogenetic overdispersion and a significantly high concentration of long phylogenetic branches. Significant centers of phylogenetic endemism discovered by CANAPE include California, Florida and the Gulf Coast, and isolated areas throughout the mountainous west. These patterns can be explained in part by the magnitude and seasonality of current precipitation, however historical factors including glaciation migration patterns and refugia from more ancient climate regimes also appear to play an important role in explaining the current distribution of lineages across the region.
Hornwort (Anthocerotophyta) diversity in Mexico
* Ariadna Ibarra-Morales, Centro de Investigación Científica de Yucatán A.C., Mexico
Susana Valencia-Avalos, Universidad Nacional Autónoma de México
María Eugenia Muñiz-Díaz de León, Universidad Nacional Autónoma de México
Hornworts (Anthocerotophyta) are classified within the non-vascular embryophytes, characterized by a laminar gametophyte and a protruding horn-like sporophyte; the most recent diversity estimation recognizes 12 genera and 205 species worldwide within the division. Hornwort diversity concentrates near the tropics; crossed almost to the middle by the Tropic of Cancer, Mexico harbors unique scenarios were Neartic and Neotropical taxa distribute. Nevertheless, Mexican hornwort floristic studies are scarce. In 1863, Gottsche enlisted seven hornwort species for the country; since then, Mexican hornwort flora was partially included in North American studies; however, a complete and updated documentation is lacking. In 2012, Delgadillo-Moya and Juárez-Martínez estimated Mexican hornwort diversity to nine species and four genera, recognizing three endemic species. The aim of this study is to document and update Mexican hornwort species diversity, contributing to the biogeographical knowledge of this group, and to facilitate their identification. Herbarium and literature revisions were carried out alongside field collections. Seven genera and 26 species of Anthocerotophyta are recognized for Mexico in the present study; two new records for America and four new records for the country are documented. Mexican hornwort flora, dominated by Anthoceros species, presents a mixture of Nearctic, Neotropical, endemic and cosmopolitan taxa. The fact that a few collecting expeditions resulted in several new records highlight the needs of increasing sampling efforts, and of implementing molecular resources to test the monophyly of geographically disjunct or ill-defined taxa.