|Wednesday, July 07|
Effects of elevation and disturbances on the diversity of bryophytes in laurel forests of Madeira island
* Manuela Sim-Sim, cE3c, Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, Campo, Portugal
Steffen Boch, WSL Swiss Federal Research Institute, Birmensdorf, Switzerland
Anabela Martins, cE3c, Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, Campo
Michael Stech, Naturalis Biodiversity Center, PO Box 9517, 2300 RA Leiden, Leiden, The Netherlands; Leiden University, Leiden, The Netherlands
Ariel Bergamini, WSL Swiss Federal Research Institute, Birmensdorf, Switzerland
The laurel forest of Madeira island is a bryophyte diversity hotspot. On Madeira, climate change scenarios predict a precipitation decrease of about 30% until 2,100. Moreover, not only the precipitation sum will change, but it is likely that also seasonal climatic conditions change in the future with longer drought periods or a decrease of fog and mist frequency in combination with increasing temperatures. These changes might have a strong negative impact on bryophyte diversity. Actually, many specialized species depend on the constantly humid conditions of the closed laurel forest at intermediate elevations or on light and moist conditions in the more open tree-heath forests at high elevations, for example many endemic bryophytes and other drought-sensitive species such as many liverworts. In particular endemic bryophyte species might suffer from future climate change on Madeira, as suitable habitats might decrease by 62–87% depending on the species. According to the latest European Red List of bryophytes, all endemic species of Madeira were considered as threatened (three Critically Endangered, six Endangered, and one Vulnerable), and 80 % of them occur in the laurel forest. Our findings indicate the need for a strict protection status of the laurel forest on Madeira island to minimize human-related disturbances, for the development of management measures that could mitigate climate change effects by maximizing habitat suitability and for the implementation of species conservation programs to prevent future extinctions, in particular of endemic species.
Vegetation structure in boreal peatlands of North-western Québec
* Marc-Frédéric Indorf, CBA-ABC, Canada
Yves Bergeron, Université du Québec en Abitibi-Témiscamingue
Nicole J. Fenton, Université du Québec en Abitibi-Témiscamingue
Located in the Canadian boreal forest, the Eeyou Istchee James-Bay territory (EIJB) of North-western Québec is largely occupied by peatlands, up to 40% in some sectors. To date, only one extensive study of EIJB peatland vegetation exists (Grondin, 1980) focusing mainly on tracheophytes. We seek to better understand today’s distribution of bryophyte and tracheophyte species in EIJB peatlands and their interactions with environmental factors. Vegetation and environmental data were obtained from 36 peatlands in 3 sectors along a 1000km transect. Vegetation communities were classified into groups by species composition and verified by randomisation. Multivariate analyses established correlations between environmental data and identified vegetation groups. Results show that the poor fen group exhibits the greatest variation in species composition. While many species are common, woodland species such as Blepharostoma trichophyllum, Calypogeia integristipula, Campylium stellatum, Clintonia borealis, Lepidozia reptans, Obtusifolium obtusum, Sphagnum squarrosum, and Syzygiella autumnalis tend to be absent in poor fens while the more hydric environment of this group favours species such as Carex spp., Drosera anglica, Eriophorum spp., Menyanthes trifoliata, Pallavicinia lyellii, Sphagnum riparium, S. tenellum, and S. venustum. Our data also show that water table depth is the most important determining factor for peatland vegetation community composition, while water chemical composition is little correlated with community composition. These results show how plant peatland communities and hydrology are intricately related in EIJB and that this interaction should be taken into consideration in developmental decisions, especially in the current situation of a changing environment, both climatic and socioeconomic.
Dispersal and taxonomy in disjunct oceanic-montane liverworts
Maren Flagmeier, Universidad Autónoma de Madrid
Jane Squirrell, Present address: Peterborough, United Kingdom
Mary Woodhead, Present Address: Perth, United Kingdom
David Long, Royal Botanic Garden Edinburgh
* Neil Bell, Royal Botanic Garden Edinburgh, United Kingdom
Joanne Russell, The James Hutton Institute
Wayne Powell, Scotlands Rural College
Peter Hollingsworth, Royal Botanic Garden Edinburgh
The globally rare mixed northern hepatic mat community is dominated by large, charismatic liverwort species, most of which have highly disjunct distributions consistent with the very scattered occurrence of the habitats in which they are found, such as oceanic-montane heath (OMH). These habitats are defined by conjunctions of topographic and climatic factors, including continually high levels of precipitation and a seasonally relatively stable temperature regime. Climate modeling suggests that they may shift northwards or be significantly modified, while populations of many species in Scotland have apparently lost the ability to reproduce sexually and may be at their distributional climatic limit. Understanding the origins, taxonomy and dispersal biology of OMH species is therefore key to their conservation. Our ongoing research is examining genotypic diversity, taxonomic boundaries and biogeographical origins in a number of OMH species, including Anastrophyllum alpinum, Plagiochila carringtonii and Adelanthus lindenbergianus. Microsatellite markers were used to investigate genetic differences between six populations of Anastophyllum alpinum from Nepal and Scotland. A nested allele distribution of Scottish populations within Nepalese, and lower genetic diversity of Scottish populations, indicated that Scottish populations likely have their origins in the Sino-Himalaya, with disjunct populations certainly representing the same species. Work is in progress using chloroplast and nuclear markers to investigate the taxonomic identity of Scottish populations of Plagiochila carringtonii and Adelanthus lindenbergianus in relation to their disjuncts in the Sino-Himalaya, and in the Americas and South Africa respectively, with preliminary results pointing to a diversity of biogeographic and taxonomic patterns among different OMH species.
Can species distribution modelling improve climate threat assessments for bryophytes-at-risk in Canada?
* Emma Menchions, University of British Columbia, Canada
* Victoria Knoblauch, University of British Columbia
* Isla Francis, University of British Columbia
Caleb Weinhagen, University of British Columbia
G. Karen Golinski, University of British Columbia
British Columbia is a hotspot for bryophyte biodiversity in Canada. Assessments of the impact of future climate change on bryophytes-at-risk based on widely used IUCN methodologies typically incorporate regional scale climate data and generalized qualitative predictions. Bartramia halleriana (Haller’s Apple Moss) – assessed as Threatened in Canada – was chosen as a test species to develop a framework to quantitatively predict the impacts of future climate on species with low numbers of occurrences and/or occupying climatically heterogeneous environments such as the Rocky Mountains, where B. halleriana occurs. We used the ensemble of small models (ESM) species distribution modeling technique to predict differences between areas of climatically suitable habitat now and under the future climate change scenarios RCP 4.5 and 8.5 for 2085. We hypothesized that climatically suitable habitat will shift upslope and northward in the future, and that range size will contract. Projected models support these hypotheses and indicate that the northward shift in suitable climate will also expand northeastward under both scenarios. Challenges to modelling the current distribution of B. halleriana include limited published microclimatic data, a paucity of information describing species-specific ecological requirements, and poor coverage of high-resolution environmental data. We intend to test the efficacy of the framework for other bryophytes-at-risk in Canada and will report on our progress during the symposium.
Bryophytes are predicted to lag behind future climate change despite their high dispersal capacities
* Florian Zanatta, Meise Botanic Garden, Belgium
Alain Vanderpoorten, University of Liège
Flavien Collart, University of Liège
The extent to which species can balance out the loss of suitable habitats due to climate warming by shifting their ranges is an area of controversy. Here, we assess whether highly efficient wind-dispersed organisms like bryophytes can keep-up with projected shifts in their areas of suitable climate. Using a hybrid statistical-mechanistic approach accounting for spatial and temporal variations in both climatic and wind conditions, we simulate future migrations across Europe for 40 bryophyte species until 2050. The median ratios between predicted range loss vs expansion by 2050 across species and climate change scenarios range from 1.6 to 3.3 when only shifts in climatic suitability were considered, but increase to 34.7–96.8 when species dispersal abilities are added to our models. This highlights the importance of accounting for dispersal restrictions when projecting future distribution ranges and suggests that even highly dispersive organisms like bryophytes are not equipped to fully track the rates of ongoing climate change in the course of the next decades.