**S.212.1 Long-term**
**monitoring of alpine**
**ecosystems**

Christian Körner¹, Erika Hiltbrunner¹,
Christian Newsely², Ulrike Tappeiner²

1 University of Basel, Basel, Switzerland. 2 University of Innsbruck, Innsbruck, Austria

Naturally treeless by definition, the vegetation cov-
ered terrain of the alpine belt amounts to ca. 2 %
of all land outside Antarctica. Despite the assumed
hostility for life, it embraces an estimated 4 % of all
flowering plant species. Habitat diversity created
by topography and a microclimate that deviates
strongly from what meteorological stations report,
are the explanation for this unexpected biodiversity.
The habitat diversity across short distances offers
unique opportunities to study the long-term effect of
contrasting environmental conditions on biodiversi-
ty and ecosystem functioning. We present concepts,
definitions, challenges and pitfalls in monitoring ter-
restrial ecosystems and the study of steep gradients
of life conditions related to snow duration and length
of growing season, with a focus on snowbed and
adjacent grassland communities. We provide a syn-
thesis of findings obtained during seven consecutive
seasons of monitoring with a standardized protocol,
across four monitoring sites in the Swiss and Austri-
an Alps. We show that plant dry matter allocation is
highly conserved across such gradients, tbwhile the
ratio of graminoid to herb biomass emerges a sen-
sitive indicator for season length. Microclimate and
phenology data will be presented that illustrate the
key role of 'timing' for alpine plant life, and underpin
the central role of the aerodynamic boundary lay-
er near the ground and exposure for alpine plants.
Data from such late successional ecosystems will
facilitate projections of the consequences of future
changes in season length and they complement
findings from early successional systems such as
those studied in the GLORIA network. For further read-
ing see: Körner C (2021) Alpine Plant Life, Springer;
Körner and Hiltbrunner (2021) Diversity 13:383; Körner
et al. (2022) EcoMont 14:48-69.

**S.212.2 Using long-term**
**remote sensing series to**
**upscale the vegetation**
**shifts along elevation in the**
**GLORIA network** Italian peaks

Marco Vuerich¹,², Francesco Boscutti¹,²,
Davide Mosanghini¹,³, Giacomo Trotta¹,
Graziano Rossi⁴, Francesco Porro⁴,
Simone Orsenigo⁴, Silvano Lodetti⁴,
Margherita Tognela⁴, Elena Barni⁵,
Ludovica Oddi⁵, Umberto Morra di Cella⁶,
Angela Stanisci⁷, Maria Laura Carranza⁸,
Pau Carnicero⁹, Brigitta Erschbamer⁹,
Lena Nicklas⁹, Michele Carbognani¹⁰,
T'ai G.W. Forte¹⁰, Marcello Tomaselli¹⁰,
Alessandro Petraglia¹⁰

1 Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy. 2 National Biodiversity Future Center, Palermo, Italy. 3 FOR NATURE SRL, Udine, Italy. 4 Department of Earth and Environmental Sciences, University of Pavia, Pavia, Italy. 5 Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy.; 6 Aosta Valley Regional Environmental Protection Agency, Saint-Christophe, Italy. Department of Botany. 7 Department of Bioscience and Territory, University of Molise, Termoli, Italy. 8 Department of Bioscience and Territory, University of Molise, Pesche (IS), Italy. 9 Department of Botany, University of Innsbruck, Innsbruck, Austria. 10 Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy

Plant species and communities' distribution are re-
markably affected by the climate change, particular-
ly in arctic and alpine biomes. In alpine ecosystems,
species and communities are shifting upwards due
to the temperature increase, seeking for the optimum
growth conditions. As a prominent effect, a progres-
sive increase of vegetation cover is leading an alpine
greening, with important consequences for the over-
all plant diversity. Nonetheless, little is known about
how this trend may produce different effects along
<figure><img src="image_493.png" /></figure>

elevation gradients. Innovative upscaling approaches able to link field monitoring evidence to remote sensing data represent a promising tool to get new insights into the ecological mechanisms involved in these changes, and to produce reliable projections over time. This study aimed at parsing the long-term trends of remote sensing-derived vegetation indices in five GLORIA network target regions, located across the Italian Alps and Apennines. NDVI was calculated for each growing season (June-September) in the period 1985-2022, using Landsat 5 and 8 multispectral satellite images of each mountain summit. Linear mixed-effects models were used to analyze the relationships between NDVI, time and climate variables, in different elevation belts. NDVI linearly increased over the last 37 years, but with significant higher increase rates and values at the treeline, lower alpine and alpine zones, compared to the upper alpine, subnival and nival belts. Moreover, NDVI was significantly affected by the interaction between temperature and rain precipitation at lower altitudes. These results provided further evidence of the ongoing alpine greening and showed that vegetation at the treeline is responding faster than the other communities to a warmer and drier climate. Therefore, future scenarios depicting the fate of alpine plant community communities should not neglect for the interplay of temperature and precipitation regimes. Our finding opens future perspectives on the interpretation of GLORIA field evidence, in a continental upscaling perspective.

### S.212.3 Results of the 17-year GLORIA survey: Has there been a change in the plant diversity in the mountains of central Spain?

Rosina Magaña Ugarte¹, Alba Gutiérrez-Girón¹, Daniel Sánchez-Mata¹, Rosario G. Gavilán¹

1 Botany Unit, Pharmacology, Pharmacognosy and Botany Dept., Complutense University, Madrid, Spain

The environmental particularities of the Mediterranean - a dry season during the vegetative period and a cold season during the rest of the year - make the plausible climate change impacts on the unique Mediterranean summits more severe. A significant number of endemic species, primarily orophytes, are found in this region as a result of

the particular conditions that have worked as a selective pressure on plant species. Nevertheless, the biodiversity found in these areas may be in jeopardy as a result of climate change. Dry spells have become more common in central Spain over the last decade, and experts predict that these high elevations will experience even more dry spells as a result of global warming. Our research is centred on identifying the most significant changes in plant diversity that have occurred or are occurring in the summits of the Sistema Central (Sierra de Guadarrama, Sierra de Gredos and Sierra de Béjar) a 300 km mountain range in the centre of the Iberian Peninsula that separates the southern and northern plateaus. This has been accomplished by utilising climatic data derived from GLORIA soil temperature dataloggers and supplementary records from the AEMET (National Meteorological Institute), as well as vegetation data gathered from permanent plots of three surveys of two GLORIA study regions over a span of 17 years (2006-2023). We used multivariate approaches and GLMMs to examine the relationships between diversity patterns and climatic conditions. Here, we go over the main findings concerning species richness, species cover (especially for endemic species and shrubs), colonisation or loss events and how they relate to trends in temperature and precipitation.

### S.212.4 Impact of climate change on plant phenology in a Mediterranean mountain (Sierra Nevada, SE Spain) using herbarium specimens

Katy V. Rondinel-Mendoza¹, Matilde García-Valdecasas Ojeda², Eva Cañadas¹, Juan Lorite¹

1 Department of Botany, University of Granada, Spain. 2 Department of Applied Physics, University of Granada, Spain

Mediterranean mountains are extraordinarily diverse and host a high plant diversity, especially of endemic plants. However, these mountain ecosystems are particularly vulnerable to climate change, and significant changes in plant communities and the life cycle of many species are expected. Plant phenology is considered one of the most important bioindicators of climate change, as trends can pro-
<figure><img src="image_494.png" /></figure>

vide considerable temporal and spatial information on changes in species and ecosystems. This work aimed to analyze the phenological trends of 89 endemic and conservation-important plant species of Sierra Nevada (SE Spain) over period of 187 years. A total of 5,262 records were obtained from herbarium samples. Phenological variability was analyzed considering: altitudinal gradient and climatic data series (temperature and precipitation) extracted from raster layers with temporal climate models from 1950 to 2020. As preliminary results, we found a clear tendency to advance the flowering and fruiting events at the massif scale. And, at the species level, the response was more significant in one than in the others. These results may improve the understanding of phenological changes in endemic plants under the current climate change scenario in a Mediterranean water-limited mountain. Thus, serving as early warning indicators, providing appropriate mitigation and adaptation strategies and measures at the species level. Moreover, the study highlights the crucial role that historical records harboured in herbarium sheets have for monitoring the effects of climate change on biodiversity.

Mountain region in southwestern China to study pollination networks by investigating their topologies, structuring mechanisms and spatial-temporal dynamics. We investigated how ecological and historical factors, including functional traits of plants and pollinators, phylogenetic history and environmental factors influence of structure of pollination networks. In this talk, we presented our key findings. 1) Compared to other mountain ecosystems, the specialization of pollination networks in our communities was much lower, potentially due to the key roles of super generalists including bumblebees and honeybees. 2) Species abundance, functional trait and phylogenetical history strongly shaped network structures. The matching between insect tongue length and the floral tube/spur length determined the structure and stability of networks. The physical match between floral morph and insects were significantly varied among different insects groups and influenced by elevation. 3) Pollination networks showed a strong spatial and temporal variation. In conclusion, our studies uncover the uniqueness of pollination in the mountains of Southwestern China compared with other mountain ecosystem in the world providing new understanding of plant-pollinator interaction at alpine and subalpine regions.

## S.212.5 Two Decades of Pollination and Pollinator Studies on the Hengduan Mountains: The Importance of Super-generalist Eusocial Bees

Zong-Xin Ren¹, Hong Wang¹

1. Kunming Institute of Botany, Chinese Academy of Sciences

Mountain ecosystems are natural labs for species evolution providing natural experiments awaiting us to explore. Alpine environments at high mountains are sensitive to environmental changes, plants and their pollinators as well as their interactions at mountain regions are threatened under the current global change and human disturbance situation. Changes of the composition of plants and pollinators at different spatial and temporal scales will reshape the pollination networks, eventually influence ecosystem function and stability. Currently, the topology and structure of pollination on the mountain ecosystem were not fully explored and the spatial and temporal pattern along elevation and factors determining network structures are not fully understood. We selected several typical elevation gradients on the Hengduan

## S.212.6 Differences in seed traits determine ‘winners’ and ‘losers’ of climate change in European alpine plant communities.

Andrea Mondoni¹, Sergey Rosbakh², Margherita Tognela¹, Graziano Rossi¹, Silvano Lodetti¹, Simone Orsenigo¹, Francesco Porro¹, Fiona White¹

1. Department of Earth and Environmental Science, University of Pavia, Pavia, Italy. 2. Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark

Alpine habitats are threatened by climate change because their cold-adapted species are experiencing some of the fastest rates of warming. In response, alpine plants have altered their performance, population dynamics, community structure and geographic distribution, ultimately affecting the functions and services alpine ecosystems provide. Yet, there is a general lack of mechanistic explanations about these complex responses. In this context, application of functional traits, that is morphological, physiological, phenological or behavioural characteristics impacting individuals' fit-
<figure><img src="image_495.png" /></figure>

ness, has been considered as a promising approach in assessing climate change vulnerability of alpine plants. In particular, seed traits are expected to have a good predictive power in explaining the observed patterns of alpine species migration, adaptation, and persistence, as seeds are the main plant organ fulfilling these functions. Here, we investigated whether species with contrasting long-term population dynamics differ in their seed traits related to germination, dispersal, and persistence. Specifically, we correlated data on 20-yr population dynamics collected within the GLORIA network (https://www.gloria.ac.at/) for 146 alpine species occurring in temperate, sub-Mediterranean and Mediterranean mountain ranges with seed traits (mass, shape, number, dormancy, germination time, base temperature for germination, anemochory and epi-

zoochroy potential) measured following standardised protocols We revealed that the focal species displayed mountain range-specific changes in abundance, with Mediterranean and sub-Mediterranean ranges having the largest variations. The relationship between seed traits and abundance change were significant only in the sub-Mediterranean ranges. Here, species that increased in abundance exhibited weaker dormancy (e.g. shorter cold stratification period), required higher temperatures for germination, and produced larger seeds, all traits that enable long-distance dispersal and improved performance under a warmer climate. Our results show that seed traits may explain differences in recently observed population dynamics and highlight important insights for assessing extinction risk and predicting future community structure.

# S.213 AN UPDATE ON THE PHYLOGENY OF SEED PLANTS. SESSION 2

## S.213.1 Seed structure in Bennettites morieri (Bennettitales) and its implications

Peter R. Crane¹,², Kaj Raunsgaard

Pedersen⁴, Else Marie Friis³,⁴

1 Oak Spring Garden Foundation, Upperville, VA, USA. 2 Yale School of the Environment, New Haven, CT 6511, USA. 3 Department of Palaeobiology, Swedish Museum of Natural History, Box 50007, Stockholm, Sweden. 4 Department of Geoscience, University of Aarhus, Aarhus, Denmark

Understanding the structure of bennettitalean seeds is important so they can be compared with those of other seed plants, but their interpretation has been controversial for more than a century. A key question is whether or not the integument is surrounded by an envelope, as in seeds of Gnetales and Erdtmanithecales, and hence whether the seeds are, or are not, chlamydospermous. Resolving this question, even in well preserved material, is difficult because the seeds are small and tightly packed in a mass of interseminal scales causing different tissue layers to adhere closely together. Non-destructive research of exceptionally well-preserved permineralized seeds of *Bennettites morieri* using three dimensional visualization by synchrotron radiation

X-ray tomographic microscopy (SRXTM) indicates the presence of an envelope, as well as two distinctive features seen in several dispersed fossil chlamydospermous seeds; i) closure of the micropyle by radial expansion of the cells of the inner epidermis of the micropylar tube (as also occurs in extant *Gnetum gnemon*, extinct *Protoephedrites* and extinct *Williamsonia*); and, ii) the presence of distinctively angled and radially aligned cells in the apical portion of the envelope (not easily seen in some other permineralized bennettitalean ovules). These results support the hypothesis that Bennettitales, Erdtmanithecales and Gnetales are closely related, and suggest that the ovulate 'flowers' of Bennettitales are multiaxial compound heads.

## S.213.2 Impact of new taxa and morphological interpretations on seed plant phylogeny and the origin of angiosperms

Mario Coiro¹, James A. Doyle², Andrés Elgorriaga³, Leyla J. Seyfullah¹

1 University of Vienna, Vienna, Austria. 2 University of California, Davis, USA. 3 University of Kansas, Lawrence, USA
Recent discoveries of new fossil taxa, improved data on poorly known fossils, and major reinterpretations of the morphology of several key taxa have potential to strengthen or refute previous hypotheses on seed plant phylogeny. To test the impact of these developments, we have amassed a new data set including *Doylea* (Cretaceous, recently assigned to the mainly Triassic seed fern order Umkomasiales, = corystosperms), *Petriellaea* (Triassic), and *Protoephedrites* (Cretaceous) and substantially redefined many previously used characters. We have revised the scoring of glossopterids in light of evidence that the ovule-bearing structures are axillary cladodes with ovules on the surface facing the subtending leaf and have rescored Bennettitales based on evidence that the ovules are borne on simple sporophylls and lack a cupule, while we interpret *Doylea* as having compound strobili with axillary fertile short shoots bearing ovules enveloped by lobes of the short shoot. Preliminary analyses associate glossopterids with coniferophytes rather than angiosperms, *Doylea* with conifers rather than corystosperms, *Protoephedrites* with Gnetales, and *Petriellaea* and *Caytonia* with angiosperms. The positions of Bennettitales and *Pentoxylon* are particularly unstable, presumably due in part to the uncertain morphological homologies of their reproductive structures. These results are consistent across different methods (parsimony, maximum likelihood, Bayesian inference) and models for character evolution. They may favor origin of the angiosperm leaf by webbing of a pinnately compound or lobed leaf, rather than differentiation of vein orders in a simple taeniopterid- or glossopterid-type leaf, and derivation of the carpel from a megasporophyll with pinnately borne cupules (bitegmic ovule homologs), rather than a leaf plus an axillary cupule-bearing branch.

### S.213.3 Embracing uncertainty: the way forward in plant fossil phylogenetics

Mario Coiro¹

1 University of Vienna, Vienna, Austria.

Although molecular phylogenetics remains the most widely used method of inferring the evolutionary history of living groups, the last decade has seen a renewed interest in morphological phylogenetics. This has mostly been driven by the promises that integrating the fossil record offers to our understanding of macroevolutionary

processes and dynamics, as well as the possibility that the inclusion of fossil taxa could lead to more accurate phylogenetic hypotheses. The plant fossil record presents some challenges to its integration in a phylogenetic framework. Phylogenies including plant fossils often retrieve uncertain relationships with low support, or lack of resolution. This is due to the pervasiveness of morphological convergence among plant organs and the fragmentary nature of many plant fossils, and it is often perceived as a fundamental weakness reducing the utility of plant fossils in phylogenetics. Here I discuss the importance of uncertainty in morphological phylogenetics, and how we can identify important information from different patterns and types of uncertainty. I also review a set of methodologies that can allow us to understand the causes underpinning uncertainty, and how this can help us to further our knowledge of plant fossils. I also propose that a new visual language, including the use of networks instead of trees, represents an improvement on the old visualization based on consensus trees, and more adequately serves phylogeneticists working with plant fossils. This set of methods and visualization tools represents an important way forward in a fundamental field for our understanding of the evolutionary history of plants.

### S.213.4 Reassessment of the presumed Phylica inflorescence from Cretaceous amber: Laurales rather than Rhamnaceae

Simon Beurel¹, Julien B. Bachelier², Alexander R. Schmidt³, Eva-Maria Sadowski¹

1 Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany. 2 Freie Universität Berlin, Institute of Biology/Dahlem Center of Plant Sciences, Berlin, Germany. 3 University of Göttingen, Göttingen, Germany.

Cretaceous fossil flowers are highly significant, if not essential, for understanding origin and evolution of angiosperms. Kachin amber from northern Myanmar represents a valuable source of three-dimensionally preserved mid-Cretaceous (approximately 100-million-year-old) plant fossils, including diverse flowers. Systematic placement of early angiosperm fossils is sometimes challenging as they often possess surprising, unique combinations of floral traits which are absent in Cenozoic taxa. Using the published original microXCT data, we reconstructed the fossil inflorescence
from Kachin amber previously assigned to the extant genus *Phylica* (Rhamnaceae; Shi et al., 2022), visualized new diagnostic features and reassessed the fossil. The dichasial inflorescence bears bisexual flowers with a spiral phyllotaxis, an undifferentiated perianth with a floral cup, stamens with bilocular valvate anthers and a pair of basal filament appendages, inner staminodes, and a semi-inferior ovary. The characteristic flap dehiscence and the pair of basal staminal glands suggest Lauralean affinities. Using the morphological dataset of extant basal angiosperms by Kvaček et al. (2016) we placed the fossil in the Siparunaceae-Gomortegaceae-Atherospermaceae (SGA) clade of the core Laurales. Our results challenge the notion of the presence of a modern genus of Rhamnaceae in the mid-Cretaceous and are in line with most previous age estimates of Laurales and angiosperms as a whole.

References: Shi, C., Wang, S., Cai, H. H., Zhang, H. R., Long, X. X. et al. (2022). Fire-prone Rhamnaceae with South African affinities in Cretaceous Myanmar amber. Nature Plants, 8(2), 125-135. Kvaček, J., Doyle, J. A., Endress, P. K., Daviero-Gomez, V., Gomez, B., & Tekleva, M. (2016). *Pseudoasterophyllites cretaceus* from the Cenomanian (Cretaceous) of the Czech Republic: A possible link between Chloranthaceae and Ceratophyllum. Taxon, 65(6), 1345-1373.

## S.213.5 Paleogenomics reveals angiosperm karyotype evolution during their early history and shows that Amborella belongs in the Nymphaeale

Pengchuan Sun¹, Susanne S. Renner², Jianquan Liu¹

1 College of Life Sciences, Sichuan University, Chengdu, China. 2 Department of Biology, Washington University, Saint Louis, USA

Chromosome-scale genomes provide a basis for inferring ancestral linkage groups and processes of karyotype evolution. We have reconstructed the karyotypes of numerous representatives of the major groups of flowering plants, using an approach that starts from retained intact chromosomes and syntenic blocks. The results show that the most recent common ancestor of the flowering plants had 16 unique protochromosomes and that nine of these protochromosomes are still retained in at least one

extant species without any fusion or fission. Other protochromosomes underwent rare and probably irreversible fusion events, detectable through repeated polyploidizations. Amborella trichopoda shares a unique nested chromosome fusion with Nymphaea colorata, Euryale ferox and other Nymphaeales. Our data also securely resolve the position of the monocots as sister to magnoliids plus eudicots. These findings reject the low ancestral numbers for ancient angiosperms inferred with non-genomic approaches over the past 90 years and have profound implications for the early evolution and biogeography of flowering plants.

## S.213.6 Landscape genomic and introgressive hybridization in bur oak (Quercus macrocarpa)

Rebekah Mohn¹, Mira Garner², Leah Samuels¹, Paul S. Manos³, Alan S. Whittemore¹, Ian S. Pearse⁴, Jeannine Cavender-Bares⁵,⁶, Peter G. Kennedy⁷, Heather R. McCarthy⁸, Andrew L. Hipp¹

1 Science and Conservation, The Morton Arboretum, Lisle, IL, USA. 2 Pritzker Laboratory for Molecular Systematics and Evolution, The Field Museum, Chicago, IL, USA. 3 Department of Biology, Duke University, Durham, NC, USA. 4 U.S. Geological Survey, Fort Collins Science Center, Fort Collins, CO, USA. 5 Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN, USA. 6 Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA. 7 Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, USA. 8 Department of Microbiology and Plant Biology, The University of Oklahoma, Norman, OK, USA

*Quercus macrocarpa* Michx. (Fagaceae) is a common, morphologically variable, and geographically and ecologically widespread species in eastern North America. This species is one of more than 16 eastern North American members of the white oak section, *Quercus* sect. *Quercus*. All are capable of interbreeding in sympatry and have been the subject of numerous previous studies, but limited genomic work. It has been proposed that multispecies introgression in the oak syngameon has contributed to the adaptation of eastern North American white oaks including *Q. macrocarpa* to a variety of ecological conditions. To evaluate the pattern of genetic diversity in the species and test for landscape-scale patterns of gene flow, we did genome resequencing.
<figure><img src="image_496.png" /></figure>

ing across this species and 10 co-occurring species. Our resequencing data includes 693 individuals across the range of Q. macrocarpa, sequenced to an average depth of 21x. Thus far, we have identified approximately 50 highly introgressed individuals with slightly more than a third F1 hybrids, but the remainder showing evidence of introgression back into parental species at around the F2 or F3 generation. Most of the hybridization is concentrated near the boundaries of the parental species. As previously documented, the chloroplast does not appear to correspond with species identity. Interestingly, it

also does not seem to strictly correspond to geographical proximity either. *Quercus macrocarpa* exhibits population structure between the northwest, northeast, and southwest regions of its distribution despite its long-range pollen movement. This work is part of a bigger collaboration to characterize the reciprocal influences of environment, migration history, and forest community structure on introgression across the range of *Quercus macrocarpa*, and the potential effects on the organisms who depend on and live with oaks.

# S.214 THE ORIGIN AND EVOLUTION OF MODERN PLANT DIVERSITY: INSIGHTS FROM MULTIPLE DISCIPLINES. SESSION 2

## S.214.1 Dissecting the impact of mating systems and genetic diversity in Euphrasia: insights into modern plant evolution

Yanqian Ding¹,², Pete Hollingsworth², Alex Twyford¹,²

1 Institute of Ecology and Evolution, The University of Edinburgh, Edinburgh, UK. 2 Royal Botanical Garden, Edinburgh, UK

The evolution of modern plant diversity is intricately linked to the dynamics of mating systems and genetic diversity. This study investigates the genus *Euphrasia*, known for its rapid speciation and diverse mating strategies, to understand these factors’ roles in shaping plant diversification. We focus on a comparative analysis of *Euphrasia micrantha*, a predominantly selfing species, and *E. arctica*, a mixed-mating species, exploring their genetic structures, diversity, and runs of homozygosity. Our results indicate that *E. micrantha*, despite its high inbreeding levels, maintains nucleotide diversity comparable to the genetically more diverse *E. arctica*. This suggests that occasional outcrossing events may play a crucial role in preserving genetic diversity within selfing species. Additionally, the pronounced genetic structure observed in *E. micrantha* is consistent with expectations for selfing species. The runs of homozygosity analysis in both species

reveal a full spectrum of demographic history related to inbreeding, indicating complex evolutionary strategies for sustaining diversity. This study enhances our understanding of the evolutionary mechanisms that drive plant diversity, especially in lineages undergoing rapid diversification. By integrating molecular phylogenetics with population genomics, our research sheds light on the intricate interplay between mating systems, genetic drift, and hybridisation in the evolution of modern plant diversity.

## S.214.2 Late Oligocene advent of monsoonal climate and evolution of the evergreen forests in South Asia

Harshita Bhatia¹,², Gaurav Srivastava¹,², R.C. Mehrotra¹

1 Birbal Sahni Institute of Palaeosciences, Lucknow, India. 2 Academy of Scientific and Innovative Research, Ghaziabad, India

India plays a crucial role in understanding current biogeographical patterns in paleotropical flora, as its vegetation has likely experienced more changes than any other tropical region. This is attributed to the Indian plate traveling a distance of ~9,000 km from the Southern to the Northern Hemisphere. Climatic changes have led to the extension of the majority of the lineages that contribute for its rich diversity of evergreen forests.
<figure><img src="image_497.png" /></figure>

However, very little evidence for this rich history comes from the examination of the present-day flora of the Indian subcontinent. Deciphering the story of the origin of the modern-day flora is important for the conservation of this highly biodiverse flora. In South Asia, the evergreen forests are confined to the Western Ghats and northeast India, influenced by the South Asian Monsoon (SAM) or Indian Summer Monsoon (ISM). The evolutionary history and relationship of these evergreen forests with SAM are still poorly known. Here, we present a detailed study on the late Oligocene megafossil record from Makum Coalfield, northeast India, using qualitative and quantitative techniques of paleoenvironmental reconstructions. Qualitative data indicate the presence of mostly megathermal plant families and the dominance of tropical wet evergreen taxa with modern-like floristics diversity. Quantification of climate by using the Coexistence Approach (CA) and CLAMP (Climate Leaf Analysis Multivariate Program) methodologies indicates a tropical warm, humid, and seasonal climate during the late Oligocene. Moreover, leaf physiognomic data obtained from CLAMP indicate the presence of a modern-like SAM during the late Oligocene. Our study suggests that the initiation of modern like evergreen forests and SAM have occurred synchronously during the late Oligocene in South Asia.

### S.214.3 How cacti colonized the hyperarid Atacama Desert?

Pablo C. Guerrero¹,²,³, Sandy Toledo¹,², José A. García-Beltrán¹,²

1. Departamento de Botánica, Facultad de Ciencias Naturales & Oceanográficas, Universidad de Concepción, Concepción, Chile. 2. Instituto de Ecología y Biodiversidad, Facultad de Ciencias, Universidad de Chile, Santiago, Chile. 3. Millennium Institute Biodiversity of Antarctic and Sub-Antarctic Ecosystems, Santiago, Chile.

The evolution of the hydrological niche and its contribution to the biogeographical expansion into hyperarid areas enhance our understanding of how lineages adapt to and occupy some of the harshest zones on the planet. This study focuses on a globose and diverse cactus genus, investigating the evolutionary dynamics of the hydrological niche and its associated functional traits. The study encompasses the genus Eriosyce, distributed along a 2,300 km arid gradient on the Pacific coast of southwestern South America. We reconstructed genomic, time-calibrated phylogenies for Eriosyce, analyzing evolutionary shifts in the hydrological niche

and functional traits, together with inferences in the historical biogeography related to the occupation of the Atacama Desert. Phylogenetic reconstructions were based on genomic data obtained from whole genome sequencing. Historical biogeography results were compared with independent geological data on the origins of these deserts. We characterized the water sources used by these plants, differentiating between rainfall, groundwater, dew, or fog, by studying water isotopes (²H and ¹⁸O). Variations in niche breadth and isotopic signals were found to be related to the microhabitats occupied and the growth forms of the species. Significant lag times were observed between the colonization of the region and the invasion of hyperarid habitats by Eriosyce subclades, with an inferred historical biogeographical route from less arid habitats, such as Mediterranean central Chile, to the hyperarid desert. The findings suggest that adaptation to extreme environments like deserts, which have been evolving for millions of years, is a slow and complex process. This presents significant challenges for the survival of various species in the face of rapid climate change.

### S.214.4 Botany and Geogenomics: constraining geological hypotheses with large-scale genetic data derived from plants

Ana M. Bedoya

Department of Biological Sciences, Louisiana State University

Decades of empirical research have revealed how the geological history of our planet shaped plant evolution by establishing well-known patterns (e.g., how mountain uplift resulted in high rates of diversification and replicate radiations in montane plant taxa). Under this approach, information is passed from geology to botany by interpreting data in light of geological processes. Instead, in this synthesis, I describe how by integrating natural history, phylogenetics, and population genetics, botanical research can inform our understanding of past geological and climatic processes. This conceptual shift aligns with the goals of the emerging field of geogenomics. In the Neotropics, plant geogenomics is a powerful tool for the reciprocal exploration of two long standing questions in biology and geology: how the dynamic landscape of the region came to be and how it shaped the evolution of the richest flora. I describe what
<figure><img src="image_498.png" /></figure>

makes some groups of plants excellent model systems for geogenomics research.

## S.214.5 The origin and evolution of phytohormone signaling systems driven by horizontal gene transfer

Qia Wang¹, Steven M. Smith², Jinling Huang¹,³,⁴

1 Key Laboratory for Plant Diversity and Biogeography of East Asia, Yunnan Key Laboratory for Fundamental Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China. 2 ARC Centre of Excellence for Plant Success in Nature and Agriculture, School of Natural Sciences, University of Tasmania, Hobart, Australia. 3 State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China. 4 Department of Biology, East Carolina University, Greenville, NC, USA

Plants respond to environmental cues through physiological and developmental changes that are largely regulated by various signaling molecules. The phytohormones strigolactones (SLs) and exogenous compounds karrikins (KARs) are butenolides that influence multiple aspects of plant growth and development. D14 and KAI2 are members of the α/β-fold hydrolase superfamily and act as receptors of SLs and KARs, respectively. In this study, we found that the plant D14/KAI2 gene family was derived from bacterial gene RsbQ via horizontal gene transfer (HGT) during plant colonization of land. The D14/KAI2 and RsbQ proteins share conserved tertiary structures and functional features. We suggest that the acquisition of RsbQ by plant cells was fundamental to the formation of a butenolide sensing system, which provided a key innovation associated with the transition of green plants from aquatic to terrestrial environments. Recruitment of additional signal transduction components and gene duplication subsequently led to diverse SL and KAR signaling systems in land plants. This finding highlights the critical importance of HGT in plant evolution.

# S.215 FERN AND LYCOPHYTE EVOLUTION: A PHYLOGENOMIC PERSPECTIVE. SESSION 2

## S.215.1 Elaphoglossum phylogenomics: perspectives and challenges in the study of one of the most diverse groups of tropical ferns.

Alejandra Vasco¹, Weston Testo²

1 Botanical Research Institute of Texas, Fort Worth, USA, 2 University of Vermont, Burlington, USA

The fern genus *Elaphoglossum* (Dryopteridaceae) is one of the most species-rich and taxonomically complex genera of ferns globally, with over 600 recognized species. Despite extensive taxonomic and systematic studies, numerous species groups within *Elaphoglossum* pose persistent taxonomic challenges and several key evolutionary relationships within the genus remain unresolved. This complexity highlights the significance of improving our understanding of *Elaphoglossum* diversity, given its status as one of the most

species-rich, dominant, and frequently collected vascular plant genera in many areas of tropical America, where approximately 500 species of *Elaphoglossum* occur. This presentation introduces the first phylogenomic study of *Elaphoglossum*, including a dataset of more than 230 accessions and target-capture data from around 300 nuclear loci. The resulting phylogenetic hypothesis is largely congruent with those reported previously, but with improved support and resolution, and the recovery of novel clades and previously unsampled taxa. Our phylogenomic analyses also show, for the first time, that reticulate evolution was important and prevalent during *Elaphoglossum* evolutionary history. Integration of our phylogenomic data with information derived from floristic inventories, herbarium specimens, and rigorous taxonomic studies enables a data-driven assessment of the current state of knowledge for *Elaphoglossum*. From this, we highlight persistent challenges hindering the study of *Elaphoglossum* today and identify priorities and research opportunities for future exploration and research of this and other highly diverse and taxonomically complex fern genera.
<figure><img src="image_499.png" /></figure>

## S.215.2 Diverse origins of horizontal gene transfers in Ophioglossaceae mitogenomes

Li-Yaung Kuo¹, Huei-Jiun Su², Yu-Hsin Tseng³, Blake D. Fauskee⁴, Pei-Jun Xie¹, Atsushi Ebihara⁵, Yi-Han Chang⁶

1 Institute of Molecular & Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan. 2 Department of Earth and Life Sciences, University of Taipei, Taipei, Taiwan. 3 Department of Life Sciences, National Chung Hsing University, Taichun, Taiwan. 4 Department of Biology, Duke University, Durham, USA. 5 Department of Botany, National Museum of Nature and Science, Tsukuba, Japan. 6 Taiwan Forestry Research Institute, Taiwan

Several horizontal gene transfers (HGT) found in ferns are interpreted to significantly benefit their adaptation. As the recent advances of mitogenome sequencing in these plants, more HGT cases are discovered from these genomes. In the fern family Ophioglossaceae, we assessed mitogenome assemblies from all genetic representatives, and confirmed numerous HGTs inside their mitogenomes. In the most extreme case, up to one third of mitogenome is HGT-originated. Newly compiled phylogenomic datasets revealed that these HGTs are derived from diverse donors, primarily root parasite angiosperms but also a few from ferns and lycophytes. To evaluate the functionality of these horizontally-transferred genes within the host mitogenomes, we generated transcriptomic data to examine their expression levels and RNA editing patterns. Our novel insights emphasize a unique and unusual evolutionary process by which ferns can acquire a substantial number of foreign genes from angiosperms through plant-to-plant HGTs.

## S.215.3 Deciphering reticulate evolution in Isoetes: comprehensive analyses with multifaceted sequencing approaches

Jovani B. S. Pereira*¹,², Dietmar Quandt¹, Jefferson Prado²

1 Bonn Institute of Organismic Biology - Plant Bio-diversity & Evolution, Bonn, Germany. 2 Instituto de

Pesquisas Ambientais, Herbarium SP, São Paulo, Brazil. *Correspondence: jbernar1@uni-bonn.de

Polyploidy is arguably a dominant force shaping the evolutionary histories of many, if not most, plant lineages. It can fuel evolutionary novelties and, in some cases, facilitate speciation and diversification. Among the free-sporing vascular plants, the lycophyte genus *Isoetes* L. exhibits one of the highest proportions of polyploids, constituting approximately 50% of its species. The globally distributed genus comprises about 250 species, with plants occurring in aquatic environments, fully to partially submerged, and more rarely, terrestrial. Although several phylogenetic studies converge on seven major well-supported clades, the relationships within these clades remain highly unresolved. Since *Isoetes* polyploids mostly have a hybrid origin, polyploidy poses a confounding factor in phylogenetic analyses. In this study, we employed data from multiple sequencing approaches to elucidate phylogenetic relationships and polyploid origins in recently diverged *Isoetes* groups in the Neotropics. Using nuclear datasets derived from double-digest restriction-site associated DNA (ddRAD) and PacBio long-read amplicon sequencing, along with organellar data from skimmed genome sequencing, we showed that while polyploidy evolved early in *Isoetes*, the deep divergences inferred from nuclear and organellar data are identical. On the other hand, relationships in recently diverged groups exhibit strong discordance between organellar and nuclear datasets, reflecting recent hybrid speciation within the genus. Furthermore, ddRAD-Seq data analyses result in well-resolved phylogenetic relationships within the Neotropical species groups. These groups present clear geographical distribution patterns and we discuss the factors that led to their current distribution in the Neotropics. We showcase the robustness of nuclear data in establishing a phylogenetic framework to address evolutionary questions and demonstrate how incongruence between nuclear and organellar data can offer insights into the origin of polyploids. Our findings contribute to a comprehensive understanding of polyploid origins and deepen our insights into the biogeography of the genus in the Neotropics.
<figure><img src="image_500.png" /></figure>

## S.215.4 Unfurling a reticulate Andean fern clade using phylogenomic methods

Sarah K. Morris¹, Weston L. Testo¹, Michael A. Sundue²

1 Pringle Herbarium, Department of Plant Biology, University of Vermont, Burlington, VT, USA. 2 Royal Botanic Garden Edinburgh, UK

Nearly one-third of fern speciation events involve ploidy changes, compared to 15% in angiosperms, highlighting the unparalleled importance of reticulate evolution in fern diversification. Despite fern diversity peaking in the tropics, few studies have addressed hybridization and polyploidy in tropical fern lineages. *Pleopeltis* is a group of about 100, mostly epiphytic species found throughout the American tropics. Species of *Pleopeltis* occur in a broad spectrum of ecosystems, ranging from pluvial lowlands to dry alpine zones and with a great diversity of morphologies. Hybridization appears to be frequent throughout the group, challenging the delimitation of species and application of names. Evolutionary investigations have been hampered by several polytomies, re-calcitrant nodes and short branch lengths in the backbone of the phylogeny, suggesting a possible rapid speciation event. Here, we focus on the Andean *Pleopeltis* species complex, a clade of pinnately divided species found in mid to upper elevations in the northern and central Andes and the putative hybrids between them. Using an integrative approach including geography, morphometrics, spore size and admixture analyses, we developed the first hypothesis of reticulate relationships within this complex and tested this hypothesis using recently developed phylogenomic techniques. Sourced from herbarium specimens and silica gel dried material, we produced DNA sequence data for all members in the Andean *Pleopeltis* species complex using the Genealogy of Flagellate Plants (GoFlag) target capture probe set, and we used a suite of newly developed allele-phasing bioinformatic tools to infer relationships between allopolyploid species and their diploid progenitors in this clade and elucidate the role of introgression and incomplete lineage sorting. This is the first phylogenomic investigation of this genus as well as one of the first investigations of polyploid speciation in a tropical fern clade using modern sequencing and bioinformatic techniques.

## S.215.5 A phylogenomic approach for inferring cryptic taxa within the Eurasian allopolyploid fern Polypodium vulgare

Jonas I. Mendez-Reneau¹, Erin M. Sigel²

1 Department of Biology, University of Louisiana at Lafayette, Billeaud Hall, Lafayette, LA U.S.A. 2 Department of Biological Sciences, University of New Hampshire, Durham, NH, U.S.A

We present a case study using the GoFlag 408 target-capture probe set for ferns to test hypotheses about the progenitors of the allotetraploid fern *Polypodium vulgare* (Polypodiaceae) across Eurasia. Using our recently published SORTER bioinformatic pipeline, we accurately phased homeologs in 65 allopolyploid individuals, allowing us to resolve different progenitor pairs for *P. vulgare* in Asia and Europe, as well as three progenitors in the closely allied allohexaploid *P. interjectum*. We then used by-catch reads to assemble plastid genomes for a subset of samples and generated a time-calibrated phylogeny revealing the maternal progenitors of each polyploid taxon. The results of our combined plastid and nuclear phylogenomic analyses provide support for the segregation of 'P. okiense' in Asia from *P. vulgare* in Europe. We highlight the effectiveness of the SORTER pipeline to generate allopolyploid datasets for phylogenetic analyses incorporating a large number of samples at varying ploidy levels.

## S.215.6 A systematic revision of the lady fern (Athyrium filix-femina) species complex in the Americas

Bertrand Black¹, Michael Sundue²

1 Plant Biology Department, University of Vermont. 2 Royal Botanical Gardens Edinburgh

*Athyrium filix-femina* (L.) Roth is a terrestrial fern that is widespread in forest regions across the Northern Hemisphere and South America. Despite its prevalence, its taxonomy in the Americas remains unresolved and the evolutionary relationships between taxa remain poorly understood. Uncertainty about whether to recognize a single widespread *A. filix-femina* or several endemic American species
<figure><img src="image_501.png" /></figure>

has persisted to the present day due to unclear
morphological differences between regional vari-
eties and a lack of a comprehensive study across
its range. To address this uncertainty, we sampled
herbarium specimens from four continents and em-
ployed an integrative methodology that combined
molecular, morphological, and biogeographic data
to examine evidence for speciation, hybridization,
and cryptic diversity in this species complex. Our
results indicate that there are at least five mono-
phyletic lineages in North America with diagnosable
morphology, habitat preferences, and discreet geo-
graphic ranges. In spite of many documented hy-
brids in Asia, we found no evidence for widespread
hybridization or reticulation among North American
species. In South America, we did not find clear spe-
cies boundaries defined by morphology, geography
or molecular evidence to recognize more than a
single species. Allele phasing identified a single pu-
tative hybrid from Queretaro, Mexico of unknown or-
igin. Research such as this enhances our capacity to
recognize and document American floristic diversity
that may be concealed in plain sight and highlights
the value of utilizing integrative molecular methods
to facilitate biologically accurate classification of
plant species.
<figure><img src="image_502.png" /></figure>

Symposia Session 13

# S.216 COMPARATIVE SPATIAL PHYLOGENETICS OF MEDITERRANEAN-TYPE FLORAS OF THE WORLD

## S.216.1 Scaling issues in spatial phylogenetics, in relation to testing hypotheses about biodiversity and its causes

Brent D. Mishler¹, Robert Guralnick², Nico Cellinese², Shawn Laffan³

1 University of California, Berkeley, USA. 2 University of Florida, Gainesville, USA. 3 University of New South Wales, Sydney, Australia

Newly available distributional data from global museum databasing efforts, rapidly increasing coverage of DNA sequence data, and improvements to computer hardware and software has enabled a new “big data” approach to the application of PD-based metrics and randomization-based hypothesis tests called “spatial phylogenetics.” It can be defined most simply as mapping a phylogeny onto geographic space, which can then be used with GIS layers to understand drivers of phylodiversity patterns and for conservation prioritization. Alpha- and beta-phylodiversity can be measured using interestingly different ways of representing branch lengths on a given topology (called “facets.” e.g., chronograms, phylograms, or cladograms), and hypotheses about ecology and evolution can be tested using spatial randomization. Scaling questions are present with both the spatial and phylogenetic data. Spatially, what size should be used for the basic spatial units, and how much of the Earth's surface should be studied at once? Likewise, there are similar issues at both the small and large scales in phylogenetics -- what should the OTUs represent, and how much of the tree of life should be studied at once? All these questions involve both theoretical considerations and practical data limits. These scaling issues will be explored using Mediterranean-climate regions as a test case. For example, we compare the results of comparative phylodiversity analyses of monocots alone as com-

pared to results for all angiosperms. We also compare results obtained using different levels of OTUs, different spatial unit sizes, and local vs. global regions.

## S.216.2 Spatial phylogenetic patterns in a biodiversity hotspot, the Cape of South Africa

Félix Forest¹, Jonathan F. Colville², Colin Beale³, Brent D. Mishler⁴, Andrew Thornhill⁵, G. Anthony Verboom⁶, Richard M. Cowling⁷

1 Royal Botanic Gardens, Kew, Richmond, Surrey, UK. 2 Statistics in Ecology, Environment and Conservation, Department of Statistical Sciences, University of Cape Town, Cape Town, South Africa. 3 Department of Biology, University of York, York, UK. 4 University & Jepson Herbaria, Dept. of Integrative Biology, University of California, Berkeley, USA. 5 N.C.W. Beadle Herbarium, University of New England, Armidale, New South Wales, Australia. 6 Department Biological Sciences, University of Cape Town, Cape Town, South Africa. 7 African Centre for Coastal Palaeoscience, Nelson Mandela Metropolitan University, Port Elizabeth, South Africa

The Greater Cape Floristic Region (GCFR) of South Africa is a small area found in the southwestern corner of the African continent and comprising an incredible floral diversity (ca 11,500 species, ca 75% endemic). Small-leaved sclerophyllous shrubs and geophytes are the predominant growth forms in the region while tree and annual species represent only a small proportion of the flora. Furthermore, the floristic composition of the region is very distinctive with families such as Iridaceae, Aizoaceae, Ericaceae, Proteaceae and Restionaceae dominating, all of which are minor groups in otherfloras of the world. Understandably, this diversity has attracted a lot of speculation as to which environmental and/or ecological factors may be the prevailing drivers explaining the uniqueness of the region. This contri-
<figure><img src="image_503.png" /></figure>

bution reports on ongoing studies focussing on large-scale spatial phylogenetic patterns within the region. First, we present a spatial phylogenetic analysis using phylogenetic diversity and phylobetadiversity metrics based on a set of species-level phylogenetic trees and fine-scale species distribution modelling comprising all species found in the GCFR. In particular, we investigate the west-east decreasing longitudinal gradient in plant diversity observed in the region, termed the Levyns' Law. We explore the predictions made to explain this gradient by the age and area (i.e., high diversity is the result of biome and climate stability over evolutionary times) and ecological opportunity (high diversity is the result of increased ecological heterogeneity) hypotheses. Secondly, we examine the phylogenetic endemism patterns in the GCFR using Categorical Analysis of Neo-and Paleo-Endemism (CANAPE) to characterize local centres of endemism. We compare these species-level results with preliminary analyses performed at the genus-level to observe the effects of using different taxonomic levels. All these diversity measures are used in concert to try to understand both the origin of this extraordinary biodiversity hotspot and to prioritize conservation efforts.

## S.216.3 Comparative Spatial Phylogenetics of Mediterranean-Type Floras of The World: The Case of Chilean Protected Areas

Rosa A. Scherson¹, Taryn Fuentes-Castillo¹, Federico Luebert¹⁻², Andrew Thornhill³, Brent D. Mishler⁴, Patricio Pliscoff⁵, ⁶, ⁷

1. Departamento de Silvicultura y Conservación de la Naturaleza, Universidad de Chile, Santiago, Chile.
2. Facultad de Ciencias Agronómicas, Universidad de Chile, Santiago, Chile.
3. NCW Beadle Herbarium, Armidale, New South Wales, Australia.
4. Department of Integrative Biology, University and Jepson Herbaria, University of California, Berkeley, California, USA.
5. Facultad de Historia, Geografía y Ciencia Política, Instituto de Geografía, Pontificia Universidad Católica de Chile.
6. Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile.
7. Center of Applied Ecology and Sustainability, Pontificia Universidad Católica de Chile.
8. Institute of Ecology and Biodiversity, Santiago, Chile

Determining the factors that explain diversity patterns helps to understand the processes that have shaped different types of biodiversity hotspots. Phylogenetic

Diversity (PD) and related evolutionary indicators have been increasingly used to understand patterns of bio-diversity distribution and as a tool to aid in evaluating conservation targets. Mediterranean-like climatic areas around the world are characterized as being floristically diverse and vulnerable, and all of them are considered biodiversity hotspots. Central-southern Chile is one of these areas, showing high floral diversity and endemism. In this study, we calculated PD and other related metrics for the Chilean hotspot, identifying several interesting areas (hotspots within a hotspot). In areas such as Mediterranean Chile where lack of locality information is a problem to study biodiversity spatial patterns, species distribution models (SDMs) can be very useful in filling in missing locality information. Using SDMs, we analyzed how protected areas can act as a reservoir of PD in a climate change scenario in Mediterranean Chile, identifying museum-like and cradle-like areas. Randomizations were performed to identify areas in which these metrics departed from values expected by chance, for example identifying places in which phylogenetic overdispersion of taxa occurs. We correlated these areas with parameters such as geodiversity and climatic factors that could influence the spatial distribution of PD. Protected areas in MedChile are expected to harbor more PD than expected in climate change scenarios, but responses of individual areas differ depending mainly on climatic and geographic factors.

## S.216.4 Spatial phylogenetics in the western Mediterranean Region: phylogenetic diversity and endemism of the Iberian angiosperm flora

Alberto J. Coello¹,², Ignacio Ramos-Gutiérrez²,³, Rafael Molina-Venegas²,³, Antoni Buira⁴, Mario Mairal⁵, Pablo Vargas⁴, Rosa A. Scherson⁶, Brent D. Mishler⁷, Juan Carlos Moreno Saiz²,³, Mario Fernández-Mazuecos²,³

1. National Museum of Natural History, Smithsonian Institution, Washington, D.C., United States.
2. Universidad Autónoma de Madrid, Madrid, Spain.
3. Centro de Investigación en Biodiversidad y Cambio Global (UAM), Madrid, Spain.
4. Real Jardín Botánico (CSIC), Madrid, Spain.
5. Universidad Complutense de Madrid, Madrid, Spain.
6. Universidad de Chile,
<figure><img src="image_504.png" /></figure>

Santiago, Chile. 7 University of California, Berkeley, United States

The Iberian Peninsula is one of the main centers of plant diversity in the Mediterranean biodiversity hotspot. The Iberian flora has been the subject of scientific attention for centuries, and biogeographical patterns of plant species richness across Iberia are well known. However, a full understanding of the geographical patterns of biodiversity requires an evolutionary framework, as provided by the field of spatial phylogenetics. Here, we aimed to explore the spatial phylogenetics of Iberian angiosperms, including patterns of phylogenetic diversity and endemism, as a tool to inform conservation actions. We used distribution data from the Atlas of the Vascular Flora of the Iberian Peninsula (AFLIBER) at 10-km resolution and a global species-level mega-phylogeny of seed plants, resulting in a coverage of ca. 60% of Iberian angiosperm species. To analyze spatial phylogenetic patterns, we employed the R package *canaper*, including the mapping of endemism areas according to Categorical Analysis of Neo- and Palearctic-Endemism (CANAPE). Uncertainty associated with the phylogenetic placement of unsampled species was addressed using the *randtip* package and compared with results using only sampled species. Our results indicate a concentration of relative phylogenetic diversity (RPD) in peripheral areas of the Iberian Peninsula under oceanic influence. According to CANAPE, areas of super-endemism (with a high concentration of both neo- and paleo-endemism) are found in the Pyrenees, the Balearic Islands and the Baetic Mountains. Areas of neo-endemism are concentrated mostly in the Baetic Mountains and the Balearic Islands, while areas of paleo-endemism are scattered across the Peninsula. The abiotic drivers of these patterns have been investigated using generalized linear models. Based on these findings, we conduct an evaluation of the adequacy of Spanish and Portuguese networks of protected areas to preserve phylogenetic diversity and endemism of the Iberian flora.

**S.216.5 The role of traits in community assemblages across Mediterranean-type ecosystems**

Israel Borokini¹, Brent D. Mishler², Shawn Laffan³

1 Montana State University, Bozeman, USA. 2University of California, Berkeley, USA. 3 University of New South Wales, Sydney, Australia.

Mediterranean-type ecosystems (MTEs) are found in five regions (southwestern Australia; the Cape region of South Africa; central Chile; California; and the Mediterranean Basin). These areas are characterized by warm and dry summers, mild and wet winters, and frequent fire, to which resident plants and animals must be adapted. Floristic diversity and endemism are exceptionally high in all five MTEs. Consequently, all five MTEs have been recognized as global biodiversity hotspots. Studies have suggested that biodiversity in the MTEs is influenced by several eco-evolutionary drivers including high net diversification rates, fire, and geological history. As a result, biodiversity in the MTEs is hypothesized to be strongly coupled with plant traits; thus, understanding patterns of functional diversity can increase our understanding of the biodiversity drivers. We integrated spatial occurrence data for native seed plants, four selected traits, and a corresponding phylogeny for plants of the five MTEs, and employed a novel metric based on phylogenetic diversity (PD) called *trait diversity* (TD), to evaluate and identify areas of significant phylogenetic and/or trait diversity. Areas with different combinations of high or low PD and TD can be used to infer biodiversity drivers and the relative contribution of niche vs neutral processes in these regions. All data used in this analysis were obtained from open access and published empirical studies. The ranges of the plants were restricted to their natural distributions to exclude non-native distributions in other MTEs. We selected four traits that are hypothesized to be associated with the persistence of native flora in the MTEs. Phylogenetic and trait diversity (and spatial randomization hypothesis tests) were computed using *Biodiverse* software (https://shawnlaffan.github.io/biodiverse/), allowing comparison of these patterns across the five global MTEs. Biodiversity in the MTEs appears to be influenced by an unusually complex mixture of past and current biogeographic, ecological, and evolutionary processes

**S.216.6 World spatial phylogenetics of the angiosperms**

Andrew H. Thornhill¹, Alexandre R. Zuntini²,
Tom Carruthers², Shawn W. Laffan³,
William J. Baker², Joseph T. Miller⁴, Félix
Forest², Wolf L. Eiserhardt⁵, Nunzio J. Knerr⁶,
Naia Morueta-Holme⁷, Brent D. Mishler⁸.

1 N.C.W. Beadle Herbarium, University of New England, Armidale, NSW, Australia. 2 Royal Botanic Gardens, Kew, UK. 3 University of New South Wales,
Sydney, NSW, Australia. 4 Global Biodiversity Research Facility, Denmark. 5 Aarhus University, Aarhus, Denmark. 6 National Research Collections, CSIRO, Canberra, ACT, Australia. 7 University of Copenhagen, Copenhagen, Denmark. 8 University of California, Berkeley, California, USA

Spatial phylogenetic analyses combine phylogenies and spatial data at any taxonomic and geographic level. All studies to date have concentrated on either a particular taxonomic group, for example Australian Acacia, or the flora of a particular geographic region, for example analyses on the flora of Australia, California, or Chile. The recent PAFTOL angiosperm phylogeny created the opportunity to make a spatial phylogenetic world analysis at the genus level. We cleaned institutional plant records stored in the Global Biodiversity Information Facility (GBIF) to reflect the worldwide native range of each spe-

cies (over 200000 species), then combined them into the PAFTOL genera. The final spatial dataset contained over 23 million records and was projected using World Mollweide at 50 ×50 km grid cells. The PAFTOL tree and spatial data were combined using Biodiverse to make diversity analyses and randomizations for CANAPE, Relative Phylogenetic Diversity and Phylogenetic Diversity tests. The results of two spatial phylogenetic analyses will be presented, one using a PAFTOL phylogram and one using a PAFTOL chronogram. We also present comparisons of results against climatic variables and the biodiversity hotspots of the world. We particularly focus on the 'Mediterranean-climate' regions of the world and compare the world-analysis results with what has been found previously when analyses have just focused on one particular area.

# S.217 EVOLUTIONARY HISTORY OF ARID FLORAS AND THEIR UNDERLYING BIOLOGICAL SURVIVAL MECHANISMS

## S.217.1 Did succulents originate and diversify in response to aridity?

Jamie B Thompson¹, Marilyn Vásquez-Cruz², Israel Loera³, Melina Del Angel⁴, Miguel Nakamura⁴, Kevin R. Hultine⁵, Santiago Ramírez-Barahona⁶, Nicholas K. Priest¹, Tania Hernández-Hernández⁵

¹The Milner Centre for Evolution, Department of Life Sciences, University of Bath, Bath, UK. ²Tecnológico Nacional de México/ITS Irapuato, Gto, México. ³Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA. ⁴CIMAT, Guanajuato, Gto, México. ⁵Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, AZ, USA. ⁶Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, México

Succulents have been typically considered the iconic example of arid adapted plants. Although distributed globally, plants possessing the succulent syndrome are assumed to have evolved to adapt to arid climates, because they possess modifications that increase their water use efficiency. Though suc-

culence is considered a classic case of convergent evolution driven by shared environmental drivers, we lack a full understanding of whether the timing and drivers of the diversification of succulent lineages are, in fact, concordant; or even whether their climatic niches are indeed trending towards arid climatic conditions. We present our recent findings about the timing; climatic niches and evolutionary dynamics of major succulent lineages globally. Our analyses reveal different levels of evolutionary synchronicity and relation with aridity. The impact of atmospheric CO2 on succulent macroevolution is varied. While transitions and radiations are especially concentrated in recent time, following a collapse of atmospheric CO2 ~15 Mya, CO2-dependent diversification is not supported in most lineages. With the exception of *Euphorbia*, we find that succulence elevates net diversification, though the effects on underlying speciation and extinction disagree. The phylogenetic distribution of transitions to succulence and rate shift increases suggests these phenomena are decoupled, indicating that succulence might not adhere to a classic key innovation model. The climatic niches of succulents are not differentiated from their non-succulent relatives, but narrower, and contained within the non-succulents', showing no relationship with extreme conditions such as
<figure><img src="image_505.png" /></figure>

high aridity or temperatures. Our results reveal the complexity of the succulent strategy, as well as the abiotic conditions and ecological contexts under which the different succulent lineages evolved.

### S.217.2 Characterization of drought-resistance traits in the leaf-succulent genus Crassula

Marc Fradera-Soler¹,²,³, Jozef Mravec²,⁴, Jesper Harholt⁵, Olwen M. Grace³,⁶, Bodil Jørgensen²

1 Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden.

2 Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark.

3 Royal Botanic Gardens, Kew, Richmond, Surrey, UK. 4 Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences, Plant Science and Biodiversity Center, Nitra, Slovakia. 5 Carlsberg Research Laboratory, Copenhagen, Denmark. 6 Royal Botanic Garden Edinburgh, Edinburgh, UK

Succulent plants have specialized water-storage tissues with collapsible cell walls that reversibly fold as water is lost. However, the ecophysiological significance of cell wall traits has often been overlooked in succulents. We focused on southern African species of the leaf-succulent genus *Crassula* and used comprehensive microarray polymer profiling (CoMPP) and glycan-binding antibodies to analyse cell wall polysaccharide and glycoprotein content in leaves. We found significant differences in leaf glycomic profiles that can be linked to increased drought resistance in one of the two main growth forms in *Crassula*. Furthermore, some cell wall components correlate positively with increasing aridity, which suggests that they are likely advantageous in terms of arid adaptation. A deeper insight into the relationship between cell walls and the succulent function would be particularly useful given the potential of succulents as natural capital to mitigate the effects of climate change. Numerous hydathodes are another peculiarity of *Crassula* species, foliar structures that are usually associated with guttation. Foliar water uptake (FWU) through hydathodes has long been suspected in *Crassula*, particularly in species that occur in fog-influenced arid habitats in southern Africa. To provide empirical observations linking FWU to hydathodes in *Crassula*, we used the apoplastic fluorescent tracer Lucifer Yellow in combination with different imaging techniques. The resulting images confirm that hydathode-medi-

ated FWU does indeed occur in *Crassula* and is likely widespread across the genus. Surprisingly, FWU is operational in *Crassula* species that occur in rather mesic environments, beyond fog-influenced arid habitats, and even in species with seemingly hydrophobic leaves, in which the hierarchically sculptured leaf surfaces may facilitate FWU thanks to hydrophilic leaf surface microdomains. These findings confirm the ecophysiological relevance of FWU in *Crassula* and reassert the importance of atmospheric humidity for some arid-adapted plant groups.

### S.217.3 Evolutionary lessons from the Chihuahuan Desert gypsum endemic flora

Michael J. Moore¹, Clare Muller², Andreu Cera³, Norman A. Douglas⁴, Hilda Flores Olvera⁵, Helga Ochoterena⁵, Rebecca Drenovsky², Pablo Tejero Ibarra⁶, Sara Palacio⁶

1 Oberlin College, Oberlin, OH, USA. 2 John Carroll University, University Heights, OH, USA. 3 Université de Caen-Normandie, Caen, France. 4 University of Florida, Gainesville, FL, USA. 5 Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, México. 6 Instituto Pirenaico de Ecología, CSIC, Jaca, Spain

Gypsum outcrops occur in arid and semi-arid regions around the globe, and present a significant barrier to plant growth due to challenging soil nutrient levels (excess sulfur and calcium, minimal nitrogen and phosphorus) and the presence of well-developed soil crusts. Nevertheless, these difficult soils host a wide variety of endemic plants. The Chihuahuan Desert region of Mexico and the USA has the largest known gypsum endemic flora in the world, with over 240 plant taxa known only from gypsum. Ongoing research into the diversification of this flora has revealed a number of repeated evolutionary patterns. For example, the dominant gypsum endemic taxa in the Chihuahuan Desert region typically belong to clades of gypsum endemics that likely originated in the Pliocene or latest Miocene, and that have survived the climatic oscillations of the Pleistocene. Likewise, the dominant gypsum endemic taxa of the Chihuahuan Desert belong to genera and families with many independent evolutionary origins of gypsum endemism, strongly suggesting that preadaptations to life on gypsum exist in these groups. One such pre-adaptation may be the ability to accumulate sulfur
<figure><img src="image_506.png" /></figure>

within leaves—an ability that has now been documented in many of the dominant gypsum endemics of the Chihuahuan Desert. The presence of this trait in what are likely the oldest clades of gypsum endemics and some of their closest non-endemic relatives suggests that foliar sulfur accumulation may be one of the driving factors in explaining the historical assembly and evolution of the Chihuahuan Desert gypsum endemic flora. Similar patterns related to sulfur accumulation are also present in the independently derived Spanish gypsum flora, suggesting that this ecophysiological trait may be of global importance in understanding gypsum plant evolution.

### S.217.4 Biogeographic and evolutionary history of the Atacama Desert Flora

Tim Böhnert¹, Federico Luebert², Maximilian Weigend¹

1. Bonn Institute of Organismic Biology, University of Bonn, Bonn, Germany. 2. Departamento de Ciencias Ambientales y Recursos Naturales Renovables and Departamento de Silvicultura y Conservación de la Naturaleza, Universidad de Chile, Santiago, Chile

Post-Miocene climate history, particularly in arid environments, has emerged as a key factor in shaping species dispersal and diversification. The Atacama Desert in northern Chile, one of the driest regions on Earth, stands out for its presumed Oligocene-Miocene age, as well as its unexpectedly high biodiversity and elevated number of endemic species thriving under hyperarid conditions. Contrary to expectations, the extreme aridity of the Atacama predates the estimated divergence times of most extant genera. The initial onset of hyperaridity cannot have been the primary driver of diversification in these extant groups. We argue that recent climatic history, marked by intervals of pluvial and arid phases, especially during the Pliocene-Pleistocene transition, played an important role in shaping the current desert flora. Our research uses next-generation sequencing and molecular clock dating to unravel how this complex biogeographic and evolutionary history was influenced by past climate variability and Andean orogeny. Here, we briefly review our findings on the historical biogeography of selected Atacama taxa and discuss their broader implications for the existing body of knowledge on the Atacama Desert flora. A striking example is the genus *Cristaria* (Malvaceae), an element of the Chilean Mediterranean flora that colonized the Atacama during Pliocene pluvial phases. This led to in-situ diversification likely fueled by repeated introgressions and the emergence of new species.

Conversely, the ca. 15 endemic species of *Atriplex* (Amaranthaceae) do not originate from local radiation alone: they arose from multiple colonization events (including by long-distance dispersal) followed by local divergence. The paleoendemic lineage *Huidobria fruticosa* (Loasaceae), on the other hand, appears to have undergone little if any diversification, despite being genetically separated from its closest relatives for about 50 million years. However, our data suggest that its recent population history can be traced to the Pliocene-Early Pleistocene transition.

### S.217.5 Dispersal, not vicariance, drives the diversification of native Australian tobacco (Nicotiana section Suaveolentes; Solanaceae) in the arid zone

Luiz A. Cauz-Santos¹, Rosabelle Samuel¹, Dominik Metschina¹, Maarten J. M. Christenhusz²,³, Ovidiu Paun¹, Mark W. Chase¹,²,³

1. Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria. 2. Royal Botanic Gardens, Kew, Richmond, UK. 3. Department of Environment and Agriculture, Curtin University, Perth, Western Australia, Australia

For the last six million years, the Australian Eremaean Zone (EZ) has been as dry as today. The flora and fauna of arid regions worldwide, including the EZ, have been hypothesised to have diversified widely before aridification began, in this case 20 Mya, and slowly adapted as aridity developed. Undocumented are more recently arrived plants that developed arid specialisations in situ. Here, we investigate the biogeography and timing of native allotetraploid tobaccos, Nicotiana sect. Suaveolentes, which putatively entered the EZ 5 Mya. The original allotetraploid migrants from South America were adapted to mesic areas of Australia and only recently radiated in the EZ after developing drought adaptations. Based on coalescent and maximum likelihood analyses designed to corroborate timing of the Australian radiation independently, arrival of Nicotiana sect. Suaveolentes occurred approximately 6 Mya, followed by spread via multiple invasions across the EZ from the ecologically highly diverse Pilbara District (Western Australia).
<figure><img src="image_507.png" /></figure>

lia), which served as a mesic refugium and cradle for adaptations to harsher conditions. These results demonstrate that poorly adapted plant groups can develop novel adaptations that permit them to disperse extensively and rapidly despite the extremes of heat and drought in the EZ.

## S.217.6 Comparative evolutionary history of the Australian Amaranthaceae

Anže Žerdoner Čalasan¹², Kelly A. Shepherd², Karol Krak³, Bohumil Mandák³, Gudrun Kadereit¹

¹ Systematics, Biodiversity and Evolution of Plants, Faculty of Biology, Ludwig Maximilian University of Munich, Germany. ² Western Australian Herbarium (PERTH), Biodiversity and Conservation Science, WA, Australia. ³ Plant Biodiversity and Evolution, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Czech Republic

The vast arid region covering about 70% of Australian continent remains one of the world's largest and least explored territories. Despite its extremely adverse environmental conditions, this area is rich in xerophytic plant life that has adapted to challenging physiological and ecological constraints. Despite such a high diversity, this flora is thought to have evolved along a similar evolutionary trajectory, known as the littoral connection hypothesis. This hypothesis states that the most recent common ancestors of contemporary arid floral elements arrived in Australia already preadapted

to increased aridification and/or salinisation, and were thus able to thrive in environmental conditions that have otherwise driven most mesic floral elements to extinction. Alongside Asteraceae, Fabaceae, and Myrtaceae, Amaranthaceae are one of the species-richest plant families in this arid zone that underwent rapid diversification events. In our studies, we employed various RAD-seq and HybSeq techniques to resolve the phylogenies of numerous recalcitrant groups of xerophytic Australian Amaranthaceae and compare their evolutionary histories. Our analyses focused on understanding the spatiotemporal patterns in these lineages and the underlying biological mechanisms that drove their rapid diversification and survival. Despite their separate arrivals in Australia during the Miocene/Pliocene transition, our analyses unveiled shared spatiotemporal patterns among these groups, lending support to the littoral connection hypothesis. Some lineages exhibited floral exchanges between Australia and South Africa, while polyploidisation, potentially driving speciation, appeared to be restricted to certain taxa. Future research aims to expand these investigations to other arid-adapted elements in the Australian outback with the main aim to further validate the littoral connection hypothesis and understand the broader role of polyploidisation in the evolution of Australian arid clades beyond Amaranthaceae. Our research sheds light on the evolutionary adaptations of plants in some of Earth's harshest environments, providing valuable insights into the mechanisms driving biodiversity in arid regions.

## S.218 THE KEY ROLE OF REFUGIA IN FACING THE GLOBAL BIODIVERSITY CRISIS

### S.218.1 Climate Change Refugia Conservation as a 21st Century Solution

Toni L. Morelli

Northeast Climate Adaptation Science Center, U.S. Geological Survey, Amherst, USA

Anthropogenic climate change is posing a serious risk to Earth's biodiversity. As scientists and practitioners,

we can document the erosion of our biodiversity, and can model how those changes will increase with each warming increment. However, we can also work together to identify ways to reduce those impacts. Climate adaptation focuses on conducting and translating research to minimize the impacts of climate change, including threats to biodiversity and human welfare. One adaptation strategy is to focus conservation on climate change refugia, areas that remain relatively buffered from contemporary climate change over time and enable persistence of valued physical,
ecological, and socio-cultural resources. Climate refugia is a concept that has existed for more than 100 years, originating in the paleontological literature to understand what fostered the survival of disjunct populations despite severe and rapid past climate change events. The refugia concept has captured the attention of scientists, practitioners, and the public more recently, in part because it offers some hope of maintaining current conditions, at least in some places and for the short term. The field transcends disciplines and sectors and intersects with knowledge about other global change stressors like fire, drought, and invasive species to create actionable science that can, in its own small way, address the biodiversity crisis. This talk will synthesize the work that has been to develop and implement the climate change refugia concept and where it is headed in the 21st century.

## S.218.2 Karst depressions as past, present and potential future microrefugia

Zoltán Bátori, Kata Frei, Gábor Li, Csaba Tölgyesi

University of Szeged, Szeged, Hungary

Karst landscapes cover about 15-20% of the Earth's terrestrial surface, providing high topographic complexity that may facilitate the persistence of plant species despite unfavourable macro-environmental changes. Enclosed depressions (i.e., dolines) are the most common and typical landforms in karst landscapes. Microhabitats in dolines, such as bottoms, north-facing, south-facing, east-facing, and west-facing slopes, may act as microrefugia for many endangered and highly specialized plant species (e.g., species listed in the IUCN regional and/ or global Red Lists). Notable examples include *Cerastium dinaricum* (Slovenia), *Dracocephalum ruysschiana* (Hungary and Serbia), *Biebersteinia orphanidis*, *Horstrissea dolinicola* (Greece), and *Magnolia aromatica* (China). Dolines also have the potential to maintain natural and restricted vegetation types (e.g., beech forest patches at low altitudes in Central Europe). Our aim is to provide an overview about the ecological factors of dolines in general, to discuss the mechanisms underpinning their role as microrefugia, and to highlight research priorities that will advance our understanding of plant diversity in dolines. Firstly, we illustrate the importance of geomorphology on ecological factors (such as air temperature, relative air humidity, and soil properties)

within dolines, and the long-term stability of these factors. Secondly, we evaluate the effects of these factors on local and regional biodiversity, highlighting the role of dolines as past, present and potential future microrefugia. Finally, we identify key knowledge gaps that need to be addressed to improve our knowledge on the effects of various stressors (e.g., temperature increase, drought, and forestry management) on the refugial capacity of dolines.

## S.218.3 Refugia for biodiversity: identification and role in plant persistence

María B. García¹, Raúl Hoffrén Mansoa², Marta Quintana-Buil¹, Ane Múgica¹, Héctor Miranda¹, Manuel Pizarro¹, Daniel Gómez¹

1 Pyrenean Institute of Ecology (CSIC), Zaragoza, Spain. 2 Geoforest-IUCA, Department of Geophysics and Land Management, University of Zaragoza, Zaragoza, Spain.

Mountains are home to a rich biodiversity thanks to the environmental heterogeneity they offer, and considered highly vulnerable to climate change. Indeed, many studies have shown how rapidly mountain land cover is changing in response to both climate change and the abandonment of traditional land uses. However, mountains can also be conceived as mosaics of microclimates that can facilitate the survival of species in the face of contemporary climate change through short migrations, and home to refugia where species withstand climate crisis. In this presentation we combine different approaches to shed light on the characteristics of climatic refugia in the Pyrenean mountain range, as well as their role for the persistence of biodiversity. On the one hand, by deploying numerous small sensors in rough terrain, and thermal images taken from the ground or drones, we identify areas with a narrow thermal range where maximum summer temperatures are damped: climate refugia. On the other hand, based on floristic inventories, we explore what fraction and type of plant diversity inhabits those climate refugia. Finally, from the population monitoring of some unique plants typical of refugia, we demonstrate the environmental stability they offer. The integrity and proper management of mountains, their microclimates and the refuges they shelter, are key to preserving biodiversity in the current climate change scenario.
<figure><img src="image_508.png" /></figure>

## S.218.4 Not only climatic refugia - the multifaced concept of refugia for the long-term survival of species during the Anthropocene

Rodolfo Gentili¹, Gabriele Galasso², Sandra Citterio¹

1 Department of Earth and Environmental Sciences, University of Milano-Bicocca, Milano, Italy. 2 Museo di Storia Naturale di Milano, Milano, Italy

The refugium concept in biogeography, evolutionary biology and conservation science has traditionally been associated with glacial and interglacial periods. Particularly, it has been linked to regions or locations with stable climatic conditions over long time in comparison to the surrounding areas. However, over the last decades the massive global environmental changes and the increase of extinction rate of species has led to the need to identify stable areas for species with respect to different environmental factors and temporal and spatial scales. According to this view refugia are landscape elements that remain marginally affected by anthropogenic environmental factors and that subsequently can continue to support native species and community with reference to ecosystem functions, and biodiversity levels. Therefore, depending on the scale, they are location or regions resilient to disturbances and environmental changes. Recent literature has highlighted the existence of Anthropocene refugia or potential areas providing spatial and temporal shelter to species from human activities in the long-term. However, Anthropocene refugia have not been ecologically characterized which is pivotal for recognizing their role in allowing the persistence of species in context of global environmental changes. Works have emphasized the presence of different kinds of refugia for biodiversity such as urban refugia, marine refugia, biocultural refugia, dark refugia, and fire refugia. Therefore, in this work we aimed at reviewing the recent concepts of refugia over different ecological scales and to define their value for biodiversity accounting, landscape conservation and species' evolution as well as identify conservation and management strategies.

## S.218.5 Pictorial Conceptualization of Glacial Refuges in the Mediterranean Quaternary

Gabriela Amorós¹, Victoria Sánchez-Giner¹, Ariadna Amorós¹, Juan Ochando²,¹, Donatella Magri², Manuel Munuera³, Juan Manuel Jiménez-Arenas⁴, Ana B. Marín-Arroyo⁵, José Carrión¹

1 University of Murcia, Spain. 2 University La Sapienza, Rome, Italy. 3 University Polytechnic of Cartagena, Spain. 4 University of Granada, Granada, Spain. 5 University of Cantabria, Santander, Spain

The importance of glacial plant refugia has been and continues to be a subject that sparks great intellectual excitement and promotes the development of many research activities specifically oriented towards biogeographic, ecological, evolutionary, and conservation biology issues, among others. These investigations aim to address an extensive spectrum of questions that lie on the frontiers of knowledge and have implications in a scenario of climate emergency and biodiversity crisis. It is crucial for society to be properly informed about the conclusions and corollaries arising from all these activities, mostly funded with public money. Scientific illustration and paleoart are essential tools in transmitting the knowledge acquired about refugia to different educational and cultural levels in each social context. Similarly, the pictorial representation, a result of synergy between the artist and paleoecological scientists, provides new avenues of research by highlighting biases, deficiencies, and methodological and interpretative inconsistencies in the study of paleoecosystems. In this poster, we present several paleoartistic proposals for representing glacial refugia in the Mediterranean Basin during the cold Quaternary stages, considering the originality of the depicted communities, the lack of current analogs, their probable landscape structure, and above all, the unique floristic components. The scientific data stem from palynological analyses complemented with other botanical remains and paleoclimatic inferences derived from non-botanical proxies. We put emphasis on hydroclimatic refugia in the driest territories and the evidences in support of these strongholds as reservoirs and sources of biodiversity which favoured the survival of hominins during periods of highly unfavorable climate across most of the European continent
<figure><img src="image_509.png" /></figure>

## S.218.6 Assessing how climate will change in world's terrestrial protected areas: are they behaving as proper climatic refugia?

Arnau Bosch-Guiu¹, Cindy Q. Tang², Neus Nualart¹, Tetsuya Matsui³,⁴, Haruka Ohashi³, Takuto Shitara⁵, Ileana Herrera⁶,⁷, Jordi López-Pujol¹,⁶

1 Botanical Institute of Barcelona, CSIC-CMCNB, Barcelona, Spain, arnau.bosch@csic.es 2 Institute of Ecology and Geobotany, College of Ecology and Environmental Science, Yunnan University, University Town, Chenggong New District, Kunming, Yunnan, China. 3 Forestry and Forest Products Research Institute, Forest Research and Management Organization, Tsukuba-shi, Ibaraki-ken, Japan. 4 Faculty of Life and Environmental Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki, Japan. 5 Institute of Agriculture, Tokyo University of Agriculture and Technology, Saiwai-cho, Fuchū-shi, Tokyo, Japan. 6 Escuela de Ciencias Ambientales, Universidad Espíritu Santo, Samborondón, Ecuador. 7 Instituto Nacional de Biodiversidad, Quito, Ecuador

Climatic changes play an essential role in shaping biodiversity. As global climate change accelerates, comprehending its potential impacts on ecosystems and species has become increasingly vital; indeed, climate change is considered a key driver for species extinction. Therefore, climatic refugia will play a crucial role for the conservation of extant biodiver-

sity, and conservation efforts should be directed towards protecting these areas. Protected areas (PAs) are currently regarded as fundamental to ensure biodiversity conservation; thus, evaluating how future climatic change is affecting PAs would be helpful in prioritizing or redesigning the existing ones. Moreover, identifying areas with high climatic stability (i.e., climatic refugia) could also guide the designing of new PAs. This study employs the Climate Stability Index (CSI), developed by Herrando-Moraira et al. [1], to assess the vulnerability of the current network of world's terrestrial PAs to climate change. The CSI originally used an uncorrelated set of the 19 WorldClim bioclimatic variables from present to year 2100 at 2.5 arcmin (ca. 5 km) grid resolution, and here is updated with the latest fourteen general circulation models of climate change at higher resolution (ca. 1 km) of four periods available from WorldClim. This research evaluates the projected climate changes considering the current network of PAs as a whole, but also considering different levels of protection of PAs (e.g. the IUCN six management categories), different biogeographic regions, or different levels of species richness and endemism. The findings will contribute valuable insights to conservation strategies, aiding policymakers and land managers in mitigating and adapting to the impacts of ongoing climate change in the world's terrestrial PAs, ensuring informed decision-making in the face of environmental challenges.

References: Herrando-Moraira, S., et al. (2022). Climate Stability Index maps, a global high resolution cartography of climate stability from Pliocene to 2100. Scientific Data 9, 48.

## S.219 BACK TO BASICS: USING MICRO-MORPHOLOGY, ANATOMY AND HISTOLOGY TO INVESTIGATE EVOLUTION IN BRYOPHYTES

### S.219.1 The contributions of electron microscopy to bryology

Jeffrey G Duckett, Silvia Pressel

Life Sciences, Natural History Museum, Cromwell Road, London, UK

The 1950s to the early 21st century was the Golden Age of biological electron microscopy: almost ev-

ery university Biology department had both transmission (TEM) and scanning electron microscopes (SEM). The benefits to bryology have been enormous. In 1952, Manton and Clarke discovered the compound nature of the sperm flagella in *Sphagnum* and suggested it was the same as in algae, ferns and humans. Sectioning then revealed the sperm cytoskeleton, the microtubule spline and multilayered structure. Consequent on meticulous reconstructions, initiated by Carothers spermatozoid ultrastructure now provides a suite of fea-
<figure><img src="image_510.png" /></figure>

tures key to defining the different lineages of land
plants and their algal ancestors. Manton was also
the first to observe the ultrastructure of hornworts:
though disappointed that their cells are basically
the same as other bryophytes she illustrated their
unique channelled thylakoids. Decades later immu-
nogold labelling confirmed pyrenoids as crystalline
arrays of RUBISCO. The same technique has then
been used to unravel the unexpected complexities
of bryophyte cell walls particularly those of con-
ducting cells, whose unique features had been well
documented by Hébant, and stomata. Though TEM
has revealed that the structure and biogenesis of
oil bodies are unique to liverworts, we have still to
solve the mystery of their function. The biggest con-
tributions of SEM have been to illustrating surface
and spore ornamentation and the unrivalled beauty
of peristomes. Cryo-SEM from the late 1990s added
an extra dimension in enabling the observation of
bryophytes in different stages of cytorrhytic dehy-
dration and rehydration. In vascular plants intercel-
lular spaces are gas-filled from the outset where-
as in bryophytes they are liquid-filled. They remain
in this condition in the gametophytes but become
gas-filled following stomatal opening in mosses and
liverworts. Except for hydroids, bryophyte cells are
highly resistant to cavitation. Cryo-SEM also demon-
strates that bryophytes have a mixture of hydrophil-
ic and hydrophobic surfaces.

S.219.2 Peristome evolution
in the Dicranidae revealed
by SEM and histology

Ruche M.¹, Pressel S.², Price M.J.¹,³

1 Conservatory and Botanical Garden of the City of Geneva, Geneva, Switzerland .2 Life Sciences Department, Natural History Museum, London, UK. 3 Plant Sciences Department, University of Geneva, Geneva, Switzerland

The peristome is considered the most complex and
conservative morphological structure in mosses. The
arthrodontous peristome is composed of a single, or
double, ring of teeth surrounding the opening of the
capsule. Peristome characters have long been used
for classification at the higher taxonomic ranks, and
for understanding evolutionary events across mosses.
In the monophyletic Dicranidae, which contain a
third of total moss diversity and are characterized
by a haplepidous peristome, the peristome architecture
has been found to be informative across
the group. A thorough morpho-anatomical investigation
of the haplepidous peristome was carried

out across a large sampling in the Dicranidae, using
histology and state-of-the-art SEM. The peristome
tooth-insertion region, studied with thin longitudinal
sections, was delimited, and described. The com-
parative anatomy of the peristome teeth-insertion
region has revealed conserved and variable ana-
tomical features, at the lower levels, that are useful
for elucidating relationships in the Dicranidae. The
imaging of teeth ornamentations and morphology,
using SEM, revealed an unsuspected diversity across
the group. The main patterns and traits of ornamen-
tations have been reassessed, and a newly discov-
ered set of shapes and sizes of ornamentations have
been redefined. The ornamentations have proven
to hold taxon-specific information across and be-
tween the various taxonomic ranks. The combina-
tion of anatomy and micro-morphology allowed for
a global comparison of peristomes in the Dicrani-
dae. This study confirms the taxonomic importance
of the peristome at the species, generic and familial
level in the Dicranidae. It will allow the use of new
diagnostic features for further investigations on the
relationships across the Dicranidae, as well as for
the establishment of stable characteristics for peri-
stome descriptions.

S.219.3 Evolution and
development of water-
related traits in the dryland
moss Syntrichia caninervis
(Mitt.)

Javier Jauregui-Lazo, Florian Deligne,
Siobhan Brady

Department of Plant Biology and Genome Center,
University of California Davis, USA

In contrast to vascular plants, most mosses rely on
external water transport and absorption over the
entire plant surface, a condition known as ectohydry.
Morphological characters (i.e., papillae) create cap-
illary pathways or increase the surface area to fa-
cilitate water uptake and transportation. As a moss
acquires water, small chambers and capillary spac-
es fill up with water and the moss expands rapidly.
Then, a new set of structural features appear, rang-
ing from modifications in their overall morphology to
extensive changes of cells in the leaf. The way these
features develop over time, function, and/or reflect
adaptation to different environmental regimes is an
area that remains poorly understood in mosses. This
<figure><img src="image_511.png" /></figure>

research applies genomics and cutting-edge im-
aging to (1) characterize leaf development with re-
spect to water-related traits, (2) identify how stages
of leaf development facilitate ectohydric capabili-
ties and relate to changes in water conducting cell
types, (3) identify gene expression profiles in re-
sponse to dehydration/hydration cycles in the moss
S. caninervis. This presentation will describe prelim-
inary data encompassing multiple biological levels
of organization (cells, tissues, and organs) along
with cutting-edge confocal microscopy to provide a
basis for a better understanding of the mechanisms
underlying leaf organogenesis, and more broad-
ly how plants evolve complex traits crucial for their
adaptation to terrestrial environments.

S.219.4 Complex thalloid going simple: the importance of microanatomic traits in unveiling Dumortiera hirsuta's diversity

David Horcajada¹, Belén Estébanez²,
Rafael Medina³

1 Universidad Pablo de Olavide. Sevilla, Spain. 2 Uni-
versidad Autónoma de Madrid. Madrid, Spain. 3 Uni-
versidad Complutense de Madrid. Madrid, Spain.

Complex thalloid liverworts (class Marchantiopsida) represent a good example of the importance of microanatomical characters when the macroscopic ones fall short in taxonomic decisions. Some representative microscopic structures showing traits with taxonomical relevance in the group include dorsal epidermis cells, dorsal papillae, hairs, air pore cells, photosynthetic filaments, scales, or rhizoids. *Dumortiera hirsuta* (Sw.) Nees is a widespread pantropical species present also in some temperate regions, characteristically lacking some typical complex thalloid traits, such as air pores or a developed epidermic reticulum. This liverwort displays, nonetheless, a remarkable variation of other microscopic traits. This fact led 18th and 19th-century botanists to describe multiple species that were later synonymized to *D. hirsuta*, concurrently with the lumping trend that thalloid liverwort taxonomy experienced throughout the 20th century. Recently, the likelihood of the ancient multiple-species hypothesis is again being reconsidered according to molecular data. We have chosen this liverwort as a model

to study the importance of microscopic characters
in Marchantiopsida systematics. For that purpose,
the presence or absence of epidermal papillae, the
vestiges of epidermal reticulum (in the form of ver-
tical walls on the dorsal epidermis), the morphology
of hairs and rhizoids, as well as the morphology and
ornamentation of spores, were studied in a selection
of D. hirsuta specimens, mainly from Europe, Mac-
aronesia, and the Americas. The integration of the
morphoanatomical and newly generated molecu-
lar data, which is coherent with the multiple-species
hypothesis, is discussed together with the next steps
to improve our understanding of this lineage.

S.219.5 Fungal symbioses
in bryophytes: anatomical
insights on the evolution of
mycorrhizal associations in
land plants

Silvia Pressel¹, Katie Field², Martin
Bidartondo³, Roberto Ligrone⁴, Jeffrey
Duckett¹

1 Natural History Museum, London, UK. 2 School of Biosciences, University of Sheffield, Sheffield, UK. 3 Department of Life Sciences, Imperial College London, UK. 4 Università degli Studi della Campania, Caserta, Italy.

Light microscope studies, many dating back to the
nineteenth century, showed the ubiquitous pres-
ence of fungi in many liverworts and hornworts. Their
identity and function were unknown. Transmission
electron microscopy revealed the endophytes as
belonging to a range of major fungal groups; Asco-
mycota in the rhizoids of Cephaloziaceae, Cepha-
loziellaceae, Lepidoziaceae, Schistochilaceae and
Mylia anomala where the fungus induces rhizoid
swelling and branching, Basidiomycota in the stems
of Scapaniaceae and in the thalli of Aneuraceae,
and Mucoromycota (Glomeromycotina and Mucor-
omycotina) in the Haplomitriopsida, hornworts and
many simple and complex thalloid liverworts. The
demonstration of healthy fungi in healthy host cells
and specialised interfaces comparable to those of
mycorrhizal associations in vascular plants, were
strongly indicative of symbiotic relationships. Se-
quencing enabled more precise identification of
the fungi. The rhizoid ascomycete is Rhizoscyphus
ericae, with the exception of Meliniomyces in My-
lia anomala, the same fungi as in ericaceous hair
roots. The basidiomycete genus Serendipita is found
<figure><img src="image_512.png" /></figure>

in leafy liverwort families but a later fungal lineage, *Tulasnella*, is the endophyte in the Aneuraceae. Underlying their unusual cytology, also found in some Devonian fossils, the endophytes in the Haplomi-triopsida are exclusively members of the subphy-lum Mucoromycotina whereas hornworts, simple and complex thalloids contain a mixture of Glom-eromycotina and Mucoromycotina. From the first establishment of symbiosis, in the Haplomi-triopsida, at the foot of the land plant tree, liverwort evolution has witnessed several gains and losses of fungi. Mi-crocosm experiments combined with anatomical analyses are now demonstrating major differenc-es in nutrient exchanges between Mucoromycotina and Glomeromycotina fungi and in their response to elevated carbon dioxide levels on a par with those at the dawn of plant terrestrialisation. Ultrastructural observations of living hyphae in close proximity to Nostoc colonies suggest potential plant-fungus-cy-anobacterium synergistic interactions in hornworts.

## S.219.6 Refining our understanding of hygroscopic movements in moss peristomes using histology

Michelle J Price¹,², Sylvain Loubery², Mathilde Ruche¹,²

1 Conservatory and Botanical Garden of Geneva, Chambèsy-GE, Switzerland. 2 Department of Plant Sciences, University of Geneva, Geneva, Switzerland

The peristome in mosses plays a role in spore mat-uration and release. Arthrodontous peristomes are formed from one or two rings of cell-wall remnants of opposing cell layers that are divided into distinct, articulated teeth. These teeth are reactive to humid-ity and move in response to changes in the ambient water levels in their immediate surroundings. The hygroscopic movements of the peristome teeth are hypothesised to facilitate spore dispersal. Two main types of response of the peristome teeth to water availability extremes are documented, peristomes that are open when wet and closed when dry ver-sus peristomes that are open when dry and closed when wet. Cell wall deposition patterns on the in-ternal and external faces of the teeth influence the movements based on water diffusion patterns and absorption-loss dynamics. The presence of a hydro-phobic substance between the two cell layers of the single or outer ring of teeth has been documented in certain moss species, with several hypotheses proposed to explain its function in the hygroscopic movements and what the substance may be com-posed of. Histological examination of peristomes from species across the Dicranidae allowed us to clarify the composition of the layer and, when pres-ent, clarify its role in the mediation of the hygro-scopic movements. Reflections on the responses of peristomes, with and without the hydrophobic layer, revealed a potential link with ecological preferences.

## S.220 APG V AND THE CHALLENGE OF TRANSLATING PHYLOGENY INTO CLASSIFICATION WHEN GENE TREES CONFLICT

### S.220.1 Nightmare or delight: taxonomic circumscription meets reticulate evolution in the phylogenomic era

Ze-Tao Jin¹,²,³, Richard G.J. Hodel⁴, Dai-Kun Ma²,³, Hui Wang²,³,⁵, Guang-Ning Liu³, Chen Ren⁶, Bin-Jie Ge⁷, Qiang Fan⁸, Shui-Hu Jin⁵, Chao Xu²,³, Jun Wu¹, Bin-Bin Liu²,³

1 State Key Laboratory of Crop Genetics & Germ-plasm Enhancement and Utilization, College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu, China. 2 State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, Beijing, China. 3 China National Botanical Garden, Beijing, Beijing, China. 4 Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA. 5 College of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, Hangzhou, Zhejiang, China. 6 Key Laboratory of Plant Resources Conservation and Sustainable Utilization & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences
<figure><img src="image_513.png" /></figure>

my of Sciences, Guangzhou, Guangdong, China. 7 Eastern China Conservation Center for Wild Endangered Plant Resources, Shanghai Chenshan Botanical Garden, Shanghai, Shanghai, China. 8 State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong 51075, China

Phylogenetic studies in the phylogenomics era have demonstrated that reticulate evolution greatly impedes the accuracy of phylogenetic inference, and consequently can obscure taxonomic treatments. However, the systematics community lacks a broadly applicable strategy for taxonomic delimitation in groups identified to have pervasive reticulate evolution. The red-fruit genus, *Stranvaesia*, provides an ideal model for testing the effect of reticulation on generic circumscription when hybridization and allopolyploidy define a group's evolutionary history. Here, we conducted phylogenomic analyses integrating data from hundreds of single-copy nuclear (SCN) genes and plastomes, and interrogated nuclear paralogs to clarify the inter/intra-generic relationship of *Stranvaesia* and its allies in the framework of Maleae. Analyses of phylogenomic discord and phylogenetic networks showed that allopolyploidization and introgression promoted the origin and diversification of the *Stranvaesia* clade, a conclusion further bolstered by cyto-nuclear and gene tree discordance. The well-inferred phylogenetic backbone revealed an updated generic delimitation of *Stranvaesia* and a new genus, *We nosemes*, characterized by purple-black fruits, trunk and/or branches with thorns, and fruit core with multi-locular separated by a layer of sclereids and a cluster of sclereids at the top of the locules. Here, we highlight a broadly-applicable workflow for inferring how analyses of reticulate evolution in phylogenomic data can directly shape taxonomic revisions.

## S.220.2 Reconciling gene-tree discordance in classification

Douglas E. Soltis

Florida Museum of Natural History, University of Florida, Gainesville, FL, USA

The first four iterations of the APG classification were largely based on sequence data from the plastid genome. Over the past decade, the use of numerous nuclear loci across many taxa has become increasingly common in phylogenetic analyses of plants. In many cases, nuclear and plastid-based topologies for

angiosperms agree, providing increased support for inferred relationships. However, in other cases, comparison of nuclear and plastid-based topologies has revealed surprising instances of incongruence at levels much deeper than those likely resulting from recent hybridization or incomplete lineage sorting over recent timescales. These examples of conflict provide important insights into evolution, showing that reticulation has been common and widespread throughout angiosperm evolutionary history. But how best to reflect these examples of deep incongruence in classification, especially in the next APG classification? Various approaches deserve consideration as we attempt to construct classifications that are maximally informative about phylogenetic history. When nuclear and plastid phylogenies conflict, the classification could alternatively follow: (1) the nuclear topology, with symbols indicating where the plastid genome provides an alternative topology; or (2) both the nuclear and plastid topologies by placing a taxon in alternative clades (as allowed under the PhyloCode). Each of these approaches presents challenges. For example, what percentage of nuclear genes would be required for a particular placement to be the favored placement in APG? And what navigation tools might be needed to alert users that a taxon is placed in two alternative groups? A system that provides maximum information and flexibility should be employed.

## S.220.3 Whence APG: a short history

Mark W. Chase¹,²

1 Department of Environment and Agriculture, Curtin University, Bentley, WA, Australia. 2 Royal Botanic Gardens, Kew, Richmond, UK.

In the middle to late 1990s, as DNA data began to accumulate, it became clear that no modern angiosperm classification resembled the emerging DNA results. In Uppsala, Sweden, Kåre and Birgitta Bremer and their colleagues created a booklet with a new classification based on the DNA results with the idea that it could be used in teaching plant systematics. At that time, several of their PhD students were collecting molecular data in the molecular systematics laboratory at Kew, and on a supervisory visit to Uppsala in 1998 I was shown this teaching booklet. We decided that their largely DNA-based classification should be published. At the time, although molecular systematists were identifying the same clades of families, different order names, formal and informal, were being applied to these, which made commu-
<figure><img src="image_514.png" /></figure>

nication difficult and was undesirable. We contact-
ed other botanists who were also working broadly
on angiosperm phylogenetics, both with DNA and
morphological data, to get their input and decided
that a new system should be published under the
APG acronym, to avoid the situation in which the
new classification was authored by one authority.
Although the APG classification has gone through
some minor changes in philosophy and four up-
dates, with a fifth in progress, the general framework
remains unchanged.

### S.220.4 Phylogenomics and a revised classification of the Cucurbitales

Hanno Schaefer, Gentaro Shigita,
Edgardo M. Ortiz

Technical University of Munich, Freising, Germany

Cucurbitales currently includes eight plant families
with diversity centers in the Tropics: Anisophylleaceae,
Apodanthaceae, Begoniaceae, Coriariaceae, Coryno-
carpaceae, Cucurbitaceae, Datiscaceae, and Tetra-
melaceae. These families comprise 109 genera with
more than 3,100 species. Morphologically, the taxa of
Cucurbitales are rather diverse ranging from the ho-
loparasitic Apodanthaceae, to annual and perennial
herbs in Datiscaceae and Begoniaceae, to trees and
shrubs in Anisophylleaceae, Corynocarpaceae, Cori-
riaceae, and Tetramelaceae and finally to woody
or herbaceous climbers and creepers in Cucurbita-
ceae. Based on target-capture and whole genome
sequencing data of 125 Cucurbitales samples repre-
senting all 102 genera currently accepted in the order,
we inferred coalescent species trees and networks.
We infer monophyletic and well supported families
and tribes. The holoparasitic Apodanthaceae are
placed outside Cucurbitales. For the remaining seven
Cucurbitales families, the relationships vary. The best
supported alternative shows a grade Coriariaceae +
Corynocarpaceae, followed by Anisophylleaceae and
then the remaining clades, but there is also consider-
able gene tree and site support for a clade Anisophyl-
leaceae, Corynocarpaceae + Coriariaceae, rest. The
woody Tetramelaceae is resolved as sister to the her-
baceous families Begoniaceae and Datiscaceae but
again there is also considerable gene support for the
two alternative combinations within the triplet. Within
Cucurbitaceae, there is gene support for different re-
lationships between the tribes but the best supported
topology is a clade Actinostemmateae + Gompho-

gyneae grouping as sister to the remaining tribes. A
network analysis revealed ancient reticulation within
and between Benincaseae, Coniandreae, and Cu-
curbiteae, suggesting that Benincaseae are the result
of ancestral hybridization between Coniandreae and
Cucurbiteae. A similar pattern of reticulation is found
between Schizopeponeae and Sicyoeae. Finally, there
is evidence for recent reticulation within Coniandreae
and within Thladiantheae, indicating frequent hybrid-
ization events in the evolutionary history of Cucurbita-
ceae. We present a revised taxonomic classification of
Cucurbitales and discuss the implications for charac-
ter evolution in the group.

### S.220.5 The impact of nuclear data on APG V

Alexandre R. Zuntini*, the PAFTOL
community

1 Royal Botanic Gardens, Kew, Richmond, Surrey, UK.
*a.zuntini@kew.org

For the past 25 years, the Angiosperm Phylogeny Group
has revolutionised the systematics of angiosperms
by providing a stable classification system based on
robust phylogenetic evidence. This classification has
largely been informed by plastid markers. Now, due
to advances in high throughput sequencing, the nu-
clear genome is more easily accessed, allowing us to
infer phylogenetic trees from hundreds of nuclear loci.
Target sequence capture (e.g. using Angiosperms353
probes) is now routinely used to tap into the nuclear
genome, even using DNA from historical collections.
These advances, however, demonstrate that the evo-
lutionary history of plants is more complex than the
plastid genome suggests, challenging previous classi-
fications. Here, we present novel phylogenetic insights
from nuclear data on the circumscription of families,
orders and major clades of angiosperms. These in-
sights arise from anuclear phylogenomic research
of the Plant & Fungal Trees of Life (PAFTOL) project at
the Royal Botanic Gardens, Kew, which has resulted
in genome-scale phylogenetic trees including all an-
giosperm families and nearly 60% of extant genera.
Importantly, many relationships by plastid evidence
are corroborated, such as the delimitation of major
clades, and deep relationships in the ANITA grade, the
monocots and the early-diverging eudicots. However,
conflict between nuclear and plastid data is evident
across the tree, leading to several changes, e.g., the
inclusion of Chloranthales in magnoliids; in rosids, the
reduction of fabids and expansion of malvids, and the
disintegration of the COM-clade; and in asterids, the
<figure><img src="image_515.png" /></figure>

break-up of orders Aquifoliales, Bruniales and Icacinales. In other groups, like Santales and Brassicales, notable conflicts are observed, but refining family circumscriptions requires denser sampling in those clades. As expected, cytonuclear conflict is evident throughout

the angiosperm tree of life. Future classifications must embrace this conflict to ensure that our knowledge infrastructures are consistent with the complex history of angiosperms.

# S.221 ATYPICAL SUBSTRATES AS ENGINES FOR PLANT AND LICHEN EVOLUTION I: GYPSUM SOILS

## S.221.1 The gypsum outcrops of North America: islands of high floristic endemism and diversity

Juan Pablo Ortiz-Brunel¹, Hilda Flores²,
Helga Ochterena², Michael J. Moore³

1 Departamento de Botánica, Universidad de Guadalajara, Jalisco, Mexico. 2 Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico. 3 Department of Biology, Oberlin College, Ohio, USA.

Isolated gypsum outcrops along Mexico and southwestern USA are diverse in terms of size and flora. Over 250 plant species restricted to gypsum (gypsophytes) are known there, mostly within the Chihuahuan Desert. The dominant North American gypsum endemics are often physiologically and morphologically highly distinctive from their nearest relatives, and many belong to clades that may have originated several million years ago. Nevertheless, biogeographic patterns of endemism and the ultimate origins of the gypsum flora of North America (including endemic and non-endemic taxa) are poorly known. This is particularly true for the gypsum outcrops in tropical Mexico, which are poorly investigated. Recent efforts showed that the gypsicolous flora of tropical Mexico is highly diverse despite inhabiting much smaller outcrops than in the Chihuahuan Desert. However, no comprehensive studies of diversity patterns, including phylogenetic diversity, have been conducted in North America. Here we use different diversity metrics to analyze the composition of the gypsum floras of North America. We used 6,211 herbarium-based records to estimate the spatial distribution of species richness, endemism, phylogenetic diversity, and phylogenetic endemism. We found that tropical gypsum patches possess a more diverse

flora but with significantly reduced endemism as compared to those in the arid regions further north. We detected a mix of Nearctic and Neotropical elements, with the latter especially prominent in western and southern Mexico. Total species richness followed global latitudinal diversity gradients, but remarkable cases of high diversity were identified in the Cuatrociénegas Basin, in the Sierra Madre Oriental at Nuevo León, and in Oaxaca. Categorical analysis revealed examples of neo- and paleo-endemism. Species endemism and phylogenetic endemism are heterogenous throughout the study area, but are higher in the Chihuahuan Desert Region, which may reflect the much greater geographic extent of gypsum outcrops in these areas compared with the tropical patches.

## S.221.2 Facilitation in gypsum soils is promoted by homogeneous microenvironmental conditions under the nurses

Ricardo Sánchez-Martín¹, Alicia Montesinos-Navarro¹, Helga Ochterena², Irene Pisanty³, Mariana Rodríguez-Sánchez², Miguel Verdú¹, Hilda Flores Olvera²

1 Centro de Investigaciones sobre Desertificación (CSIC) Moncada, Valencia, Spain. 2 Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, México. 3 Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, México

Besides the environmental stress in arid and semi-arid regions, gypsum outcrops are a barrier to plant growth due to challenging soil nutrient levels. In such
<figure><img src="image_516.png" /></figure>

extreme conditions, biotic interactions are highly affected by species traits and micro environmental variability. Studies on facilitation have shown that nurse species alleviate abiotic stress for beneficiary species, but the impact of the micro-environmental variability generated by nurse plants in shaping facilitation outcomes is poorly understood. Here, we assess which traits define beneficiary species and whether nurse and non-nurse species differ in their ability to reduce abiotic stress and its variability under their canopy. We sampled recruits in two gypsum arid and stressful environments in the Cuatro Ciénegas' valley in Coahuila, Mexico. Our aims were to assess i) which species accumulate more juveniles beneath their canopy controlling for their coverage (nurse vs. non-nurse species); and ii) which species benefited from facilitation by determining whether they tend to recruit more species beneath or on the bare ground (beneficiary/ non-beneficiary). Then, we compared how nurse and non-nurse species modify the physical and chemical microenvironments underneath their canopy, both in terms of magnitude and variation. Furthermore, comparisons were made between root growth, water retention, and nutrient accumulation in juvenile plants of beneficiary and non-beneficiary species. We found that facilitation is enhanced by species that provide a more homogeneous microenvironment rather than an intense reduction of microenvironmental stress under their canopy. In addition, the juveniles of beneficiary species invest more in root development, accumulate Ca and S in their shoot tissues, and show a higher water content than non-beneficiary species. Our results suggest that the homogeneity of microenvironments plays a crucial role in facilitative interactions, and the juveniles of beneficiary species show a less conservative strategy, investing more in resource acquisition than juveniles of non-beneficiary species.

### S.221.3 Mapping gypsophile vegetation in Armenia – solution to former misconceptions?

Alexander Rudov¹,², Razmik Papikyan¹, Hripsik Qosyan¹, Mehdi Dehghani³, Anna Asatryan¹, Maria Perez-Serrano⁴, Aurora Bartolome⁴, Alicia Perez⁴, Yekaterina Shcherbakova¹, Sara Palacio⁴

1 Institute of Botany after A.L. Takhtajyan of National Academy of Sciences of Armenia, Yerevan, Armenia. 2 Halophytes and C4 Plants Research

Laboratory, Department of Plant Sciences, School of Biology, College of Sciences, University of Tehran, Tehran, Iran. 3 Department of Biology, Faculty of Science, University of Zabol, Zabol, Iran 4Instituto Pirenaico de Ecología, Jaca, Huesca, Spain

Armenia, with an area of less than 30.000 km², is an important biodiversity hotspot with about 3800 plant species and a very diversity of landscapes and vegetation, that ranges from subalpine communities to forests, steppes, semideserts and even a small sand desert. The semidesert belt is very diverse in soil types, including gypsum. However, botanists of the former century have often misclassified plant communities as gypsophile, while in fact dealing with marls and clays. Due to these misconceptions, up to date no detailed map and no complete floristic inventory of gypsum rich soils has been published. Additionally, to the lack of precise data, gypsum outcrops and semideserts as a whole, are not highly valued for conservation by local populations and are highly threatened by destruction and fragmentation, while harboring a good amount of the country's biodiversity. To address this problem, we mapped all gypsum outcrops by satellite imaging (SentinelHub). Within extensive fieldwork we collected soil and herbarium data from all gypsum outcrops in the Republic of Armenia. We created a species inventory for all the species occurring on gypsum and analyzed the soil composition and gypsum content in each gypsum area. Finally, we evaluated current threats to these small and unique habitats and the possibility of their conservation. As a result, we present an updated and corrected critical checklist of plants occurring on gypsum outcrops in the Republic of Armenia and a detailed map of gypsum habitats in Armenia. Finally, we present recent data on the conservation of gypsum habitats and discuss the actual threats to these unique ecosystems.

### S.221.4 Secondary metabolic pathways and gypsum endemism

Rebecca E. Drenovsky

John Carroll University, Ohio, USA.

Gypsum soils are rich in calcium and sulfate, creating a challenge for plant life. Despite these stressful conditions, many gypsophiles (gypsum-loving plants) accumulate high levels of these mineral nutrients in their tissues, particularly in leaves, without suffering toxicity effects. Based on these patterns, we seek to investigate mechanisms, such as assimilation or sequencing
tration, supporting excess mineral nutrient accumulation in plants growing on gypsum. Two secondary metabolites of particular interest are glucosinolates and sulfated flavonoids. These sulfur-rich metabolites are naturally present in taxa common on gypsum (glucosinolates in members of the Brassicaceae and sulfated flavonoids in members of a variety of families but particularly the Asteraceae). Our data suggest that gypsophiles may have higher glucosinolate levels than non-endemics. Similarly, we have data that suggests that plants growing on gypsum produce sulfated flavonoids in flowers and leaves and that the likelihood of their expression may be related to evolutionary history, as some taxonomic groups were more likely to produce these compounds than others. We hypothesize that glucosinolates and sulfated flavonoids may serve as sulfur sinks in gypsophiles and that glucosinolates may also support water uptake in drying soils in these taxa. Future work will investigate how widespread these patterns are in gypsophiles, as well as how plastic these responses are. Identifying the mechanisms supporting plant life on gypsum may help us understand fundamental biological processes such as speciation, adaptation, and how biotic and abiotic factors influence community assembly.

## S.221.5 Extreme variability in gypsum lichen species: the case of Squamarina

Maria Prieto¹, Sergio Muriel¹, Isaac Garrido²

1 Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, Móstoles, Madrid, Spain. 2 Departament de Botànica i Geologia, Facultat de Ciències Biològiques, Universitat de València, Burjassot, València, Spain

The genus Squamarina is a predominant component in Biological Soil Crusts (BSC) from gypsum soils in the Iberian Peninsula. It is considered to be well known with only two species cited in this habitat, i.e., S. cartilaginea and S. lentigera. However, the high morphological variability led us to more thoroughly assess the species of Squamarina from gypsum soils. Our molecular data revealed the existence of at least five lichen taxa in gypsum soils instead of two. These five taxa were not evenly distributed in gypsum soils in Spain. Subsequent analyses were driven to understand these distributional differences. First, we discovered that these taxa had seven different photobiont haplotypes. Differences in photobiont partner were related with location and lichen species. Functional traits related with water re-

tention were also different in the different locations but not related with the lichen species. Also, traits related with photosynthetic activity were related with location and photobiont haplotypes. These results point out that functional variability in this group is more related to environmental variation and photobiont composition than to lichen species identity.

## S.221.6 Bridging Gaps between Mining and Restoration: Insights from Gypsum Quarry Succession

Alejandro Gomez¹, Juan F. Mota Poveda², Fabián Martínez Hernández², Antonio J. Mendoza Fernández³, Francisco J. Pérez García², Esteban Salmerón Sánchez², Federico Escudero Clarés², Rebecca E. Drenovsky⁴, Hailey Whitten⁴, M. Encarna Merlo Calvente²

1 New Mexico University, New Mexico, USA. 2 University of de Almería, Almería, España. 3 University of Granada, Granada, España. 4 John Carroll University, Ohio, USA.

This research delves into reconciling gypsum mining with sustainable development in a scenario of Global Change. Our research was conducted in a quarry situated within the Protected Area of the Gypsum Karst Natural Park in Sorbas (Almería, Spain). The exploitation of this quarry ceased eight years prior to the initiation of this study, which spans from 2009 to 2024. Ten permanent plots were established there, with dimensions of 20 x 50 m. The presence of perennial vascular plants was documented in these plots over the course of 15 years. Our main objective revolves around monitoring the temporal trajectory of spontaneous succession within the quarry, juxtaposing it with undisturbed shrubland as the reference ecosystem. To this end, we also sampled five similar plots within the shrubland. We hypothesized that a largely predictable convergent successional development will occur, which can serve as a model for habitat restoration. Based on the floristic composition of the plots and the functional types present (based on the degree of gypsophily), we investigated the convergence/divergence of species composition and functional types, characterized by the degree of gypsophily. Non-metric multidimensional scaling (nMDS) analysis was used considering 15 succession points (years) relative to the five cor-
responding reference points in undisturbed shrub-
lands. Reductions in dispersion over time indicate
convergence, while increases signify divergence.
Our findings consistently demonstrate a conver-
gent trajectory towards the reference ecosystem,
albeit with varying rates of convergence. These
results underscore the importance of autogenic
succession as a geoecological model to consider
for habitat restoration. This research advances our

understanding of primary succession dynamics in
gypsum quarries after mining cessation, shedding
light on the intricate relationship between natural
environments and disturbed areas. Importantly, it
highlights the fundamental role of scientific knowl-
edge transfer in facilitating effective ecological res-
toration within gypsum habitats, designated as pri-
ority habitats by the EU.

# S.222 LET PEOPLE COME TO BOTANY II: IMPROVING FLORA KNOWLEDGE THROUGH INATURALIST

## S.222.1 Flora of Russia on iNaturalist: moving forward

Alexey P. Seregin, Dmitriy A. Bochkov, Julia V. Shner, Sergey R. Mayorov, Natalia S. Gamova, Sergey A. Lednev

Lomonosov Moscow State University, Moscow, Russia

Since 2008, iNaturalist has been crowdsourcing bio-
diversity observations made by citizen scientists
and professional biologists. Thousands of publica-
tions have already taken into account these data for
use in research, conservation and policy. There are
three key themes that iNaturalist embraces: social
interaction; shareability of data, tools and code; and
scalability of the platform and community. The "Flora
of Russia" project on iNaturalist (https://www.inatu-
ralist.org/projects/flora-of-russia) brought together
professional scientists and amateur naturalists from
all over the country since 9 Jan 2019. The main goal
of the project is to maintain crowdsourced data for
the national atlas of vascular plants in the absence
of an appropriate national platform. By 2023, over
25K+ people were involved in the data collection.
Within 5 years, the participants accumulated 3M+
photo observations of 8K+ species of the Russian
vascular plants. This constitutes the largest dataset
of open spatial data on the country's biodiversity
and a leading source of data on the current state
of the national flora. The key index of the project is
the number of uploaded observations. The project
reached 2.5M observations of "Research Grade"
quality on 7 May 2023, whereas ca. 0.5M unverified
observations make the project's backlog. The Mos-

cow Oblast and the City of Moscow take the lead by
the number of observations and observers, whereas
Dagestan harbours the highest number of observed
species. The Moscow University team of professional
botanists leads the expert efforts within the project.
About 90% of all project data, are available under
free licences (CC0, CC-BY, CC-BY-NC) and can be
freely used in scientific, educational and environ-
mental activities. Due to the project, Russia is cur-
rently one of top-five countries of the platform by
the number of observations and the leading country
on iNaturalist by share of records available in GBIF.

## S.222.2 The age of colour in alpha taxonomy: new frontiers for online species discovery

Farminhão, J.¹,²

1 Jardim Botânico da Universidade de Coimbra, Coimbra, Portugal. 2 Sociedade Portuguesa de Botânica, A-dos-Potes, Portugal

Platforms such as iNaturalist provide botanists with
unprecedented, accurate and universal access to
information on spatially structured and taxonom-
ically significant colour variation in angiosperms,
which was historically inaccessible through herbar-
ium specimens or, more recently, highly dispersed
through slide collections and multiple web resources.
This wealth of newly and readily available data will
accelerate the pace of species description and tax-
onomic revision of multiple taxa in which flower co-
lour is key to diagnosis. As a proof of concept, I here
illustrate the potential of iNaturalist, and other online platforms, to uncover unaccounted or long-neglected taxonomic diversity in three genera of the Iberian Flora. On a more practical side, I present a quick guide for online species discovery using photographic data and introduce a citizen science initiative to map colour variation in iris plants on iNaturalist, championed by the Botanical Society of Portugal.

### S.222.3 Citizen science, higher education and iNaturalist: a multifaceted approach for biodiversity conservation in Latinamerican cities.

Nora H. Oleas¹, Natasha Baer¹, Mónica Paez¹,², David Salazar¹, Laura Salazar³, Ibon Tobes¹

1 Universidad Tecnológica Indoamérica, Machala y Sabanilla, Quito, Ecuador. 2 Centro Jambatu de Investigación y Conservación de Anfibios, Fundación Jambatu, San Rafael, Quito, Ecuador. 3 Universidad Regional Amazónica Ikiam, Napo, Ecuador

University education in Ecuador is conceptualized as a dynamic interplay among academia, research, and societal engagement. Furthermore, academia serves society by providing the information necessary to address problems. Additionally, the dissemination of scientific knowledge to the broader community constitutes an integral facet of university endeavors. Within this framework, to ensure the conservation of biodiversity and its ecological services within cities, multidisciplinary approaches are required to engage the community. This study describes the mechanisms through which these channels of reciprocal enrichment have been cultivated. As an integral component of their academic curriculum, students enrolled in the Biodiversity Engineering program at the Universidad Tecnológica Indoamérica in Quito, Ecuador, actively participated in projects that fostered connections with society. This involvement entailed the practical application of data collection tools, such as surveys, and the utilization of platforms like iNaturalist during various community events. Through these initiatives, a collective repository documenting the city's flora was established, showcasing contributions from both students and citizens. This collaborative effort facilitated the identification of novel findings, including

new plant records and endangered species. Furthermore, the outcomes of these projects were disseminated through the creation of posters and other communication materials, as well as environmental education talks conducted in schools and among residents in the neighborhoods where the activities were carried out. In addition to these community interactions, students assumed the role of for articles presented at conferences and subsequently published in scientific journals. This multifaceted approach underscores the university's commitment to knowledge dissemination, practical application, and community engagement.

### S.222.4 Using iNaturalist in Plant Research: Strengths and Challenges

Eduard López-Guillén¹, Ileana Herrer²,³, Badis Bensid ¹,⁴, Carlos Gómez-Bellver¹, Neus Ibáñez¹, Pedro Jiménez-Mejías⁵, Mario Mairal⁶, Laura Mena-García¹, Neus Nualart¹, Mònica Utjés-Mascó¹, Jordi López-Pujol¹,²

1 Institut Botànic de Barcelona, CSIC-CMCNB, Barcelona, Catalonia, Spain. 2 Escuela de Ciencias Ambientales, Universidad Espíritu Santo, Samborondón, Ecuador. 3 Instituto Nacional de Biodiversidad, Quito, Ecuador. 4 Departament de Biologia Animal, Biologia Vegetal i Ecologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain. 5 Área de Botánica, Departamento de Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Sevilla, Spain. 6 Departamento de Biodiversidad, Ecología y Evolución (Unidad de Botánica), Facultad de Ciencias Biológicas, Universidad Complutense de Madrid, Madrid, Spain

iNaturalist (https://www.inaturalist.org/) self-defined as an "online social network of people sharing biodiversity information to help each other learn about nature", and it is likely one of the largest citizen science web portals of the world as it includes nearly 165 million observations of over 430,000 species produced by a community of almost 2.9 million users by December 2023 (for plants, almost 67 million observations of over 154,000 species by nearly 2 million users). This platform presents some strengths and potentialities such as its usability and low technical requirements, immediacy, open-access, the possibility of interacting with other users, artificial intelligence-aided identification, versatility and the auto-
<figure><img src="image_517.png" /></figure>

matic incorporation of the validated records to GBIF. However, there are some features that scientists need to take into account when using data from this science portal in research, making sure that the quality of observations does not limit or hinder its usefulness in plant research. While these are identified, we are providing some suggestions to overcome them and, by doing so, increasing the use and adding value of iNaturalist in plant research.

**S.222.5 Contribution of citizen science through iNaturalist to the knowledge of the Mexican Flora**

Jesús G. González-Gallegos, J. Fernando Pío-León

Instituto Politécnico Nacional, CIDIR Unidad Durango

iNaturalist is an online visual network allowing the interaction between citizens attracted by the natural world, and experts on different taxonomic groups, who would help them to identify the species documented by pictures linked to spatiotemporal data. The platform pursues to promote a connection between people and biodiversity, and to support biodiversity and conservation science. Mexico was one of the first countries to ascribe to this new way of socializing

and collecting biodiversity data, under the lead of the Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (CONABIO), which keeps promoting it. At first, there was some reluctance from the Mexican scientific community on biodiversity studies, but progressively more researchers have gotten involved in the uploading and identification of observations; and it is becoming more common to find scientific papers benefited by iNaturalist data. The observations have helped to better document the distribution of some species with the addition of unknown localities, and their morphological variation with and increasing number of photographs, long forgotten species have been rediscovered, or even new ones have been named based on clues given by iNaturalist observations. Here we present a revision of the contributions of iNaturalist to the knowledge of the diversity of Lamiaceae family in western Mexico as a case study. A numerical analysis was performed on the comparison of richness patterns revealed in the study area based on two databases; the first downloaded from iNaturalist, and the other assembled from herbarium specimens of more than 20 herbaria. Although the patterns extracted from iNaturalist data are clearly biased in comparison to those obtained from herbarium specimens, the platform helped in adding additional localities and to detect previously unrecorded plants, or even new arrivals in terms of new naturalized species. Recommendations for the use and improvement of iNaturalist impact are also compiled.

**S.223 DIVERSIFICATION IN LARGE DOMINANT PLANT LINEAGES: INTEGRATION OF PHYLOGENY, ECOLOGY, PHYSIOLOGY, AND BIOGEOGRAPHY**

**S.223.1 Evolution in plant function and ecological niches in the oak adaptive radiation inform community assembly at continental scale**

Jeannine Cavender-Bares¹,², Jesús Pinto-Ledezma¹, Clarissa Fontes¹, Kieran Althaus³,⁴, Andrew L. Hipp³

1 Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, Minnesota, USA.
2 Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA.
3 Morton Arboretum, Lisle, Illinois, USA.
4 Biological Sciences, University of Chicago, Chicago, Illinois, USA

Oaks (genus Quercus L) are an important adaptive radiation that includes ecological dominants on five continents with extraordinary diversity and abundance. They are major contributors to ecosystem function, including climate regulation and support of biodiversity in Northern Hemisphere temperate for-
<figure><img src="image_518.png" /></figure>

est systems. Biogeographic history, including past environmental change, have influenced the diversification process and evolution of functional traits. Trait evolution, in turn, has influenced the habitats that the species across the lineage can occupy. Trait evolution in the oaks shows evidence for phylogenetic inertia and adaptation in response to novel environments. We show examples of freezing tolerance and vulnerability to drought as well as chemical and structural foliar traits of leaves as derived from spectral signatures. We test how traits evolved in response to new environmental challenges and whether evolutionary shifts in traits allowed species to colonize new habitats. We show that the coordinated process of diversification in traits and ecological niches explains community assembly processes at continental scale in the Americas. Insights from addressing these questions have far reaching implications for understanding the nature of trait and niche evolution in other lineages across the tree of life.

### S.223.2 Ecophysiological adaptations and realized height growth shape *Eucalyptus* distributions along an Australian rainfall gradient

Duncan D. Smith¹, Mark A. Adams²,³, Amanda M. Salvi¹, Cécile Ané⁴, Katherine A. McCulloh¹, Thomas J. Givnish¹

1 Department of Botany, University of Wisconsin-Madison, Madison, USA. 2 Faculty of Science, Engineering, & Technology, Swinburne University of Technology, Hawthorn, Australia. 3 School of Ecosystem and Forest Sciences, University of Melbourne, Creswick, Australia. 4 Department of Statistics, University of Wisconsin-Madison, Madison, USA

Tradeoffs between the energetic benefits and costs of traits can shape the distributions of species and traits along environmental gradients. Here we test predictions based on tradeoffs involving photosynthesis and water loss using survival, growth, and 50 photosynthetic, hydraulic, and allocational traits of ten *Eucalyptus* species grown in four common gardens along an 8-fold gradient in relative moisture supply – as measured by precipitation/pan evaporation (P/Ep) – from mallee to tall wet sclerophyll forest in Victoria, Australia. Phylogenetically structured tests show that most trait-environment relationships

accord qualitatively with theory. Most traits appear adaptive across species within gardens (indicating fixed genetic differences) and within species across gardens (indicating plasticity). However, species from moister climates have lower stomatal conductance than others grown under the same conditions. Responses in stomatal conductance and five related traits appear to reflect greater mesophyll photosynthetic sensitivity of mesic species to lower leaf water potential. Our data support adaptive crossover, with realized height growth of most species exceeding that of others in climates they dominate. Our findings show that pervasive physiological, hydraulic, and allocational adaptations shape the distributions of dominant *Eucalyptus* species along a subcontinental climatic moisture gradient, driven by rapid divergence in species P/Ep and associated adaptations over the past 4 million years. Across the entire genus, the rate of net species diversification has increased substantially over this period, especially in areas of low climatic moisture availability, which are often associated with smaller species ranges.

### S.223.3 Disentangling the drivers of diversity at multiple taxonomic scales in the rapid radiation of the South African Protea

Nora Mitchell¹, Kent E. Holsinger²

1 Department of Biology, University of Wisconsin - Eau Claire, Eau Claire, WI USA. 2 Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT USA

The genus *Protea* of South Africa is an iconic plant radiation with remarkable variation in growth form, leaf functional traits, and pollination syndromes. Their center of diversity and center of origin is the Cape Floristic Region of southwestern South Africa, a biodiversity hotspot, and a region characterized by multiple climatic gradients, substantial edaphic heterogeneity, fire-dominated ecosystems, and multiple mountain ranges resulting in both topographic variation and geographic isolation. Here, we synthesize our research on the drivers of diversity in *Protea* across taxonomic scales, asking the extent to which the radiation has been driven by adaptive versus nonadaptive mechanisms. We investigate these questions 1) across the genus in a phylogenetic context, 2) within a restricted clade, 3) across populations within a single species, and 4) between hybridizing species at a single
<figure><img src="image_519.png" /></figure>

site. We use a variety of approaches, including phylogenomics and Bayesian phylogenetic frameworks, common garden studies assessing trait differentiation and gene expression, in situ measurements of plants growing across climatic gradients, and population genomics tools to assess the roles of geographic and environmental differences. Our findings present a paradox, where we detect trait-environment relationships at multiple scales (suggesting that adaptive processes underlie the radiation) while our population genomic evidence points to a potential role for geographic isolation (suggesting that nonadaptive processes underlie the radiation). Moreover, within a given site, many *Protea* species often co-occur, and co-occurring species often represent wildly disparate morphologies. We attempt to reconcile the roles for these difference mechanisms and point to future work to disentangle the effects of adaptive processes (driven by both biotic and abiotic interactions) as well as nonadaptive mechanisms.

**S.223.4 Global drivers of diversification and assembly are spatially structured in the megadiverse Carex (Cyperaceae)**

Daniel Spalink¹, Pedro Jiménez-Mejías²,⁴,
Tamara Villaverde³, Santiago Martín-Bravo⁴, Marcial Escudero⁵, Katie Sanbonmatsu¹, José Ignacio Márquez-Corro⁵, Isabel Larridon⁶,⁷, Eric Roalson⁸, Kenneth J. Sytsma⁹, Andrew L. Hipp¹⁰,¹¹

1 Texas A&M University, College Station, Texas, USA. 2 Universidad Autónoma de Madrid, Madrid, Spain. 3 Université Complutense de Madrid, Madrid, Spain. 4 Universidad Pablo de Olavide, Seville, Spain. 5 University of Seville, Seville, Spain. 6 University of Seville, Seville, Spain. 7 Royal Botanic Gardens, Kew, Richmond, Surrey, UK. 8 Ghent University, Gent, Belgium. 9 Washington State University, Pullman, Washington, USA. 10 University of Wisconsin-Madison, Madison, WI, USA. 11 The Morton Arboretum, Lisle, IL, USA. 12 The Field Museum, Chicago, IL USA

The processes of speciation and assembly are inextricably linked. Diversification drivers vary among clades and are often determined by the geographic context where speciation is occurring. We should therefore expect patterns of assembly to be influenced by spatially variable speciation dynamics. We use the

globally distributed, mega-diverse genus *Carex* (Cyperaceae) to test the hypothesis that both drivers of diversification and assembly are spatially varied, such that observed patterns of phylogenetic diversity and endemism are determined by context-specific physiological traits associated with individual lineages and the ecological conditions of different geographic areas. We used 4.35 million museum records, a global *Carex* phylogeny, historical biogeographical estimations, and rate analyses to test for spatially structured correlations to diversification and patterns of assembly using structural equation modeling. We find that all previously hypothesized drivers of diversification in the genus are associated with elevated speciation rates. However, these drivers have interacted in different combinations in different geographical areas, with no two regions exhibiting the same combination of drivers. This has resulted in spatially varied patterns of phylogenetic diversity and endemism. Our results demonstrate that integrating analyses of diversification and assembly with spatial scaling improves the resolution at which we can understand the origins and distribution of our extant biodiversity.

**S.223.5 Diversity and divergence: the ecology and evolution of defenses in the tropical tree genus Inga**

Dale L. Forrister¹, María-José Endara¹,²,
Abrianna J. Soule¹, Gordon C. Younkin³,⁴,
Anthony G. Mills¹, John Lokvam¹, Kyle G. Dexter⁵, R. Toby Pennington⁶, Catherine A. Kidner⁷,⁸, James A. Nicholls⁹, Oriane Loiseau⁵, Thomas A. Kursar¹, Phyllis D. Coley¹

1 Department of Biology, University of Utah, Salt Lake City, UT, USA. 2 Centro de Investigación de la Biodiversidad y Cambio Climático e Ingeniería en Biodiversidad y Recursos Genéticos, Facultad de Ciencias de Medio Ambiente, Universidad Tecnológica Indoamérica, Quito, Ecuador. 3 Boyce Thompson Institute, Ithaca, New York, USA. 4 Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York, USA. 5 School of Geosciences, University of Edinburgh, Old College, Edinburgh, UK. 6 Department of Geography, University of Exeter, Exeter, UK. 7 School of Biological Sciences, University of Edinburgh, Edinburgh, UK. 8 Royal Botanic Gardens Edinburgh, Edinburgh, UK. 9 The Commonwealth Scientific and Industrial Research Organisation, Australian National Insect Collection, Black Mountain ACT, AU
Because plants and their insect herbivores together account for more than half of the macroscopic diversity on land, their interactions play an extremely important role. From an evolutionary perspective, they are thought to be locked in a coevolutionary arms race, in which plants evolve novel defense traits to which herbivores evolve counter adaptations. We discuss evidence for the role of plant-herbivore interactions in shaping the ecology and evolution of *Inga* (Fabacea) a specious tropical tree genus. With a particular focus on the evolution of plant secondary metabolism and ecological significance. To do so we characterized the chemical profile of one-third of species in the genus *Inga* (ca. 100) using ultraperformance liquid chromatography-mass spectrometry-based metabolomics and applied phylogenetic comparative methods to understand

the mode of chemical evolution. Each *Inga* species contains structurally unrelated compounds and high levels of phytochemical diversity; closely related species have divergent chemical profiles, with individual compounds, compound classes, and chemical profiles showing little-to-no phylogenetic signal; at the evolutionary time scale, a species' chemical profile shows a signature of divergent adaptation. At the ecological time scale, sympatric species were the most divergent, implying it is also advantageous to maintain a unique chemical profile from community members; finally, we integrate these patterns with a model for how chemical diversity evolves. We find that this chemical divergence plays an important role in shaping the community assembly of tropical trees and shaping the host choice of insect herbivores.

# S.224 ADVANCES IN FERN ECOLOGY: RESPONSES TO ENVIRONMENTAL AND BIOTIC STRESS FACTORS

## S.224.1 Advances in Fern Ecology: a synthesis and future research directions

Klaus Mehltreter¹, Rafael P. Farias²

1 Instituto de Ecologia, A.C., Xalapa, Mexico. 2 Universidade Federal do Bahia, Salvador, Brazil

In the last decade, studies on fern ecology have overcome many of the historical misjudgments. Some of these preconceptions included the allegedly old evolutionary age of extant ferns, their supposedly low growth rates, low nutrient concentrations, low ability to compete with seed plants, to defend themselves against herbivores, and to withstand environmental catastrophes and anthropogenic disturbances. Furthermore, a high vulnerability of the gametophytic life stage, a low diversity of biochemical compounds, and a reputedly low usefulness for medical or industrial purposes were assumed. We present an overview of the advances in Fern Ecology based on exemplary case studies, which have demonstrated that ferns are much more functionally, ecologically, physiologically, and biochemically diverse than previously thought. In addition, we discuss how the results of current research

have changed our perception of the ecological role of ferns in different ecosystems and show how ferns effectively differ from seed plants. Research gaps and open questions are outlined, and future research directions are proposed such as holistic approaches integrating all life stages of ferns, comparative studies between ferns and angiosperms, and conservation approaches to deal with anthropogenic disturbances and climate change. To face these challenges, the future study of fern ecology still requires more inter- and multidisciplinary approaches and intensive collaboration efforts.

## S.224.2 Water use efficiency explains differences in global diversity patterns between ferns and angiosperms

Daniela Aros-Mualin¹, Amanda Taylor², Patrick Weigelt², Michael Kessler¹

1 Department of Systematics and Evolutionary Botany, University of Zurich, Switzerland. 2 Faculty of Forest Sciences & Forest Ecology, University of Göttingen, Germany
<figure><img src="image_520.png" /></figure>

The colonization of land by plants strongly depended on their ability optimize the use of water. Vascular plants have successfully colonized a broad range of habitats, but their diversity is lower under physiologically stressful conditions. Ferns, the second most diverse extant land plant group, exhibits disparate global patterns of species richness when compared to angiosperms. This contrast becomes more evident under water-limited environments, where the diversity of ferns sharply declines. To understand this disparity, we combined greenhouse experiments of water use efficiency (WUE) with studies of global macroecological distribution patterns. In the greenhouse, we compared WUE, quantified as the biomass produced per unit of water usage, of 12 fern and 12 angiosperm species, encompassing both terrestrial and epiphytic ones. We found that among terrestrial species, ferns exhibit lower WUE and consequently higher water loss compared to angiosperms. At the macroecological scale, this is reflected by an increase in the proportion of ferns relative to angiosperms as water availability increases. Conversely, fern and angiosperm epiphytes had a comparable WUE in the greenhouse, which at the macroecological scale is reflected by a constant proportion of fern richness in relation to water availability. These findings reveal the key role of water in shaping the competitive dynamics between ferns and angiosperms, and their diversity patterns. Moreover, it suggests that terrestrial ferns serve as potential early indicators of climate change.

### S.224.3 Thermal tolerance and competition of two tropical relict ferns

Sofía Ruiz Cano¹, Luis G. Quintanilla², Nagore G. Medina¹

1 Universidad Autónoma de Madrid, Madrid, Spain.

2 Universidad Rey Juan Carlos, Madrid, Spain.

Studying the thermal niche of organisms is crucial in the current context of climate change. However, it is a complex task as physiological requirements, species distributions and the modulating factors such as competition need to be analysed simultaneously. We present a study that combines germination experiments along an environmental gradient both with and without interspecific competition, with thermal niche analyses based on estimated climatic data from global distributions. We evaluated the thermal niches by setting up experiments on

germination and growth of two fern species: *Culcita macrocarpa* and *Woodwardia radicans*. Both species, which are potential competitors, are tropical relics that share distribution, habitat and exhibit synchronous spore dispersal. Spore germination was compared at eight temperatures ranging from 5 to 35 °C and gametophyte growth at 10, 20 and 30°C. Our findings demonstrated that spores of *W. radi-cans* germinated faster and to a higher percentage, and their gametophytes grew faster than those of *C. macrocarpa*, especially at moderate to high temperatures. Additionally, interspecific competition reduced germination only in *C. macrocarpa*. Besides, our results reveal an exceptionally high correlation between climatic parameters and germination parameters in both species. In the case of *C. macro-carpa*, this correlation increased when examining germination under competition. These findings show the advantages of ferns for culture experiments, and their potential usefulness for tackling many research questions, such as community-level experiments on coexistence, dispersal, effects of community structure on ecosystem functioning or ex situ conservation. These results also hold particular relevance for studying the impacts of climate change even in early life stages, shedding light on how competitive interactions among species can shape their thermal responses and ultimately influence their adaptation.

### S.224.4 Nutrient ecology of lithophytic ferns: responses to different substrates

Catalina Flores-Galván¹, Judith Márquez-Guzmán², Martín Mata-Rosas³, James E. Watkins Jr.⁴, Klaus Mehltreter¹

1 Red de Ecología Funcional, Instituto de Ecología, A.C., Xalapa, Veracruz, Mexico. 2 Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico. 3 Red de Manejo Biotecnológico de Recursos, Instituto de Ecología, A.C., Xalapa, Veracruz, Mexico. 4 Department of Biology, Colgate University, Hamilton, New York, USA

Many plants grow only on specific soil types. Ferns are no exception. In the family Pteridaceae, many fern species are limited to alkaline limestone or acidic volcanic soils. Although the reasons for soil specialization of plants have received some attention, our knowledge about the consequences of growing on alkaline or acidic substrates is poor. Consequently, we studied the distribution of 19 fern
<figure><img src="image_521.png" /></figure>

species on 37 sites and the mineral nutrient composition of the shallow soils as well as calcicole (limestone-loving) and calcifuge (limestone-avoiding) fern species in central Mexico, supposing that the former will have higher Ca and lower Al and P concentrations than the latter. All fern species, except the soil-indifferent *Myriopteris aurea*, were restricted to one soil type. As expected, calcicole fern species had higher nutrient contents except for P and Mn, but surprisingly they also contained higher amounts of Al and Fe. This was even more surprising because limestone soils had only higher pH and Ca concentrations, but lower concentrations of exchangeable Fe and P. These results indicate that calcicole fern species possess limited or no mechanism to avoid the uptake of Al but are more efficient in absorbing Fe and P, even when those concentrations are lower than on acidic soils. On the other hand, calcifuge fern species can limit the uptake of Al but are not as efficient as calcicole fern species in absorbing Na, K, Mg, S, and N even if these nutrient elements are available at similar concentrations as on limestone soils. However, there is a considerable variation in the nutrient concentrations of each fern species, which implies that they also differ in their nutrient metabolism independently from the exchangeable nutrient concentrations of the soils.

### S.224.5 Haplopteris yakushimensis, a new model for fern independent gametophyte

Cheng-Wei Chen¹,², Katsuhiro Yoneoka³, Tao Fujiwara⁴, Atsushi Ebihara⁴, Van Truong Do⁵, Noriaki Murakami³, Yi-Shan Chao², Yao-Moan Huang⁶, Ko-Hsuan Chen¹, Kuo-Fang Chung¹

1 Academia Sinica, Taipei, Taiwan. 2 National Taiwan Normal University, Taipei, Taiwan. 3 Tokyo Metropolitan University, Tokyo, Japan. 4 National Museum of Nature and Science, Ibaraki, Japan. 5 Vietnam National Museum of Nature, Hanoi, Vietnam. 6 Taiwan Forestry Research Institute, Taipei, Taiwan

In the 1960s, two papers published in the journal Science fundamentally altered our understanding of fern gametophytes, giving the concept of 'independent gametophyte' a prominent place in the field of pteridology. Ferns and lycophytes (pteridophytes) stand out among land plants by having two independent

phases in their life cycles: gametophytes and sporophytes. Independent gametophytes refer to those long-lived gametophytic populations that extend beyond the geographic distribution of their sporophyte counterparts. Unlike typical cordiform (heart-shaped) gametophytes, independent gametophytes are non-cordiform and some of them can reproduce asexually through gemmae. In this study, we propose to investigate the origin of the independent gametophyte in a rare species *Haplopteris yakushimensis* utilizing an integrated approach including molecular biology, reproductive biology, and ecology. Genetic data reveal that the species comprises two diverged lineages (hereafter α and β) but their sporophytes are morphologically indistinguishable. The distribution of these two lineages is asymmetric, with the α lineage being endemic to Japan, while the β lineage is found in Japan, Taiwan, and Vietnam but persisting solely as independent gametophytes in Japan. This system, featuring two sister lineages with distinct reproductive behaviors (i.e., with and without independent gametophytes), offers a unique opportunity to explore the origins of independent gametophytes. Our preliminary data suggest a complex origin of *Haplopteris yakushimensis*, involving multiple hybridization and polyploidization events. Additionally, both environmental and genetic factors may play roles in shaping the current distribution of the independent gametophytes. Our study is poised to be the most comprehensive in the field and is expected to significantly advance our understanding of gametophyte ecology in general. Furthermore, it will also contribute to the conservation of *Haplopteris yakushimensis*.

### S.224.6 Insect herbivory and defense mechanisms in ferns

Rafael P. Farias¹, Lucas E.N. Costa², Klaus Mehltreter³

1 Universidade Federal da Bahia, Bahia, Brazil. 2 Instituto Tecnológico Vale, Pará, Brazil. 3 Instituto de Ecología, Xalapa, Mexico.

For ferns, an abundant component of tropical understories, knowledge about their insect interactions and defense mechanisms is still very limited. Consequently, the ecological and evolutionary drivers of herbivory, as well as the ecological role of ferns in these interactions are overlooked. Here, we investigated fern-insect interactions.
<figure><img src="image_522.png" /></figure>

teractions in three different ecosystems asking the fol-
lowing questions: 1. How do ferns structure their defense
mechanism (syndromes)? 2. Does the leaf damage
of ferns differ from angiosperms in mangroves? 3. Are
there herbivore effects on *Pteridium* after fire events?
Our sample included 34 species of ferns from the Atlan-
tic Forest, *Acrostichum aureum* L. (and two angiosperm
species) in the mangroves, and *Pteridium* in burnt iron-
stone campo rupestre. We measured some leaf traits
for our first (SLA, water content, trichome density, nitro-
gen, phosphorus, alkaloids, phenols, saponins, tannins
and triterpenoids) and second question (phenols). Leaf
damages were estimated by relative leaf area loss per
plant and species. All traits were correlated with each
other and compared with leaf damages. We identified
three different defense syndromes: (i) high nutritional

quality combined with a variable trichome density (14
species), (II) low nutritional quality, but high phenol con-
centrations, and often high trichome density (4), and
(III) intermediate nutritional quality combined with a
low trichome density or no trichomes (16). Leaf dam-
ages ranged between 0 and 32.3% but did not differ
among defense syndromes. *Acrostichum aureum* had
lower phenol concentrations than the angiosperms
mangrove species but was damaged than *Rhizopho-
ra mangle*. Postfire resprouts of *Pteridium* were highly
damaged by herbivores (almost 75%). We conclude
that ferns combine a variety of defensive traits against
insects, with a similar resistance against insects, that
ferns can exhibit similar damages than angiosperms in
mangroves; and that *Pteridium* may constitute a cru-
cial resource for herbivores after fire events.

# S.225 FLORAL NECTAR: POLLINATION SYNDROMES, PRODUCTION ATTRIBUTES, REGULATION EVOLUTION. SESSION 1

S.225.1 Floral nectar: cost, regulation and partner manipulation

Zong-Xin Ren¹, Graham H. Pyke¹,²

1. Kunming Institute of Botany, China 2. Macquarie University, Australia

Floral nectar is central to most relationships between
plants and animal pollinators, and has been the sub-
ject of much investigation for a long time. However,
much about nectar remains poorly known and un-
derstood. We know, for example, costs of floral nectar
production to a plant are significant, however, rele-
vant evidence is scant and difficult to interpret. Also
unknown is the extent to which plant costs and gains
associated with nectar production can be expressed
in a single currency such as energy. There is also
growing evidence that plants can both secrete and
absorb nectar, possibly enabling them to regulate
nectar attributes in their flowers and thus manipu-
late pollinator behaviour to their advantage. In some
circumstances, floral nectar may also attract or re-
pulse potential pollinators by virtue of its attributes,
but such circumstances are likely rare. In this talk,
we present our new findings on cost, regulation and
partner manipulation based on the evidence from

multiple plant species pollinated by various animal
pollinators in Australia and China. By doing a series
of floral nectar removal, nectar reabsorption and ar-
tificial nectar addition experiments, we provide evi-
dence of simultaneous nectar secretion/ absorption
and consequent regulation for sugar volume, sugar
concentrations and sugar type. We also show that
some floral nectar attributes between neighbouring
flowers within an individual plant are correlated in
both bagged and open pollination treatments indi-
cating potential partner manipulation.

S.225.2 Color & chemistry:
how flowers signal reward
quality to pollinators

Casper van der Kooi¹, Kira Tiedge¹

1 Groningen University, Groningen, The Netherlands

The vast majority of flowering plants require animal
pollinators for sexual reproduction, and in turn, many
animal pollinators rely on floral rewards. Floral co-
lour and scent are the two main signals that plants
employ to attract potential pollinators. Our central
hypothesis is that flower colour and scent have co-
evolved with the sensory systems and preferences
of pollinators and that those signals convey reli-
<figure><img src="image_523.png" /></figure>

able ('honest') information about a flower's reward. To answer this question, we are trying to determine how flower signals and rewards match pollinator visual systems, ecology, and resource requirements among many independent transitions between pollinators with widely different visual systems, olfactory preferences and/or nutritional requirements. We are collecting and integrating data from a) (micro-) spectroscopy, anatomy, and state-of-the-art optical models to quantitatively understand how floral structure and pigmentation generate visual signals, b) volatile metabolomics to capture and analyse floral scents and c) semi-targeted metabolite profiling to study the nutritional properties of nectar (and pollen). This comparative approach enables identifying how the colour and scent of flowers and the nutritional properties of nectar (and pollen) have co-evolved at a broad taxonomic scale. How plant-pollinator interactions have evolved and shaped biodiversity is a fundamental question in biology and has direct implications for agriculture and species conservation.

### S.225.3 Nitrogen at night: do volatile aldoximes serve as index signals of nectar amino acids to hawkmoth pollinators?

Geoffrey T. Broadhead¹,², Robert A. Raguso¹

¹Cornell University, Ithaca, USA. ²University of Florida, Gainesville, USA

Hawkmoths are important pollinators worldwide, whose powerful dispersal flights can promote gene flow between geographically distant plant populations. That same flight capacity generates high energetic demands, and hawkmoths are known to maximize caloric intake in the face of thermal, osmoregulatory and biophysical constraints. Thus, hawkmoth-pollinated flowers tend to secrete copious quantities of relatively dilute (15-30%) sugar solutions at anthesis, just as they emit strong fragrances known to attract hawkmoths from a distance. One surprising feature of such fragrances is the presence of nitrogenous aldoximes, volatile compounds derived from essential amino acids (LEU, ILE, VAL, and PHE). Aldoximes are uncommon fragrance components in day-blooming plants and are better known for their roles in the indirect de-

fenses of wounded poplar foliage, or as precursors to direct defenses such as mustard oils and cyano-genic glycosides. Nevertheless, they have evolved in dozens of angiosperm families with night-blooming flowers, from Darwin's star orchid to jasmines and gingers. Given that aldoximes are derived from amino acid precursors, we explored their potential to function as volatile "index signals" – unfakeable indicators – of the presence of amino acids in nectar, using the night-blooming flowers of *Oenothera flava* and *Datura discolor* as model systems. First, we tested whether volatile aldoximes are correlated with nectar amino acids, either naturally or under soil fertilizer manipulation, using GC-MS and HPLC, respectively. Next, we designed behavioral assays to test whether flower-naïve hawkmoths (*Hyles lineata*) are attracted to aldoximes derived from LEU and ILE in a nectar-feeding context. Finally, we used behavioral assays to test whether hawkmoths prefer nectars with amino acids, and whether such fortified nectars provide additional fitness benefits to the moths. Our findings suggest an important role for N metabolism as a non-caloric component of floral advertisement and reward in "moonflowers" pollinated by hawkmoths.

### S.225.4 Honesty of floral signaling is dependent on neighborhood kinship

Rubén Torices¹, Inés Álvarez²; Lucía DeSoto³; Camilo Ferrón¹; Yedra García¹⁴; Luis Giménez-Benavides¹; José María Gómez⁵; Javier Jiménez-López¹; Eduardo Narbona⁶; John Richard Pannell⁷; Cristina Poyatos¹; Luis G. Quintanilla¹; Violeta Quiroga¹,⁵,⁸

¹University Rey Juan Carlos, Móstoles, Spain. ²Real Jardín Botánico de Madrid, Consejo Superior de Investigaciones Científicas, Madrid, Spain. ³Universidad Complutense de Madrid, Madrid, Spain. ⁴Lund University, Lund, Sweden. ⁵Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones Científicas, CSIC), Almería, Spain. ⁶Universidad Pablo de Olavide, Seville, Spain. ⁷University of Lausanne, Lausanne, Switzerland. ⁸Universidad de Granada, Granada, Spain

Although pollinators have innate preferences for specific floral signals such as petal color, they can quickly adapt their preferences by associative learning, based on the quality and quantity of rewards (e.g., nectar) provided to them. In this sense, we might expect the local intraspecific neighborhood
<figure><img src="image_524.png" /></figure>

to have important consequences for an individu-
al plant's optimal strategy of both display and re-
ward. Cohen and Shmida (1993) modelled the as-
sociation between floral advertisement and reward,
with specific attention to flower density. Their model
predicts that allocation to signaling traits should be
increased when flower density is low, thereby facili-
tating visibility, whereas allocation to reward should
be favored under conditions of high flower density or
low visitation rate, thereby capitalizing on favorable
pollinator choice. However, to our knowledge, we still
lack formal theoretical foundations for predicting the
potential kinship effects on the relationship between
floral signaling and reward. In our study, we experi-
mentally examined how neighboring kinship affects
the relationship between floral signaling and reward.
We found that the genetic relatedness of neighbors
significantly altered the relationship between floral
color and reward quantity. Specifically, plants grow-
ing with non-kin exhibited a positive relationship be-
tween petal color and nectar production. However,
this relationship became negative when plants had
no neighbors or when their neighbors were kin. The
observed plastic sensitivity to neighborhood compo-
sition in the honesty of floral signals might have im-
portant effects on pollinator behavior and visitation,
with direct and indirect effects on plant reproductive
success and mating patterns.

S.225.5 Anatomical,
ecological, and evolutionary
trends of nectary and nectar
traits in Acanthaceae

Leonardo Galetto¹, Carolina Torres¹

1 Departamento de Diversidad Biológica y Ecología, Universidad Nacional de Córdoba and CONICET, Argentina.

Pollinators are linked with plant reproduction and
with evolutionary diversification of some clades
of angiosperms. Modifications in floral form and
function can suggest the best match with differ-
ent pollinator functional groups implying a positive
interaction in reproductive terms. Acanthaceae in-
cludes species with diverse floral sizes, shapes and
colours that are visited by different pollinators. Pre-
vious studies analyzing different floral shapes (floral
syndromes) and nectar in Acanthaceae indicated
stronger relationships with floral shapes and nec-
tar sugar composition or concentration rather than
with phylogenetic trends. Nevertheless, some ana-

tomical nectary particularities may restrict the ex-
pression of nectar traits in some groups (clades or
genera) although the occurrence of floral form di-
versification within them. Moreover, nectar secretion
patterns may be related with the preferences and
needs of different pollinator groups. Thus, the vari-
ations in nectary and nectar traits in Acanthaceae
may be shaped by a combination of the preferenc-
es of the main plant-pollinator interactions (func-
tional or ecological) and/or by the basic anatomy
and developmental constraints (phylogenetical) of
the flower present in some clades or genus within
this family. In consequence, complex trends be-
tween nectar and nectary traits could be analyzed
using the hypothesis of pollination syndromes but
also considering the most accepted hypothetical
phylogeny of the family. If nectar and nectary traits
are linked with pollinator preferences, associations
between floral traits and different groups of polli-
nators will be stronger than the evolutionary trends
within different clades. Species from major clades of
Acanthaceae are used to test this hypothesis and
predictions. Original data for anatomical features
and nectar traits > 20 species distributed among
different phylogenetic clades were analyzed. More-
over, a data set from the literature of nectar traits for
>100 species were obtained to present a better pic-
ture for the family linking developmental, ecological,
and evolutionary trends.

S.225.6 Nectar sugar concentration, foraging currencies and floral preferences in bumblebees

Jonathan G. Pattrick¹

1 University of Oxford, UK

One way in which nectar sugar concentration can
contribute to partitioning of pollinator floral prefer-
ences is through between-species differences in
how viscosity influences rates of nectar transport.
However, preferred nectar sugar concentrations
may also vary between species depending on the
strategy, or 'currency' through which pollinators are
optimising their foraging. Here I discuss our recent
work in bumblebees investigating both of these
factors. Firstly, we investigated how nectar viscos-
ity influences multiple aspects of nectar transport.
Secondly, to explore the energetics of foraging, we
used a lab-based assay using a biomechanical for-
aging challenge to test if bumblebees can make a
<figure><img src="image_525.png" /></figure>

trade-off between nectar valence and the time/energy expended obtaining it. Bee foraging behaviour in this paradigm was in agreement with maximisation of the currency of net rate, but not in agreement with maximisation of the currency of energy

efficiency. Given this currency differs from reported results in honeybees, we consider the implications for expected floral preferences between these two important generalist pollinators.

# S.226 ECOLOGICAL DRIVERS OF PALM SPECIATION

## S.226.1 Can plant-fungal symbioses underpin plant diversity?

Vincent Savolainen¹, Kyle Macleod¹, Martin Bidartondo¹, Colin Turnbull¹, Roger Butlin², Ian Sanders³, Ian Hutton⁴

1 Imperial College London, London, UK. 2 University of Sheffield, Sheffield, UK. 3 University of Lausanne, Lausanne, Switzerland. 4 Lord Howe Island Museum, Lord Howe Island, Australia

Our understanding of how species originate (speciation) has changed considerably since Darwin's seminal work. One aspect, however, that has been ignored is the role that microbes can play in driving speciation. Here, we propose a new mechanism for the origin of species, whereby coevolutionary divergence in plant-mycorrhizal associations increases local adaptation and leads to the completion of speciation, using one of the most compelling examples of speciation in the face of gene flow as our model system: The *Howea* palms of Lord Howe Island. While it is well known that species can diverge due to geographic barriers such as mountain ridges or oceans, populations can also split in the face of gene flow without geographic isolation, for example through specialisation to habitats or resources. In this context, symbiotic associations that plants have with microbes may be particularly powerful in simultaneously facilitating local adaptation and reproductive isolation leading to speciation. We focus on two sister species of palms (*Howea*), endemic to Lord Howe Island, a remote island in the Tasman sea, and their interactions with arbuscular mycorrhizal fungi. *Howea* palms represent the dominant vegetation on the island. The speciation scenario for *Howea* involves adaptation to different soils, volcanic rocks and calcareous deposits, and associated fitness trade-offs. We hypothesise that soil and soil

microbes have affected local adaptation of the ancestral palm population, which in turn led to differences in flowering time, and ultimately promoted speciation. Differing levels of mycorrhizal colonisation and gene expression co-regulated in *Howea* and mycorrhizal associations may have led to the emergence of distinct forms of *Howea* populations occupying different soils. We test these key hypotheses using metagenomics and RNA-seq combined with long-term field experiments on Lord Howe Island.

## S.226.2 Climatic-based diversification of a hyperdominant species complex in Western Amazonia and endangered species in the Central Andes

Julissa Roncal¹, Marinoli Rivas-Chamorro², Víctor Jiménez-Vasquez², Betty Millán², Nicolas Peñafiel Loaiza¹, Nora H. Oleas³, Monica Moraes⁴

1 Memorial University of Newfoundland, St. John's, Canada. 2 Universidad Nacional Mayor de San Marcos, Lima, Peru. 3 Universidad Tecnológica Indoamérica, Quito, Ecuador. 4 Universidad Mayor de San Andrés, La Paz, Bolivia

Landscape reconfigurations in South America have influenced the evolution of tropical plants by triggering diversification through niche partitioning, by facilitating dispersal, or separating ancestral populations. However, the genetic characterization of intraspecific entities or species delimitation remains a primary objective to which we can link the ecological factors that influence their evolution. Using several sequencing technologies and marker types, we
<figure><img src="image_526.png" /></figure>

assess the genetic variation within two palm lineages growing in two biomes, Amazonia and the Andes; and link the resulting genetic entities to putative environmental conditions that may be acting as selection. *Astrocaryum* section *Huicungo* is a complex of 15 morphologically defined species, the majority of which grow in western Amazonia. We found evidence of cytonuclear discordance where the two major lineages recovered in phylogenetic analyses almost matched. A Bayesian species delimitation test rendered three putative species occupying areas of contrasting geological activity. Preliminary ecological niche modeling show that putative species have different niches characterized by elevation and precipitation seasonality. The case of the Andean palm genus *Parajubaea* is similar in that we found genetic groups occupying different elevations, habitats and geological substrates. The delimitation of two morphologically defined, endemic, IUCN endangered species in Bolivia was challenged by our sequencing data that favored the recognition of three intraspecific genetic groups. Genetic groups showed admixture, no evidence of inbreeding, and we use them to propose management units for conservation. Many palm lineages, especially widespread species complexes, still await an assessment of intraspecific variation or a reconsideration of species limits combined with fine scale niche analyses. High throughput sequencing provides an unparalleled opportunity to unmask genetic differences, which is needed to improve our knowledge of ecological speciation in palms at higher resolutions.

## S.226.3 Advances in the study of population dynamics of transposable elements and application to date palm genomics

Yann Bourgeois¹

1 Institut de Recherche pour le Développement, Montpellier, France

Quantifying the factors that drive the accumulation of genetic variation in genomes is essential to understand the rules of life and has widespread applications in agronomy and conservation. However, our understanding of the determinants of genetic diversity is still strongly biased towards the study of point mutations such as single nucleotide polymorphisms (SNPs). More must be done to understand

the evolutionary dynamics of structural variation. A common type of such variation includes transposable elements (TEs). These elements are among the most variable genomic features across the living world and can have a dramatic effect on their host's fitness. In this presentation, I introduce some of the most recent advances in our understanding of TEs, adopting a population genetics perspective. I show how combining information about TEs and flank-ing SNPs may help addressing key questions, such as the distribution of TEs fitness effects. I illustrate the interest of such approaches by applying some of these methods to the date palm (*Phoenix dactylifera*), a keystone species of oasis agrosystems particularly adapted to arid environments, in which recently active TEs account for ~3% of the ~850Mb genome, making them promising candidates to study the bases of (mal)adaptation.

## S.226.4 Evolutionary dynamics of central African rain forest plants reveal contrasting responses to past climatic fluctuations

Thomas L.P. Couvreur¹ Andrew J. Helmstetter¹ Kevin Bethune¹ Narcisse G. Kamdem² Bonaventure Sonké²

1 Institut de Recherche pour le Développement, UMR-DIADE, BP 64501, F-34394, Montpellier, France. 2 Université de Yaoundé I, Ecole Normale Supérieure, Département des Sciences Biologiques, Laboratoire de Botanique systématique et d'Ecologie, Yaoundé, Cameroon

Central African rain forests are mega diverse and harbor the world's second largest expanse of this biome. Yet, how plant species have adapted to past climate change remains understudied. Palms might not be that diverse in this region, but they are nevertheless omnipresent. Here, we infer the evolutionary and demographic dynamics of three co-distributed palm species using comparative phylogeography based on hundreds of nuclear markers. In addition, we contrast our results with four tree species of Annonaceae, an equally important component on rain forests in Africa. For all species we estimated population variation and the temporal origin of this structure using dated phylogenetic trees. Finally, we explicitly tested how different environmental factors such as soil, climate stability and geography have shaped intraspecific genetic variation in each
<figure><img src="image_527.png" /></figure>

of our species. Levels of genetic variation varied among palms and Annonaceae, all showing some level of structure. Divergence between populations emerged primarily during the Pleistocene but were rarely concordant. Demographic trends ranged from repeated contraction and expansion to continuous growth. Furthermore, patterns in genetic variation were linked to disparate environmental factors, including climate, soil, and habitat stability. Using a strict refugia model to explain past TRF dynamics in central Africa is too simplistic. Instead, individualistic evolutionary responses to Pleistocene climatic fluctuations have shaped patterns in genetic diversity in central African rain forests. Overall, our results suggest that predicting the evolutionary responses of TRF plant diversity under climate change will be challenging. More emphasis is needed on individual species ecology if conservation of this incredible diversity is to be effective.

**S.226.5 The geography of speciation in palms and pines**

Ingrid Olivares¹, Søren Faurby², Rodrigo Cámara-Leret¹, Alex Pigot³

1 Department of Systematic and Evolutionary Botany, University of Zurich, Switzerland. 2 Department of Biological & Environmental Sciences, University of Gothenburg, Sweden. 3 Centre for Biodiversity

and Environment Research, University College London, UK

Linking phylogenies to the geographical distribution of a lineage allows inferring the geographical mode of speciation. Here, we used the geographical distribution of sister species and their estimated divergence times to infer if there is a predominant mode of geographical speciation (allopatry or sympatry) in two diverse groups of plants from tropical (palms) and temperate regions (pines). We selected two approaches previously used to infer the mode of speciation in vertebrates: 1) the proportion of sister species showing zero and complete range overlap, and 2) a modelling framework that calculates the probability that a sister species pair exists in its current geographical state (i.e., allopatry or sympatry). In contrast to birds, for which the first indicator shows that sympatric speciation accounts for only 5% of speciation events, our results hint towards a greater role of sympatric speciation (ca. 30-45%) in palms and pines. We further find that palms and pines can diverge through either allopatry or sympatry and undergo reverse transitions back to the initial state. In contrast, previous studies showed that the best suited model for primates, amphibians, and birds is one in which species diverge exclusively in allopatry and then undergo an irreversible transition to sympatry. Our work therefore suggests that the sympatric speciation of *Howea* palms might not be an exceptional case, but rather, that sympatric speciation might be an important mode of plant speciation in palms and other plant families.

**S.227 THE JOURNAL OF PLANT RESEARCH'S SYMPOSIUM ON BIOTIC INTERACTIONS AND BIOLOGICAL INVASION. SESSION 1**

**S.227.1 Below- and above-ground mutualisms slows invasion success of alien brooms (Fabaceae) in South Africa**

Geerts, S.¹, Le Roux, J.J.²

1 Department of Conservation and Marine Sciences, Cape Peninsula University of Technology, PO Box 652, Cape Town, South Africa. 2 Department of

Biological Sciences, Macquarie University, Sydney, New South Wales, Australia

Mutualisms are thought to be important in the invasion dynamics of alien plant species. There is no guarantee that plants will encounter suitable mutualistic partners in a novel environment. When a mutualistic partner is co-introduced, or is a generalist and easily co-opts mutualists, invasion is more probable. If plants are more specialized in their mutualistic requirements or require multiple mutualistic partners, invasion might be curbed. Most studies consider only one type of mutualistic relationship,
<figure><img src="image_528.png" /></figure>

but many plant species typically interact with multiple types of mutualists. Therefore, in this study we explore the interactions between two non-native legumes (Genista monspessulana and Spartium junceum) and their associated below-ground (nitrogen-fixing rhizobia) and above-ground (pollinators) mutualists. We conducted pollinator observations, breeding system experiments and collected root nodules for 16S rRNA gene amplification. Both G. monspessulana and S. junceum are dependent on pollinators for seed production but are successfully pollinated in South Africa. Genista monspessulana is pollinated largely by honeybees and carpenter bees whilst the bigger flowers off S. junceum are only pollinated by carpenter bees. Differences in rhizobium associations (nodulation) were much more pronounced. We found G. monspessulana populations to be nodulated by at least four distinct lineages of Bradyrhizobium, while for S. junceum this was much less. The wider distribution of S. junceum compared to G. monspessulana likely reflects the differences in propagule pressure (S. junceum was a popular garden plant). The inability to nodulate, and relative low rates of pollination of S. junceum, suggest it currently poses a much lower risk than G. monspessulana in becoming a widespread invasive species in South Africa.

X. strumarium. Herbaria play a crucial role in botany as they offer a wealth of untapped knowledge and a portal into plants' historical past. The potential invasion paths of X. orientale subsp. italicum were traced using geographic profiling techniques and phylogenomic analyses of herbarium specimens. Moreover, the potential effect of allelopathy and competition for the decline of the native X. strumarium were studied through garden experiments. Geographic profiling is a technique initially developed in criminology, and then also applied for imputing biological invasion routes. The inferred spreading point for X. orientale subsp. italicum was the area close to Pavia or Monzambano. Phylogenetic analyses were conducted on nuclear and chloroplast data using network and ML tree approaches, suggesting a possible area of origin in Texas (US), around the town of Greenville. To test allelopathic effect of X. orientale on X. strumarium, we compared germination and growth of seedlings under treatment (watered with X. orientale exudates) and control conditions. The presence of a significant effect has been observed on the growth of the two species. Concerning the competition experiments, we used dried biomass, number of burs and bur biomass as measure of fitness, showing a significant effect of the interspecific competition on X. strumarium.

### S.227.2 The invasion of X. orientale in Europe and its effect on the native X. strumarium reconstructed on herbarium specimens and garden experiments

Eleonora Manzo¹, Anna-Lena Köster¹, Lina-Marie Deussig¹, Franka Neiß¹, Alessio Papini², Salvatore Tomasello¹

1 Georg-August University Göttingen, Germany. 2 Università degli studi di Firenze, Firenze, Italy

Xanthium orientale, an American species complex presently disseminated across the whole world, was first introduced in Europe via natural fiber trading, as the fruits stick easily to fibers owing to their peculiar spiny diaspores. Various lineages can presently be found in the continent, with X. orientale subsp. italicum being the first to have been observed in the wild around 1820. The presence of X. orientale in Europe has been hypothesized as a contributing factor to the contemporary decline of its indigenous relative,

### S.227.3 Brachypodium distachyon complex associated soil microbial differences across the native and invaded ranges

Emma Aronson¹, Jon Botthoff¹, Pilar Catalán²

1 University of California, Riverside, CA, USA. 2 Universidad de Zaragoza, Spain

In the last few decades, Brachypodium distachyon has emerged as a model grass to study fundamental topics in plant biology, including seed development, genomics, plant-pathogen interactions, and root architecture. This temperate grass is closely related to important biofuel crops, such as sorghum and switchgrass. Another research advantage of B. distachyon is that there are wild, naturally occurring isolates in its broad native circum-Mediterranean range. Not only are the species of the B. distachyon complex found across the native range, but they have been introduced to the US, Australia, China,
<figure><img src="image_529.png" /></figure>

South Africa and South America, and are invasive in some of these areas, notably Southern California. Although there has been a number of recent research articles on the genomic architecture and microbiome of *Brachypodium* species, there remains a dearth of information on associated rhizosphere microorganisms. In order to better understand the microbial associations of the *B. distachyon* complex, we sampled root, rhizosphere, and bulk microbiomes of *B. distachyon* and *hybridum* across their native and invaded ranges, including 4 countries across Mediterranean Europe, as well as *B. hybridum* from California in the United States. Here we describe the variability in the wild microbiome of this important grass. *Brachypodium hybridum* is a rampant invasive grass across coastal California, and a contributor to fire danger and severity. This data may help us to better understand the invasive qualities of this grass, and potentially could lead to mitigation strategies, which may improve fire conditions in California. Further, we hope that generating model grass microbiome data will contribute to a growing global scientific community working on cereal and biofuels crop genetics, and beyond.

## S.227.4 When roses go rogue: Expanding ranges of invasive Rosaceae in South Africa

Sandy-Lynn Steenhuisen¹, Grant D. Martin¹,²,
Karabo T. Moloi¹, Lehlohonolo D. Adams³,
Stephanie L. Payne¹, Onalenna Gwate¹,
Patricia Masole¹, Lesego Malekana¹, Colleen
Downs³, Vincent R. Clark¹

1 Afromontane Research Unit, University of the Free State, Phuthaditjhaba, South Africa. 2 Centre for Biological Control, Rhodes University, Makhanda, South Africa. 3 South African National Biodiversity Institute and Centre for Functional Biodiversity, University of KwaZulu-Natal, Pietermaritzburg, South Africa

Invasive fleshy-fruited Rosaceae are becoming problematic in the grasslands and mountains of South Africa, where they can have severe impacts. Here we review current and ongoing research into the expansion of these species. Plant reproductive ecology experiments have been conducted on a number of the most problematic invasive Rosaceae species. These have included determining seed production, soil seed banks, aviary feeding experiments with frugivorous birds, camera trapping and observations to determine frugivores in the field, and faecal seed counts.

To determine altitude and climate impacts on their survival and growth, Rosaceae species were translocated and planted in both natural vegetation and in open top chambers at low and high-altitude sites to represent future climate warming scenarios. Results show that these species produce millions of seeds/m² invasion, which are long-lived in the soil. Fruits are eaten and dispersed by animals and different Rosaceae species appear dependent on different guilds of frugivores. Larger bird species, eland and baboons were highlighted as potential long-distance dispersers. Transplant experiments show that these species are able to survive at high altitudes up to 3100 masl and future climates may favour their spread into mountain ecosystems. These invasive Rosaceae species possess several reproductive traits that make them formidable invaders and difficult to manage. More study is needed to understand all factors involved in exacerbating spread in warmer climate scenarios as climate change experiments suggest the entire altitudinal range of the Drakensberg Mountain system is suitable for the establishment of these invasive Rosaceae.

## S.227.5 Plant defense against herbivores of native and non-native populations of Datura stramonium

Juan Núñez-Farfán¹, Juan Arroyo²

1 Instituto de Ecología, Universidad Nacional Autónoma de México, México. 2 Departmento de Biología Vegetal y Ecología, Universidad de Sevilla, España.

Datura stramonium has successfully established in many regions worldwide from its native range in America. Historical accounts indicated that it was introduced to Europe (Spain) after the conquest of Mexico. In the introduced range *D. stramonium* lacks the biotic interactions maintained in its native range opening the opportunity to further evolution. Here, we present field and experimental evidence on changes in plant defense hypothetically promoted by the difference in specialist herbivores between ranges. Results indicate that damage exerted by specialist and generalist herbivores on native and non-native plants differ; specialist herbivores preferred the native plants. There are differences between populations, of both ranges, in resistance to herbivores. The tropane alkaloid scopolamine has a higher concentration on a native population whereas the alkaloid atropine is higher in a non-native population.