system functioning under climate change due to
niche complementarity between species. Mixing
species with different leaf habit can increase car-
bon and nutrient stocks in forest soils. However, the
effect of admixture on tree nutritional status has
been less explored. In this study, we compared the
foliar nutrient status of Pinus sylvestris and Quer-
cus pyrenaica in mixed and monospecific stands
in Mediterranean mountains. Our results showed
interspecific differences in foliar nutrient concen-
tration. Pines showed higher C concentrations
while oaks had higher P concentrations in leaves,

which resulted in higher C:N and N:P in pines. De-
spite no significant differences were found in the
nutritional status of study species between mixed
and monospecific stands, we found an improve-
ment in the nutritional status of the trees of both
species in mixed stands as the proportion of basal
area of the other species increased in the vicini-
ty. These results show that complementarity be-
tween these two species occurs at the local scale,
which has practical implications for the design of
forest management actions aimed at diversifying
monospecific stands.

**S.183 FERN AND LYCOPHYTE EVOLUTION: A**
**PHYLOGENOMIC PERSPECTIVE. SESSION 1**

S.183.1 Phylogenomic
data reveal the complex
evolutionary history
of Neotropical
Phlegmariurus
(Lycopodiaceae)

Weston L. Testo¹

1Department of Plant Biology, University of Vermont, Burlington, USA. 2 Pringle Herbarium, University of Vermont, Burlington, USA. 3 Botanical Research Institute of Texas, Fort Worth, USA

The clubmosses (Lycopodiaceae) are one of three extant families of lycophytes, which hold an important phylogenetic position as sister to the remaining vascular plant lineages. An ancient lineage, the Lycopodiaceae is comprised of an estimated 400 species distributed in 17 genera and presents a cosmopolitan distribution, though species richness is highest in the tropics. The most species-rich lineage of Lycopodiaceae by far is the genus *Phlegmariurus*, which includes at least 300 species that are distributed throughout tropical and subtropical regions of the world. A handful of studies have attempted to reconstruct the evolutionary history of this clade and revealed that it has been shaped by complex biogeographic scenarios and recent rapid diversification, but these studies relied on sequence data from a handful of chloroplast loci and thus were limited in the conclusions they could draw. In this talk, I present a

new perspective on the evolution of *Phlegmariurus*
in the American tropics, based on target-capture
sequence data from hundreds of nuclear loci.
These data reveal previously undetected bioge-
graphic patterns, provide evidence for reticulate
evolution, and illustrate the evolutionary success
of *Phlegmariurus* in tropical America, from lowland
rainforests to alpine grasslands.

S.183.2 The genomic
landscape of ferns and
lycophytes

Fay-Wei Li¹,²

1 Boyce Thompson Institute, Ithaca, New York, USA. 2 Plant Biology Section, Cornell University, Ithaca, New York, USA

Cracking the giant genomes of pteridophytes
had been seemed as a formidable challenge.
However, thanks to the rapid drop of sequenc-
ing cost and the development of highly accurate
long-read sequencing, we now have around a
dozen pteridophyte genomes already published
with many more in the pipeline. Here, I summarize
the current state of pteridophyte genomics and
synthesize the trends emerging from compara-
tive analyses. I particularly highlight the genomic
contrasts between homosporous and heterospo-
rous lineages, and discuss the implications on the
evolution of chromosome number and genome
size. Lastly, I point out future directions and areas
worth exploring further.
<figure><img src="image_424.png" /></figure>

### S.183.3 First genomic evidence of hybrid evolution in Phlegmariurus

Ashley Field¹, Weston Testo², Thais Almeida³, Lars Nauheimer¹

1Australian Tropical Herbarium, Cairns, Queensland, Australia. 2 Pringle Herbarium, The University of Vermont, Burlington, Vermont, USA. 3 Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil

Phlegmariurus (Huperzioideae, Lycopodiaceae) is a worldwide genus of 200 to 300 species comprised of a Neotropical radiation predominantly associated with mountain chains, and a Palaeotropical radiation predominantly associated with the canopies of rainforests. Our understanding of evolutionary radiation and species diversity in the Palaeotropical clade has remained a frontier due to the unresolved nature of species-level phylogenies, extreme homoplasy, and morphological intermediates between distant species. We present the first species-resolved phylogeny for Palaeotropical Phlegmariurus based on a comprehensive HybSeq dataset of 236 collections. We provide evidence that Palaeotropical Phlegmariurus comprises 13 major clades, each with morphological, ecological or geographic specialisation. Using the bioinformatics workflow HybPhaser, we present the first molecular evidence for hybrids in Phlegmariurus. Phlegmariurus of hybrid origin are common. We identify seventeen Phlegmariurus that are of hybrid origin, including five already described species and 12 that are newly identified, as well as evidence of hybrid species complexes. We postulate that, in addition to the long-distance dispersal, vicariance and habitat-driven diversification pathways previously identified, hybridisation has been an important species diversification pathway in Phlegmariurus.

### S.183.4 Rampant hybridization in a tropical fern genus (Danaea, Marattiaceae)

Venni Keskiniva¹, Samuli Lehtonen¹, Weston Testo², Hanna Tuomisto¹,³

1 University of Turku, Turku, Finland. 2 University of Vermont, Burlington, USA. 3 Aarhus University, Aarhus, Denmark

The amount of known hybrids has been observed to be lower in tropical than temperate ferns, but patterns of

hybridization are poorly known in the tropics. We examined hybridization in the Neotropical eusporangiate fern genus Danaea (Marattiaceae) using a phylogenomic approach with single or low-copy nuclear and chloroplast loci. We found a relatively high rate of hybridization in Danaea and suggest that the apparent paucity of hybrids in tropical ferns is due to an observation bias. We also show evidence that hybridization can function as both a diversifying and a homogenizing evolutionary force within the same genus. We found further evidence for the previously proposed low reproductive barriers in ferns, enabling hybridization between lineages separated possibly as far back as the Cretaceous.

### S.183.5 Population genomics of Woodwardia radicans (Blechnaceae) in northern Iberian Peninsula

Guillermo Santos Rivilla¹, Mario Mairal¹, Cornelia Krause², Sonia Molino de Miguel¹,³, Anita Roth-Nebelsick², Mike Thiv², Mario Fernández-Mazuecos⁴

1 Universidad Complutense de Madrid, Madrid, Spain. 2 Natural History Museum Stuttgart, Stuttgart, Germany. 3 Universidad Europea de Madrid, Spain. 4 Universidad Autónoma de Madrid, Madrid, Spain

Climatic refugia, deemed as natural laboratories for investigating species' responses to historical climatic shifts, offer valuable perspectives into the evolutionary dynamics of floras. The Palaeotropical flora, originating in the northern hemisphere during pre-Quaternary times, is believed to have endured in microclimatic subtropical zones across Europe and the Macaronesian islands. This research focuses on Woodwardia radicans (Blechnaceae), a fern historically recognized as a Palaeotropical relict, thriving in the Macaronesian archipelagos and southern Europe, particularly the northern Iberian Peninsula. Employing the genotyping by sequencing (GBS) technique, we scrutinized the genetic and phylogeographic patterns of northern Iberian populations and estimated times of lineage divergence. Despite the species having diverged from its sister, W. unigemmata, around the Pliocene, European populations diverged in the Quaternary, challenging the presumed pre-Quaternary relict status of these continental populations. Population-level analyses of the northern Iberian Peninsula reveal low genetic diversity and noteworthy differentiation among populations. Our findings challenge the assumed
<figure><img src="image_425.png" /></figure>

pre-Quaternary relict status of continental popula-
tions, indicating a Quaternary recolonization from
Macaronesia. The absence of a distinct phylogeo-
graphical pattern in the northern Iberian Peninsu-
la is attributed to fragmentation and genetic drift,
signaling a departure from a more widespread dis-
tribution range in the late Quaternary. Beyond illu-
minating the biogeographic history of this unique

species, our results yield crucial insights for defin-
ing conservation strategies. The study underscores
the imperative to reassess assumptions about the
historical persistence of Palaeotropical species in
subtropical environments and emphasizes the sig-
nificance of considering late Quaternary dynamics
in comprehending current genetic and phylogeo-
graphic patterns.

S.184 PLANT ECOLOGY – HOW AND WHY
GENOME SIZE MATTERS

S.184.1 Ecological
implications of the effects
of genome size evolution
on trait flexibility &
diversification in a tropical
plant family

Streetama Bhadra¹,², Ilia J. Leitch³, Sidonie Bellot³, William J. Baker³, Renske E. Onstein⁴,¹,²

1 German Centre for Integrative Biodiversity Research, Halle-Jena-Leipzig, Evolution and Adaptation, Leipzig, Germany .2 Leipzig University, Leipzig, Germany. 3 Royal Botanic Gardens, Kew, Kew Green, Richmond, UK. 4 Naturalis Biodiversity Center, Leiden, The Netherlands

Survival of plants in their environment depends on their
ability to adapt and diversify. Genome size, due to its
biophysical effects, may influence evolution of func-
tional traits, and hence adaptation and diversification.
However, this has never been tested in a quantitative
macroevolutionary framework. Here we hypothesize
that genome size evolution plays a fundamental role
in influencing 'trait flexibility' (i.e., evolvability of traits
over macroevolutionary times), and hence diversifica-
tion rates. We predict that larger genomes will lead to
lower trait flexibility, while higher rates of genome size
evolution will positively influence trait flexibility of plant
lineages allowing for greater partitioning of ecological
space, leading to speciation, and hence diversification.
To address this hypothesis, we integrated genome
size, functional trait, and phylogenetic data for palms
(Arecaceae) - a pantropical plant family comprising
c. 2600 species that express wide functional diver-
sity. Using macroevolutionary and structural equation

models we show that diversification rates of palms in-
creased ca. 20 Mya, concordant with increased rates
of genome size and trait evolution. Furthermore, rate
of genome size evolution was positively influenced by
genome size itself, contrary to the idea that large ge-
nomes constrain evolution. Finally, we found that high-
er rate of genome size evolution was associated with
greater trait flexibility (e.g., higher rates of fruit size, leaf
size, and stem height evolution). Overall, our findings
suggest that interactions between rates of genome
size and trait flexibility have played a role leading to
higher diversification rates in palms. Our results sug-
gest that genome size evolution acts as a key driver
of diversification in palms both directly, and indirect-
ly via its influence on trait evolution. This may explain
the complex interplay between genomic factors, traits
and diversification leading to some of the most enig-
matic evolutionary radiations across angiosperms
and the ecological success of certain plant lineages.

S.184.2 Fine-tuning plants to
the environment – a role for
genome size

Adam B. Roddy¹, Arezoo Dastpak¹, Kevin A. Simonin²

1 Institute of Environment, Department of Biologi-
cal Sciences, Florida International University, Miami,
USA. 2 Department of Biology, San Francisco State
University, San Francisco, USA

Genome size has been postulated as being a key trait
predictive of numerous anatomical, physiological, and
ecological traits in plants. While genome size correlates
with many organismal traits, the strongest relationship
has been with minimum (or meristematic) cell size
because a cell cannot be smaller than the volume of
<figure><img src="image_426.png" /></figure>

its nuclear envelope. Though mature cells are often orders of magnitude larger in volume than the minimum volume defined by the size of the genome, the maximum volume of stomatal guard cells—and possibly other cell types—is invariant across species. These patterns suggest that species with smaller genomes can produce not only smaller cells but also a greater range in mature cell size than species with larger genomes, i.e., smaller genomes may allow for greater plasticity to fine tune anatomy to the environment. Using intraspecific and interspecific data from various experiments and observations, we test the role of genome size in limiting trait plasticity. Our results highlight that while genome size may limit the range of cell sizes a plant can produce, there are multiple alternative ways of overcoming these limitations depending on the functional implications of these traits. Thus, partitioning the effects of genome size from higher-order architectural traits is important for understanding how abiotic conditions may select for leaf traits and, thus, on genome size and, similarly, the distributions of genome size across environmental gradients.

## S.184.3 Ecological and evolutionary processes acting on plant species dependant on their genome sizes

Andrew R. Leitch<fnref n="1" />, Marie Henniges<fnref n="1" />,<fnref n="2" />, Joseph Morton<fnref n="1" />,<fnref n="2" />,³, Lubna Faizullah<fnref n="1" />,<fnref n="2" />, Xiaotong (Elaine) Wang<fnref n="1" />,<fnref n="2" />, Jaume Pelicer<fnref n="2" />, Maite Guignard<fnref n="1" />,<fnref n="2" />, Erika Hersch-Green³, Ilia J. Leitch<fnref n="2" />

1 Queen Mary University of London, London, UK. 2 Royal Botanic Gardens, Kew, Surrey, UK. 3 Michigan Technological University, Houghton, Michigan, USA

The amount of DNA in each cell of an organism, called the 'genome size', varies enormously between species. Indeed, amongst flowering plants there is a known ~2,500 fold range in genome size (from 60,000 -160,000,000 bp per 1C genome). However, most plant species have smaller genomes than would be expected given the incidence of polyploidy and (retro) transposition in their ancestries, suggestive of evolutionary selection against large genome sizes. This talk first explores ecological selection acting on genome size, focussing in particular on nutrient limitation. We show from grassland nutrient experiments in UK, Germany, Inner Mongolia and from the Nutrient Network that species with large genomes are favoured in the presence of nitrogen and phosphate fertilizers, sug-

gestive of ecological selection against large genomes when they are limiting (as in most soils of the world). But it is unknown if such ecological selection translates to evolutionary selection against large genomes, because available data suggests that there are only small rates of DNA loss per generation (4–70 Mb/million years, <500 bp/generation). This poses a problem as to how evolutionary selection might act, given that the size of even the smallest plant genome is three orders of magnitude larger than these DNA losses. We propose that a solution to this problem might be that genome downsizing is an emergent property of polyploidy, which after time has ecological advantages to plants growing in nutrient poor habitats.

## S.184.4 How and why genome size constrains the global distribution of plants

František Zedek<fnref n="1" />, Tammy L. Elliott<fnref n="1" />,<fnref n="2" />, Pavel Veselý<fnref n="1" />, Petr Šmarda<fnref n="1" />, Félix Forest³, Ilia J. Leitch³, Eimear Nic Lughadha³, Marybel Soto Gomez³, Samuel Pironon³,⁴, Matilda J. M. Brown³, Jakub Šmerda<fnref n="1" />, Petr Bureš<fnref n="1" />

Angiosperms, spanning diverse habitats across continents, showcase substantial genome size variations, offering a prime platform to explore global genome size distribution hypotheses. Among these, the large-genome-constraint, mutational-hazard, polyploidy-mediated, and climate-mediated hypotheses stand central. We present the most extensive dataset to date, comprising 16,017 angiosperm species, representing over 5% of the known diversity. Leveraging this dataset alongside comprehensive geographic distribution data, we conducted an in-depth analysis of genome size distribution among angiosperms. Our findings reveal a correlation between small range sizes in angiosperms and larger genomes, supporting the large-genome-constraint hypothesis. Unlike the unimodal U-shape pattern in latitudinal distribution observed in polyploid proportions, we observed the S-shape with the increase in angiosperm genome sizes between the equator and 40-50°N/S and a decrease in genome sizes beyond 40-50°N northwards. Climate, especially

<footnote n="1">¹ Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic.</footnote>

<footnote n="2">² Department of Biological Sciences, University of Cape Town, Cape Town, South Africa. 3 Royal Botanic Gardens, Kew, Richmond, Surrey, UK. 4 UN Environment Programme World Conservation Monitoring Centre, Cambridge, Cambridgeshire, UK.</footnote>
<figure><img src="image_427.png" /></figure>

temperature, emerges as a dominant factor shaping genome size distribution along this global latitudinal gradient. Conversely, the influence of polyploidy frequency and growth form types appears negligible. Our comprehensive analysis underscores the significant role of climatically mediated non-adaptive processes, including purifying selection, genetic drift, relaxed selection, and environmental filtering, in sculpting the global distribution of angiosperm genome sizes.

**S.184.5 Genome size and cell size in mosses: the impact of DNA content on moss anatomy and physiology**

Pere M. Mir-Rosselló¹, Jaume Flexas¹, Antoni J. Far, Marc Carriquí¹

1 Universitat de les Illes Balears, Palma, Spain

The DNA content in the nucleus, commonly measured as genome size (GS), is considered a strong predictor of minimum cell size in eukaryotic organisms. In tracheophytes, the scaling between GS and cell size determines leaf anatomy and, consequently, plant growth capacity. However, the few studies involving bryophytes, which only considered stomatal guard cells of the diploid phase, suggest that GS-cell size scaling does not apply to this group. We measured leaf area, cell dimensions and cell wall thickness from mid-lamina, largest and smallest cells in phyllosidia of 160 moss species with known GS. From these, cell area and volume and different key anatomical traits determining photosynthesis were calculated. We contrasted cell sizes with GS data through Standardized Major Axis (SMA) analyses. GS weakly explained the variability of laminal and maximum cell sizes (width, area and volume), but explained more than half of the variability in minimum cell sizes. While GS positively correlated with moss phyllid area, it did not significantly explain cell wall thickness or other anatomical traits. Notably, SMA slopes for cell sizes were considerably steeper than those reported for tracheophytes. Furthermore, maximum to minimum volume ratios showed greater variability in species with smaller GS. Our findings suggest that GS is a determinant of the minimum cell size in mosses, resembling trends observed in tracheophytes. This similarity holds between tracheophyte sporophytes (diploid leaf and guard cells) and moss gametophytes (haphloid leaf cells), but not in moss sporophytes (diploid guard cells), implying a differential impact of GS based on cell and phase function. The relatively steeper SMA slopes and maximum to minimum volume ratios support the hypothesis that smaller GS (as seen in mosses) allow a greater cell size variability. Although not directly determining their physiology, GS could indirectly influence moss productivity and growth capacity by affecting phyllid area.

**S.184.6 Genome size is positively correlated with extinction risk in herbaceous angiosperms**

Marybel Soto Gomez¹, Matilda J. M. Brown¹, Samuel Pironon¹,², Pavel Veselý³, Petr Bureš³, Tammy L. Elliott³, František Zedek³, Jaume Pellicer¹,⁴, Félix Forest¹, Eimear Nic Lughadha¹, Ilia J. Leitch¹

1 Royal Botanic Gardens, Kew. Richmond, UK. 2 UN Environment Programme World Conservation Monitoring Centre, Cambridge, UK. 3 Masaryk University. Brno, Czech Republic. 4 Institut Botanic de Barcelona Barcelona, Spain

Angiosperms with large genomes experience nuclear-, cellular- and organism-level constraints that may limit their phenotypic plasticity and ecological niche. Therefore, we test the hypotheses that extinction risk is higher in large-genomed compared to small-genomed species, and that the effect of genome size on risk is mediated by life form, range size, and climatic zone. We combined an angiosperm-wide genome size dataset with the newly released World Checklist of Vascular Plants, the IUCN Red List of Threatened Species and a species-level angiosperm phylogeny to analyse the relationship between genome size and extinction risk across life forms, climates and range sizes using an evolutionary framework. We found that angiosperm genome size and extinction risk are linked directly, and indirectly via range size and climate. Across sampled angiosperms as a whole, genome size is positively correlated with extinction risk. Partitioned by life form, extinction risk increases with genome size in herbaceous species across climates, especially in single-country endemics. However, genome size and risk are not correlated in woody species. Genome size may serve as a proxy for difficult-to-measure parameters associated with resilience and vulnerability, especially in herbaceous angiosperms. Therefore, it merits further exploration as a useful genomic trait for understanding extinction risk and enhancing plant conservation efforts.
# S.185 BEYOND BIOGEOGRAPHY: ADAPTATION AND DIVERSIFICATION ACROSS THE INDO-PACIFIC

## S.185.1 From Refugium to Radiance: understanding Smilacaceae speciation in the Himalayas

Geetika Sukhramani¹, Joongku Lee², Ritesh K. Choudhary¹

1 Agharkar Research Institute, Pune, India. 2 Department of Forest and Environment Resources, Chungham National University, Daejeon, Korea

The Himalayan region, a biodiversity hotspot, has undergone significant geological and climatic changes over millions of years. Due to its unique ecological and evolutionary trajectory, the Smilacaceae family in the Himalayan refugium offers valuable insights into evolution and conservation priorities. The present study delves explicitly into how examining Himalayan Smilacaceae contributes to our comprehension of evolution, biogeography, and the impacts of climate change. The endemic nature of various Smilax taxa, such as S. elegans subsp. osmastonii, S. microphylla, S. quadrata, S. sailenii, S. turbans in the Himalayan refugium, along with their probable isolated evolutionary paths evident from the disjunctive distribution of S. wightii, unveils unique adaptations and genetic variations. Our findings shed light on fundamental evolutionary processes and the mechanisms underlying speciation. The investigation extends to analyzing inter/intraspecific morphological evolution among Himalayan Smilax species, aiming to decipher their phylogenetic relationships. Moreover, their plastome comparison enables the identification of molecular markers that contribute to the resolution of evolutionary relationships and the detection of genetic diversity within the Smilacaceae family. Past researchers underscored the pivotal role of the Himalayan Smilax in linking species across East Asia, Southeast Asia, and Africa. Therefore, examining the phytogeography of Himalayan Smilax becomes crucial in unravelling the temporal origins and biogeographic processes shaping the disjunctive distribution of these species. Smilacaceae in the Himalayan refugium not only aids in reconstructing historical biogeography but also provides insights into species movement, adap-

tation to changing environments, and the impact of historical events on plant evolution. Utilizing molecular data-derived phylogenetic insights facilitates evaluating evolutionary relationships among the Smilax species in the Himalayan region. This research also endeavours to resolve longstanding taxonomic discrepancies, synthesize synonyms, and establish a more comprehensive framework for identifying and classifying Smilacaceae in the region.

## S.185.2 Taxonomic circumscription and biogeography: Dysoxylum s.l. (Meliaceae) across Indomalesia-Australasia and the Southwest Pacific

Laura Holzmeyer¹,², Frank Hauenschild²,³, Alexandra N. Muellner-Riehl²,⁴

1 IRD, UMR DIADE, Université de Montpellier, Montpellier, France. 2 Department of Molecular Evolution and Plant Systematics & Herbarium (LZ), Institute of Biology, Leipzig University, Leipzig, Germany. 3 Centre for Teacher Training and School Research, Leipzig University, Leipzig, Germany. 4 German Centre for Integrative Biodiversity Research, Halle-Jena-Leipzig, Leipzig, Germany

Dysoxylum s.l. had long been speculated to be a polyphyletic taxon. Recently, six strongly supported clades within the group were exhibited based on phylogenetic analyses employing several DNA marker regions. To ensure monophyly, five previously recognized genera (Didymocheton Blume, Epicharis Blume, Goniocheton Blume, Prasoxylon M.Roem. and Pseudocarapa Hemsl.) were reinstated, and Dysoxylum s.s. Blume ex Raspail was re-defined. This taxonomic revision, based on the most extensively sampled molecular phylogenetic tree of this group established so far, and morphological characters, resulted in the re-assignment of 94 presently acknowledged Dysoxylum species, generating forty-five new combinations and complementary lectotypifications as required. This taxonomic groundwork set the stage
<figure><img src="image_428.png" /></figure>

for biogeographic exploration. Our sampling encompassed 75% of the *Dysoxylum* s.l. species diversity, covering the entire distribution range and all major lineages. Results showed that *Dysoxylum* s.l. originated and firstly diversified in the western part of its current distribution range (including Indochina) during the Miocene to Pliocene, followed by an overall eastern range expansion towards Malesia, Australia and the Southwest Pacific in the Pliocene. This southeastward expansion into Wallacea and Australia coincided temporally with the convergence of the Asian and Australian tectonic plates and followed the expected dispersal directionality bias. We were able to establish long-distance dispersal as the primary mechanism shaping the current distribution. Furthermore, we identified two dispersal pathways into the Southwest Pacific: one from New Guinea and the Solomon Islands to Fiji, and another one from New Zealand to Fiji. Remarkably, Fiji served as an important secondary source area for dispersal into the Southwest Pacific from both New Guinea through the Solomon Islands, as well as from New Zealand.

**S.185.3 Using community-scale genetic data to understand adaptation and diversification in island systems**

Isaac Overcast¹,²,³

1 California Academy of Sciences, San Francisco, CA, USA. 2 American Museum of Natural History, New York, NY, USA. 3 Virginia Museum of Natural History, Martinsville, VA, USA

Islands are classical 'natural laboratories', encompassing the majority of terrestrial endemic species, yet they are substantially vulnerable to numerous human impacts (agriculture, invasions, climate change, etc). The relative isolation of islands, so important for generating their striking patterns of endemicity, also make them tractable systems for modeling biodiversity processes. Many open questions remain as to how the biodiversity we observe in nature has accumulated. For example, how do the dynamics of adaptation, competition, speciation, and colonization result in the communities that we observe today? And, how have local environmental conditions and human mediated disturbance modulated or amplified these processes? Community-scale genetic sequence data (e.g. DNA metabarcoding) provides a record of past popula-

tion dynamics that can unveil processes that have structured contemporary observed biodiversity. In this talk I describe the Massive Eco-evolutionary Synthesis Simulation (MESS) model, a multi-scale model of biodiversity which jointly accounts for processes operating on ecological, population genetic, and phylogenetic timescales. The goal of MESS is to integrate abundance and trait data with phylogenies and population genetic data into a single mechanistic framework, with the goal of estimating the contribution of colonization, local adaptation, and ecological interactions to the generation and maintenance of biodiversity in insular systems. MESS can also provide insight on "community genetic health" and all for development of indicator metrics which can reliably identify genetically healthy and unhealthy communities. MESS simulations coupled with machine learning inference methods facilitate the investigation of processes that lead to resilient and genetically healthy communities and reciprocally address questions of how community genetic health contributes to promoting invasion resistance and/or providing resilience to disturbance. As a case study, I demonstrate the application of MESS to understand the impact of forest fragmentation and land use on floral community structure using DNA metabarcoding data from rainforests on Sumatra.

**S.185.4 Phylogenomic data informs biogeographic and diversification patterns of Serianthes (Fabaceae) in the Indo-Pacific region**

Else Demeulenaere¹, J. Gordon Burleigh², Tom Schils³, Stefanie M. Ickert-Bond⁴

1 University of Guam Center for Island Sustainability and Sea Grant, University of Guam, UOG Station, Mangilao, Guam. 2 Department of Biology, University of Florida, PO Box 118525, Gainesville, FL, USA. 3 Marine Laboratory, University of Guam, UOG Station, Mangilao, Guam. 4 UA Museum of the North Herbarium and Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, USA

The Indo-Pacific region contains six of the 25 world's biodiversity hotspots harboring many endemics. *Serianthes* consists of 17 island endemics and one littoral species, *S. dilmyi*. The endemics occur in the Pacific Islands, while *S. dilmyi* occurs in Malaysia, Indonesia, and the Philippines. Twelve of the 18 *Serianthes* species are listed on the Red List of Threatened Species. Although
<figure><img src="image_429.png" /></figure>

the circumscription of the genus has not been ques-
tioned, the phylogenetic relationships and diversifica-
tion through time and space remain unclear. To study
diversification we collected 81 samples across *Serian-
thes' Indo-Pacific distributional range and employed a
targeted sequence capture approach and produced
a time tree. We present the first robust, genus-wide,
time-calibrated phylogeny and biogeographic hy-
pothesis of *Serianthes* based on phylogenomics
and densely sampling all species. We identified two
well-supported clades representing two subgenera:
One clade, subgenus *Serianthes*, comprising all taxa
from Malesia, Papuaasia and southern Micronesia, and
the other clade, subgenus *Hayunia*, is uniting all taxa
from Polynesia and northern Micronesia. Both Micro-
nesian species, *Serianthes nelsonii* and *S. kanehirae*
have disjunct populations with unique genotypes
within their archipelagoes. Testing geographic range
evolution under the DEC+j model, we inferred the
most common ancestor originated in either Papuasia
or New Caledonia during the Miocene. Most founder
events in *Serianthes* happened during the Quaterna-
ry, aligning with the ages of the islands and support-
ing the progression rule of oceanic islands. *Serianthes
dilmyi* crossed the Wallace Line and established pop-
ulations in the Philippines and Indonesia. We may at-
tribute this to its ability to thrive in mangrove habitats
during the Quaternary era when sea levels were lower.
Our study highlights the role of LDD during the diversi-
fication of *Serianthes* in the Indo-Pacific corroborating
the important role of LDD using a Austro-Melanesia
dispersal route similar to other tropical lineages such
as *Hernandia* and *Pandanus*.

S.185.5 Exploring the
Diversification of
Araucariaceae with
Targeted Capture Data

Lorena Endara¹, Gordon Burleigh²

1 Clemson University, Clemson, USA. 2 University of Florida, Gainesville, USA

The gymnosperm family Araucariaceae consists of 27 extant species organized in three genera: *Araucaria*, *Agathis*, and the monospecific *Wollemia*. The extant Araucariaceae are confined to the southern hemisphere, although there is evidence of their presence in the northern hemisphere during the Mesozoic. The rich fossil record of this family, combined with the distribution patterns of its extant species makes the Araucariaceae an ideal system to explore evolutionary hypotheses about the diversification and biogeography of the Indo-Pacific region. We generated a large nuclear dataset from 126 Araucariaceae samples using targeted enrichment with the GoFlag 408 flagellate land plant probe set. These data help elucidate species boundaries and resolve phylogenetic relationships among taxa. We dated the tree and described the geographic patterns of diversification, focusing on the putative radiation in New Caledonia.

S.186 BENEFICIAL PLANT-MICROBE
INTERACTIONS. SESSION 1

S.186.1 Comparative
altitudinal analysis
of microbial diversity
in cultivated soils in
Ecuadorian Andes

Paolo Chasi¹*, Ellana Boada¹,², Andrés
Valencia³

1 Faculty of Agricultural Sciences and Natural Resources, Technical University of Cotopaxi, Latacunga, Ecuador. 2 Molecular Microbial Ecology Group,

Institute of Aquatic Ecology, Faculty of Sciences,
University of Girona, Spain. 3 School of Agricultur-
al and Environmental Sciences, Pontifical Catho-
lic University of Ecuador, Ibarra Campus, Ecuador
*wilman.chasi@utc.edu.ec

The Ecuadorian Andes are a unique and highly ex-
ploited ecosystem both ecologically and economi-
cally. Several species of agricultural interest are pro-
duced only in these areas and are therefore known
as "Andean crops", that is, they are produced above
2000 meters above sea level and under climatic, hy-
drological and geological conditions typical of the An-
des. The type of soil in these ecosystems directly influ-
ences the growth of these plant production systems.
<figure><img src="image_430.png" /></figure>

Taking into account that existing microorganisms are key actors in soil formation, we carried out an analysis of the diversity of native bacterial communities in cultivated soils of the Ecuadorian Andes. These communities could influence carbon and nitrogen fixation, promoting soil fertility and promoting innovations in sustainable high mountain agriculture. Genetic material was extracted from soil samples from potato crops (Solanum tuberosum) located in two altitudinal levels at 3400 and 3800 m. The 16s rRNA V4 region was amplified using the Illumina technique to perform a diversity analysis of the microbial community. These sequences were subsequently refined in silico using the Mothur software. As a result, a central community or "core" with 437 identified genera was obtained for each altitudinal level, of which 19 are representative members at 3400 m and 16 for 3800 m. The predominant genera regardless of the altitudinal level were: Raoutella, Stenotrophomonas, and Lysobacter. Rhodanobacter was representative for the community at 3800 m and the Gemmatimonas for 3400 m. We establish then that the richness of the bacterial communities found in the two altitudinal levels and their metabolic functionality balances the agricultural system and contributes to its health and fertility, which promotes the development and productivity of cultivated species and soil conservation.

## S.186.2 Plant-soil feedback as a key of competitors' coexistence

Ezequiel Antorán-Pilar¹, Jaime Madrigal-González², Joaquín Calatayud¹

1 Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, Móstoles, Madrid, Spain. 2 Ei-FAB-iuFOR, Universidad de Valladolid, Soria, Spain

Understanding species coexistence is not only about exploring the classic paradigm of competitive exclusion but also considering the role of other ecological mechanisms. In plants, plant-soil feedback (PSF) has been identified as a relevant factor influencing plant performance and population dynamics, but its role in the coexistence of competing species is still poorly explored. This study explores how PSF mediated by microorganisms, may regulate or impact coexistence mechanisms of two competing species. Rather than relying exclusively on direct competition, we hypothesized that population dynamics and distribution of species could be driven by PSF. A common garden experiment were conducted involving two species,

Cistus ladanifer and C. laurifolius. Performance measures, focusing on root and shoot biomass, were recorded under experimental conditions. We used soils dominated by each of the two species, conducted a cross-experimental approach that used sterilized soils and soil microorganism inoculum from both species. This separation aimed to discern the effects of soil physic-chemical properties and living microorganisms. We found that the interaction of soil properties and microorganisms drive early growth of both species. Both species grow better in richer soils where only one species prevails. Yet, this only occurs when plants are experiencing microorganisms from their own soil. Consequently, our findings suggests that PSF play a key role in regulating population dynamics of competing species, challenging the conventional understanding dominated by direct competition.

## S.186.3 Effect of AMF and PGPB inoculation on the growth and volatilome of Artemisia annua plants

Valeria Todeschini¹, Flavio Anastasia¹, Copetta Andrea², Valentina Gianotti³, Nadia Massa¹, Patrizia Cesaro¹, Elisa Bona³, Elisa Gamalero¹, Giorgia Novello¹, Consolata Siniscalco⁴, Guido Lingua¹

1 Università degli Studi del Piemonte Orientale A. Avogadro, Alessandria, Italia. 2 CREA-Centro di Ricerca Orticoltura e Florovivaismo, Sanremo, Italia, Italia. 3 Università degli Studi del Piemonte Orientale A. Avogadro, Vercelli, Italia. 4 Università degli Studi di Torino, Torino, Italia

Artemisia annua is a ruderal plant belonging to the Asteraceae family. Besides the production of artemisinin, a bioactive compound used against malaria, Plasmodium, the glandular trichomes of this plant release many VOCs (Volatile Organic Compounds). Since arbuscular mycorrhizal fungi (AMF) and plant growth promoting bacteria (PGPB) can strongly affect plant growth and physiology, the aim of this work was to test (in controlled conditions) different AMF and PGPB strains (alone or in combination) on two artemisia clones (CL7 and CL26) to assess their effects on plant growth parameters and secondary metabolite production. Plants were grown in growth chamber for two months and irrigated three times a week with Long Ashton solution. At harvest, AMF colonization in root, plant biomass (fresh and dry), leaf pigment and artemisinin concentrations (HPLC analysis) were detected.
<figure><img src="image_431.png" /></figure>

Moreover, the composition of leaf volatilome was analyzed in CL26 clone by GC-MS. The results highlighted that the two clones differently responded to the different tested inocula and, conversely, different microorganisms affected the same clone in a different way, especially for plant growth parameters. The GC-MS analyses of the leaf volatile profile resulted in the identification of 120 molecules (a higher number than that reported in previous works). All these compounds (some of which detected for the first time in this plant species) were grouped in the most representative chemical classes (alkenes, alcohols, aldehydes, acids, ketones, ethers, esters, and "other compounds"), whose percentage changed depending on the used inoculum. The fact that some molecules were only present in a certain treatment and that others were present in different percentages meant that plants of each treatment had its own specific particular odor, mainly due to the bioactive molecules present in the complex mixture of plant essential oil, whose production was modulated by the interaction between plant and soil beneficial microorganisms.

## S.186.4 Root Rhythms: revealing the biota's dynamic dance in response to the climatic symphony in Rhododendron anthopogon

Sayantika Banerjee¹,²*, Dina in 't Zandt²,³, Dinesh Thakur², Zuzana Münzbergová¹,²

¹Department of Botany, Faculty of Science, Charles University in Prague, Praha, Czech Republic. ²Institute of Botany, Czech Academy of Sciences, v. v. i., Průhonice, Czech Republic. ³Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands *banerjesa@natur.cuni.cz

Lately studies on root microbe interactions have gained prominence as plant roots in their natural environment are in constant interaction with diverse microorganisms. Plant roots assemble two distinct microbial compartments rhizosphere and endosphere. Root biota influences plant growth and performance by modulating the effects of biotic and abiotic stressors. However, climate change is causing changes in the composition of root biota that affects host plant functions. While plant's primary response to changes in climate is adjustment of their physiology, root biota which has shorter generation times, responds by rapid changes in community composition. Changes in cli-

matic factors occur in combination of precipitation, temperature and their fluctuations. Understanding the separate and interactive effects of different climatic drivers is important. Vegetation composition and soil chemistry also strongly affect root biota. Identification of the direct effect of climate on root biota is difficult as both soil chemistry and vegetation composition are changing along climatic gradients. Hence, there is a need to deepen our understanding of how root microbial diversity and functional composition will shift in root biota of specific plant species as climatic and edaphic conditions are changing most strongly in montane ecosystems. In this study root associated fungal communities were studied along a climatic gradient in a dominant alpine Himalayan shrub species. Site and elevation significantly affected both rhizosphere and root fungal communities. Variation in rhizosphere and root fungal communities was related to soil moisture, soil chemistry and plant community composition. Highest number of OTUs were found in rhizosphere as compared to endosphere fungal communities. This study contributes to our knowledge of below ground biotic mechanisms that affect the functioning and adaptation of natural plant populations under stressful conditions in vulnerable ecosystems. It will enable in the formulation of evidence-based conservation and management strategies especially for species under threat of climate change.

## S.186.5 The genera Gymnostoma and Ceuthostoma (Casuarinaceae) can establish symbioses with cluster 1 and with cluster 3 Frankia.

Celestino Quintela-Sabarís¹, Lo Chor Wai², Hasna Boubakri³, Philippe Normand³, Sukaibin Sumail⁴, Aude Herrera-Beloussi³, Manuel Aira¹, Farnidah Jasnie², Siti-Aminah Mohamad², Jorge Domínguez¹

¹Animal Ecology Group, Universidade de Vigo, Vigo, Spain. ²Fakulti Sains Gunaan, Universiti Teknologi MARA - Cawangan Sabah, Kota Kinabalu, Malaysia. ³Laboratoire d'Écologie Microbienne, Université Lyon 1, Lyon, France. ⁴Kinabalu Park Herbarium, Sabah Parks, Kota Kinabalu, Malaysia
<figure><img src="image_432.png" /></figure>

The family Casuarinaceae comprises four genera (from more basal to more recent): *Gymnostoma, Ceuthostoma, Casuarina* and *Allocasuarina*. Casuarinaceae have actinorhizal symbioses with *Frankia* N-fixing actinobacteria. This symbiosis is an intriguing model of evolution of plant-microbe interactions, as *Gymnostoma* established a nonspecific symbiotic association with easy-to-isolate, more saprophytic *Frankia* strains which belong to cluster 3 frankiae, whereas the genera *Casuarina* and *Allocasuarina* are in symbiosis with hard-to-isolate strains from the cluster 1c frankiae. To date, there is no information about the symbiont associated to the genus *Ceuthostoma*, whose origin is intermediate between *Gymnostoma* and *Casuarina* + *Allocasuarina*. To advance our knowledge on the *Frankia*-Casuarinaceae symbioses and to obtain first evidences on the strains associated to *Ceuthostoma*, a genus with a narrow geographical range, we collected actinorhizal nodules from the species *C. terminale*, *Gymnostoma nobile* and *G. sumatranum* from different sites in Sabah (Malaysia). After surface sterilisation and peeling, we extracted DNA from the nodules and amplified and sequenced a fragment of the bacterial *pgk* gene, which has been used previously for the identification of *Frankia* strains. After aligning our sequences with published sequences of standard *Frankia* strains covering all the diversity in the bacterial genus, we constructed a maximum-likelihood tree. We found that all the *G. nobile* and the majority of *G. sumatranum* and *C. terminale* trees had symbioses with cluster 3 frankiae, whereas 10% and 18% of the *C. terminale* and *G. sumatranum* trees had symbioses with *Frankia* strains in cluster 1. Interestingly, those strains were not grouped with the strains from *Casuarina* and *Allocasuarina*. Instead, they were in a different group, closer to *Frankia* species that enter symbiosis with *Alnus* and *Morella*. Overall, this study points to a complex scenario of evolution of actinorhizal symbiosis in this group.

S.186.6 Microbial
communities and seeds:
Home-field advantage
effects in holm oak
germination

Rosina Magaña Ugarte<fnref n="1" />, Francisco I.
Pugnaire²

Complutense de Madrid, Madrid, Spain. 2 Estación Experimental de Zonas Áridas. CSIC. Almería, Spain.

Germination onset is the first choice in the phenological plant cycle, influenced by abiotic and biotic factors. Both soil and seed microbiota are key drivers of germination, influencing seed storage, dormancy release, and germination rates. Interactions between plants and soil microbes contribute to plant adaptation to their environment. Therefore, plants could benefit more from interacting with soil microbes from the local ('home') environment rather than with those from different origins. As crucial germination drivers, plants may select for specific microbial taxa that provide them with a home-field advantage, despite having less microbial richness and diversity. Here, we look at the role of seed-associated microbes on holm oak (Quercus ilex) germination, whether the soil or the seed microbes have a greater impact on this process, and how the interaction between the seed microbiome and soil microbiota influence holm oak germination. We found that microbes on Q. ilex seeds have a significant effect on germination, with non-sterilised seeds having higher germination rates than sterilised ones. Moreover, when co-occurring, soil microorganisms enhance the effect of seed-associated microbes on holm oak germination. Overall, our results evidence a home-field advantage where local soil communities, along with seed-associated microorganisms, enhance Q. ilex germination over that of different soil or species-linked communities.

<footnote n="1">1 Department of Pharmacology, Pharmacognosy and Botany. Faculty of Pharmacy. Universidad</footnote>
<figure><img src="image_433.png" /></figure>

# S.187 EVOLUTION AND DIVERSITY OF CARBON CONCENTRATING MECHANISMS (CCM) IN LAND PLANTS. SESSION 1

## S.187.1 C2 photosynthesis across scales

Marjorie R. Lundgren¹

1 Lancaster Environment Centre, Lancaster University, UK

Plants have evolved extraordinary diversity in the carbon fixation pathways of photosynthesis that allow species to survive and thrive across a broad array of ecological niches. While most plants use only C₃ photosynthesis, this physiology is heavily affected by high rates of photorespiration under warm and arid environments. In response, some plant lineages have evolved carbon concentrating mechanisms (CCMs) to improve net carbon assimilation in these high photorespiration environments. C₂ photosynthesis is one such CCM that can increase net CO₂ assimilation by capturing, concentrating, and re-assimilating CO₂ released from photorespiration. This talk will discuss C₂ photosynthesis across scales, from the evolutionary history and biography of C₂ plants, to their unique whole-plant growth patterns, and to specifics of their mesophyll structure, vascular patterning, and ultrastructure. In all cases, C₂ plants will be compared to their close C₃ and C₄ relatives for context. The talk will conclude with a discussion on the potential for C₂ photosynthesis engineering programs to improve the efficiency of C₃ crops.

## S.187.2 Evolution of facultative and constitutive gene regulation in plants with CAM photosynthesis

Ian S. Gilman¹,², Robert VanBuren¹,²

1 Department of Horticulture, Michigan State University, East Lansing, MI, USA. 2 Plant Resilience Institute, Michigan State University, East Lansing, MI, USA

The evolution of stress response mechanisms and their regulation have broad implications from the origins of evolutionary novelties to climate change adaptability across the tree of life. Crassulacean acid metabolism (CAM) is an adaptation to water and CO₂ limitation that

has evolved convergently in many dozens of plant lineages through the co-option of core carbon metabolic pathways. Despite the near-universal set of gene families exapted in each CAM origin, a diverse landscape of CAM phenotypes has evolved that vary along multiple axes, including the extent of nocturnal stomatal conductance, the amount of CO₂ sequestered as malic acid, and the degree to which CAM is facultative or constitutive. The mounting genomic resources for CAM species across the vast number of convergent CAM origins makes CAM an ideal system for understanding the evolution of stress response gene regulation, and how such facultative responses can become constitutive. Here, we compare the regulatory elements of CAM gene networks from multiple independent origins of facultative and constitutive CAM plants to identify convergent patterns of regulatory evolution.

## S.187.3 Comparative analysis of distribution and climatic preferences of C4 lineages

Jessica A. Berasategui¹,², Anže Žerdoner Čalasan¹, Alexander Zizka⁴ & Gudrun Kadereit¹,³

1 Prinzessin Therese von Bayern Lehrstuhl für Systematik, Biodiversität & Evolution der Pflanzen, Ludwig-Maximilians Universität München, Germany. 2 Institute for Molecular Physiology, Johannes Gutenberg-University Mainz, Germany. 3 Botanischer Garten München-Nymphenburg und Botanische Staatssammlung München, Staatliche Naturwissenschaftliche Sammlungen Bayerns, Germany. 4 Department of Biology, Philipps-Universität Marburg, Germany

Photosynthetic pathways play a pivotal role in shaping the ecological and structural diversity of plant species. The C₄ photosynthetic pathway has independently evolved over 61 times in multiple angiosperm lineages and consists of a series of anatomical and biochemical modifications to the ancestral C₃ pathway increasing plant productivity under warm and light-rich conditions. C₄ eudicots entail an enormous structural
<figure><img src="image_434.png" /></figure>

and ecological diversity, whereas the C₄ syndrome in grasses is more uniform and phylogenetically constrained. Using GBIF (Global Biodiversity Information Facility) database we compiled an occurrence data matrix for 1514 C₄ taxa, covering more than 80% of currently known C₄ grasses and eudicots. The highest C₄ species diversity is in Mexico/Southern United States and Australia. Furthermore, C₄ grasses predominantly thrive in more humid regions compared to their eudicot counterparts, and among the latter, various biochemical subtypes exhibit specific climate preferences, with C₄ eudicots often adapting to drier conditions through features like succulence and salt tolerance. Our study illustrates that GBIF is a valuable resource for meta world-wide biogeographical studies.

### S.187.4 CAM evolution is associated with gene family expansion in an explosive bromeliad radiation

Clara Groot Crego¹,², Jaqueline Hess¹,³, Gil Yardeni¹,⁴, Marylaure de La Harpe¹,⁵, Clara Priemer⁶,⁷, Francesca Beclin¹,²,⁸, Sarah Saadain¹,², Luiz A. Cauz-Santos¹, Eva M. Temsch¹, Hanna Weiss-Schneeweiss¹, Michael H.J. Barfuss¹, Walter Till¹, Wolfram Weckwerth⁶,⁷, Karolina Heyduk⁹, Christian Lexer¹, Ovidiu Paun¹, Thibault Leroy¹,¹⁰

1 Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria. 2 Vienna Graduate School of Population Genetics, Vienna, Austria. 3 Cambrium GmbH, Berlin, Germany. 4 Institute of Computational Biology, Department of Biotechnology, University of Life Sciences and Natural Resources, Vienna, Austria. 5 Office for Nature and Environment, Canton of Grisons, Chur, Switzerland. 6 Department of Functional and Evolutionary Ecology, Molecular Systems Biology, University of Vienna, Vienna, Austria. 7 Vienna Metabolomics Center, University of Vienna, Vienna, Austria. 8 Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria. 9 Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT USA. 10 GenPhySE, Université de Toulouse, INRAE, ENVT, Castanet Tolosan, France †deceased

The subgenus Tillandsia (Bromeliaceae) belongs to one of the fastest radiating clades in the plant kingdom and is characterised by the repeated evolution of the water-conserving Crassulacean Acid Metabolism (CAM), which is regarded as a key innovation trait and driver of ecological diversification in Bro-

meliaceae. By obtaining physiological and transcriptionic data under control and drought conditions of a Tillandsia species pair representing the phenotypic extremes of photosynthetic metabolism found in the clade, we were able to characterise the range of CAM phenotypes in Tillandsia with unprecedented detail. We found that species previously identified as C3 are CAM intermediates which activate a latent CAM cycle under drought conditions. However, the CAM-specific response to drought in this facultative species has little overlap with the constitutive CAM cycle of the strong CAM species. By producing high quality genome assemblies of a facultative and a constitutive CAM Tillandsia, and combining genome-wide investigations of synteny, TE dynamics, sequence evolution, gene family evolution and temporal differential expression, we were able to pinpoint the genomic drivers of CAM evolution in Tillandsia. Our analyses show that rewiring of photosynthetic metabolism towards constitutive CAM is mainly obtained through regulatory evolution rather than coding sequence evolution, as CAM-related genes are differentially expressed across a 24-hour cycle between the two species, but are no candidates of positive selection. Gene orthology analyses reveal that CAM-related gene families manifesting differential expression underwent accelerated gene family expansion in the constitutive CAM species, further supporting the view of gene family evolution as a driver of CAM evolution.

### S.187.5 Diversity and evolution of CAM and CAM-related traits in the most species-rich Macaronesian plant radiation

Thibaud F.E. Messerschmid¹, Jurriaan M. de Vos², Jessica A. Berasategui³, Susanne E. Hamburger⁴, Sophie C. Simon⁴, Gülsem Kara⁴, Siwi A.W. Astuti³, Gudrun Kadereit¹,³

1 Botanischer Garten München-Nymphenburg, München, Germany. 2 Universität Basel, Basel, Switzerland. 3 Ludwig-Maximilans-Universität München, München, Germany. 4 Johannes Gutenberg-Universität Mainz, Mainz, Germany

CAM photosynthesis involves the nocturnal assimilation and storage of carbon in the form of malic acid in the vacuole. It is mostly but not exclusively associated with succulence which may optimize the vacuolar storage capacity of malic acid. Plants
<figure><img src="image_435.png" /></figure>

that express CAM rely on diurnal closure of stomata while internal CO₂ concentrations are high, limiting transpiration to its cuticular rather than stomatal component during parts of the day. Cuticular transpiration barrier properties may thereby represent an understudied trait related to CAM. To investigate the interrelation and evolution of cuticular transpiration barrier properties, succulence and CAM expression, we set up a climate chamber experiment sampling most species of *Aeonium* and *Aichryson* (Crassulaceae), the iconic houseleeks that largely diversified on the Canary Islands. Under varied treatments of heat and drought, over-night acidification of leaves was quantified as a means to study CAM expression patterns. Transpiration barrier properties of the cuticle as well as the degree of succulence were quantified through leaf drying curves and measurement of minimum conductance (g_min). Our results reveal a negative correlation of CAM activity and g_min such that species with strong or constitutive CAM were more likely to have an efficient cuticular transpiration barrier. However, leaf succulence was not correlated with CAM activity which is in contrast to the remarkable role of succulence in the function of CAM photosynthesis. In conclusion, we present first evidence for the need of reduced cuticular transpiration in CAM plants which is to be expected under selection for high water-use efficiency.

## S.187.6 Leveraging facultative CAM for engineering synthetic CAM into C3 photosynthesis plants

John C. Cushman¹

1 Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557-330, USA

The global climate crisis is rapidly increasing major crop losses around the world due to increased intensity and duration of drought events. Therefore, novel strategies are needed to create more climate-resilient crops. Remarkable progress has been made in advancing our understanding of the functional genomics of crassulacean acid metabolism (CAM) in the last decade. Dozens of CAM plant genomes have now been sequenced including obligate CAM species such as *Kalanchoë fedtschenkoi*, facultative CAM species such

as *Mesembryanthemum crystallinum*, and important crops such as *Agave*, *Ananas*, *Hylocereus*, and *Opuntia*. Well-annotated genomes along with extensive transcriptomic, proteomic, and metabolomic datasets and associated co-expression and transcriptional regulatory networks provide a strong foundation for understanding the biochemical and regulatory frameworks that underpin the diel and circadian operation of CAM. Detailed time-resolved transcriptome profiling analysis in the facultative CAM plant *M. crystallinum* has revealed hundreds of genes with putative CAM-associated functions that provide the building blocks for creating synthetic versions of CAM in the C₃ photosynthesis model *Arabidopsis thaliana*. We have built different gene circuits to recreate synthetic versions of the carboxylation, decarboxylation, and core diel carboxylation + decarboxylation modules of CAM. The carboxylation module increased CO₂ assimilation, nocturnal malate accumulation, and plant biomass whereas the decarboxylation module improved water-use efficiency. Combining the carboxylation and decarboxylation modules resulted in increased CO₂ assimilation, nocturnal malate accumulation, plant biomass, and improved water-use efficiency. Design and implementation of new iterations of the SynCAM design cycle (SynCAM 2.0) also target soybean, a major crop that suffers large economic losses due to damage from drought events. CAM functions optimally within succulent leaves so the benefits of tissue succulence engineering will also be discussed.
<figure><img src="image_436.png" /></figure>

# S.188 ADVANCES IN MICROCLIMATE RESEARCH FOR CRYPTOGAM ECOLOGY. SESSION 1

## S.188.1 BryoMicroClim: collecting bryophyte-relevant microclimate data to assess the gap between macro- and microclimate

Helena Hespanhol¹,², João F. Gonçalves¹,²,³, Ana P. Portela¹,², Alain Vanderporten⁴, Ángel Lareo Fernández⁵, Carlos Vila-Viçosa¹,², Cristiana Vieira⁶, Fernando Lima¹,², Irene Bisang⁷,⁸, Jesús Muñoz⁹, Joana Marques¹,², Joaquín Hortal¹⁰,¹¹, John Spill¹², Lars Hedenäs⁷, Lizzie Wilberforce¹³, María Leo¹⁴, Nagore G. Medina⁵, Neil Bell¹⁵, Niklas Lönnell¹⁶, Robbie Blackhall-Miles FLS¹², Rui Seabra¹,², Salvador Arenas-Castro¹⁷, Vincent Hugonnot¹⁸

1 CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, Vairão, Portugal. 2 BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal. 3 Instituto Politécnico de Viana do Castelo, Viana do Castelo, Portugal. 4 University of Liège, Liège, Belgium. 5 Universidad Autónoma de Madrid, Madrid, Spain. 6 Museu de História Natural e da Ciência da Universidade do Porto (PRISC), Porto, Portugal. 7 Swedish Museum of Natural History, Stockholm, Sweden. 8 IUCN SSC Bryophyte Specialist Group. 9 Real Jardín Botáni-co (CSIC), Madrid, Spain. 10 Museo Nacional de Ciencias Naturales (CSIC), Madrid, Spain. 11 cE3c -Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal. 12 Plantlife Cymru, Llan-beris, Gwynedd, UK. 13 Plantlife Cymru, Salisbury, UK. 14 Instituto de Ciencias Agrarias (CSIC), Madrid, Spain. 15 Royal Botanic Garden Edinburgh, Edinburgh, UK. 16 Swedish University of Agricultural Sciences, SLU Artdatabanken, Uppsala, Sweden. 17 Facultad de Ciencias, Universidad de Córdoba, Spain. 18 le Bourg, Blassac, France

Significant mismatches between macro- and microclimates challenge our ability to accurately estimate the climatic conditions experienced by organisms and thus to predict responses to climate change. This study aims to evaluate the relationship between macro- and microclimate for small-scale

plants such as bryophytes, which are highly dependent on local environmental conditions. To achieve this, we established a Europe-wide collaborative network of bryologists (the BryoMicroClim project), to measure the microclimate experienced by a bryophyte species. The moss *Hedwigia striata*, evaluated as near-threatened in Europe (Hodgetts et al., 2019), was selected as the target species. This species grows mainly in forests or rocky areas. We selected 15 sampling sites across Europe, spanning a wide range of climate conditions (Portugal, Spain, France, Belgium, Wales, Scotland, and Sweden). In each site, mostly continuous forested areas, we measured air temperature and humidity using three dataloggers (Envloggers, Environmental loggers) installed near H. striata populations. In the Iberian Peninsula, we also installed other dataloggers (BtMs, Bryolichen Temperature Moisture), specifically designed to measure ambient temperature, humidity, and water content of nonvascular cryptogams. We used the slope and equilibrium approach (Grill et al., 2022) to infer if the microclimate temperature and relative humidity variability (as measured by the in-situ dataloggers) is buffered or amplified in relation to the macroclimate variability (from ERA5-Land and ERA5 data). We observed that microclimate temperatures were buffered or amplified depending on site conditions. As hypothesized, microclimate temperatures had a buffered variability in dense forest sites. Our results suggest that collecting bryophyte-relevant microclimate data at fine spatial resolutions and long time scales will be critical to better understand the potential vulnerability of bryophytes to climate change.

## S.188.2 Microclimate and intraspecific variation mediate the effects of biotic interactions on lichen performance

Sonia Merinero¹,², Caroline Greiser², Kristoffer Hylander², Alicia Valdés², Johan Ehrlén²

1 Universidad Rey Juan Carlos, Móstoles, Spain. 2 Stockholm University & Bolin Centre for Climate Research, Stockholm, Sweden.
<figure><img src="image_437.png" /></figure>

Climate and biotic factors, and their complex interactions, drive species performance and distributions. Climate at the local scale (i.e., microclimate) drives population dynamics, ultimately determining local species abundance and fine-scale distribution. If populations are locally adapted to their environment, we would expect different responses to environmental change among populations across the species' range. Understanding how microclimate affects biotic interactions and accounting for intraspecific variation in responses can improve our predictions of species performance and distribution. We examined the direct and indirect effects of microclimate and mollusc grazing on five distant populations of the ground-dwelling forest lichen *Peltigera aphthosa*. We transplanted individuals from each population to 56 boreal forest sites covering a wide microclimate gradient in central Sweden and recorded their growth for one year. We quantified the direct and indirect effects of microclimate, grazing and populations origin on lichen growth using confirmatory path analyses approaches (piecewise Structural Equation Models). We found indirect effects of microclimate and populations origin mediated by grazing: 1) lichen growth decreased with increasing grazing pressure, which was enhanced by increasing temperature and air humidity during the growing season; and 2) populations differed in their susceptibility to grazing, as one population experienced higher damage. Our study adds evidence on the importance of climate-mediated antagonistic biotic interactions. When predicting future species distributions in the face of climate change, in addition to microclimatic drivers, both the presence of natural enemies together with local population differentiation needs to be considered.

### S.188.3 The most important microclimatic variables for temperate forest bryophytes and lichens

Matěj Man, Martin Macek, Anna Růžičková, Jiří Malíček, Vojtěch Kalčík, Josef Brůna, Jiří Prošek, Jan Wild, Martin Kopecký

Institute of Botany of the Czech Academy of Sciences, Průhonice, Czech Republic

The in situ measured microclimate is increasingly acknowledged as a pivotal determinant influencing species diversity and distribution. The affordability and widespread utilization of microclimate loggers in ecological research globally have yielded an extensive

dataset from biotopes traditionally devoid of climate data due to the absence of meteorological stations. Forest interiors represent a paradigmatic case, exhibiting microclimates substantially divergent from meteorological observations typically obtained from open land. The influx of this massive volume of microclimatic data has facilitated innovative approaches and insights while concurrently introducing new challenges in the processing, analysis, and meta-analysis of microclimate data. In response to these challenges, we present the development of the myClim R package, specifically designed for seamless microclimate data processing and analysis, including the computation of standard, ecologically relevant microclimate variables. Leveraging myClim in conjunction with our expansive national forest microclimate monitoring network, "CzeMiN," and the national database gathering the occurrence of lichens and bryophytes "DaLiBor," we discerned the principal microclimatic variables steering the diversity and distribution of forest bryophytes and lichens. Moreover, through a comprehensive assessment, we partitioned the variance among microclimate, macroclimate, forest structure, and topography. Our findings indicate that the variation in temperate forest bryophyte and lichen diversity elucidated by in-situ measured microclimate cannot be accurately estimated through alternative proxy variables. This underscores the indispensable nature of microclimate data for comprehending the distribution of bryophytes and lichens and underscores its potential utility in their protection and conservation efforts. Specifically, our investigation identified growing degree days, maximum air temperature, and soil volumetric water content as the foremost variables influencing these ecological communities.

### S.188.4 Variation of epiphytic bryophyte communities through the lens of a spatially-explicit microclimatic model in SE Asian sky trees

Fabien Spicher¹, Flavien Collart², Thing Shen³,⁴,⁵, Marianne Laslier¹, Eva Grill¹, Alain Vanderpoorten³, Jonathan Lenoir¹

1 UMR CNRS 7058 Ecologie et Dynamique des Systèmes Anthropisés, Université de Picardie Jules Verne, Amiens, France. 2 Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland. 3 Institute of Botany, University of Liège, Liège, Belgium. 4 Xishuangbanna Tropical Botan-
<figure><img src="image_438.png" /></figure>

ical Garden, Chinese Academy of Sciences, Menglun, Mengla, China. 5 Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China

At the interface between atmosphere and vegetation, epiphytes are exposed to dramatic variations of light exposure and microclimatic conditions along a tree, from the buffered conditions at the base to the amplified conditions in the outer canopy. They appear therefore as an ideal model to assess the impact of the spatial variation in microclimatic conditions at fine scales and its change under ongoing climate warming. A canopy crane giving access to 1.1 ha of tropical rainforest in Yunnan (China) was used to record hourly light, temperature and relative humidity from 54 sensors during 3 years and 408 plots of epiphytic bryophyte communities. To quantify how microclimates are buffered or amplified relative to macroclimates, we implemented, at each sensor, linear regressions between the hourly variation in microclimate and macroclimate. The slope of this regression represents an integrative parameter describing the buffering (slope < 1) or amplification (slope > 1) capacity of the canopy. We then employed a series of spatially-explicit predictors of canopy structure derived from a terrestrial LiDAR scan to predict the slope of the macro-microclimate relationship. This resulted in a spatially-explicit model of microclimatic variation in 3D, allowing for predicting the microclimatic conditions that prevail at any point in the canopy under present and future macroclimatic conditions. Microclimatic variation accounted for 33% and 18% of the variation in vertical turnover in mosses and liverworts, respectively, highlighting the crucial role of microclimates in determining the composition of epiphytic communities. Ensemble of small models were finally implemented to predict the distribution of the dominant species under present climatic conditions and evaluate the shift of their distribution under ongoing climate change.

### S.188.5 Exploring environmental drivers of the non-vascular community with a process-based model

Yunyao Ma¹, Maaike Y. Bader², Philipp Porada¹

1 Universität Hamburg, Hamburg, Germany. 2 University of Marburg, Marburg, Germany

Environmental filtering is a fundamental process that shapes plant community assembly. Understanding the impact of this process on composi-

tion of non-vascular vegetation, such as mosses and lichens, is important since the organisms provide essential ecosystem functions in many regions around the world. Responses of individual non-vascular vegetation to different environmental factors have been explored in a range of field and laboratory experiments. These observational data, however, have rarely been assembled into a comprehensive, consistent framework that allows quantitative exploration of the roles of multiple environmental factors for the performance of non-vascular vegetation, in particular across climatic regions. Here, we applied a data-driven mechanistic model that is driven by microclimate (air temperature, relative humidity, short- and longwave radiation etc.) at six study sites along a climate gradient from dryland, temperate to alpine regions to simulate the annual carbon (C) balance of lichen- and moss-dominated biocrusts, a key measure of their growth and survival. Furthermore, we performed several sensitivity analyses to investigate the relative importance of the driving factors. We found substantial effects of air temperature and CO₂ concentration on biocrust C balance, which differed, however, in their patterns across regions: ambient CO₂ concentration was the most important factor for biocrusts from drylands, while air temperature had the strongest impact at alpine and temperate sites. Further, we estimated a small annual carbon gain of biocrusts in drylands (e.g., 1.9 gm⁻² yr⁻¹ by moss-dominated biocrust), while the biocrusts lost substantial carbon at some temperate sites (e.g. ~92.1 gm⁻² yr⁻¹ for lichen-dominated biocrust), which contradicts the observed survival of the organisms at the sites. We thus conclude that the uncertainties in air temperature, CO₂ concentration may be a relevant source of error and should be taken into account in future approaches that estimate the long-term C balance.

### S.188.6 Urban lichens and bryophytes: diversity, distribution and response to the urban heat islands

Tim Claerhout¹,², Michael Stech², Paul J.A. Keßler¹, Laurens B. Sparrius³

1 Hortus botanicus - Universiteit Leiden, Leiden, the Netherlands. 2 Naturalis Biodiversity Center, Leiden, the Netherlands. 3 Dutch Bryological and Lichenological Society, Utrecht, the Netherlands

With the increasing urbanization and likelihood of extremely hot summers due to climate change,
<figure><img src="image_439.png" /></figure>

there is a need for investigating the impacts of the urban environment on the species communities living therein. Two ubiquitous, but often overlooked species groups are lichens and bryophytes, which have a historic background as bio-indicators. Here, we explore for the first time whether the urban heat island influences the diversity and distribution of lichens and bryophytes living epiphytically on urban trees. Additionally, we investigate the possibility of using these two groups as bio-indicators for the urban heat island. Furthermore, we investigate the patterns of temperature and humidity in different urban settings on a smaller scale using sensor data and link this with the prevalent lichen and bryophyte

diversity. We conducted vegetation surveys on Tilia trees in three cities in the Netherlands (Amsterdam, Leiden and Rotterdam) and analysed species diversity and distribution patterns. Based on an indicator species analysis, we defined groups indicative for different levels of heat stress. For example, acrocarpous mosses are indicative for urban regions with much heat stress, whilst crustose lichens with photobionts belonging to the genus *Trentepohlia* Martius, 1817 are more indicative for the outer semi- rural regions. These results will be further analysed in relation to urban microclimate (temperature and humidity using sensor data) and are also being implemented in a citizen science project.

# S.189 ORCHID PHYLOGENOMICS: DIVERSIFICATION, TRAIT EVOLUTION AND BIOGEOGRAPHY. SESSION 1

## S.189.1 Assembling the orchid tree of life – origin and evolution of one of the largest plant families on earth

Oscar A. Pérez-Escobar¹, Diego Bogarin²*,
Natalia Przelomska¹,³, William J. Baker¹,
Alexandre Antonelli¹,⁴,⁵,⁶

1 Royal Botanic Gardens, Kew, UK. 2 Lankester Botanic Garden, Universidad de Costa Rica, San José, Costa Rica. 3 University of Portsmouth, Portsmouth, UK. 4 Gothenburg Global Biodiversity Centre, Gothenburg, Sweden. 5 University of Oxford, Oxford, UK. 6 Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China.

Orchids represent one of the most striking examples of flowering plant diversification, thriving in nearly all terrestrial environments and often standing out as one of the most species-rich plant groups in tropical floras. However, their origin, spread across the globe, and hotspots of speciation remain uncertain due to the lack of an updated, densely sampled, robust phylogenomic framework. We present the most densely sampled phylogeny of the Orchidaceae utilizing combined high-throughput and Sanger sequencing datasets. Our analysis covers all five subfamilies, and included representative sampling for 17 out of 22 tribes, 40 out of 49 subtribes, 285 out of 736 gen-

era, and ~7% (1,921) of the 29,524 accepted species. By integrating curated geographical distribution records, we infer geographic range evolution, diversity, and speciation patterns. We found that the orchids' most recent common ancestor probably lived in the Late Cretaceous Laurasia. Despite their ancient origin, modern orchid species' diversity mainly originated over the last 5 million years, with highest speciation rates in montane forests of Panama and Costa Rica. These results alter our understanding of the geographic origin of orchids, previously proposed as Australian, and pinpoint Central America as a region of recent and explosive speciation.

## S.189.2 Scaphosepalum phylogenomics

Lorena Endara¹, Jana U'Ren², Gordon Burleigh³

1 Department of Biological Sciences, Clemson University, Clemson, South Carolina, USA. 2 Department of Plant Pathology, Washington State University, Pullman, Washington, USA. 3 Department of Biology, University of Florida, Gainesville, Florida, USA

Scaphosepalum is a comparatively small orchid lineage (ca. 53 spp.) within the diverse Neotropical orchid subtribe Pleurothallidinae. Species within the genus are primarily restricted to microhabitats in Central America's and the northern Andes' premontane and
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montane forests. We use targeted enrichment data generated with the GoFlag 408 angiosperm probe set to infer the phylogeny of *Scaphosepalum* to test the monophyly of the genus and elucidate relationships within *Scaphosepalum* previously unresolved by Sanger sequencing. These data produced a strongly supported tree that illuminates our understanding of species circumscriptions, especially for groups (i.e., *Scaphosepalum antenniferum*, *S. breve*, *S. swertifolium*) where a mosaic distribution of phenotypic characters has been confounding and has resulted in species over description. This well-resolved phylogenetic tree represents a fundamental tool towards a better understanding of the evolutionary and ecological drivers that led to the diversification of this orchid group. We also discuss insights from the first *Scaphosepalum* genome and metagenomic sampling of microbial communities within the flowers of *Scaphosepalum*.

## S.189.3 Phylogenomics provides insights into the diversification and range evolution of the mega genus Bulbophyllum (Orchidaceae)

Consolata Nanjala¹,²,³, Lalita Simpson¹, Ai-Qun Hu⁴, Vidushi Patel⁵, James Nicholls⁵, Stephen J. Bent³, Stephan Gale⁶, Gunter Fischer⁸, Darren Crayn¹, Mark Clements⁷, Katharina Nargar¹,³

1 Australian Tropical Herbarium, James Cook University, Smithfield, Queensland, Australia. 2 College of Science and Engineering, James Cook University, Smithfield, Queensland, Australia. 3 National Research Collections Australia, Commonwealth Industrial and Scientific Research Organisation, Canberra, Australian Capital Territory, Australia. 4 Singapore Botanic Gardens, Singapore. 5 Australian National Insect Collection, Commonwealth Industrial and Scientific Research Organisation, Canberra, Australian Capital Territory, Australia. 6 Kadoorie Farm and Botanic Garden, Tai Po, Hong Kong. 7 Centre for Australian National Biodiversity Research (Joint Venture), Canberra, Australia. 8 Missouri Botanical Garden, St Louis, United States

The hyperdiverse orchid genus *Bulbophyllum* constitutes the second largest genus of flowering plants with more than 2,100 species and exhibits exceptional morphological and ecological diversity. The genus, comprising predominantly epiphytic species, exhibits

a pantropical distribution with the highest species diversity in tropical Asia (over 1560 species), particularly in the floristic regions of Malesia and Papuasia. The high species richness and complex patterns of morphological diversity within this genus have presented significant challenges to constructing a stable and informative infrageneric classification, and to understanding patterns of evolutionary relationships and trait evolution (including ancestral range evolution). Poor resolution on phylogenetic trees from previous molecular studies based on few DNA loci has greatly hampered our understanding of the diversification of its evolutionary lineages in time and space. Here we present results from a broad-scale plastid phylogenomic study including over 450 samples, representing 398 species and 61 (of 97) sections of *Bulbophyllum*, with taxonomic focus on the highly diverse Asian clade. Maximum likelihood analyses based on 65 plastid markers yielded well-resolved and well supported phylogenetic reconstructions, clarified infrageneric relationships, and identified several non-monophyletic sections within *Bulbophyllum*, such as *Beccariana*, *Brachyantha*, *Cirrhopetalum*, *Minutissima*, *Polymeres* and *Sestochilus*. Divergence-time analyses based on secondary calibration points within a broader outgroup sampling in Orchidaceae using BEAST placed the origin of the genus in the early Oligocene and the onset of crown diversification in the late Oligocene. Species distributions were extracted from World Flora Online and biogeographic areas coded based on botanical continents and for a more-fine scaled coding within tropical Asia and Australasia, based on floristic regions following Brummit (2001). Ancestral range analyses were carried out in BIOGEOBEARS testing six biogeographic models. The findings of this study provide important insights into the phylogenomic relationships and spatiotemporal dynamics of the taxonomically complex genus *Bulbophyllum*.

## S.189.4 Phylotranscriptomis to tease apart introgression from incomplete lineage sorting in the diversification of the Ophrys genus

Lucas Vandenabeele¹, Joris Bertrand¹, Hervé Philippe²

1 Laboratoire Génome et Développement des Plantes, Université de Perpignan, Perpignan, France. 2 Station d'Ecologie Théorique et Expérimentale, (CNRS), Moulis, France
<figure><img src="image_441.png" /></figure>

The orchid genus *Ophrys* is an outstanding example of an important and recent plant adaptive radiation. However, both this rapid diversification and the large size of its genome make its systematics and evolution difficult to study, and most of the phylogenetic hypotheses published so far are either poorly resolved and prone to display gene trees incongruences. In this context, we decided to use phylotranscriptomics as a genome complexity reduction technique to work at the genomic scale and be able to simultaneously obtain and compare thousands of gene trees to improve resolution and tease apart the relative contribution of introgression and Incomplete Lineage Sorting in *Ophrys* diversification. We *de novo* assembled more than 150 *Ophrys* floral transcriptomes to obtain an important pool of orthologous genes that we used to reconstruct a phylogeny of the *Ophrys* genus with an unprecedented resolution. This phylogeny largely confirms the relationships between the main *Ophrys* lineages obtained by other methods but also provides new insights within each of these lineages. We show that the incongruence between gene trees is not only due to Incomplete Lineage Sorting. Although introgression has been hypothesised to play an important role in *Ophrys* evolution we provide for the first time quantitative characterisation of this reticulate evolution at the genus scale. We implemented several introgression tests with different levels of complexity, from D-statistics to phylogenetic network inference, and were able to highlight several complex introgression events between the *Ophrys* lineages. This introgression analysis provides us a set of introgressed genes which will be further analysed to find their impact on phenotypic variation, in order to explore a putative adaptive role of introgression in *Ophrys* diversification.

## S.189.5 Vanillomics: towards a phylogenomic monograph of neotropical vanillas

Alexander Damián-Parizaca¹², Adam Karremans³, Oscar A. Pérez-Escobar⁴, Gerardo Salazar⁵, Eric Hagsater⁶, Andrés Barona⁷, Mathias Engels⁸, Marcelo Rodrigues⁹, John Janovec¹⁰, Segundo Oliva¹¹, Nicole Mitidieri¹, Luis Baquero¹², Gabriel Iturralde¹², Wilfrido de la Cruz¹³, Álvaro Pérez¹⁴, Marco Jiménez¹², Miguel Lozano¹⁷, Rebeca Menchaca¹⁷, Iván Tamayo-Cen¹⁸, German

Carnevali¹⁸, Henry Garzón¹⁵, Leisberth Vélez¹⁶, Yader Ruiz¹⁹, Kenneth Cameron¹

1 Department of Botany, University of Wisconsin-Madison, Wisconsin, USA. 2 Inka Terra Asociación, Madre de Dios, Perú. 3 Jardín Botánico Lankester, Universidad de Costa Rica, Costa Rica. 4 Royal Botanic Gardens, Kew, Richmond, UK. 5 Instituto de Biología, Universidad Nacional Autónoma de México, Mexico. 6 Herbario AMO, Miguel Hidalgo, Mexico. 7 Instituto Amazónico de Investigaciones Científicas Sinchi, Colombia. 8 Universidade Federal do Paraná, Brazil. 9 Caraguatatuba São Paulo, Brazil. 10 Sam Houston State University Natural History Museum, TX, USA. 11 Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas, Amazonas, Perú. 12 Universidad de Las Américas, Quito, Ecuador. 13 Fundación Pachamama, Puyo, Ecuador. 14 Pontificia Universidad Católica del Ecuador, Quito, Ecuador. 15 Herbario HA, Universidad del Azuay, Cuenca, Ecuador. 16 Herbario HUTPL, Universidad Técnica Particular de Loja, Loja, Ecuador. 17 Tropical Research Center-Universidad Veracruzana, Mexico. 18 Centro de Investigación Científica de Yucatán, Merida, Mexico. 19 Universidad de El Salvador, San Salvador, El Salvador

The biodiversity of the Neotropics presents an excellent opportunity to study different evolutionary phenomena. Early divergent lineages, such as the genus Vanilla, show promise as a system to test these processes. Despite their unique characteristics, including a wide floral diversity and specialization in complex ecological interactions, many aspects of the evolution, taxonomy, and ecology of the genus remain poorly studied. This project aims to generate a comprehensive and detailed phylogeny of Neotropical vanillas through an unprecedented international collaborative effort that includes extensive taxonomic sampling and the use of high-throughput sequencing techniques, specifically the Angiosperm353 probe set. We use the species tree generated as a framework to examine the evolutionary relationships of the group, the diversification rate of major clades, their biogeography, and the evolution of certain characters. At the same time, we propose a modern monograph of the group by integrating the molecular data we generate with field studies and an extensive review of herbarium collections. Among the preliminary results are: a tissue bank of over 400 samples, covering ~85% of the total Neotropical species, with 70% resulting from the ' fieldwork; and a matrix of over 2500 specimens (including herbarium samples and flowers in alcohol) from 43 examined herbaria. This project demonstrates how regional collaborative work and the exchange of capabilities at different levels can contribute to the study of our Neotropical flora, the most diverse on the planet.
## S.189.6 Assessing genomic diversity and taxonomic delimitation in the threatened Cooktown orchid species complex using target capture

Evelin Krol¹,²,³, Alicia Grealy³, Ashley R.

Field²,⁴, Mark Clements⁵, Keith Mc Donald⁶,

Heidi Zimmer⁵, Natascha D. Wagner¹,

Katharina Nargar²,³

¹Department of Systematics, Biodiversity and Evolution of Plants, Georg August University of Göttingen, Göttingen, Germany. ²Australian Tropical Herbarium, James Cook University, Cairns, Australia. ³National Research Collections Australia, Commonwealth Industrial and Scientific Research Organisation, Canberra, Australia. ⁴Queensland Herbarium, Department of Environment and Science, Mount Coot-tha Botanic Gardens, Brisbane, Australia. ⁵Centre for Australian National Biodiversity Research (Joint Venture between Parks Australia and CSIRO), Canberra, Australia. ⁶Queensland Museum, Brisbane, Australia

Conservation of wild species is a major responsibility given the global extinction crisis. Wild orchids face threats from illegal harvesting and trade, driven by demand for horticultural, ornamental, cosmetic, and medicinal use. For effective conservation management, it is crucial to accurately assess the genomic diversity of natural populations and determine their taxonomic boundaries. However, delimitation of species complexes in orchids remains a considerable challenge due to shallow

genetic differentiation and conflicting morphological and genetic signals resulting from hybridization. The Cooktown orchid complex (Dendrobium bigibbum s.l.) comprises epiphytes and lithophytes with striking purple-pink flowers, rendering it a popular group for horticulture. Spanning over 140,000 km², the complex primarily occurs in the subtropical Cape York Peninsula of Queensland (Australia) and represents the state's floral emblem. Its popularity has caused overcollection in easily accessible areas, resulting in local extinctions and taxa of this complex being classified as endangered or vulnerable under national legislation. Despite being of high public interest, the taxonomic delimitation remains unclear. Since its original description, multiple species, subspecies and varieties have been proposed. This study uses next-generation sequencing to disentangle the evolutionary relationships within the Cooktown orchid complex. Over 200 individuals across its geographic distribution and morphological diversity were sampled, including associated taxa as well as intermediate forms. We compared the performance of three target capture bait kits regarding informativeness and capture efficiency: a universal bait set for all flowering plants (Angiosperms353), a custom bait set for Orchidaceae (Orchidaceae963), and a lineage-specific custom bait set for *Bulbophyllum/Dendrobium*. Based on our assessment, we selected the best-performing kit to generate target capture data. Our results shed light on the evolutionary patterns and genetic diversity within this threatened orchid species complex, allowing for a reassessment of taxonomic delimitation and informing conservation management to protect Queensland's botanical treasure.

## S.190 NATURAL HYBRIDIZATION AND SPECIES CONSERVATION. SESSION 2

### S.190.1 You may say I'm a hybrid, but I'm not the only one: assuming the dilemma of species admixture in conservation

Draper, D.,* Laguna, E.², Marques, I.³

¹Center for Ecology, Evolution and Environmental Changes & Global Change and Sustainability Institute, Universidade de Lisboa, Lisbon, Portugal, ddmunt@gmail.com. ²Centro para la Investigación y la Experimentación Forestal de la Generalitat Valenciana Quart dePoblet, Valencia, Spain. ³Forest Research Centre & Associate Laboratory TERRA, Instituto Superior de Agronomía, Universidade de Lisboa, Lisbon, Portugal

Speciation through hybridisation is a complex and long evolutionary process occurring in nature, where several intermediate stages might oc-
<figure><img src="image_442.png" /></figure>

cur, all with divergent evolutionary outcomes and therefore, difficult to deal with in terms of conservation policies. The main existing tools to define conservation priorities are based on the delimitation of geographic areas and the elaboration of categorized lists of species usually prioritizing "pure species". Generally, these approximations are subsequently transposed into legislation (local, national or international) defining the uses and restrictions on the territories or taxa. The whole process has proven effective in most cases and has been adapted and updated throughout history. Yet, these conservation policies overlook any potential benefits in promoting the protection of hybrids. Despite potential advantages that many hybrids might have in facing environmental changes, they are often tagged with negative connotations: hybrids are not to be conserved as hybridization itself is a threat to the persistence of species. But even if we consider hybrids as a threat, there is an overall gap of knowledge limiting the success of any action or the creation of accurate guidelines to deal with hybrids. In this talk, we addressed the question of hybridization being considered a threat to species survival using 120,369 global species assessments available on the IUCN Red List Data. Altogether, the results showed that hybridization has been involved in species extinctions less often than thought, leaving the question: in what circumstances should hybrids be considered a threat? Should we only conserve natural hybrids? Considering the large evidence supporting the presence of hybrids, the debate dealing with the conservation of hybrids should be re-opened.

## S.190.2 Identifying climatic drivers of hybridization with a new ancestral niche reconstruction method

Ryan A. Folk¹, Michelle L. Gaynor²,³, Nicholas J. Engle-Wrye¹, Brian C. O'Meara⁴, Pamela S. Soltis²,⁵,⁶, Douglas E. Soltis²,³,⁵,⁶, Robert P. Guralnick²,⁶, Stephen A. Smith⁷, Charles J. Grady⁸, Yudai Okuyama⁹, Ryan A. Folk¹, Michelle L. Gaynor²,³, Nicholas J. Engle-Wrye¹, Brian C. O'Meara⁴, Pamela S. Soltis²,⁵,⁶, Douglas E. Soltis²,³,⁵,⁶, Robert P.

Guralnick²,⁶, Stephen A. Smith⁷, Charles J. Grady⁸, Yudai Okuyama⁹

1 Department of Biological Sciences, Mississippi State University, Mississippi State, MS, USA. 2 Florida Museum of Natural History, University of Florida, Gainesville, FL, USA. 3 Department of Biology, University of Florida, Gainesville, FL, USA. 4 Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA. 5 Genetics Institute, University of Florida, Gainesville, FL, USA. 6 Biodiversity Institute, University of Florida, Gainesville, FL, USA. 7 Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA. 8 Biodiversity Institute, University of Kansas, Lawrence, KS, USA. 9 Tsukuba Botanical Garden, National Museum of Nature and Science, Tsukuba, Japan

Applications of molecular phylogenetic approaches have uncovered evidence of hybridization across numerous clades of life, yet the environmental factors responsible for driving opportunities for hybridization remain obscure. Verbal models implicating geographic range shifts that brought species together during the Pleistocene have often been invoked, but quantitative tests using paleoclimatic data are needed to validate these models. Here, we produce a phylogeny for Heuchereae, a clade of 15 genera and 83 species in Saxifragaceae, with complete sampling of recognized species, using 277 nuclear loci and nearly complete chloroplast genomes. We then employ an improved framework with a coalescent simulation approach to test and confirm previous hybridization hypotheses and identify one new intergeneric hybridization event. Focusing on the North American distribution of Heuchereae, we introduce and implement a newly developed approach to reconstruct potential past distributions for ancestral lineages across all species in the clade and across a paleoclimatic record extending from the late Pliocene. Time calibration based on both nuclear and chloroplast trees recovers a mid- to late-Pleistocene date for most inferred hybridization events, a timeframe concomitant with repeated geographic range restriction into overlapping refugia. Our results indicate an important role for past episodes of climate change, and the contrasting responses of species with differing ecological strategies, in generating novel patterns of range contact among plant communities and therefore new opportunities for hybridization. The new ancestral niche method flexibly models the shape of niche while incorporating diverse sources of uncertainty and will be an important addition to the current comparative methods toolkit.
<figure><img src="image_443.png" /></figure>

## S.190.3 Recurrent natural hybridisation in Mediterranean Cyclamen: towards a conservation strategy for sites of ongoing evolution

Emmanuele Farris¹, Jordi López-Pujol², Alfredo Maccioni¹, Guillaume Papuga³, Virginie Pons⁴, Alfonso Susanna², John D. Thompson⁴, Roser Vilatersana²

1 University of Sassari, Sassari, Italy. 2 Institut Botan-ic de Barcelona (CSIC-CMCNB), Barcelona, Spain. 3 University of Montpellier, Montpellier, France. 4 Centre d'Ecologie Fonctionnelle et Evolutive-CNRS, Montpellier, France

Homoploid hybridisation gives rise to new lineages having the same chromosome numbers as parental species. Therefore the reproductive isolation of hy-brid individuals from parental ones is complex and slow. Moreover, homoploid hybrids act as a bridge between the two parental species, favoring intro-gression events among them. These often com-bined processes form hybrid zones where homo-ploid hybrid populations and introgressed parental populations coexist. This is the case for the western Mediterranean *Cyclamen* subgenus *Psilanthum*, composed of two closely related allopatric taxa (*Cyclamen repandum* and *C. balearicum*). *Cycla-men repandum* is a geographically widespread tax-on (central Mediterranean Basin), whereas the sec-ond is endemic to the Balearic Islands and the south of France west of the Rhône valley. In 2002, three small populations of *C. balearicum*, *C. repandum* and bicoloured flowers were discovered in northern Corsica. These populations grow on limestone out-crops in a disjunct, until then unknown, peripheral part of the distribution of the endemic species and in an ecologically marginal area for the widespread species. Further, based on floral traits and genetic variability, it was highlighted that bicoloured floral types in these populations were of homoploid hy-brid origin. Later a wide hybrid zone was discovered in north-western Sardinia, where bicoloured floral types dominate in hybrid populations, revealing a more advanced hybridisation process compared to Corsican populations. Recent findings showed that the cpDNA of all floral types in Sardinian popula-tions is of *C. balearicum* rather than *C. repandum*, highlighting a bi-directional asymmetric introgres-

sion. These findings emphasise the need for precise comprehension of ongoing hybridisation processes to plan appropriate conservation strategies. These should include both small areas with incipient hy-bridisation events (like in Corsica) and wide hybrid zones where reticulate introgression among paren-tal and hybrid lineages is the prevailing process on wide spatial scales (like in Sardinia).

## S.190.4 Species delimitation in intensively hybridising genera based on herbarium specimens – the CARRARA approach

Lara Escherich¹, Marco Dorfner¹, Frank H. Hellwig², Robert Vogt³, Christoph Oberprieler¹

1 University of Regensburg, Regensburg, Germany. 2 Friedrich-Schiller-University Jena, Jena, Germany. 3 Freie Universität Berlin, Berlin, Germany.

In contrast to polyploid species formation, the high fre-quency of homoploid hybridisation among flowering plant species poses an even harder problem for an objective discovery and naming of phytodiversity. The formation of so-called syngameons and of introgres-sive hybrid swarms are incompatible with the biological species concept (BSC) and urge for additional criteria to delimit species in plant taxonomy. Even greater prob-lems for species delimitation in hybridising plant groups arise when the biological situation is not studied and evaluated in the field, but a taxonomic judgement has to be based on herbarium specimens due to the deliber-ate or unavoidable abstinence from additional field work and/or the wilful usage of the rich treasure of plant specimens in museum collections. The different crite-ria stressed in the opposed species concepts varies among separate speciation events and are best con-sidered being just mere indicators for independently evolving metapopulation lineages (the 'unified species concept' of De Queiroz). The Carrara approach to spe-cies delimitation in intensively hybridising plant groups follows the idea of classifying metapopulation systems as infraspecific entities (subspecies) vs. species by dis-criminating between primary and secondary hybrid zones. By implementing high-throughput molecular techniques based on herbarium material (AFLPseq) in combination with the automated extraction of mor-phological characters and ecological niche-modelling based on museum material, we aim at the fast discov-
ery and delimitation of evolutionary significant units (species) without the necessity of additional field work. Our approach will be exemplified in two plant groups of the sunflower family (Compositae, Asteraceae) known for their critical taxonomy caused by extensive hybridization: the *Senecio nemorensis* syngameon (8 species) in Europe and the genus *Baccharis* L. in Chile (14 species, 26 hybrid combinations).

## S.190.5 The Iberian Peninsula as a major hotspot for white oak conservation and analysis of species syngameons

Carlos Vila-Viçosa¹,²,³,⁴, Ricardo Arraiano-Castilho⁵, Andrew L. Hipp⁶, Francisco M. Vázquez⁷, Rubim Almeida¹,²,³,⁴, Cristina García⁸, Albano Beja-Pereira¹,²,⁹, Herlander Azevedo¹,²,⁴

1 BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO. Campus de Vairão, Vairão, Portugal. 2 Research Center in Biodiversity and Genetic Resources - Research Network in Biodiversity and Evolutionary Biology, University of Porto. Campus Agrário de Vairão, Vairão, Portugal. 3 Museu de História Natural e da Ciência da Universidade do Porto - Herbário PO, Universidade do Porto, Porto, Portugal. 4 Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal. 5 Department of Ecology and Evolution, University of Lausanne, 115 Lausanne, Switzerland. 6 The Morton Arboretum, Lisle IL, USA. 7 Department of Forest Production and Vegetal Biodiversity, Institute of Agricultural Research "Finca La Orden Valdesequera", Guadajira, Spain. 8 Department of Biological Science. Centre for Evolution, Ecology and Behaviour, Royal Holloway University of London, Egham, Surrey, UK. 9 DGAOT, Faculdade de Ciências, Universidade do Porto, Porto, Portugal

The Iberian Peninsula is a wide known hotspot and refugia for the Eurasian white oak species. In classic literature, this group of oaks are traditionally assumed to form common hybrid swarms, and their resulting nothotaxa have suffered of nomenclatural uncertainty. This comes from natural history artifacts and the unknown validation of putative parent species, as valid taxa that have been suffering of distinct rankings, with no consensus by the broad that treated the Iberian oaks. Here, we aimed to re-assess the phylogeographic relationships among species and investigate the occurrence of hybrid swarms in marcescent oak species (Subsection *Macrantherae*) across the Iberian Peninsula,

disentangling putative hybridization and ancestral relationships. Towards this end, we used restriction-site associated DNA sequencing (RADSeq) to identify single nucleotide polymorphisms across the genomes of 275 samples representing eight widespread Iberian oak species, including infraspecific taxa and nothotaxa. Our results show that the marcescent oak species addressed in this study hold high levels of hybridization, validating several nothotaxa (Q.xcoutinhoi, Q.xcerrioides, Q.xsubpyrenaica, Q.xtlemcenensis) known to form hybrid swarms in particular biogeographic areas of the Iberian Peninsula, where sometimes they exclude at least one of the parental species. We discuss these results in the framework of the Iberian oak forests conservation, and the implications it brings to understanding the western Mediterranean biogeography. Finally, we conclude that binding taxonomic and biogeographic awareness, rooted in strong historical collections and literature review is of extreme relevance for solving difficult groups of plants displaying reticulate evolution.

## S.190.6 Supporting practitioners in the management of hybridization for the conservation and sustainable use of (genetic) biodiversity

Myriam Heuertz¹, Pauline Garnier-Géré¹, Juan Galindo², Peter Galbusera³, José Godoy⁴, Carles Vilà⁴, Sven Winter⁵, Katharina B. Budde⁶, Tsipe Aavik⁷, Maria Kachamakova⁸, Elena Bužan⁹, Cristiano Vernesi¹⁰, Laura D. Bertola¹¹, Milomir Stefanović¹², Frank E. Zachos¹³, Christina Hvilsom¹⁴, Aleksandra Biedrzycka¹⁵, Dragana Šnjegota¹⁶, Roberta Gargiulo¹⁷, Joukje Buiteveld¹⁸, Isa-Rita M. Russo¹⁹, Maud C. Quinzin²⁰, Belma Kalamujić Stroil²¹, Barbora Rolečková²², Ivaylo N. Tsvetkov²³, Craig Primmer²⁴, Pamela Burger²⁵, Tamer Albayrak²⁶, Snæbjörn Pálsson²⁷, Philippine Vergeer²⁸, Sabrina Träger²⁹,³⁰, Małgorzata Pilot³¹, Julia Barth³², Margarida Fernandes Lopes³³
1 BIOGECO, INRAE, Univ. Bordeaux, Cestas, France. 2 Centro de Investigación Mariña, Universidade de Vigo, Facultad de Biología, Vigo, Spain. 3 Centre for Research and Conservation, Royal Zoological Society of Antwerp, Antwerp, Belgium. 4 Estación Biológica de Donana, CSIC, Sevilla, Spain. 5 Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria. 6 Northwest German Forest Research Institute, Hann. Münden, Germany. 7 Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia. 8 Institute of Biodiversity and Ecosystem Research at Bulgarian Academy of Sciences. 9 University of Primorska, Faculty of Mathematics, Natural Sciences and Information Technologies, Koper, Slovenia. 10 Research and Innovation Centre, Fondazione Edmund Mach, Italy. 11 Department of Biology, University of Copenhagen, Copenhagen, Denmark. 12 Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Serbia. 13 Natural History Museum Vienna, Vienna, Austria. 14 Copenhagen Zoo, Copenhagen, Denmark. 15 Institute of Nature Conservation, Polish Academy of Sciences, Krakow, Poland. 16 Faculty of Natural Sciences and Mathematics, University of Banja Luka, Bosnia and Herzegovina. 17 Royal Botanic Gardens, Kew, UK. 18 Centre for Genetic Resources, the Netherlands, Wageningen University & Research, Wageningen, The Netherlands. 19 School of Biosciences, Cardiff University. 20 Independent researcher. 21 University of Sarajevo-Institute for Genetic Engineering and Biotechnology. 22 Institute of Vertebrate Biology, Czech Academy of Sciences, Brno, Czech Republic. 23 Forest Research Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria. 24 University of Helsinki, Finland. 25 Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria. 26 Burdur Mehmet Akif Ersoy University, Science and Art Faculty, Department of Biology, Turkey. 27 University of Iceland, Iceland 28 Plant Ecology and Nature Conservation Group, Wageningen University, Wageningen, The Netherlands. 29 Institut of Biology / Geobotany and Botanical Garden, Halle (Saale), Germany. 30 German Cen-

tre for Integrative Biodiversity Research, Halle-Jena-Leipzig, Leipzig, Germany. 31 Faculty of Biology, University of Gdańsk, Poland. 32 Zoological Institute, Department of Environmental Sciences, University of Basel, Basel, Switzerland. 33 Centro em Rede de Investigação em Antropologia, Pólo da NOVA FCSH, Campus de Campolide, Lisboa, Portugal

In the context of the ongoing biodiversity and climate crises, the conservation genetics community has a strong mission to support practitioners in suggesting the most useful and applicable management actions for the conservation of biodiversity, especially genetic diversity, and its sustainable use. Practitioners may have specific and variable knowledge on the effects of hybridization on biodiversity and a variety of views on its relevance in conservation strategies. To effectively support practitioners, we took advantage of the cooperation network of COST Action G-BIKE - Genomic Biodiversity Knowledge for Resilient Ecosystems - to consult practitioners, e.g., policy makers, natural areas managers, and coordinators of species action plans, from European countries about their experience, knowledge and perceptions with regard to hybridization in conservation and its management. We identified key actors in each country and presented them with a questionnaire to fill out either autonomously or through a guided interview. We interpret the results of the questionnaire in the context of the legal framework pertaining to hybridization in nature management in Europe. Furthermore, we derive recommendations combining common practices and current research findings for the management of hybridization in the most common situations or species where it occurs, in support of the conservation of genetic diversity and biodiversity more generally.

# S.191 CLIMATE CHANGE EFFECTS ON ALPINE PLANT SPECIES AND COMMUNITIES: INSIGHTS FROM THE GLORIA NETWORK. SESSION 1

## S.191.1 Emerging insights from global mountain research initiatives - MIREN & GLORIA meeting up at treeline

Peter Wolff¹, Svenja Wanke¹*, Anke Jentsch¹

1 University of Bayreuth, Germany *svenja.wanke@uni-bayreuth.de

We summarize and synthesize emerging insights from MIREN and GLORIA, including additional analyses on species reshuffling around the treeline eco-tone. MIREN: Climate change threatens plant diversity in mountains worldwide. Evidence suggests that plant species respond by changing their elevational ranges. The Mountain Invasion Research Network (MIREN)
<figure><img src="image_444.png" /></figure>

systematically quantifies global patterns of native and non-native species distributions along elevation gradients and shifts arising from interactive effects of climate change and human disturbance. GLORIA: Global evidence suggests that species from lower elevations are colonizing habitats on mountain summits at an accelerating pace, with five times faster rates than half a century ago. Repeated in situ surveys in permanent plots showed a widespread transformation of alpine plant community assemblages toward more warmth-demanding and/or less cold-adapted species. Concurrently to widespread increases in overall species richness, high elevation plant species have declined in abundance and frequency. Strongly cold-adapted plant species may directly suffer from warmer and longer growing seasons. We suggest the treeline ecotone to be the critical observational zone for species reshuffling in mountain environments. Although MIREN and GLORIA permanent plots do not match in location, they jointly provide clues on changing alpine plant community dynamics.

## S.191.2 Compositional shifts of alpine plant communities across the high Andes

Francisco Cuesta¹, Julieta. Carilla², Luis. D. LLambí³,⁴, P. Muriel⁵, María. V. Lencinas⁶, R. I. Meneses⁷, Kenneth. J. Feeley⁸, H. Pauli⁹,¹⁰, N. Aguirre¹¹, S. Beck¹², A. Bernardi¹,⁵, S. Cuello², S. A. Duchicela¹,¹³, P. Eguiguren¹¹, L. E. Gamez³, S. Halloy¹⁴, L. Hudson¹⁵, R. Jaramillo⁵, P. L. Peri¹⁶, L. A. Ramírez³, P. Rosero-Añazco¹, N. Thompson¹², K. Yager¹⁷, C. Tovar¹⁵

1 Grupo de Investigación en Biodiversidad Medio Ambiente y Salud - BIOMAS, Universidad de las Américas, Quito, Ecuador. 2 Instituto de Ecología Regional, Universidad Nacional de Tucumán - Consejo Nacional de Investigaciones Científicas y Técnicas, Tucumán, Argentina. 3 Instituto de Ciencias Ambientales y Ecológicas, Universidad de Los Andes, Mérida, Venezuela. 4 Consorcio para el Desarrollo Sostenible de la Ecorregión Andina, Lima, Peru. 5 Laboratorio de Ecofisiología, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador. 6 Centro Austral de Investigaciones Científicas, Consejo Nacional de Investigaciones Científicas y Técnicas, Tierra del Fuego, Argentina. 7 Instituto de Investigaciones Arqueológicas y Museo, Universidad Católica del Norte, San Pedro de Atacama, Chile. 8 Biology Department, University of Miami, Coral Gables, Florida, USA. 9 Institute for Interdisciplinary Mountain

Research, Austrian Academy of Sciences, Vienna, Austria. 10 Department of Integrative Biology and Biodiversity Research, University of Natural Resources and Life Sciences, Vienna, Austria. 11 Carera de Ingeniería Forestal, Centro de Investigaciones Tropicales del Ambiente y Biodiversidad, Universidad Nacional de Loja, Loja, Ecuador. 12 Herbario Nacional de Bolivia, Museo Nacional de Historia Natural - Instituto de Ecología, La Paz, Bolivia. 13 Department of Geography and the Environment, University of Texas at Austin, Austin, Texas, USA. 14 Ministry for Primary Industries, Wellington, New Zealand. 15 Jodrell Laboratory, Royal Botanical Gardens Kew, Surrey, UK. 16 Instituto Nacional de Tecnología Agropecuaria, Universidad Nacional de la Patagonia Austral, Consejo Nacional de Investigaciones Científicas y Técnicas, Santa Cruz, Argentina. 17 School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York, USA

Climate change is transforming mountain summit plant communities worldwide, but we know little about such changes in the High Andes. Understanding large-scale patterns of vegetation changes across the Andes and the factors driving these changes is fundamental to predicting the effects of global warming. We assessed trends in vegetation cover, species richness (SR) and community-level thermal niches (CTN) and tested whether they are explained by summits' climatic conditions and soil temperature trends. Between 2012 and 2017/2019, using permanent vegetation plots placed on 45 mountain summits and soil temperature loggers situated along a~6800 km N-S gradient, we measured species and their relative percentage cover and estimated CTN in two surveys (intervals between 5 and 8 years). We then estimated the annual rate of changes for the three variables and used generalized linear models to assess their relationship with annual precipitation, the minimum air temperatures of each summit and rates of change in the locally recorded soil temperatures. Over time, there was an average loss of vegetation cover (mean=-0.26%/yr), and a gain in SR across summits (mean=0.38 species m²/yr), but most summits had significant increases in SR and vegetation cover. Changes in SR were positively related to minimum air temperature and soil temperature rate of change. Most plant communities experienced shifts in their composition by including greater abundances of species with broader thermal niches and higher optima. However, the measured changes in soil temperature did not explain the observed changes in CTN. High Andean vegetation is changing in cover and SR and is shifting towards species with wider thermal niche breadths. The weak relationship with soil temperature trends could have resulted from the short study period that only marginally captures changes in vegetation through time.
<figure><img src="image_445.png" /></figure>

### S.191.3 Using multi-scale tools to detect how climate change affects alpine vegetation dynamics in subtropical moist region

Chu-Chia Kuo¹, Yu Su², Ho-Yih Liu³, Cheng-Tao Lin²*

1 Department of Biological Resources, National Chiayi University, Taiwan. 2 School of Forestry and Resource Conservation, National Taiwan University, Taiwan. 3 Department of Biological Sciences, National Sun Yat-sen University *oral speaker/corresponding author

Climate change is notably affecting natural vegetation, especially in mountainous regions. Alpine plants, adapted to harsh conditions such as cold, low nutrients, and high radiation, are particularly vulnerable to climatic shifts. Changes including uneven precipitation, increased droughts, and fewer rainy days significantly impact these plants. To assess the long-term effects on Taiwan's alpine vegetation, we established dynamic plots on 15 high mountain summits, aiming to study these impacts and develop conservation strategies. Our study used three methodological scales. On a landscape level, we employed the Standardized Precipitation Evapotranspiration Index (SPEI), Temperature Anomaly Index (TA), and Enhanced Vegetation Index (EVI) to link moisture balance with vegetation changes. Community-scale analysis involved examining alpine plant communities using moist-philic and thermophilic indices, diversity indices, and principal component analysis. At the species level, we assessed changes through climatic ecological niches to understand species richness variations. Our third survey revealed negative SPEI and extreme TA values, suggesting drought and high-temperature impacts. These conditions led to reduced plant growth, a decrease in EVI, fewer species, reduced diversity, and shifts towards species suited to warmer, drier environments. This suggests significant effects on Taiwan's alpine vegetation, decreasing its resilience to environmental disturbances. Considering ongoing climate change and its expected reduction in Taiwan's precipitation, our findings underscore the urgent threat of drought to alpine ecosystems, even in typically moist areas like Taiwan. Given the high sensitivity of alpine vegetation to these changes, proactive and robust conservation measures are critical to protect these vital ecosystems.

### S.191.4 Climate-driven loss of plant diversity in African mountains

JD Vidal Junior¹,², C Carbutt³, VR Clark², AJ Plumptre⁴, F Senbeta⁵, T⁶ Woldemariam, C Chapano⁷, C David⁸, L Aiah⁹, C Tovar¹⁰, E Lulekal¹¹, AS Uwase¹², M Kordofani¹³, B Kaplin¹⁴, A Antonelli¹⁰,¹⁵,¹⁶, T Pearce¹⁰, J White¹⁰, B Loeuille¹⁰, CB Langa¹⁷, IS Chelene¹⁷, T Fremout¹⁸, CB Schmitt¹

1 Universität Passau, Passau, Germany. 2 Afromontane Research Unit & Department of Plant Sciences, University of the Free State, Qwaqwa Campus, Phuthaditjhaba, South Africa. 3 Ezemvelo KZN Wildlife, Montrose, South Africa. 2 Afromontane Research Unit & Department of Geography, University of the Free State, Qwaqwa Campus, Phuthaditjhaba, South Africa. 4 Key Biodiversity Area, London, UK. 5 Addis Ababa Herbarium, Addis Ababa, Ethiopia. 6 Environment and Coffee Forest Forum (ECFF) Addis Ababa, Ethiopia. 7 National Herbarium of Zimbabwe, Harare, Zimbabwe. 8 University of Zambia, Lusaka, Zambia. 9 Njala University Njala Campus, Njala, Sierra Leone. 10 Royal Botanic Gardens, Kew, UK. 11 Addis Ababa University, Addis Ababa, Ethiopia. 12 National Herbarium of Rwanda University of Rwanda Huye campus, Huye, Rwanda. 13 University of Khartoum Herbarium Al-Gama'a Avenue, Khartoum, Sudan. 14 Center of Excellence in Biodiversity & Natl Res Management (CoEB), University of Rwanda, Huye campus, Huye, Rwanda. 15 Gothenburg Global Biodiversity Centre, Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden. 16 Department of Biology, University of Oxford, Oxford, UK. 17 Herbário LMA do Instituto de Investigação Agrária de Moçambique, Maputo, Moçambique. 18 Alliance of Bioversity International and International Center for Tropical Agriculture, Rome, Italy

Mountains host some of the most diverse and vulnerable communities of plants in Africa. With the 1.5 to 5 °C increase in temperature projected for the upcoming decades, it is hypothesised that plants will shift their distribution to track their environmental constraints along elevation and latitudinal gradients depending on their dispersal capacity. Responses like upslope and poleward shifts may result in accelerated rates of species turnover and amplified habitat loss in high elevations. Little is known about how such processes will transform the floristic composition of African mountains. Here, we apply a community-scale modelling approach to quantify and map how different climate change scenarios may affect species ranges and community richness
<figure><img src="image_446.png" /></figure>

of vascular plants in African mountains. Using niche models and dispersal buffers, we project the distributions of 416 species to three climate and land use change scenarios for the late century. Our comparisons between predicted ranges indicate that, without dispersal, species will lose an average of 22-52% of their suitable areas, depending on the SSP. We also observed a pattern of upslope elevational shifts and higher suitability losses for species occurring in higher elevations. Higher proportional losses are projected for ferns, herbs, and shrubs than for trees, with the highest losses projected for Southern Africa and Madagascar. Our results provide novel evidence for the disproportional impact of climate change on mountains and highlight target regions and species requiring more intensive conservation efforts and reforestation strategies, which need to improve the coverage of other life forms than trees. Furthermore, our findings emphasise that the current rate of change may be too rapid for some species to track based solely on their natural dispersal capacity, and alternatives like assisted migration must be carefully considered.

**S.191.5 Plant ecology of Mediterranean high-mountains and GLORIA: two decades of research synergies**

Alba Gutiérrez-Girón¹, Rosina Magaña Ugarte¹, Rosario G. Gavilán García¹

1 Complutense University of Madrid Pharmacy Faculty Department of Pharmacology, Pharmacognosy and Botany, Madrid, Spain

Since the establishment of the GLORIA monitoring area in central Spain in 2005, a series of plant ecology research projects have been carried out, which have allowed us to gain a deeper understanding of the ecology of this type of ecosystem. In these environments, in addition to the stress factors of temperate high mountain communities (short growing season, low temperatures, snowfall, limited soil development, etc.), the existence of a summer drought period is an additional determining factor. Presented here are the most important findings from the past twenty years about the ecology of these Mediterranean communities in the heart of the Iberian Peninsula, and their global and continental contexts are also briefly discussed. Topics covered include

the environmental influences on these communities composition, as well as their spatial and functional structure. Also discussed is the role of facilitative interactions in the structure of these communities. Additionally, C recycling research and the susceptibility of these ecosystems to changes to these cycles brought about by climate change have been addressed. Recent research has revealed that several species of the mountainous Mediterranean have developed unique physiological, metabolic, and morphological responses to water stress and photoprotection. Our understanding of the ecology of high mountain habitats in the Mediterranean has been enhanced by these contributions. Going forward, we are optimistic that the GLORIA monitoring data can provide additional insight on the ecosystems' vulnerability to the effects of climate change.

**S.191.6 Shift in vascular plant diversity across alpine ecosystems: insights from the Italian Gloria Network**

Silvano Lodetti¹, Alessandro Petraglia², Andrea Mondoni¹, Angela Stanisci³, Brigitta Erschbamer⁴, Elena Barni⁵, Ludovica Oddi⁵, Fiona Jane White¹, Graziano Rossi¹, Lena Nicklas⁴, Luciano di Martino⁶, Marcello Tomaselli², Margherita Tognela¹, Michele Carbognani², Pau Carnicero⁴, Pietro Fanchini¹, Simone Orsenigo¹, Valter di Cecco⁶, Francesco Porro¹

1 University of Pavia, Pavia, Italy. 2 University of Parma, Parma, Italy. 3 University of Molise, Termoli, Italy. 4 University of Innsbruck, Innsbruck, Austria. 5 University of Torino, Torino, Italy. 6 Majella National Park, Sulmona, Italy

Since 2001, the vegetation of 28 mountains has been monitored in the Italian Alps and Apennines across seven different GLORIA Target Regions (TR). The Italian Gloria Network aims to provide insights into how Italian alpine vegetation is responding to global warming. Here we present our preliminary findings regarding changes in species richness, species abundance and diversity. Species richness increased significantly in all TRs, with an average of +4.3 species per Summit Area Sections (SASs) recorded since the first survey. The
highest numbers of new species were recorded in the Alps sites, with an average of +21.5 species (+13% of the total species richness), in contrast to what has been observed for Apennine TRs (on average +7 specie; +7.4%). Local species loss was also observed but was not as pronounced and did not show clear patterns, ranging from 7 species lost in the Dolomites (S-Alps) to none in the Mont Avic (W-Alps). Species' abundance changed significantly, with "winning" and "losing" species becoming more dominant or rarer, respectively, highlighting an ongoing process of community change. The disproportionate increment of "winning species" led to an overall decrease in species evenness, especially in the Apennines, which com-

munities are becoming more dominated by fewer species. These findings highlight an alarming bio-diversity loss associated with a warmer climate. Overall, although local site diversity (alpha-diversity) increased in most TRs due to new colonizing species, diversity among sites (beta-diversity) decreased consistently across sites, due to site-specific species loss and turnover, revealing a trend of floristic homogenization in Italian mountains. Finally, we observed a generalized increment of species belonging to similar growth forms (e.g., graminoids). However, further multidisciplinary studies (e.g., SENTINEL project, started in 2023) are needed to fully disentangle the role of functional traits in driving vegetation dynamics.

# S.192 AN UPDATE ON THE PHYLOGENY OF SEED PLANTS. SESSION 1

## S.192.1 Fossil Mesozoic Seed Plants and their Utility

Patrick S. Herendeen¹

1 Chicago Botanic Garden, Glencoe, USA

Paleontology provides a unique window on the history of life. Fossils reveal biological diversity that is now extinct and will remain unknown unless fossilized remains of these organisms are discovered, described, and interpreted. Knowledge of extinct diversity is essential to understanding the full diversity and evolutionary history of plants or animals. Paleontological data can also illuminate the history of climate or biogeography or morphological diversity through time. However, consumers of paleontological data must be aware that the identifications of fossils have the potential to be wrong, just as the identifications of herbarium specimens can be wrong and must be verified by the investigator who is using the specimens. Similarly, the stated ages of fossils can be incorrect or lack precision. If the fossils are being used as calibration points for molecular dating analyses, for example, these sources of potential error must be taken seriously. These cautions notwithstanding, this is an exciting time in plant paleontology and the fields that draw on paleobotanical data. Mesozoic age fossil seed plants have been the subject of much research in recent decades. A diversity of early fossil angiosperms have been described from a wide variety of fossil sites, and re-

search is being conducted in geographic areas that were previously neglected. Documenting the morphology and timing of appearance of the earliest flowers continues to be of broad evolutionary and ecological interest. In addition, numerous fossil gymnospermous seed plants have also been described from many geographic areas and have included some very interesting newly discovered taxa. Understanding the origin of angiosperms and their phylogenetic relationships is important, but it cannot be accomplished without a detailed understanding of the diversity, morphology and relationships of gymnospermous seed plants. While much progress has been made there are still many discoveries to be made in the fossil record of gymnosperms.

## S.192.2 Current challenges and perspectives on seed plant phylogeny

Susana Magallón¹, Adriana Benítez-Villaseñor², Laura Calvillo-Canadell¹, César A. González-Martínez², Andrea M. López-Martínez², Eduardo Torres-Flores², Karina Yáñez-Aroche²

1 Institute of Biology, Universidad Nacional Autónoma de México, Mexico City, Mexico. 2 Graduate Program in Biological Sciences, Universidad Nacional Autónoma de México, Mexico City, Mexico
<figure><img src="image_447.png" /></figure>

Seed plants diversified profusely during the Paleozoic, giving rise to most of their major lineages, and a vast morphological and functional diversity. Reconstructing seed plant relationships has been a major challenge due to a deep conflict between morphological and molecular phylogenies. Here, we review some major challenges, summarize what has been learned, and propose potential ways forward. Representative sampling is a major obstacle because the number of extinct lineages vastly surpasses the five extant branches, and includes those derived from the earliest radiation of the group; extinct crown group lineages; and stem members of extant branches, which may hold clues to understanding relationships. The nature of plants typically results in fragmentary preservation and missing data. Recognition of the need to strive for whole plant reconstructions and to include species as terminals are important advances. Molecular phylogenetic estimation is complicated because extant species represent recent branches within lineages that diverged in the deep past. Molecular data has been shown to be systematically biased, and genomic datasets have not improved resolution. Paleobotanical discoveries and revised interpretations of fossil characters can critically improve phylogenetic estimation. Inconsistent taxon representation among different data sets precludes direct comparison of estimated relationships. Furthermore, different interpretations of primary homology, of structural attributes of particular fossils, and scoring philosophy result in phylogenetic lability. Analyses combining morphological and molecular data under model-based phylogenetic methods have been insufficiently exploited in the estimation of seed plant relationships, and implementation of novel approaches to model morphological character substitution hold promise. The Fossilized Birth-Death model, which integrates fossils and extant species into a single diversification process, may represent a potential alternative. Nevertheless, placement of fossils ultimately relies on morphological data, hence rigorous character assessment based on meticulous observations and thoughtful postulations of primary homology is inescapable.

## S.192.3 A synthesis of new phylogenetic insights from phylogenetic studies of living and fossil seed plants

Sarah Mathews¹

1 Department of Biological Sciences, Louisiana State University, Baton Rouge, USA

Analyses of morphological data sets are especially important when attempting to reconstruct phylogenies for clades whose diversity has been significantly reduced during historic periods of high extinction rates. Two such clades are seed plants, and one of its included clades, the cycads. These clades have evolutionary histories that increase the difficulty of accurate phylogenetic inference from molecular data: They are deeply diverged and extant members represent a fraction of their former diversity. In the case of cycads, of the forty described genera, just ten are extant. In seed plants, approximately 70% of its major lineages are extinct. Morphology thus provides a critical line of evidence in efforts to infer accurate phylogenies for these groups. In this study, we seek to address some of the challenges inherent in phylogenetic analyses of morphological data using recently assembled morphological data sets. First, different character sets within a matrix of living and fossil taxa may vary considerably in information content and may have discordant phylogenetic signals. We therefore are using a Bayesian approach to explore information content, and using Bayes Factors to explore discordance among characters and character sets that might lead to erroneous results and/or reduced resolution. Second, development of models of evolution for use in phylogenetic analyses of morphological data sets has lagged far behind that of models of nucleotide evolution. Recent advances have, however, enabled analyses to be conducted under more realistic assumptions about the evolution of morphological characters. We thus are inferring trees using Bayesian methods that allow different relaxed models of character evolution to be tested. We discuss results from these analyses and from analyses that integrate morphological and slowly evolving molecular characters, which aim to obtain a synthetic understanding of seed plant evolution.

## S.192.4 Dating the diversification of extant conifers

Andrew B. Leslie¹, Stephen A. Smith², Jeremy M. Beaulieu³

1 Earth and Planetary Science, Stanford University, Stanford, USA. 2 Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, USA. 3 Biological Sciences, University of Arkansas, Fayetteville, USA

Conifers are the most species-rich extant gymnosperms and have the longest and best-documented fossil history of any seed plant group, making them an excellent study system for investigating
<figure><img src="image_448.png" /></figure>

plant macroevolution. An accurate time-calibrated phylogeny is important for understanding their evolutionary history, and a number of studies have developed dated molecular trees for major conifer clades or the group as a whole. Except for the possible placement of Gnetales within conifers, backbone relationships among and within conifer families are generally stable across these studies, but inferred divergence ages vary widely depending on the dating method and calibration fossils used. Our previous work in this area used a Bayesian node dating approach and generated conifer divergence age estimates that appeared both too old for many deep nodes and too young for many shallow nodes, given paleobotanical intuition as well as more recent discoveries from Southern Hemisphere fossil assemblages. Angiosperm studies have shown that rate heterogeneity among clades can bias even sophisticated molecular dating analyses, particularly for deep nodes, and this phenomenon may be important in conifers given their long branch lengths and deep divergence ages. Here we develop an updated time-calibrated molecular phylogeny of conifers (as well as other gymnosperms) using a new node-dating approach that incorporates a hidden Markov model (HMM) in estimating divergence ages. This method allows different evolutionary rate classes to be assigned to different clades, which has been shown in simulation studies to improve divergence age estimates, particularly for deep nodes. We also suggest that node dating continues to be important for fossil plants, where important characters are often found in fragmentary remains like pollen grains that do not lend themselves to total evidence analyses.

## S.192.5 The rise and fall of Peltaspermales

Stephen McLoughlin¹

1 Department of Palaeobiology, Swedish Museum of Natural History, Stockholm, Sweden

Peltasperms are extinct seed plants with simple, forked, or variably dissected fern-like leaves having thick cuticle and sunken actinocytic stomata. Triangular ovules were borne on the underside of ovate or peltate appendages attached to a slender stalk. Clustered pollen sacs were arranged at the tips of loosely branched stalks. The attachment of reproductive and vegetative organs remains unresolved, but is critical to resolving their phylogenetic

placement. The pollen is monosulcate or tae-niate to non-taeniate bisaccate. Their wood and growth habit is unknown but they are commonly assumed to have been shrubs to trees of open habitats. Phylogenetic analyses have focused on only a few representatives of this palaeoecologically heterogeneous group. Past analyses have resolved a close relationship between Peltaspermales and Umkomasiales, but inferred affinities of these groups to other seed-plants vary widely. Peltaspermales were one of the few Paleozoic 'seed fern' clades to persist into the early Mesozoic. This order originated in the Late Carboniferous and diversified primarily within northern low- to middle-palaeolatitudes in the Permian. Several distinct groups have been recognized, generally occupying discrete regions during the Permian: supaioids (southwestern United States), callipteroids (european province), tatarinoids (Volga-Uralian region), and possibly comioids (palaeotropical belt). Peltaspermales sparsely penetrated Gondwana and Cathaysia in the mid-Permian. However, following the hyperthermal end-Permian extinction event, the family abruptly spread globally and Early Triassic *Lepidopteris/Germaropteris* species developed thick cuticles, strongly protected stomata and small leaflets adapted to hot and seasonally dry conditions. The family rediversified through the Triassic, encompassing forms with complex reticulate venation. *Lepidopteris ottonis* markedly increased in abundance near the end-Triassic extinction event and produced aberrant pollen suggesting major disruption to reproductive strategies. Peltaspermales disappeared during the end-Triassic Extinction Event apart from two relictual Jurassic occurrences.

## S.192.6 Mesozoic seed plants with recurved cupules and the stem relatives of angiosperms

Gongle Shi¹, Fabiany Herrera², Patrick S. Herendeen³, Elizabeth G. Clark⁴, Peter R. Crane⁵,⁶

1 Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, China. 2 Field Museum of Natural History, Chicago, USA. 3 Chicago Botanic Garden, Glencoe, USA. 4 University of California Berkeley, Berkeley, USA. 5 Oak Spring Garden Foundation, Upperville, USA. 6 Yale University, New Haven, USA
The "Mesozoic seed ferns", a loose group of extinct seed plants with cupulate ovulate reproductive organs, have long been considered to be key for understanding the origin of angiosperms. Traditionally this group has included *Caytonia*, *Petriellaea*, corystosperms, peltasperms and several other closely related groups of plants. However, most of these plants are known based on compression or impression fossils, hindering a detailed understanding of the structure and homology of their reproductive organs, and resulting in several distinct interpretations regarding the relationships of "Mesozoic seed ferns" with other extant and extinct seed plants. Recent discoveries and careful documentation of similar cupulate ovulate structures from the Early Cretaceous of Canada, Mongolia and China based on three-dimensionally preserved, lignified specimens, and anatomically preserved, permineralized material, have significantly

enriched our knowledge of the anatomy, structure and homology of these cupules. Careful comparisons suggest that the recurved cupules of *Caytonia*, *Doylea*, *Jarudia*, *Geminispermum*, *Kanaskoppia*, *Ktalenia*, *Petriellaea*, *Reymanownaea*, *Umkomasia* are all fundamentally the same. Differences among these Mesozoic seed plants in the number of cupules per lateral unit, the number of seeds per cupule and the degree of seed enclosure probably reflect differences in their pollination ecology and/or seed dispersal strategies. These recurved cupules are fundamentally comparable with the second integument of an anatropous angiosperm ovule. Phylogenetic analyses suggest that the likely stem relatives of angiosperms are among these Mesozoic plants, which has important implications for continuing efforts to understand the phylogeny of seed plants and the origin of angiosperms.

# S.193 THE ORIGIN AND EVOLUTION OF MODERN PLANT DIVERSITY: INSIGHTS FROM MULTIPLE DISCIPLINES. SESSION 1

## S.193.1 Approaching the 'odd-man-out' of tropical rain forest diversity with a global perspective of Annonaceae evolution and biogeography

Serafin J.R. Streiff¹ Francis J. Nge¹,²,
Laura Holzmeyer¹ Delphine Tardiff¹ Roy
H.J. Erkens³ Thomas L.P. Couvreur¹ &
Annonaceae Phylogenetics Consortium⁴

1 DIADE, Université Montpellier, CIRAD, IRD, Montpellier, France. 2 National Herbarium of New South Wales, Botanic Gardens of Sydney, Mount Annan, NSW, Australia. 3 Maastricht Science Programme, Faculty of Science and Engineering, Maastricht University, Maastricht, The Netherlands. 4 http://www.couvreurlab.org/agpc.html

The longitudinal distribution of tropical rain forest plant diversity presents a distinct 'odd-man-out' pattern: Neotropical and South East Asian forests are more biodiverse than their African counterparts. Un-

derstanding the contributing present and historical patterns and processes has remained challenging for decades. However, it promises to give important insights into the evolution, ecology and conservation of some of the simultaneously richest and most threatened floras of our planet. Focusing on the ubiquitous pantropical family Annonaceae with about 2450 species, we leverage a novel pipeline to curate, clean and merge herbarium specimen records from natural history collection databases, taxonomic revisions and publicly available biodiversity datasets. With these family-wide occurrences we produce species range estimates on a global scale allowing the generation of species richness maps across its distribution. We infer global and regional correlates of diversity and combine spatial data with a new species-level phylogeny of Annonaceae and modern methods of biogeographical inference to test environmental dependent diversification models using newly generated spatialized paleoclimatic simulations. Within this framework, we investigate longstanding questions on the evolutionary history and assembly of tropical rain forest floras and get one step closer to understanding the processes leading to the 'odd-man-out' pattern.
<figure><img src="image_449.png" /></figure>

### S.193.2 The evolution of phylogenetic community structure of the northern temperate flora

Qiuyue Zhang¹, Daniele Silvestro², Yaowu Xing¹

1. CAS, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, China. 2. Department of Biology, University of Fribourg, Fribourg, Switzerland

Understanding the causes and evolution of the phylogenetic community structure (PCS) in the geological past is critical to explaining present-day biodiversity patterns and modelling biotic responses to climate change. The paleontological record provides a unique window into the causes and evolution of community dynamics. In this study, we compiled a large fossil community data during the Cenozoic for the North temperate zone. We quantified PCS for different geological times. We then reconstructed paleoclimate for the fossil assemblages and fit it to PCS. We finally estimated diversification rates for woody and herbaceous plants to discuss the driving factors of the evolution of PCS. Our results showed that most fossil communities were dominated by woody taxa and there was no significant latitudinal gradient during the warm early Paleogene due to the homogeneity of the environment and similar rates for woody and herbaceous plants. The establishment of the PCS latitudinal gradient coincided with global cooling and increased seasonality and the flourishing of herbs at high latitudes. The PCS latitudinal gradient after the Middle Miocene was less steep than that of the Oligocene and closer to modern times. Our comprehensive analyses shed critical insights into the evolution of the PCS latitudinal gradients and its climatic and evolutionary driving forces.

### S.193.3 Late Cretaceous–Paleogene monsoon and vegetation evolution in South Asia

Gaurav Srivastava¹, Harshita Bhatia¹, Su Tao²,³, Sadanand¹, R.C. Mehrotra¹

1. Birbal Sahni Institute of Palaeoscience, Lucknow, India. 2. CAS Key Laboratory of Tropical Forest Ecolo-

gy, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, China. 3. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation & Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, China

The voyage of the Indian plate from the southern to the northern hemisphere took ~150 million years and experienced varied types of climate due to changing insolation at different palaeolatitudes. This makes the biota of the Indian plate unique and a perfect natural laboratory that offers a peculiar opportunity to understand the vegetation-climate relationship during the late Cretaceous–Paleogene. During this journey, India acted as a biotic ferry and facilitated the migration of biota from Africa to Asia. Besides this, India also acted as a homeland for several biota such as *Ipomoea* of Convolvulaceae from the late Paleocene, *Olea* of Oleaceae, *Eucalyptus* of Myrtaceae, and Burseraceae from the Maastrichtian–Danian sediments of Deccan Intertrappean beds. The plant fossil data compelled to believe that orders such as Sapindales, Myrtales, Solanales, and Lamiales have roots in east Gondwanaland. Moreover, the climatic reconstruction based on leaf physiognomy and nearest living relative methodologies suggests a warm and humid climate with seasonal rainfall during the entire journey of the Indian plate. The leaf morphological traits of fossils and modern forests also inferred an Indonesian–Australian type of monsoon during the Late Cretaceous–Paleogene.

### S.193.4 Exploring an enigma – the geographic and temporal origins of the Western Ghats flora

Madhavi Sreenath¹,², Mark Hughes¹,², Catherine Kidner¹,², Rengaian Ganesan³, Gudasalamani Ravikanth³

1. Royal Botanic Garden Edinburgh. 2 University of Edinburgh. 3 Ashoka Trust for Research in Ecology and the Environment

The Western Ghats are an ancient mountain range with an origin dating back to the Late Jurassic, and an extraordinarily diverse and endemic flora. The biodiversity of these sky islands has been influenced by the separation of India from Gondwana during the Late Jurassic period, and its ultimate collision with the Eurasian plate in the Late Cretaceous. As a consequence, the flora of the Western Ghats has the potential to have accreted from several regions, in-
cluding Africa, the Himalayas, Continental Asia, and the Sunda Shelf. There is an emerging paradigm of tropical floras being geologically young and driven by high rates of species turnover. However, the unique journey of the Indian subcontinent alludes to the presence of an entirely unique floristic diversity in the Western Ghats. The aim of this project was to understand the temporal and geographic origins of the Western Ghats flora. A herbarium genomics approach was employed (Whole Genome Sequencing) to assemble DNA regions of species native or endemic to the Ghats and incorporate them into existing phylogenetic datasets of plant families with wider tropical distributions. Time-calibrated phylogenies and ancestral range evolution models were used to provide a synthetic view of the flora's origins using the families Annonaceae, Begoniaceae, Chloranthaceae, Dipterocarpaceae, Ebenaceae, Lauraceae, Sapotaceae, and Zingiberaceae as representatives. The ancestral area reconstructions show that the Western Ghats flora originated predominantly from the regions of Continental Asia and the Sunda Shelf during the Miocene-Pliocene period, showing a flora strongly influenced by geologically recent dispersal rather than ancient vicariance.

### S.193.5 Angiosperms preserved in Mexican amber: towards the integration of Neotropical Flora

Ana L. Hernández-Damián, Sergio R. S. Cevallos-Ferriz

Department of Paleontology, Instituto de Geología-UNAM, Mexico City, Mexico

The Neotropics stands out as a region that harbors remarkable biological diversity, especially within the group of angiosperms or flowering plants. A comprehensive understanding of the origin of this biodiversity involves the integration of the fossil record, which, unfortunately, is scarce in this area. Bioinclusions of angiosperms preserved in Mexican amber emerge as a unique source of information. Their relatively recent antiquity, corresponding to the Miocene (approximately 23-15 Mya), provides valuable insights into the recent history of vegetation in the region. The Miocene period appears to have played a crucial role in the "modernization" of vegetation, as the angiosperms identified in Mexican amber are strikingly like contemporary plants. This phenomenon suggests a process of evolution and adapta-

tion over time. This study focuses on reports of angiosperms in Mexican amber, identified as extinct members of the Staphyleaceae, Celastraceae, and Leguminosae families. These findings reveal a closer biogeographical connection with floristic elements of the Paleotropics, supporting the notion of a link between tropical regions through intercontinental dispersal routes during the Cenozoic, known as the Boreotropical Flora. To validate this hypothesis, it is essential to continue documenting the diversity of flowering plants in Mexican amber deposits. Analyzing current lineages with disjunct distribution patterns will allow the development of a more robust biogeographical hypothesis. This comprehensive approach will significantly contribute to our understanding of the evolution of biodiversity in the Neotropics and interconnections over geological time.

### S.193.6 Ecuadorian páramos: towards a checklist of the vascular Flora

K. Romoleroux¹, P. Muriel¹, P. Sklenář², C. Ulloa³, D.A. Espinel-Ortiz¹, C. Romoleroux¹, J. Calvo

1 Laboratorio de Botánica Sistemática. Pontificia Universidad Católica del Ecuador. Quito, Ecuador. 2 Department of Botany, Charles University in Prague. Praga, República Checa. 3 Missouri Botanical Garden, Missouri, USA. 4 Conservatoire & Jardin Bot Geneve, Ginebra, Suiza

The Ecuadorian páramos constitute a complex and heterogeneous biome, integrated by several ecosystems, whose plant composition vary according to climate, altitude, geology, biogeographic history, and disturbance degree. The uplift of the Andes and the Pleistocene glacial and interglacial events, in addition to anthropogenic activities, helped to consolidate the Andean plant communities. The present work is based on bibliographic data, field work, and the revision of herbaria collections, particularly QCA and MO. In our work, we have recorded 1897 vascular plant species, which is the highest number of species cited for this biome in Ecuador, (1682 Angiosperms, 210 Pteridophytes and five Gymnosperms), of which 1161 are native, 699 are endemic to Ecuador and 37 are introduced. We found that the 10 most diverse families in this biome were: Asperaceae, Orchidaceae, Poaceae, Melastomataceae, Campanulaceae, Cyperaceae, Rosaceae, Ericaceae, Polypodiaceae, and Lycopodiaceae; whereas the 10 richest genera were: Epidendrum, Elaphoglossum, Phlegmariurus, Calceolaria, Senecio, Gentianella, Valeriana, Miconia, Gynoxys, and Carex. Ecuadorian páramos
have a high percentage of endemism (40%), especially in the narrower and more fragmented altitudinal belt, these unique species contribute to the formation of complex communities that change from north to south and along altitudinal gradients. Although these páramos contain one of the highest numbers of native and endemic species in relation to their area, they are very

vulnerable to environmental changes and other anthropogenic processes, that is why most of these species are now endangered. It is necessary to continue with the study of the páramos to have a complete and updated checklist of the flora species, which will serve as a basic tool for conservation and decision-making processes in this important Andean landscape.

# S.194 ECOLOGY, EVOLUTION AND GENETICS OF STYLAR POLYMORPHISMS: LINKING FORM & FUNCTION

## S.194.1 Deep homology or convergence? Comparative genomics elucidates the origins of the heterostyly supergene

Elena Conti¹, Barbara Keller¹, Narjes Yousefi¹, Emiliano Mora Carrera¹, Irina Gavrilina¹, Giacomo Potente¹

1 Department of Systematic and Evolutionary Botany, University of Zurich, Switzerland

The rapid accumulation of high-quality reference genomes now enables us to re-examine long-standing questions on evolutionary convergence: Does convergence at the phenotypic level correspond to shallow convergence or deep homology at the genotypic level? Do the same genes and genetic architectures underlie convergent traits or can different genes be recruited to achieve the same phenotypic outcome? Heterostyly in Primulaceae represents an ideal system to investigate these questions. Found in 28 families of flowering plants, heterostyly refers to the co-occurrence in a population of different plants characterized by self-incompatible floral morphs with reciprocally placed male and female sexual organs, a combination promoting outcrossing while restricting selfing. Originally investigated by Darwin in *Primula*, heterostyly in this genus is now known to be controlled by the S-locus, a hemizygous supergene comprising a minimum of four genes with paralogues elsewhere in the genome. Published phylogenetic analyses of trait evolution showed that heterostyly evolved independently three times in Primulaceae, namely in the ancestor of *Primula*, in *Hottonia palustris*, and in *Androsace vitali-

ana. However, it remains unknown whether the genes determining heterostyly also evolved multiple times concomitantly with heterostyly or were already present in the common ancestor of the three heterostylous lineages but were subsequently lost in non-heterostylous relatives. To test the alternative predictions stemming from these two hypotheses, we generated highly contiguous, chromosome-scale, haplotype-phased assemblies of heterostylous and non-heterostylous genomes of Primulaceae and performed comparative genomic analyses across Ericales, the order that includes Primulaceae. Preliminary results suggest that the three independent origins of heterostyly inferred via phylogenetic analyses of trait evolution might stem from both deep homology of duplicated S-locus genes and genetic reinvention. Primulaceae thus represent an ideal system to clarify the connections and disconnections of evolutionary convergence from the genotypic to the phenotypic level and back.

## S.194.2 What we do and don't know about stylar polymorphisms in flowering plants

Spencer C.H. Barrett¹

1 Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada

Among the most remarkable floral strategies in flowering plants are those involving stylar polymorphisms. Unlike the majority of angiosperms with continuous phenotypic variation in style and stamen deployment, species with stylar polymorphism have discrete patterns of sex-organ variation and populations with
<figure><img src="image_450.png" /></figure>

morphologically identifiable, genetically controlled
floral morphs. The most well-known stylar polymor-
phisms are distyly and tristyly. Since Darwin's classic
book on heterostyly – "Forms of Flowers" – ecologists
and evolutionary biologists have been fascinated by
the origins and adaptive significance of these poly-
morphisms. We now know that at least some of these
polymorphisms are controlled by linkage groups com-
posed of major genes, and that they are maintained
in populations by negative frequency-dependent se-
lection resulting from disassortative mating between
morphs. Work on unrelated distylous and tristylous
species has revealed much about the variation in
expression and the functions of the various compo-
nents of the heterostylous syndrome. However, our
understanding of the other four classes of stylar poly-
morphism – stigma-height dimorphism, enantiostyly,
flexistyly and inversostyly – is far less complete. Here, I
summarize what we currently know about the six sty-
lar polymorphisms in an effort to synthesize similari-
ties and differences between the polymorphisms and
general principles that may apply to all of them. I fo-
cus on recent work on three main topics: 1) the genet-
ic architecture of distyly and tristyly supergenes and
patterns of molecular convergence among unrelated
lineages; 2) efforts to understand the molecular un-
derpinnings of enantiostyly and flexistyly; 3) the ecolo-
gy and evolution of breakdown in the maintenance of
stylar polymorphisms and the genomic consequenc-
es of the resulting transitions in the mating biology
of populations. I conclude by highlighting unresolved
questions in the study of stylar polymorphisms and
why these polymorphisms remain attractive systems
for the study of adaptation and evolution.

S.194.3 Telling left from right
- the genetic and molecular
basis of enantiostyly
in Wachendorfia and
Barberetta

Haoran Xue¹, Kelly Shepherd², Oliver
Marketos², Olivia Page-Macdonald²,
Caroline Robertson², Christian Kappel¹,
Robert Ingle², Nicola Illing², Michael Lenhard¹

1 University of Potsdam, Potsdam, Germany. 2 Uni-
versity of Cape Town, Cape Town, South Africa

Telling left from right is a difficult task for organisms,
as the two sides can only defined by reference to
two other axes. While genetically encoded left-right

asymmetry is found in many animals, it is very rare
in plants. One example is the mirror-image flowers
of *Wachendorfia* and *Barberetta*. Species of these
two closely related genera show enantiostyly, i.e.,
they form flowers with the style deflected to the left
of the midline and one of the three stamens to the
right, or with the opposite arrangement. All flowers
on one individual have the same handedness, indi-
cating genetic control. Functionally, the reciprocal
placement of the stigma and the opposing anther
promotes pollen placement on segregated sites
of the pollinators' bodies and efficient transfer to
stigmas of the opposite morph. We are investigat-
ing the genetic, molecular and developmental ba-
sis of mirror-image style and stamen deflection in
*Wachendorfia* and *Barberetta*. Genome assemblies
and pooled sequencing of left- and right-morph
individuals from natural populations have identi-
fied a hemizygous region whose presence causes
right-styled flowers, whereas plants lacking this re-
gion form left-styled flowers. This region contains
two conserved genes throughout all the species
tested, one of which is expressed in the developing
stamen, the other in the style around the time when
the organs begin to deflect from the midline. Efforts
to assign functions to these genes are ongoing.
Identification of the hemizygous region opens up
the possibility of assaying realized mating patterns
in natural populations and testing the efficiency of
enantiostyly in promoting disassortative mating.
Thus, our results pave the way for a mechanistic un-
derstanding of left-right asymmetry in plants and its
impact on plant reproduction.

S.194.4 Breakdown of distyly
in tropical Rubiaceae:
breeding system and
morphometric changes

Paulo E. Oliveira¹, Renata T. Telles², João
C. Cardoso³, Ebenezer B. Rodrigues¹,
Christiano P. Coelho⁴, Helder N. Consolaro⁵

1 Universidade Federal de Uberlândia, Uberlândia, Brazil. 2 Universidade Estadual de Campinas, Campinas, Brazil. 3 Universidade Federal de Ouro Preto, Ouro Preto, Brazil. 4 Universidade Federal de Jataí, Jataí, Brazil. 5 Universidade Federal de Catalão, Catalão, Brazil

The Rubiaceae is a widely distributed, megadiverse
angiosperm family. Distyly is the prevalent floral sys-
tem in many Rubiaceae, especially in the Brazilian
<figure><img src="image_451.png" /></figure>

Cerrado and other tropical environments. Besides two floral morphs with reciprocal stigma and stamens heights, distyly is associated with a heteromorphic incompatibility system and other ancillary morphological traits. Since the majority of Rubiaceae depends on precise biotic pollination services for their reproductive success, distyly is vital for their persistence. Nevertheless, morphological changes followed by the loss of floral polymorphism are common, leading to anomalous species or populations displaying homostyly, monomorphism or even dioecy. These reproductive transitions have occurred repeatedly in the Psychotrieae alliance, which includes the most speciose distylous genera, *Palicourea* and *Psychotria*. Anomalous distyly cases do not show any clear phylogenetic clustering, but seem to be associated with anthropized/disturbed or island environments, and inefficient pollination. As in other distylous groups, these changes have been explained by sudden mutation events within a supergene model, which include both morphological and self-incompatibility alleles. However, community-wide approaches have shown that distylous Rubiaceae lack precise reciprocity in the height of their sexual organs, often displaying higher inaccuracies either in low or higher organs. These changes seem to be linked to reduced floral integration, possibly under pressure from the loss of precise pollination, which seems to be required for efficient distyly functioning. The losses of ancillary features and reciprocity are often associated with less strict self-incompatibility. We suggest here that the reduction of floral integration and reciprocity, besides other ancillary features associated with distyly, may be intermediate transition stages. In more advanced stages, these changes may lead to a complete breakdown of the system. Such trends can be used as indicators of environmental pressures on distyly functioning.

Acknowledgments: We thank CAPES, CNPq, and FAPEMIG for funding.

**S.194.5 Shift in pollinator effectiveness results in chronic pollen limitation in an enantiostylous, buzz-pollinated species**

Alice L.M. Fairnie¹, Babu Ram Paudel², Kelly Shepherd³, Sam McCarren³, Eva Deinum⁴, Rob Ingle³, Lawrence D. Harder⁵, Bruce

Anderson⁶, Nicola Illing³, Spencer C.H. Barrett¹

1 University of Toronto, Ontario, Canada. 2 Tribhuvan University, Kathmandu, Nepal. 3 University of Cape Town, Cape Town, South Africa. 4 Wageningen University & Research, Wageningen, The Netherlands. 5 University of Calgary, Canada. 6 Stellenbosch University, Stellenbosch, South Africa

Diverse floral mechanisms have evolved in angiosperms to promote cross-pollination and outcrossed mating. One such innovation is the sexual polymorphism enantiostyly ('mirror-im age flowers') where styles are deflected either left (L), or right (R) of the flower's midline. This asymmetry is usually associated with heteran thery, the structural specialization of anthers for feeding and pollinating functions. Pollinating anthers are reciprocally positioned to the style pro moting bee-mediated cross-pollination between flowers of opposite 'handedness' by 'buzz-pollin ating' bees. *Cyanella* has nine species mostly endemic to the Western Cape, South Africa; six are straight-styled and two possess enantiosty ly. Here, we present current research on *C. alba* using multiple populations in the Biedouw valley and Bokkeveld plateau, all of which contained three sex phenotypes – left- and right-handed plants and those with a mixture of both flow er types (L, R, M, respectively). Surveys of hand edness revealed average frequencies of L=0.47, R=0.43, M=0.10 among 15 populations with an av erage daily display size of 1.6 flowers. Censuses of marked plants throughout two seasons in three populations revealed an increase in M frequen cy concomitant with decreases in L or R plants. Controlled crosses demonstrated moderate self-incompatibility, with plants incapable of au tonomous self-pollination. Comparisons of open versus controlled cross-pollinations revealed chronic pollen limitation of seed set. Despite 74 hours of observation, we observed only two short visits by buzz-pollinating bees and most flower visits were by beetles. Observations of stamen dimorphism at the northern range edge suggest that heteranthery may be breaking down in some populations enabling generalist pollination, per haps in response to the absence of visits by bees capable of buzz pollination. *Cyanella alba* plants display few flowers daily and this could enable enantiostyly to function effectively without ge netic determinism of floral polymorphism. Break down of heteranthery in some populations has probably resulted from a lack of buzz pollination.
<figure><img src="image_452.png" /></figure>

**S.194.6 Pollinator composition explains the symmetry of pollen transfer between floral morphs of a distylous species.**

Javier Valverde¹

1 Universidad de Sevilla, Seville, Spain

Populations of distylous species are composed of individuals of two floral morphs that exhibit contrasting but reciprocal spacial arrangement of sexual organs: in the short-styled morph (S-morph), stigmas are located below the anthers, while in the long-styled morph (L-morph) this arrangement is reversed. This feature predicts cross-pollination between morphs, promoted by the morphological fit of pollinators to flowers and sexual organs. However,

it has been reported that the pollination process can occur more efficiently in one direction (from L- to S-morph flowers or vice versa), suggesting a sub-optimal efficiency of the pollinator assemblage. This study analyses the relationship between pollinator composition and pollination efficiency in 16 populations of a distylous species. Pollination efficiency at each population and direction was assessed by quantifying pollen deposition and pollen tube growth through epifluorescence microscopy. The data shows inter-population variation in the efficiency of pollen flow, which was explained by the composition of the pollinator assemblage. In particular, in populations with a lower proportion of visits from a beefly genus, pollen flow from L- to S-morph flowers occurred less efficiently. This result points to suboptimal pollination as a driver of asymmetrical pollen flow in distylous species and highlight the importance of pollinators in the proper functioning and probably evolutionary maintenance of distyly.

**S.195 BEYOND PLANT BLINDNESS: BRINGING PLANTS INTO THE FOREGROUND**

**S.195.1 Children's perception and plant identification knowledge: Using drawing to tackle emic perspective.**

Vincent Porcher¹,², Sandrine Gallois², Victoria Reyes-García²,³, Stéphanie Carrière¹

1 Institut de Recherche pour le Développement, UMR SENS, Montpellier, France. 2 Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona, Barcelona, Spain. 3 Catalana de Recerca i Estudis Avançats, Barcelona, Spain

In small-scale societies, people learn to identify plant species during childhood. Plant recognition is an important baseline knowledge, immediately useful to avoid intoxication risk due to wrong identification. Plant recognition is at the basis of other ethnobotanical knowledge. However, despite many studies on folk classification, we still have a narrow understanding of the criteria locally used for species identification; the gap being even larger regarding children's plant identification criteria. Here, we study the criteria used by Betsileo

children and adolescents to identify wild edible plant (WEP) species using a child-adapted method including drawings and follow-up interviews. We worked with 80 teenagers (from 12 to 17 years old; 51 girls, and 29 boys). Our results suggest that teenagers use a large spectrum of visual criteria to identify plants and that these criteria match with botanical and ecological knowledge documented in the literature and herbarium vouchers. We found that 35% of the identification criteria used were non-morphological (e.g., phenology, biotic interactions), suggesting deep ecological knowledge. On average, teenagers use more than nine distinct criteria per plant, which allows them to identify most plant species with a very high level of precision. The precision level of plant representation increases with age for boys, but remains constant for girls, suggesting different dynamics in plant identification knowledge acquisition. We also found that boys and girls use different identification criteria: girls focus on morphological criteria while boys also incorporate ecological criteria, such as landscape features and biotic interactions, in their spectrum of identification keys. Our results highlight the complexity of teenagers' plant knowledge and the importance of the ecological
<figure><img src="image_453.png" /></figure>

context for plant identification. Finally, our finding suggests that gender plays an important role in plant identification's knowledge acquisition, probably because gender differentiates daily interactions with plants.

## S.195.2 Ethnobotany fosters the interest on plants. Different ways of returning knowledge to society in the Catalan linguistic area

Teresa Garnatje¹,², Airy Gras³, Montse Parada³, Joan Vallès³,⁴

1 Institut Botànic de Barcelona, CSIC-Ajuntament de Barcelona, Barcelona, Catalonia, Spain. 2 Jardí Botànic Marimurtra - Fundació Carl Faust, Blanes, Catalonia, Spain. 3 Universitat de Barcelona, Barcelona, Catalonia, Spain. 4 Institut d'Estudis Catalans, Barcelona, Catalonia, Spain

Plant blindness -or, at least a certain degree of plant myopia- does exist, as plants are often either neglected by people as objects of interest or much less considered than animals, the latter probably reflecting phylogenetic proximity and empathy. This concerns people in many aspects of their lives, and even students at different levels in academic subject preferences. Nevertheless, it is also true that there is an extended interest of people in nature, natural products useful for many purposes, and biodiversity. Ethnobotanical research can undoubtedly contribute to attracting general people's attention to plants, for different reasons. First of all, for its multidisciplinarity, for its situation in the interface between social and natural sciences, for highlighting biocultural aspects of plants. Secondly, for its important component of citizen science, in which academic and popular knowledge converge. Finally, for the ethical commitment that an ethnobotanist has to return to society (and not only to the scientific community, as is logical in any research) the knowledge that comes from it. In this communication, we delve into the ways our research team employed on ethnobotany of the Catalan linguistic area. Our objective is to disseminate the traditional knowledge on plant biodiversity and to try to increase people's interest in plants, their names and uses and their management. Different kinds of outreach publications, an open-access webpage, educational issues, conferences, practical workshops are powerful

instruments to capture people's attention for plants and their biocultural aspects, and, therefore, to diminish the extent of plant blindness.

## S.195.3 Unveiling plant blindness through mental models

Peter Pany¹,², Manuel Eichler¹, Benno Dünser¹, and Michael Kiehn¹

1 University of Vienna, Vienna, Austria. 2 University College of Teacher Education Vienna, Vienna, Austria

This study addresses the widespread problem of 'plant blindness', a phenomenon characterised by the neglect of plants in both everyday perception and educational settings. Focusing on 162 students aged 6-18, the research uses drawings as a tool to uncover their mental models (internal representations of concepts and ideas), providing insights into the depth of their understanding and attention to plants, trees, flowers, and grass. Through the analysis of drawings, the study examines the mental models associated with these botanical terms, shedding light on the prevalence of plant blindness and the simplification of ideas related to plants. The results show that the term 'tree' serves as a reliable indicator of how complex plants are perceived in nature and depicted in drawings. In particular, the study reveals consistency in mental models across age groups, highlighting common features in plant representations. Statistical analyses reveal age-related anomalies and changes in certain features of mental models. Notable findings include an increased occurrence of leaf veins from around 8-9 years of age. These findings contribute to a nuanced understanding of how students' perceptions of plants develop over the course of their schooling. Comparisons with previous research show consistency with existing findings. However, this study introduces new insights, such as the age-related emergence of specific features in mental models. These findings provide opportunities to optimise teaching strategies, address knowledge gaps and potentially reduce plant blindness. In addition, the study establishes a link between the term 'tree' and the detailed perception of plants in the environment, suggesting that drawings can be a valuable tool for assessing students' knowledge of plant structure and anatomy. Standardised methods of investigation using drawings may facilitate the identification of plant blindness within groups of students, providing a practical means of improving botanical education.
<figure><img src="image_454.png" /></figure>

**S.195.4 Beyond plant
awareness disparity:
intangible relationships with
plants among ethnobotanical
experts in the Catalan
Pyrenees**

Joaquim Querol¹, Álvaro Fernández-Llamazares¹,², Teresa Garnatje³, Joan Vallès⁴,⁵, Ariadna Casadevall⁵, Alba Garet⁵, Sandrine Gallois¹

1 Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain. 2 Unitat de Botànica, Departament de Biologia Animal, Biologia Vegetal i Ecologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain. 3 Institut Botànic de Barcelona, CSIC-Ajuntament de Barcelona, Parc de Montjuïc, Barcelona, Catalonia, Spain. 4 Laboratori de Botànica, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, Catalonia, Spain. 5 Institut d'Estudis Catalans, Barcelona, Catalonia, Spain f Department of Anthropology, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain

Although plants contribute to human well-being, their importance is vastly underestimated. This socio-psychological phenomenon, widely known as Plant Awareness Disparity (PAD), has been studied by looking at people's knowledge of plants, their interest on them, the level of attention they pay to them, and their general attitudes towards their conservation. Yet, the emotional dimensions, encapsulated through our intangible relations with plants, have been largely undervalued in the study of PAD. Moreover, while PAD has been documented among mostly urban and industrialized settings, traditional plant-related wisdom of rural communities is virtually absent from this discussion. This study explores the intangible relations between local ethnobotanical knowledge holders and plants at three levels – communal, familial, and individual – by exploring diverse aspects of expressive culture such as stories, songs, and personal recollections anchored in lived experiences. We propose a methodological approach to document and characterize these intangible connections with plants and recognize them in the study of PAD. In-depth interviews were conducted among 22 recognized ethnobotanical knowledge keepers in the Camprodon Valley (Catalan Pyrenees, Spain). Exhibiting notably low PAD levels, our informants reported a myriad of cultural, familial, and individual expressions of their bonds with the shared botanical heritage of the valley, including 36 distinct sayings, 53

anecdotes, 27 traditions, and 31 family customs. Our findings shed light on the intricate relations between humans and plants in rural communities, largely underpinned by emotional connections and a sense of cultural identity. These findings hold large implications for studies aimed at gauging plant awareness and quantifying PAD levels, while underscoring the breadth and depth of humans' many intangible relationships with the plant worlds around them.

**S.195.5 Can plant blindness be detected on the vocabulary level: poor descriptions of personally important plants, in Tartu, Estonia**

Raivo Kalle¹, Andres Kohv², Renata Sõukand³

1 Estonian Literary Museum, Tartu, Estonia. 2 Räpina School of Horticulture, Räpina, Estonia. 3 Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Venice, Italy

In modern society, knowledge about plants can originate from the family, from official sources or many hybrid forms in between (coming from media). The history of the scholarly botanical terminology in Estonia dates back to 1881, when the first botany schoolbook in Estonian was published. The next botany book, intended for a wide readership, was published in 1922 and contained greatly different content and terminology. Changing technical terms over time is only part of the problem. Looking at the present day botanical literature in Estonian, we see that the vocabulary used in current botanical literature has become increasingly specialized, understandable just to the specialists in the field. For ordinary citizens, such terms often remain distant and ambiguous. We conducted a qualitative survey on the Google Forms platform, answered by 149 people living in Tartu. We asked to free list up to 10 trees/shrubs, herbaceous plants and cultivated plants that they consider important. As additional qualitative questions, we asked why these plants are important to them and how the respondents would describe these plants. Only a few plants were described. Moreover, comparing the description of the most popular tree (birch) with the official key book gave a noticeable difference. We can clearly see that as the terminology of botanical literature diverges greatly from the local plant-related terminology, people may have less interest in those books. Neither do they need to describe different plants to each other in their everyday life,
which leads to a loss of local botanical vocabulary in
Estonian. We propose to name this phenomenon lin-
guistic plant blindness and invite colleagues to dis-
cuss whether plant key books should consider using

local plant-related vocabulary in parallel with the sci-
entific one and include local plant uses to promote the
interest in plants and through that reduce linguistic
plant blindness.

# S.196 GRASSROOTS MULTIDISCIPLINARY AND INTEGRATIVE RESEARCH ON THE GLOBAL DIVERSITY OF THE GRASSES (POACEAE).
## SESSION 2

S.196.1 Floral trait syndromes
in tropical grasses and their
environmental associations

Aluoneswi C. Mashau¹, Gareth P. Hempson¹, Caroline E.R. Lehmann¹, Maria S. Vorontsova¹, Cédrique Solofondranohatra¹, Abraham Dabengwa¹, Jan Hackel¹, Sally Archibald¹

1 Foundational Research and Services, South Afri-
can National Biodiversity Institute, Private Bag X101,
Pretoria, South Africa. Email: c.mashau@sanbi.org.
za. 2 School of Animal, Plant and Environmental
Sciences, University of the Witwatersrand, Johan-
nesburg, Private Bag X3, Wits, South Africa. 3 Trop-
ical Diversity, Royal Botanic Garden Edinburgh, Ed-
inburgh UK. 4 School of GeoSciences, University of
Edinburgh, Edinburgh UK. 5 Accelerated Taxonomy,
Royal Botanic Gardens, Kew, Richmond, Surrey UK.
6 Laboratoire de Botanique, Département de Biol-
ogie et Ecologie Végétales, Faculté des Sciences,
Université d'Antananarivo, Antananarivo, Mada-
gascar. 7 Kew Madagascar Conservation Centre,
Antananarivo, Madagascar. 8 Universität Marburg,
Fachbereich Biologie, Marburg, Germany

Grass floral structures vary greatly but we have very
little understanding of their functional significance.
Due to the varied dispersal mechanisms shown by
grasses, certain syndromes of floral traits would likely
be associated with particular strategies for dispersal,
and consequently, different environments. In partic-
ular, effective seed maturation and dispersal in fire-
prone tall grasslands would require different floral
trait syndromes than in short, frequently grazed eco-
systems. Here we quantify floral traits of nearly 200
Poaceae species from savanna and grassland eco-
systems in southern Africa and explore how their floral
structures co-vary and correlate with other functional

characteristics such as grass height. Using field infor-
mation on the dominance disturbance regime of 163
of these grass species it was tested whether certain
floral traits are more associated with fire vs grazing
and mean rainfall arranged from 323–1256 mm.yr⁻¹ in
the study areas. Non-metric multi-dimensional scal-
ing (NMDS) was used to illustrate how floral traits co-
varied among grass species, and to group them into
syndromes based on these traits. Analysis of variance
(ANOVA) was used to test whether certain floral trait
syndromes were more associated with fire vs grazing.
We identified four clear floral trait syndromes separat-
ed largely by awn length and the presence of hooks/
prickles or bristles. Long-owned species were more
likely to be found in frequently burned environments
and were also usually taller than species without awns.
Grazer-dominated systems appear to select for two
different floral trait syndromes which are no lemma
awns, blunt or no callus sharpness. The study has im-
proved our ecological and taxonomic understanding
of how floral traits differ among the range of tribes in
one family across African countries. It can help in un-
derstanding dispersal limitations in grasses and pre-
dicting which species are likely to flourish in particular
grassland habitats.

S.196.2 Poaceae as a model
clade for understanding
cold tolerance evolution and
adaptation to temperate
biomes

Aelys M. Humphreys¹, Laura Schat¹, Sylvia Pal-Stolsmo², Sofia Nilsson¹, Marian Schubert¹,², Siri Fjellheim²
<figure><img src="image_455.png" /></figure>

1 Stockholm University, Stockholm, Sweden. 2 Norwegian University of Life Sciences, Ås, Norway

Grasses (Poaceae) are thought to have originated in the moist tropics in the Late Cretaceous. Their long evolutionary history has seen multiple independent transitions to open, dry habitats as well as cold and freezing ones. The >11,000 species extant today are globally distributed, occurring on all continents including Antarctica and dominating biomes ranging from topical savannahs to alpine grasslands and boreal tundra. Grasses already constitute a model clade for understanding C4 evolution and biome formation (grasses). This research benefits from 1) a large, active community of grass taxonomists, systematists and palaeobotanists, 2) rich genetic and genomics resources, centred on economically important species such as the cereals and the model organism *Brachypodium distachyon* and 3) the fact that many species grow fast and have short lifecycles, making them easy to cultivate and manipulate experimentally. Despite this, and although grasses are both diverse and abundant across the coldest places on Earth, we have a relatively poor understanding of the details surrounding evolution of cold tolerance in the clade, whether repeated topical-temperate-transitions were facilitated by precursor traits, what traits characterise the species that occupy the coldest habitats and the order of events leading to the suite of adaptations that have made grasses so successful in temperate biomes today. In this talk, we showcase grasses as a model for understanding tropical-to-temperate transitions and present ongoing multidisciplinary work across grasses as a whole, as well as in smaller clades. Comparative, experimental, ecophysiological, ecological and genetic work is providing new perspectives on cold tolerance evolution and adaptation to temperate biomes, with implications for other angiosperms as well.

### S.196.3 Adapting to high stress environments: Grasses from geothermally heated areas of Iceland

Aelys M. Humphreys¹, Jan-Niklas Nuppenau¹

1 Stockholm University, Stockholm, Sweden

Geothermal areas are formed where Earth's inner heat is transported to the surface. This results in peculiar formations including fumaroles, geysers and heated soils. Geothermal areas are high stress, low

diversity environments, with the main factor limiting the presence of most life there being heat. The diversity of land plants occurring on geothermally heated soils is relatively well characterised, with mosses and grasses (Poaceae) being particularly common at the hottest sites. However, the geographical origin of geothermal organisms is largely unknown, as are the effects of adapting to geothermal heat, e.g. phenological shifts or performance under cooler conditions. Here we present ongoing work on geothermal grasses from Iceland, a subarctic island where scorching geothermal areas and bitterly cold non-thermal areas occur side by side. We show for the genus *Agrositis*, which occurs on soils <70°C, that *A. stolonifera* has colonised Iceland at least twice, leading to one lineage exclusive to geothermal areas and another exclusive to non-thermal areas. In contrast, *A. vinealis* has colonised Iceland just once, leading to a single widespread lineage occupying geothermal and non-thermal areas alike. We further show phenotypic differences, increased heat tolerance, reduced performance under cooler conditions and a shift in flowering phenology for geothermal compared to non-thermal *A. stolonifera*, suggesting that geothermal *A. stolonifera* represents a specialised, thermophilic lineage. Finally, we study *Festuca rubra*, which is found on moderately warmed soils (<30°C). This species showed no difference in thermal tolerance, winter survival ability or phenology in response to geothermal warming, suggesting it is adjusting plastically to the geothermal conditions. Our results highlight that responses to geothermal warming can be idiosyncratic, even among close relatives, and pave the way for further studies of both adaptations to extreme environments and responses to moderate warming, using the natural laboratory afforded by geothermal areas.

### S.196.4 Grass diversity in Brazil and the Flora of Brazil project

Cassiano A. D. Welker¹, Christian da Silva², Pedro L. Viana³, Reyjane P. Oliveira⁴

1 Universidade Federal de Uberlândia, Uberlândia, Brazil. 2 Universidade do Estado de Santa Catarina, Laguna, Brazil. 3 Instituto Nacional da Mata Atlântica, Santa Teresa, Brazil. 4 Universidade Estadual de Feira de Santana, Feira de Santana, Brazil

Brazil is a megadiverse country and houses a larger number of plant species than any other country in the world. The study of its flora has a long history, including many foreign naturalists collecting in Brazil
<figure><img src="image_456.png" /></figure>

throughout the 18th and 19th centuries and sending these plants to European herbaria. Until recently, the most comprehensive treatment of the Brazilian flora was the "Flora Brasiliensis", edited by Carl Friedrich von Martius (1840-1906). Over the past 15 years, a huge number of taxonomists have joined efforts in the Flora of Brazil project, motivated to meet Target 1 of the Global Strategy for Plant Conservation (GSPC). The Flora of Brazil project currently recognizes more than 52 thousand species of algae, fungi, and plants that occur in the country. Identification keys, morphological descriptions, illustrations, and data on their habitat and geographic distribution are available online for most taxa, including grasses. Poaceae is the fourth richest angiosperm family in Brazil, with around 230 genera and 1.560 species. These numbers correspond to almost a third of the genera and about 13% of the grass species in the world. Of these, 24 genera and about 520 species are endemic to Brazil. Representatives of all subfamilies, except Puelioideae, occur in Brazil, including Anomochlooideae, the first lineage that diverged within Poaceae. This subfamily predominates in Brazilian forests, as do Pharoideae and Bambusoideae, while Panicoideae (the richest subfamily in Brazil) dominates tropical and subtropical grasslands. On the other hand, Pooideae and Danthonioideae have a predominantly extratropical distribution in Brazil, decreasing in species richness and density from south to north. Phylogenetic studies including Brazilian grasses have increased greatly in the last decade, as well as the number of new taxonomists in this family, improving our knowledge about genera and species and resulting in several nomenclatural changes in taxa from Brazil.

## S.196.5 Taxonomic studies on the tribe Jansenelleae Voronts. (Poaceae: Panicoideae: Andropogonodae) in India

Ambika I.¹, C. Pramod¹

1 Department of Botany, University of Calicut, Malappuram, Kerala, India

Jansenelleae Voronts., a rare C₃ Asian grass lineage, was recently elevated as a tribe and comprises two genera, *Jansenella* Bor and *Chandrasekharania* V.J.Nair, V.S.Ramach. & Sreek. The former genus contains two species *Jansenella griffithiana* (Müll.Hal.)

Bor and *Jansenella neglecta* S.R.Yadav, Chivalkar & Gosavi and the latter is monotypic with *Chandrasekharania keralensis* V.J.Nair, V.S.Ramach. & Sreek. Among the three species within the tribe *Jansenella griffithiana* is the only widespread species, and is reported from India, Sri Lanka, Myanmar and Thailand. The other two species are endemic to the Western Ghats. The restricted distribution and sporadic nature of this group is evident from the limited volume of literature regarding this group. Apart from the type, *Chandrasekharania* is represented by a few collections only. *Jansenella griffithiana* is the only species in the tribe in which few investigations are undertaken; and *Chandrasekharania keralensis* and *Jansenella neglecta* are not studied thoroughly. This paper discusses the taxonomy and nomenclature of the tribe Jansenelleae in detail.

## S.196.6 The mitochondrial genome of the diploid oat Avena longiglumis

Qing Liu¹,²,³, Hongyu Yuan¹,²,⁴, Jiaxin Xu⁵, Dongli Cui¹,²,⁴, Gui Xiong¹,²,⁴, Trude Schwarzacher¹,²,⁶, and John Seymour
Heslop-Harrison¹,²,⁶*Qing Liu¹,²,³*, Hongyu Yuan¹,²,⁴, Jiaxin Xu⁵, Dongli Cui¹,²,⁴, Gui Xiong¹,²,⁴, Trude Schwarzacher¹,²,⁶, John S. Heslop-Harrison¹,²,⁶

1 Key Laboratory of Plant Resources Conservation and Sustainable Utilization / Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China. 2 South China National Botanical Garden, Guangzhou, China. 3 Center for Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China. 4 University of Chinese Academy of Sciences, Beijing, China. 5 College of Plant Protection, South China Agricultural University, Guangzhou, China. 6 University of Leicester, Department of Genetics and Genome Biology, Institute for Environmental Futures, Leicester, UK

*Avena longiglumis* Durieu (2n=2x=14) is a wild relative of cultivated oat (*Avena sativa*, 2n=6x=42) with good agronomic and nutritional traits. The plant mitochondrial genome has a complex organization and carries genetic traits of value in exploiting genetic resources, not least male sterility alleles used to generate F₁ hybrid seed. Therefore, we aimed to complement the chromosomal-level nuclear and chloroplast genome assemblies of *A. longiglumis* with the complete assembly of the mitochondrial
<figure><img src="image_457.png" /></figure>

genome (mitogenome) based on Illumina and ONT long reads, comparing its structure with Poaceae species. The complete mitochondrial genome of *A. longiglumis* can be represented by one master circular genome being 548,445 bp long with a GC content of 44.05%. It can be represented in four circular DNA molecules (isoforms or contigs), with multiple alternative configurations mediated by long (4,100-31,235 bp) and medium (144-792 bp) size repeats. Thirty-five unique protein-coding genes, three unique rRNA genes, and 11 unique tRNA genes were identified. The mitogenome was rich in duplications (up to 233 kb long) and multiple tandem or simple sequence repeats, together accounting for more than 42.5% of the length. We identified homologous

sequences between the mitochondrial, plastid and nuclear genomes, including exchange of eight plastid-derived tRNA genes, and nuclear-derived retroelement fragments. At least 85% of the mitogenome is duplicating in the *A. longiglumis* nuclear genome. We identified 269 RNA editing sites in mitochondrial protein-coding genes including stop codons truncating *ccmFC* transcripts. Comparative analysis with Poaceae species revealed the dynamic and ongoing evolutionary changes in mitochondrial genome structure and gene content. The complete mitochondrial genome of *A. longiglumis*, completes the last link of the oat reference genome and lays the foundation for oat breeding and exploiting the biodiversity in the genus.

## S.197 GENOMICS OF LOCAL ADAPTATION.
SESSION 3

### S.197.1 Subgenomic stability of progenitor genomes during repeated allotetraploid origins of the same grass Brachypodium hybridum

Wenjie Mu¹, Kexin Li¹, Yongzhi Yang¹, Adina Breiman², Jiao Yang¹, Ying Wu¹, Mingjia Zhu¹, Shuai Wang², Eviatar Nevo³, Jianquan Liu¹, Pilar Catalán⁴

1 State Key Laboratory of Herbage Innovation and Grassland Agro-Ecosystem, College of Ecology, Lanzhou University, Lanzhou, China. 2 University of Tel-Aviv, Tel-Aviv, Israel. 3 Institute of Evolution, University of Haifa, Mount Carmel, Haifa, Israel. 4 Escuela Politécnica Superior de Huesca, Universidad de Zaragoza, Huesca, Spain.

Both homeologous exchanges (HEs) and homeologous expression bias (HEB) are generally found in most allopolyploid species. Whether HEs and HEBs differ between repeated allopolyploid speciation events from the same progenitor species remains unknown. Here we detected a third independent and recent allotetraploid origin for the model grass *Brachypodium hybridum*, discarding alternative scenarios of potential introgressions of early allotetraploids with diploid progenitor species. Our HE

with replacement analyses indicated the absence of significant homeologous exchanges in any of the three types of wild allotetraploids, supporting the integrity of their progenitor subgenomes and the immediate creation of the amphidiploids. The absence of HE is probably due to the distinct structure of the "homeologous" progenitor chromosomes. Specifically, the five *B. distachyon* chromosomes resulted from four centromeric nested chromosome fusions of the ten *B. stacei* chromosomes, making homeologous crossovers highly improbable in the *B. hybridum* nucleus. Further HEB tests did not uncover significant subgenomic dominance in different tissues and conditions of the allotetraploids. This suggests a balanced expression of homeologs under similar or dissimilar ecological conditions in their natural habitats. We observed that the density of transposons around genes was not associated with the initial establishment of subgenome dominance; rather, this feature is inherited from the progenitor genome. We found that drought response genes were highly induced in the two subgenomes, likely contributing to the local adaptation of this species to arid habitats in the third allotetraploid event. These findings provide evidence for the consistency of subgenomic stability of parental genomes across multiple allopolyploidization events that led to the same species at different periods. Our study emphasizes the importance of selecting closely related progenitor species genomes to accurately assess HE with replacement in allopolyploids, thereby