Importance of scatter-hoarding rodents for seedling establishment of large-seeded palms Caroline Marques Dracxler1 & Pierre-Michel Forget1
1Muséum National d’Histoire Naturelle. carolinemdsbio@yahoo.com.br
Although rodents can also act as seed predators, seeds of certain palm species are exclusively removed and dispersed by rodents, suggesting palms may benefit from these interactions.
Nevertheless, direct evidence that rodents do not predate all removed seeds and that seedlings are the result of seed caching by rodents is still scarce. We aimed to assess to what extent seedling establishment of three palm species (Astrocaryum aculeatissimum, Astrocaryum sciophilum, Attalea humilis) is favoured by seed caching by investigating naturally established seedlings in the Amazon and the Atlantic Forest. We found that nearly all seedlings of all three species established from seeds dispersed and not recovered by rodents (mainly located 10–15m away from parents), and 83%, 94% and 75% of seedlings of A. aculeatissimum, A. sciophilum and A. humilis, respectively, established from seeds buried in the soil. Results show that the studied palm species depend almost entirely on caching of seeds by rodents to establish seedlings, improving our understanding about the net outcome of seed caching for large-seeded palms. The high dependence on scatter-hoarding
activity for regeneration also reinforces the evolutionary aspect of rodent-palm interactions and the vulnerability of large-seeded palms in scenarios of increasing defaunation.
Key words: Arecaceae, Neotropics, scatter-hoarders, seed burial, seed dispersal.
Funded by: CAPES - Ciência sem Fronteiras and UMR 7179 CNRS-MNHN
Effects of primatization on the population dynamic of a palm that is vulnerable to extinction Rita de Cássia Quitete Portela1
1Federal University of Rio de Janeiro. rita@quiteteportela.com.br
The hypothesis that increasing the abundance of a predator could lead to a negative growth rate of a palm population was tested in this study. In order to test this hypothesis, individuals of Euterpe edulis were marked in 2005, and re-sampled from 2006 to 2017 in an isolated forest fragment of 2,600 ha in a fragmented landscape of Atlantic Forest (Rio de Janeiro, Brazil). The predator of E.
edulis palm-heart (Capuchin monkey, Sapajus nigritus) is native but its population is superabundant in the fragment. Lefkovitch matrices were built for each transition year. As a result of these twelve years of study a linear decrease of population size was found. There were 839 individuals with 60 adults in 2005 and 46 individuals with no adults in 2017. This decrease is mainly due to mortality caused by the predator preying upon palm-hearts, which ranged from 10 to 49 adult individuals dying per year. According to the last three lambdas, it is estimated that the palm population is decreasing 31%, 39% and 32% in each interval. If the monkey population remains without control in the area, the palm population will be extinct in the next few years in the studied area.
Key words: Arecaceae, Euterpe edulis, fragmentation, population ecology, predator superabundance.
Funded by: Fapesp, Faperj, CNPQ, CAPES
Global patterns of palm abundance
Robert Muscarella1, Thaise Emilio2 & Henrik Balslev1
1Aarhus University; 2Royal Botanic Gardens, Kew. bob.muscarella@gmail.com
Palms (Arecaceae) are an iconic and diverse group that provide myriad ecosystem services in tropical forests. For example, palms account for 7 of the top 20 ‘hyperdominant’ species of Amazonia. Previous work has examined global patterns of palm diversity but we currently lack a quantitative global analysis of palm abundance patterns. Given the morphological and physiological differences between palms and dicot trees, the responses of these groups to environmental changes are likely to differ. As a result, a better understanding of palm dominance will help identify knowledge gaps and improve the predictive ability of global vegetation models. Using a dataset of
>1,000 tropical forest plots, we quantified (1) relative abundance of arborescent palms versus dicot trees across different scales, and (2) how abundance of arborescent palms is related to abiotic variables. We show that arborescent palm abundance is low in the African and Asian tropics compared to Neotropics. We then examined spatial variation in palm abundance in light of evolutionary, biogeographical, and ecological hypotheses, and use statistical models to examine relationships between palm abundance and plot-level environmental covariates. We introduce some novel hypotheses regarding the dominance of the arborescent palm life form in the New World.
Key words: biogeography, diversity, dominance, life forms, tropics.
Non-native palms as engineers of novel ecosystems in the Anthropocene: a global review Vincent Fehr1, 2 & Jens-Christian Svenning1, 2
1Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Bioscience, Aarhus University, Ny Munkegade, 114, 8000 Aarhus, Denmark. 2Section for
Ecoinformatics & Biodiversity, Department of Bioscience, Aarhus University, Ny Munkegade, 114, 8000 Aarhus, Denmark. vincent.fehr@bios.au.dk
Human activities are generating novel ecosystems without historical precedent, notably by moving species around the world. While the increasing emergence of novel ecosystems is widely recognized, there is still limited understanding of the involvement of many taxonomic groups in this process. We provide the first global synthesis for non-native palms. Palms are considered of high ecological importance as keystone species and are of tremendous value for humans, providing a range of ecosystem services. Of the 2550 recognized palm species, 80 species are recorded naturalized and 27 species are classified invasive. Main recipient areas are Southern America, followed by the Pacific Islands, Africa and Tropical Asia. Subtropical regions boast a lower amount of non-native palms. Forests, wetlands and anthropogenic habitats are the most frequently colonized habitats. Non-native palms are mainly reported competing with the native flora and altering vegetation structure. They are also capable of affecting native fauna, altering water and fire regimes and in some cases initiating cascading effects, leading to novel ecosystems. As the majority of reports are based on anecdotal evidence, we recommend that more empirical studies explore the ecological role that palms have in generating novel ecosystems also under future global change scenario.
Key words: invasion biology, naturalized, novel ecosystems, palms, plant invasions.
Local to regional ecology of the genus Geonoma
Anna Weigand1, Michael Kessler1, Ingrid Olivares1, Natalia Arcilla Marín2, María José Sanín2, Christian Lexer3 & Nicolas Salamin4
1University of Zurich; 2Universidad CES; 3University of Vienna; 4University of Lausanne.
michael.kessler@systbot.uzh.ch
With 68 species, the genus Geonoma (Arecaceae) is one of the largest, geographically most widespread, and most ecologically diverse Neotropical palm genera. Yet, little is known about the factors that determine the distribution of the diversity of the genus. We used a dataset of 11250 herbarium records and 750 vegetation plots to model the distribution of species richness at two spatial scales: A regional model predicting species richness in equal-area polygons of 7666 km2 each, and a local model of species richness at 4 km2. We then identified the environmental parameters that affect species richness at these different scales. Next, we used the regional predictions as proxies of the regional species pool for the local assemblages, with the aim to understand the roles of regional versus local factors in determining local richness and community composition. We document an overriding role of regional-scale factors in determining local communities.
Key words: America, diversity, macroecology, palms, scales.
Phylogenomics, biogeography, and evolution in the American palm genus Brahea
Craig Barrett1, Brandon Sinn1, Loren King1, Jesus Medina2, Christine Bacon3, Sean Lahmayer4 &
Donald Hodel5
1West Virginia University; 2California State University, Los Angeles; 3University of Gothenburg;
4The Huntington Library, Art Collections, and Botanical Gardens; 5University of California Cooperative Extension. cfb0001@mail.wvu.edu
Slow rates of molecular evolution at low taxonomic levels hamper studies of relationships among species, biogeography, and evolution. An example is the genus Brahea, which is among the most poorly understood lineages of American palms and is characterized by a variety of growth forms and intermediate morphology. We generated ~400 kb of genomic data from all three genomes for 11 currently described Brahea species to provide support for relationships, reconstruct ancestral growth form, estimate ancestral geographic ranges, and test for niche equivalency among closely related species with overlapping geographic regions. Relationships receive strong support, and conform to previous subgeneric assignments. Our phylogenetic hypothesis reveals trends in growth form including an increase in height in the B. armata clade, and independent evolution of dwarf forms in the B. pimo and B. dulcis clades. Ancestral range estimation reveals roles of dispersal and sympatric speciation. We find evidence of niche non-equivalency among species in northwestern Mexico, and between B. berlandieri and B. dulcis, which are synonymized under B. dulcis. Our findings have implications for the complex biogeographic history in Central America and Mexico, and advance our understanding of patterns of biodiversity in these ecologically and economically important palms.
Key words: Central America, diversification, growth forms, niche, phylogeny.
A revision of Mexican Chamaedorea (Arecaeae) Diego Villar-Morales1 & Laura Calvillo Canadell2
1Instituto de Biología, Universidad Nacional Autónoma de México; 2Instituto de Biología, Universidad Nacional Autónoma de México. dgo.vimo@gmail.com
The palm family (Arecaceae) is represented in Mexico by 21 genera and about 100 species. The three genera with the largest number of species in Mexico, Brahea, Chamaedorea and Sabal, also have their greatest diversity in the country. Even though Mexico has been considered as an important center of diversification for Chamaedorea, no proper revision of the Mexican species of the genus has been done. Furthermore, its species are actively threatened by deforestation, loss of habitat and uncontrolled extraction. A detailed revision of the Mexican species of Chamaedorea was done, based mainly on herbarium specimens. 50 species were recognized in Mexican territory, of which 20 are endemic to the country. This work has resulted in the discovery of new species, corrected species distribution, and a taxonomic treatment for all 50 species. This is a first step towards a better understanding of Chamaedorea in Mexico, considering the need for future work that addresses its ecology and conservation, and the Mexican species importance in the evolution and biogeography of this most interesting Neotropical palm genus.
Key words: Arecaeae, Chamaedorea, Mexico, palms, taxonomy.
Martius’ pioneering work on palm diversity
Fred Stauffer1, Johann Stauffer2, Viviane Leyman3, Sofie Smedt4 & Hans-Joachim Esser5
1Conservatory and Bot. Garden of Geneva; 2Feldstrasse 5, CH-4950 Huttwil, Switzerland;
3Herbarium, Bot. Garden Meise; 4Herbarium, Botanic Gardens Meise; 5Herbarium, Botanische Staatssammlung München. fred.stauffer1@gmail.com
The celebrated German botanist Carl Friedrich Philipp von Martius (1794-1868) is widely recognized as one of the earliest and most important contributors to palm research. An extensive study of his original specimens and documents stored at the Munich herbarium (M), as well as his private collections deposited since 1870 in Meise (BR), reveals Martius to be a meticulous palm collector with a visionary appreciation of international networks of collaboration. An analysis of the taxonomic criteria employed for his benchmark publication, Historia Naturalis Palmarum (1823-1850), is provided, and the six palm groups that he proposed (Arecinae, Borassinae, Coryphinae, Cocoinae, Lepidocaryinae, Palmae Heteroclitae) are discussed in the context of current palm classifications. Finally, an assessment of his contribution to our current knowledge of palm taxonomy (i.e., number of genera and species described), and of the Brazilian palm flora in particular, is offered.
Key words: Arecaceae, botanical history, Brazil, floristics, taxonomy.
Funded by: Conservatory and Botanic Gardens of Geneva, Switzerland
Macro and micro perspectives on Geonoma evolution
Oriane Loiseau1, Margot Paris2, Marylaure de la Harpe3, Ingrid Olivares4, Anna Weigand4, Jonathan Rolland5, Michae Kessler4, Christian Lexer3 & Nicolas Salamin1
1University of Lausanne; 2University of Fribourg; 3University of Vienna; 4Institute of Systematic Botany, University of Zurich; 5University of British Columbia. oriane.loiseau@unil.ch
The development of next generation sequencing technologies now allows biologists to obtain tremendous amount of genomic data in a time and cost-effective manner. For the palm family (Arecaceae), genomics resources have recently been developed, providing the opportunity to study the processes shaping the evolution of this iconic tropical family at different geographic and time scales. Geonoma, the third largest palm genus in the Neotropics, presents a large amount of intraspecific phenotypic variation that, on one hand, complicates taxonomic delimitation but, on the other hand, provides an ideal opportunity to study the factors promoting divergence in palm populations. Using a recently designed target-capture bait kit, we sequenced 3988 genomic regions for more than 800 individuals of Geonoma. This data allowed us to study the macroevolutionary history of this group by inferring a time calibrated phylogeny and performing biogeographic and diversification analyses. In parallel, we investigated the microevolutionary dynamics of two species complexes with very different characteristics, the G. interrupta-G. pinnatifrons group and the G.
undata-G. orbignyana group. Our analyses at different geographical and evolutionary time scales show that various factors acting at different scales have shaped the evolution of Geonoma diversity at the genetic and phenotypic levels.
Key words: Arecaceae, diversification, population genomics, species complexes, target-capture sequencing.
Phylogenomics and biogeography of South-East Asian Areceae
Sidonie Bellot1, Wolf L. Eiserhardt2, Felix Forest1, Ilia Leitch1 & William J. Baker1
1Royal Botanic Gardens Kew; 2Aarhus University. s.bellot@kew.org
Palms are a prominent plant family of rainforests, and millions of humans depend on them daily as food, medicine, timber and other materials. Many palm species are endemic to small islands in the Pacific and Indian Oceans, which makes them a good model for comparative studies of the mechanisms of speciation in archipelagos. Such analyses were so far impaired by the lack of a well-resolved species-level phylogeny of the family, leading palm specialists to initiate an international cooperation to fill this gap. Our contribution to this effort is to use targeted DNA sequence capture to generate a genus-level phylogeny of all palms (181 genera), and a species-level phylogeny of tribe Areceae (ca. 700 species). Most data have now been generated, allowing us to initiate phylogeny reconstruction. These phylogenies are crucial to better understand palm biogeography and evolution, as illustrated by current ongoing studies at Kew on the evolution of palm seed traits and genome size.
Key words: Arecaceae, Areceae, phylogenomics, South-East Asia, target sequence capture.
Palm hydraulic strategies and climatic ranges
Thaise Emilio1, Laurent Lamarque2, José Manuel Torres-Ruiz3, Sylvain Delzon2, Paula Rudall1, Wolf Eiserhardt4 & William Baker1
1Royal Botanic Gardens Kew; 2University of Bordeaux/ BIOGECO-INRA; 3University of Clermont-Auvergne / PIAF-INRA; 4University of Aarhus. thaise.emilio@gmail.com
The monocot family Arecaceae (palms) are morphologically, developmentally and functionally distinct from other large woody plants that dominate forests. It is uncertain how palms will respond to increasing drought as hydraulic studies are biased towards conifers and dicotyledonous angiosperms. Here we combine cutting-edge hydraulic studies (in vivo micro-CT X-ray and optical visualization of embolism) with macroecological analysis to understand the hydraulic strategies which allowed palms to colonize different climates. Our results show that differences in the onset of cavitation account for most of the difference in vulnerability to drought between the species studied.
Embolism commences when most of the water has been exhausted from parenchyma tissue and subsequently progresses rapidly. Phenotypes that minimize water loss (smaller leaflet size) and, maximize water storage (larger stem diameter) and supply to evapotranspiration sites (larger guard-cell sizes) are more likely to be found in drier and warmer biomes. Palms show great ability to face drought either by being highly resistant to xylem embolism or by holding water in their tissues for a long period. Trade-offs in these two hydraulic strategies allowed palms to colonize different biomes on earth and may be key to understand their fate in changing climates.
Key words: Arecaceae, drought resistance, synchrotron, succulence, xylem embolism vulnerability.
Funded by: This project has received funding from the European Unions Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement PalmHydraulics No. 706011.
Phylogenomics of palm subtribe Dypsidinae, a spectacular insular radiation from Madagascar
Wolf L. Eiserhardt1, Sidonie Bellot2, Robyn S. Cowan2, John Dransfield2, Karolina Heyduk3, James H. Leebens-Mack4, Mijoro Rakotoarinivo5 & William J. Baker2
1Aarhus University, Denmark; 2Royal Botanic Gardens, Kew, UK; 3Yale University, New Haven, CT, USA; 4University of Georgia, Athens, USA; 5University of Antananarivo, Madagascar.
wolf.eiserhardt@bios.au.dk
Madagascar is home to a spectacular palm radiation, which now for the first time has a comprehensive phylogenetic tree. In numbers, the palm flora of Madagascar resembles the palm floras of other major tropical islands, but it stands out in phylogenetic composition: 80% of the species belong to one genus, Dypsis, which has radiated extensively on the island. The mechanisms behind this radiation remain unknown, as no phylogenetic hypothesis has been available until now.
Three smaller endemic genera (Marojejyia, Masoala and Lemurophoenix; 2 species each) are classified together with Dypsis to form the subtribe Dypsidinae, but the monophyly of this group been challenged. Moreover, generic delimitation within Dypsidinae is notoriously difficult, and the monophyly of the currently accepted genera needs to be tested. To resolve the phylogenetic relationships of Dypsidinae, we have sampled >90% of the species of the subtribe in the wild or from herbarium specimens and sequenced 176 nuclear loci using target capture and high throughput sequencing. Here we present the first phylogenetic results of this study, discussing the recovered relationships mainly in relation to the systematics of the tribe, and briefly outline the macroevolutionary studies we are planning to test the drivers of this spectacular radiation.
Key words: Arecaceae, Areceae, Dypsis, systematics, target capture.
Funded by: This work was supported by the the European Union FP7-People programme (grant
#327259), the National Geographic Society - Global Exploration Fund Northern Europe (grant GEFNE125-14), the International Palm Society, the Royal Horticultural Society, the Bentham-Moxon Trust, The Lord Faringdon Charitable Trust, and Pam Le Couteur.