Maesa brevipedicellata (Primulaceae), a new species from Papua New Guinea

Maesa brevipedicellata, a new species of Maesa (Primulaceae-Maesoideae) from Papua New Guinea, is described and illustrated based on herbarium specimen observations. The collections of this species resemble M. rufovillosa and were previously determined as that species. Maesa brevipedicellata is unique with its selfsupporting habit, hispid hairs throughout and paniculate inflorescences with very short pedicels. This new species mainly differs from M. rufovillosa by the habit (tree/shrub in M. brevipedicellata vs climber in M. rufovillosa) and the inflorescence structure (panicles in M. brevipedicellata vs simple racemes in M. rufovillosa)

Megafrugivores as fading shadows of the past: extant frugivores and the abiotic environment as the most important determinants of the distribution of palms in Madagascar

The extinction of all Madagascar's megafrugivores ca. 1000 years ago, may have left its signature on the current distribution of vertebrate-dispersed plants across the island, due to the loss of effective seed dispersal. In this study, we dissect the roles of extinct and extant frugivore distributions, abiotic variables, human impact and spatial predictors on the compositional turnover, or beta-diversity, of palm (Arecaceae) species and their fruit sizes across 40 assemblages on Madagascar. Variation partitioning showed that palm beta-diversity is mostly shaped by the distribution of extant frugivores (8 lemur, 3 bird, 2 rodent and 1 bat species) and the abiotic environment (e.g., forest cover, slope and temperature), and to a lesser extent by the distribution of extinct frugivores (5 giant lemur and 3 elephant bird species). However, the contribution of these variables differed between dry western assemblages and wet eastern assemblages, with a more prominent role, albeit still small, of extinct megafrugivores in the west. These results suggest that palm distributions in the dry west of Madagascar, where megafrugivores were probably most abundant in the past, still show signatures of past interactions. With a fourth-corner analysis we observed that the distribution of palm species with relatively large fruits and seeds was negatively associated with home range of extant mammalian frugivores and frugivore richness of both past and extant communities, and positively associated with the hand-wing index (HWI) – a proxy for dispersal ability - of extant bird communities. This suggests that palm species with relatively large fruits tend to occur in places with fewer, small-ranged mammalian frugivores, which may indicate dysfunctional seed dispersal, although a few wide-ranging bird species may compensate this loss by dispersing the seeds of small-to medium-sized palm fruits. Our results shed new light on anachronisms in Madagascar, and how defaunation and past interactions may underlie current plant distributions.This data repository consists of the following folders and files: Main folder Word document containing information on each file and instructions for use (ReadMe.docx) Excel document with 4 different sheets, containing supplementary tables S1, S2 and S3 and their references (TableS1_S2_S3.xlsx) Supporting information for the manuscript (SupportingInformation.pdf) "data" folder Palm presence-absence data for each of the forty 0.3x0.3 grid cells (Palms_in_grid03.csv) Palm dispersal-related trait data (maximum stem height in meters, average fruit length in millimeters, average fruit width in millimeters, average seed length in millimeters and average seed width in millimeters) for the 165 palm species appearing in the 40 grid cells (PalmTraits.csv) Average climatic, soil and human variables per grid cell (Environment_grid03.csv): Extant and extinct frugivore presence-absence data for each of the forty 0.3x0.3 grid cell (frugivore_extant_extinct_in_grid03.csv) Extant and extinct frugivore dispersal-related trait data (frugivore_traits.csv): Body mass in kilograms, hand-wing index (HWI) and home range in hectares. Geographic coordinates in Latitude and Longitude decimal degrees for the centroids of each of the forty 0.3x0.3 grid cell (centroids_grid03.csv) Shapefile of the forty 0.3x0.3 grid cell created in QGIS 3.10.7 used to extract all the other values (0.3grid_20records) Metadata Average climatic, soil and human variables per grid cell (Environment_grid03.csv) BIO1: Annual mean temperature (°C x 10) BIO4: Temperature seasonality (standard deviation ×100) BIO6: Minimum temperature of the coldest month (°C x 10) BIO12: Annual mean precipitation (mm x month-1) pet: Annual potential evapotranspiration from the Thornthwaite equation (mm) cwd: Annual climatic water deficit (mm) alt: Altitude (in m) slop: Slope in degrees solar: Solar radiation (in Wh.m-2.day-1) percfor2010: Madagascar's forest in 2010 was derived from the 30 m resolution 2000 forest map by Harper et al. (2007). Clay: Soil clay content (0-2 micrometre) in g/100g (w%) CationEC: Cation exchange capacity (CEC measured in 1 M NH4OAc buffered at pH 7) in cmolc/kg (fine earth) Extractable_Aluminum: Extractable aluminium content (Al measured by Mehlich 3) in mg/kg (fine earth) Total_Nitrogen: Total nitrogen (N) content in g/kg of the fine earth fraction Total_Phosphorus: Total Phosphorus (P) content of the soil fine earth fraction in mg/kg (ppm) Popdensity2010: "For all locations with more than 1000 people per km−2, we assigned a pressure score of 10. For more sparsely populated areas with densities lower than 1000 people·km−2, we logarithmically scaled the pressure score using: Pressure score = 3.333 × log(populationdensity+1)" (Venter et al. 2016). HFP2009: Human footprint for 2009, calculated as a summary value from other several human-related variables such as built environments, population density, night-time lights, croplands, pasture, roads, railways, navigable waterways. Roads: "We mapped the direct and indirect influence of roads by assigning a pressure score of 8 for 0.5 km out for either side of roads, and access pressures were awarded a score of 4 at 0.5 km and decaying exponentially out to 15 km either side of the road" (Venter et al. 2016) Funding provided by: Deutsche ForschungsgemeinschaftCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001659Award Number: DFG–FZT 118Funding provided by: Deutsche ForschungsgemeinschaftCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001659Award Number: 202548816Please refer to the Methods section and Supplementary Information of the published article

Species diversity and growth forms in tropical american palm communities

To advance our understanding of the processes that govern the assembly of palm communities and the local coexistence of numerous palm species, we here synthesize available information in the literature on species diversity and growth-form composition in palm communities across the Americas. American palm communities surveyed had 4-48 (median 16) species in study plots covering 0.09-7.2 ha. Climate, soils, hydrology, and topography are the main factors determining palm community species richness. Tropical lowland terra firme rain forests are the most species-rich whereas forests that are inundated or grow on sandy soils or in areas with seasonal climate have much fewer species. Palm communities in the central-western Amazon and in Central America are significantly richer than the average region and those in the Caribbean significantly poorer in species. As for branching, the 789 species of tropical American palms belong to Corner's model (solitary, 268 species, 33%), Tomlinsons model (cespitose, 521 species, 66%) and Schoute's model (dichotomous branching, three species, < 1%). We assigned the species to eight different growth forms: (i) Large tall-stemmed Palms (102 spp), (ii) Large-leaved medium-short-stemmed Palms (31 spp), (iii) Medium-sized Palms (95 spp), (iv) Medium/Small Palms with Stout Stem (42 spp), (v) Small Palms (423 spp), (vi) Large acaulescent Palms (28 spp), (vii) Small acaulescent Palms (56 spp), and (viii) Climbing Palms (12 spp). The eight growth forms are differently represented in the palm communities, and the categories Small Palms and Large tall-stemmed Palms dominate the communities both in terms of species richness and in number of individuals

Ecological traits influence the phylogenetic structure of bird species co-occurrences worldwide

The extent to which species’ ecological and phylogenetic relatedness shape their co-occurrence patterns at large spatial scales remains poorly understood. By quantifying phylogenetic assemblage structure within geographic ranges of >8000 bird species, we show that global co-occurrence patterns are linked - after accounting for regional effects - to key ecological traits reflecting diet, mobility, body size and climatic preference. We found that co-occurrences of carnivorous, migratory and cold-climate species are phylogenetically clustered, whereas nectarivores, herbivores, frugivores and invertebrate eaters tend to be more phylogenetically overdispersed. Preference for open or forested habitats appeared to be independent from the level of phylogenetic clustering. Our results advocate for an extension of the tropical niche conservatism hypothesis to incorporate ecological and life-history traits beyond the climatic niche. They further offer a novel species-oriented perspective on how biogeographic and evolutionary legacies interact with ecological traits to shape global patterns of species coexistence in birds

A robust phylogenomic framework for the calamoid palms

Well-supported phylogenies are a prerequisite for the study of the evolution and diversity of life on earth. The subfamily Calamoideae accounts for more than one fifth of the palm family (Arecaceae), occurs in tropical rainforests across the world, and supports a billion-dollar industry in rattan products. It contains ca. 550 species in 17 genera, 10 subtribes and three tribes, but their phylogenetic relationships remain insufficiently understood. Here, we sequenced almost one thousand nuclear genomic regions for 75 systematically selected Calamoideae, representing the taxonomic diversity within all calamoid genera. Our phylogenomic analyses resolved a maximally supported phylogenetic backbone for the Calamoideae, including several higher-level relationships not previously inferred. In-depth analysis revealed low gene tree conflict for the backbone but complex deep evolutionary histories within several subtribes. Overall, our phylogenomic framework sheds new light on the evolution of palms and provides a robust foundation for future comparative studies, such as taxonomy, systematics, biogeography, and macroevolutionary research

Molecular Clocks and Archeogenomics of a Late Period Egyptian Date Palm Leaf Reveal Introgression from Wild Relatives and Add Timestamps on the Domestication

The date palm, Phoenix dactylifera, has been a cornerstone of Middle Eastern and North African agriculture for millennia. It was first domesticated in the Persian Gulf, and its evolution appears to have been influenced by gene flow from two wild relatives, P. theophrasti, currently restricted to Crete and Turkey, and P. sylvestris, widespread from Bangladesh to the West Himalayas. Genomes of ancient date palm seeds show that gene flow from P. theophrasti to P. dactylifera may have occurred by ∼2,200 years ago, but traces of P. sylvestris could not be detected. We here integrate archeogenomics of a ∼2,100-year-old P. dactylifera leaf from Saqqara (Egypt), molecular-clock dating, and coalescence approaches with population genomic tests, to probe the hybridization between the date palm and its two closest relatives and provide minimum and maximum timestamps for its reticulated evolution. The Saqqara date palm shares a close genetic affinity with North African date palm populations, and we find clear genomic admixture from both P. theophrasti, and P. sylvestris, indicating that both had contributed to the date palm genome by 2,100 years ago. Molecular-clocks placed the divergence of P. theophrasti from P. dactylifera/P. sylvestris and that of P. dactylifera from P. sylvestris in the Upper Miocene, but strongly supported, conflicting topologies point to older gene flow between P. theophrasti and P. dactylifera, and P. sylvestris and P. dactylifera. Our work highlights the ancient hybrid origin of the date palms, and prompts the investigation of the functional significance of genetic material introgressed from both close relatives, which in turn could prove useful for modern date palm breeding