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The palm tribe Phytelepheae form a clade of three genera and eight species whose phylogenetic relationships and historical biogeography are not fully understood. Based on morphological similarities and phylogenetic relatedness, it has been suggested that Phytelephas seemannii and Phytelephas schottii are synonyms of Phytelephas macrocarpa, implying the existence of only six species within the Phytelepheae. In addition, uncertainty in their phylogenetic relationships in turn results in blurred biogeographic history. We inferred the phylogenomic relationships in the Phytelepheae by target-capturing 176 nuclear genes and estimated divergence times by using four fossils for time calibration. We lastly explored the biogeographic history of the tribe by inferring its ancestral range evolution. Our phylogenomic trees showed that P. seemannii and P. schottii are not closely related with P. macrocarpa, and therefore, support the existence of eight species in the Phytelepheae. The ancestor of the tribe was widely-distributed in the Chocó, Magdalena, and Amazonia during the Miocene at 19.25 Ma. Early diversification in Phytelephas at 5.27 Ma could have occurred by trans-Andean vicariance after the western Andes uplifted rapidly at âˆ¼ 10 Ma. Our results show the utility of phylogenomic approaches to shed light on species relationships and their biogeographic history.

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In Amazonian terra-firme non inundated forests, local floristic composition and species occurrence are explained by water availability as determined by topographic conditions. Topographic complexity can render these conditions quite variable across the landscape and the effects on plant ecological responses are difficult to document. We used a set of topographically defined hydrological metrics to evaluate community composition and single-species responses of four plant groups [pteridophytes (ferns and lycophytes), Melastomataceae, palms (Arecaceae) and Zingiberales] to topographic conditions in the middle Juruá River region, in western Brazilian Amazonia. The area spans two geological formations (Içá and Solimões) with contrasting topography. River terraces are also found along the main rivers in the area. Local topographic conditions were approximated by height above the nearest drainage (HAND), slope, and Strahler´s drainage order, all obtained from a SRTM digital elevation model (DEM). Data were analyzed using linear and generalized linear mixed models and regression trees. HAND was most successful in explaining floristic composition for all plant groups, except for Melastomataceae, and was more important in the hilly Içá formation than in the Solimões. Individual occurrences of 57% species were predicted by at least one of the topographic variables, suggesting a marked habitat specialization along topographic gradients. For these species, response models using SRTM-DEM-derived variables gave similar results than models using field-measured topography only. Our results suggest that topographical variables estimated from remote sensing can be used to predict local variation in the structure of plant communities in tropical forests.(AU)

Nas florestas de terra firme não inundáveis da Amazônia, a composição florística e a ocorrência de espécies podem ser explicadas pela disponibilidade hídrica relacionada com a topografia. Dada a complexidade topográfica, a disponibilidade de água pode ser bastante variável e seus efeitos na resposta das plantas, difícil de documentar. Neste estudo avaliamos as respostas individuais de espécie de quatro grupos de plantas [pteridófitas (samambaias e licófitas), Melastomataceae, palmeiras (Arecaceae) e Zingiberales] às condições topográficas na região do médio Rio Juruá, no oeste da Amazônia brasileira. A área abrange duas formações geológicas (Içá e Solimões) com topografias contrastantes. Terraços fluviais também são encontrados ao longo dos rios principais. As condições topográficas foram medidas usando a altura acima da drenagem mais próxima (HAND), declividade e ordem de drenagem de Strahler, todas obtidas a partir de um modelo digital de elevação SRTM-DEM. Os dados foram analisados usando modelos lineares generalizados mistos e árvores de regressão. HAND foi a principal variável explicativa da composição florística para todos os grupos de plantas, exceto Melastomataceae, tendo maior efeito na formação Içá do que na Solimões. Ocorrências individuais de 57% das espécies foram explicadas por pelo menos uma das variáveis, sugerindo uma especialização marcada de habitat ao longo de gradientes topográficos. Para essas espécies, modelos usando variáveis derivadas do SRTM-DEM deram resultados semelhantes aos modelos usando apenas a topografia medida em campo, o que indicam que variáveis topográficas derivadas do SRTM-DEM podem ser usadas para prever variações locais na estrutura de comunidades de plantas em florestas tropicais.(AU)

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En ecología una de las preguntas más importantes es: ¿cuáles son los factores ambientales que explican la alta diversidad de especies de plantas en los bosques tropicales? En este trabajo, se estudiaron las comunidades de palmas y su relación con los nutrientes del suelo en dos localidades del Chocó biogeográfico. Específicamente, se investigó: (1) cómo varían los nutrientes del suelo entre las dos localidades; (2) cuál es la relación entre los nutrientes del suelo y la composición florística de palmas; (3) cuáles son los nutrientes más importantes que explican la variación en la composición florística de las comunidades de palmas; y (4) cómo varía la abundancia de las especies dominantes de sotobosque y de dosel a lo largo del gradiente de concentración de los nutrientes más importantes. Se realizaron 20 transectos de 500 x 5 m (5 ha), en los cuales se identificaron y contaron todos los individuos de palmas en sus diferentes estadios de crecimiento. Las muestras de suelo se tomaron en cada uno de los transectos a los 0 , 250 y 500 m. Los cationes (Al, Ca, Mg, K, P) se extrajeron con la técnica Mehlich-III y las concentraciones se analizaron con espectrometría de emisión con plasma de acoplamiento inductivo (ICP-OES). La concentración de macronutrientes se relacionó con la composición florística mediante el test de Mantel, el test parcial de Mantel, regresiones lineales y escalamiento multidimensional no métrico (NMDS). Se encontraron 9 158 individuos y 33 especies de palmas en las 5 ha cubiertas por los transectos. La composición florística presentó una correlación positiva y significativa con los nutrientes del suelo (rM = 0.63-0.69) y con la distancia geográfica entre los transectos (rM = 0.71-0.75), mientras que las variables edáficas mostraron una alta correlación con la distancia geográfica (rM = 0.72). Asimismo, se encontró una débil relación significativa entre la fertilidad del suelo y la abundancia de palmas de sotobosque, pero ninguna con las palmas del dosel. Nuestros resultados demuestran que los suelos juegan un papel importante en la composición de las comunidades de palmas a escalas locales en la región del Chocó, y que los suelos más pobres y ricos en fósforo presentan la mayor diversidad de palmas.

One of the most important questions in ecology is: which are the environmental factors that explain the high plant diversity of tropical forests? We studied the floristic composition of palm communities and their relationship to soil nutrients in two localities of the Chocó region to understand (1) how soil nutrients vary between the two localities; (2) what is the relationship between soil nutrients and palm floristic composition; (3) what are the most important nutrients that explain the variation in floristic composition of palm communities; and (4) how does the abundance of the most exuberant understory and canopy palm species vary along the concentration gradient of the most important nutrients? We established 20 transects (5 x 500 m) and identified all palm individuals of all growth stages. Soil samples were taken at each transect at the beginning, middle, and end. Macronutrients (Al, Ca, Mg, K, P) were extracted with the Mehlich-III technique and their concentrations were analyzed by inductively coupled plasma emission spectrometry (ICP-OES). We used Mantel test, partial Mantel tests, linear regressions, and non-metric multidimensional scaling to determine if the concentration of nutrients was related to the floristic composition. We found a total of 9 158 individuals and 33 species of palms in the 5 ha covered by our transects. Floristic composition had a positive and significant correlation with soil nutrients (rM = 0.63-0.69) and with geographical distance between transects (rM= 0.71-0.75), whereas the soil nutrients were highly correlated with geographical distance (rM = 0.72). We also found a small, yet significant, relationship between soil fertility and the abundance of understory palms, but no relationship with canopy palms. Our results demonstrate for the first time that soils play an important role in the composition of palm communities at local scales in the Chocó region, and that infertile and phosphorus-rich soils have the highest palm diversity.

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BACKGROUND: Conserving both biodiversity and ecosystem services is a major goal of the Convention on Biological Diversity. Hotspots for biodiversity in the Andes significantly overlap with areas with dense human populations that sustain their economy through agricultural production. Therefore, developing management forms that reconcile food provisioning services-such as agriculture-with biodiversity conservation must be addressed to avoid social conflicts and to improve conservation in areas where biodiversity co-occurs with other ecosystem services. Here, we present a high-resolution conservation plan for vascular plants and agriculture in the Ecuadorian Dry Inter-Andean Valleys (DIAV) hotspot. Trade-offs in conserving important areas for both biodiversity and agriculture were explored. METHODS: We used a dataset containing 5,685 presence records for 95 plant species occurring in DIAVs, of which 14 species were endemic. We developed habitat suitability maps for the 95 species using Maxent. Prioritization analyses were carried out using a conservation planning framework. We developed three conservation scenarios that selected important areas for: biodiversity only, agriculture only, and for both biodiversity and agriculture combined. RESULTS: Our conservation planning analyses, capture 33.5% of biodiversity and 11% of agriculture under a scenario solely focused on the conservation of biodiversity. On the other hand, the top 17% fraction of the agriculture only scenario captures 10% of biodiversity and 28% of agriculture. When biodiversity and agriculture were considered in combination, their representation varied according to the importance given to agriculture. The most balanced solution that gives a nearly equal representation of both biodiversity and agriculture, was obtained when agriculture was given a slightly higher importance over biodiversity during the selection process. DISCUSSION: This is the first evaluation of trade-offs between important areas for biodiversity and agriculture in Ecuadorian DIAV. Our results showed that areas with high agricultural productivity and high biodiversity partly overlapped. Our study suggests that a land-sharing strategy would be appropriate for conserving plant diversity and agriculture in the DIAV. Overall, our study reinforces the idea that friendly practices in agriculture can contribute to biodiversity conservation.

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BACKGROUND AND AIMS: Identifying the processes that generate and maintain biodiversity requires understanding of how evolutionary processes interact with abiotic conditions to structure communities. Edaphic gradients are strongly associated with floristic patterns but, compared with climatic gradients, have received relatively little attention. We asked (1) How does the phylogenetic composition of palm communities vary along edaphic gradients within major habitat types? and (2) To what extent are phylogenetic patterns determined by (a) habitat specialists, (b) small versus large palms, and (c) hyperdiverse genera? METHODS: We paired data on palm community composition from 501 transects of 0.25 ha located in two main habitat types (non-inundated uplands and seasonally inundated floodplains) in western Amazonian rain forests with information on soil chemistry, climate, phylogeny and metrics of plant size. We focused on exchangeable base concentration (cmol+ kg-1) as a metric of soil fertility and a floristic index of inundation intensity. We used a null model approach to quantify the standard effect size of mean phylogenetic distance for each transect (a metric of phylogenetic community composition) and related this value to edaphic variables using generalized linear mixed models, including a term for spatial autocorrelation. KEY RESULTS: Overall, we recorded 112 008 individuals belonging to 110 species. Palm communities in non-inundated upland transects (but not floodplain transects) were more phylogenetically clustered in areas of low soil fertility, measured as exchangeable base concentration. In contrast, floodplain transects with more severe flood regimes (as inferred from floristic structure) tended to be phylogenetically clustered. Nearly half of the species recorded (44 %) were upland specialists while 18 % were floodplain specialists. In both habitat types, phylogenetic clustering was largely due to the co-occurrence of small-sized habitat specialists belonging to two hyperdiverse genera (Bactris and Geonoma). CONCLUSIONS: Edaphic conditions are associated with the phylogenetic community structure of palms across western Amazonia, and different factors (specifically, soil fertility and inundation intensity) appear to underlie diversity patterns in non-inundated upland versus floodplain habitats. By linking edaphic gradients with palm community phylogenetic structure, our study reinforces the need to integrate edaphic conditions in eco-evolutionary studies in order to better understand the processes that generate and maintain tropical forest diversity. Our results suggest a role for edaphic niche conservatism in the evolution and distribution of Amazonian palms, a finding with potential relevance for other clades.

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BACKGROUND: The páramo is a high-elevation biogeographical province in the northern Andes, known for its great biodiversity and ecosystem services. Because there have been very few biogeographic studies encompassing the entire province to date, this study aimed at conducting a phytogeographical regionalisation of the páramo. Specifically, (1) clustering analyses were conducted to identify the main phytogeographical units in the three altitudinal belts: sub-páramo, mid-páramo and super-páramo, and examine their diagnostic flora, (2) an ordination complemented the geo-climatic characterization of the obtained units and (3) a hierarchical classification transformation was obtained to evaluate the relationships between units. METHODS: The study area included the entire Andean páramo range in northern Peru, Ecuador, Colombia and Venezuela. The analyses were based on 1,647 phytosociological plots from the VegPáramo database. The K-means non-hierarchical clustering technique was used to obtain clusters identifiable as phytogeographical units, and the Ochiai fidelity index was calculated to identify their diagnostic species. A principal component analysis was conducted to obtain the geo-climatic characterization of each unit. Finally, the relationships between clusters were traced using a hierarchical plot-based classification. RESULTS: Fifteen clusters were obtained, 13 natural and two artificial, of which two represented the sub-páramo, nine the mid-páramo and four the super-páramo. Even though data representativeness was a potential limitation to segregate certain sub-páramo and super-páramo units, the overall bioregionalisation was robust and represented important latitudinal, altitudinal and climatic gradients. DISCUSSION: This study is the first to bioregionalise the páramo province based on a substantial widely distributed biological dataset, and therefore provides important novel scientific insight on its biogeography. The obtained phytogeographical units can be used to support further research on the páramo at smaller scale and on the humid Neotropical high-elevation ecosystems at broader-scale. Finally, several units were highlighted in our results as particularly worthy of further scientific and conservation focus.

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Globally, a majority of people use plants as a primary source of healthcare and introduced plants are increasingly discussed as medicine. Protecting this resource for human health depends upon understanding which plants are used and how use patterns will change over time. The increasing use of introduced plants in local pharmacopoeia has been explained by their greater abundance or accessibility (availability hypothesis), their ability to cure medical conditions that are not treated by native plants (diversification hypothesis), or as a result of the introduced plants' having many different simultaneous roles (versatility hypothesis). In order to describe the role of introduced plants in Ecuador, and to test these three hypotheses, we asked if introduced plants are over-represented in the Ecuadorian pharmacopoeia, and if their use as medicine is best explained by the introduced plants' greater availability, different therapeutic applications, or greater number of use categories. Drawing on 44,585 plant-use entries, and the checklist of >17,000 species found in Ecuador, we used multi-model inference to test if more introduced plants are used as medicines in Ecuador than expected by chance, and examine the support for each of the three hypotheses above. We find nuanced support for all hypotheses. More introduced plants are utilized than would be expected by chance, which can be explained by geographic distribution, their strong association with cultivation, diversification (except with regard to introduced diseases), and therapeutic versatility, but not versatility of use categories. Introduced plants make a disproportionately high contribution to plant medicine in Ecuador. The strong association of cultivation with introduced medicinal plant use highlights the importance of the maintenance of human-mediated environments such as homegardens and agroforests for the provisioning of healthcare services.

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The well-being of the global human population rests on provisioning services delivered by 12% of the Earth's ∼400,000 plant species1. Plant utilization by humans is influenced by species traits2-4, but it is not well understood which traits underpin different human needs5. Here, we focus on palms (Arecaceae), one of the most economically important plant groups globally6, and demonstrate that provisioning services related to basic needs, such as food and medicine, show a strong link to fundamental functional and geographic traits. We integrate data from 2,201 interviews on plant utilization from three biomes in South America-spanning 68 communities, 43 ethnic groups and 2,221 plant uses-with a dataset of 4 traits (leaf length, stem volume, fruit volume, geographic range size) and a species-level phylogeny7. For all 208 palm species occurring in our study area, we test for relations between their traits and perceived value. We find that people preferentially use large, widespread species rather than small, narrow-ranged species, and that different traits are linked to different uses. Further, plant size and geographic range size are stronger predictors of ecosystem service realization for palm services related to basic human needs than less-basic needs (for example, ritual). These findings suggest that reliance on plant size and availability may have prevented our optimal realization of wild-plant services, since ecologically rare yet functionally important (for example, chemically) clades may have been overlooked. Beyond expanding our understanding of how local people use biodiversity in mega-diverse regions, our trait- and phylogeny-based approach helps to understand the processes that underpin ecosystem service realization, a necessary step to meet societal needs in a changing world with a growing human population5,8.

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Are the hyperdiverse local forests of the western Amazon undergoing changes linked to global and local drivers such as climate change, or successional dynamics? We analyzed local climatic records to assess potential climatic changes in Yasuní National Park, Ecuador, and compared two censuses (1995, 2012) of a palm community to assess changes in community structure and composition. Over 17 years, the structure and composition of this palm community remained remarkably stable. Soil humidity was significantly lower and canopy conditions were significantly more open in 2012 compared to 1995, but local climatic records showed that no significant changes in precipitation, temperature or river level have occurred during the last decade. Thus, we found no evidence of recent directional shifts in climate or the palm community in Yasuní. The absence of changes in local climate and plant community dynamics in Yasuní contrasts with recent findings from eastern Amazon, where environmental change is driving significant changes in ecosystem dynamics. Our findings suggest that until now, local forests in the northwest Amazon may have escaped pressure from climate change. The stability of this rich palm community embedded in the hyperdiverse Yasuní National Park underlines its uniqueness as a sanctuary for the protection of Amazonian diversity from global change impacts.

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We studied palm communities, in particular species-richness and abundance, in the tropical rainforests in southeastern Peru in 54 transects (5×500m) covering an area of 13.5 hectares in flood plain, terra firme, terrace and premontane hills. We found 42 palm species in 18 genera in the transects. Terra firme forest had the highest species richness (38 species) followed by floodplain and premontane hills with 27 species and terrace forests with 26 species. The highest palm abundances were found in premontane hill forest which had 3243 palms per hectare and terra firme forest which had 2968 palms per hectare. The floodplain forests were intermediate in palm abundance with 2647 and the terrace forests had the lowest abundance with 1709 palms per hectare. Intermediate sized palms were the most common being represented by 18 species, while large palms were represented with 16 species. There were only eight species of small palms of which one was acaulescent. Only one species of liana palm was registered. Of the 42 species observed in the 54 transects, 20 were cespitose, 21 solitary and two had colonial growth. Seven species were found 40-320 km outside of their previously known range.

Estudiamos las comunidades de palmas de los bosques pluviales tropicales del sur de Perú, con especial énfasis en su riqueza de especies y abundancia, utilizando 54 transectas (5×500m), que cubrieron un área de 13.5 hectáreas en planicie inundable, terra firme, terraza y colinas premontanas. Encontramos 42 especies de palmas en las transectas. En el bosque de terra firme se encontró la mayor riqueza de especies (38 especies), seguido por la planicie inundable y las colinas premontanas con 27 especies y los bosques de terraza con 26 especies. Las mayores abundancias se encontraron en el bosque de colinas premontanas, con 3243 palmas por hectárea, y en el bosque de terra firme con 2968 palmas por hectárea. Los bosques de la planicie inundable presentaron una abundancia intermedia con 2647 palmas por hectárea y los bosques de terraza presentaron la menor abundancia con 1709. Las palmas de tamaño intermedio fueron las más comunes, estando representadas por 18 especies, mientras que las palmas grandes estuvieron representadas por 16 especies. Se encontraron solamente ocho especies de palmas pequeñas, una de las cuales era acaulescente. Sólo se registró una especie de palma trepadora. De las 42 especies observadas en las 54 transectas, 20 fueron cespitosas, 21 solitarias y dos presentaron crecimiento colonial. Siete especies se encontraron 40-320 km fuera del rango de distribución conocido previamente.

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ETHNOPHARMACOLOGICAL RELEVANCE: Without an understanding of the geography of traditional knowledge, implementing the Nagoya Protocol and national or regional strategies for benefit-sharing with local and indigenous communities will be difficult. We evaluate how much traditional knowledge about medicinal palm (Arecaceae) uses is unique and how much is shared across (i) four countries (Colombia, Ecuador, Peru, Bolivia), (ii) two cultural groups (Amerindian and non-Amerindian), (iii) 52 Amerindian tribes, (iv) six non-Amerindian groups, (v) 41 communities, and (vi) individuals in the 41 communities. MATERIALS AND METHODS: We first sampled traditional knowledge about palms from 255 references and then carried out 2201 field interviews using a standard protocol. Using the combined data set, we quantified the number of "singletons" that were unique to one of the analyzed scales. For the 41 communities, we evaluated how many uses were cited by <10% and by ≥50% of informants. We performed a Kruskal-Wallis test to evaluate whether the number of unshared uses (cited by <10%) differed significantly in relation to the informants׳ gender and degree of expertise, and performed a two-way ANOVA to test for differences in the number of unshared and shared uses accounted for by the five birth cohorts. RESULTS: We found that most knowledge was not shared among countries, cultural groups, tribes, communities, or even individuals within them. Still, a minor knowledge component was widely shared, even across countries. General informants cited a significantly higher number of unshared uses than experts, whereas no significant differences were found in the number of unshared uses cited by men and women or by different age groups. CONCLUSION: Our region-wide analysis highlights the geospatial complexity in traditional knowledge patterns, underscoring the need for improved geographic insight into the ownership of traditional knowledge in areas where biocultural diversity is high. This high geographic complexity needs consideration when designing property right protocols, and calls for countrywide compilation efforts as much localized knowledge remains unrecorded.

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A main objective of ethnobotany is to document traditional knowledge about plants before it disappears. However, little is known about the coverage of past ethnobotanical studies and thus about how well the existing literature covers the overall traditional knowledge of different human groups. To bridge this gap, we investigated ethnobotanical data-collecting efforts across four countries (Colombia, Ecuador, Peru, Bolivia), three ecoregions (Amazon, Andes, Chocó), and several human groups (including Amerindians, mestizos, and Afro-Americans). We used palms (Arecaceae) as our model group because of their usefulness and pervasiveness in the ethnobotanical literature. We carried out a large number of field interviews (n = 2201) to determine the coverage and quality of palm ethnobotanical data in the existing ethnobotanical literature (n = 255) published over the past 60 years. In our fieldwork in 68 communities, we collected 87,886 use reports and documented 2262 different palm uses and 140 useful palm species. We demonstrate that traditional knowledge on palm uses is vastly under-documented across ecoregions, countries, and human groups. We suggest that the use of standardized data-collecting protocols in wide-ranging ethnobotanical fieldwork is a promising approach for filling critical information gaps. Our work contributes to the Aichi Biodiversity Targets and emphasizes the need for signatory nations to the Convention on Biological Diversity to respond to these information gaps. Given our findings, we hope to stimulate the formulation of clear plans to systematically document ethnobotanical knowledge in northwestern South America and elsewhere before it vanishes.

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PREMISE OF THE STUDY: Most palm systematists were surprised when molecular evidence pointed to a sister group relationship between the tribe Ceroxyleae and the phytelephantoid palms. The latter comprises three genera of morphological aberrant palms that have previously been considered a subfamily of their own. Here we present the results of a detailed study of the floral structure and development of the wax palm, Ceroxylon ceriferum, which aims at revealing derived traits shared by the sister tribes Ceroxyleae and Phytelepheae. METHODS: A series of floral stages were sampled from Ceroxylon ceriferum growing in the central coastal range of Venezuela. The samples were prepared for scanning electronic microscopy and serial anatomical sectioning. KEY RESULTS: The development of male and female flowers of Ceroxylon ceriferum was similar. The receptacle elongated early in the ontogeny. The perianth was differentiated into distinct sepals and petals and was characterized by a lack of postgenital fusion. The stamens were incepted centripetally in 2(-3) whorls. The outer whorl of three stamens was antesepalous. The inner whorl consisted of six stamens arranged in three antepetalous pairs. CONCLUSIONS: The flowers of Ceroxylon ceriferum share a lack of postgenital fusion in the perianth with members of the tribe Phytelepheae. The elongation of the receptacle is reminiscent of the receptacle expansion in Phytelepheae. However, the multistaminate condition in C. ceriferum is less extreme than in the Phytelepheae, and the stamen initiation is centripetal as opposed to centrifugal in the latter.

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Despite long-standing interest in the origin and maintenance of species diversity, little is known about historical drivers of species assemblage structure at large spatiotemporal scales. Here, we use global species distribution data, a dated genus-level phylogeny, and paleo-reconstructions of biomes and climate to examine Cenozoic imprints on the phylogenetic structure of regional species assemblages of palms (Arecaceae), a species-rich plant family characteristic of tropical ecosystems. We find a strong imprint on phylogenetic clustering due to geographic isolation and in situ diversification, especially in the Neotropics and on islands with spectacular palm radiations (e.g., Madagascar, Hawaii, and Cuba). Phylogenetic overdispersion on mainlands and islands corresponds to biotic interchange areas. Differences in the degree of phylogenetic clustering among biogeographic realms are related to differential losses of tropical rainforests during the Cenozoic, but not to the cumulative area of tropical rainforest over geological time. A largely random phylogenetic assemblage structure in Africa coincides with severe losses of rainforest area, especially after the Miocene. More recent events also appear to be influential: phylogenetic clustering increases with increasing intensity of Quaternary glacial-interglacial climatic oscillations in South America and, to a lesser extent, Africa, indicating that specific clades perform better in climatically unstable regions. Our results suggest that continental isolation (in combination with limited long-distance dispersal) and changing climate and habitat loss throughout the Cenozoic have had strong impacts on the phylogenetic structure of regional species assemblages in the tropics.

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Este artículo presenta un inventario de la flora de palmeras autóctonas de Suramérica, conformada por 457 especies y 50 géneros. Se analiza la distribución de este grupo vegetal en siete entidades fitogeográficas y se discuten los principales factores que influyen sobre la evolución de las palmeras en América del Sur.

This article presents an inventory of South American palms including 457 species and 50 genera. The distribution of palms within seven phytogeographical entities is analyzed. Factors which influence the evolution of palms in South America are discussed.

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Aphandra natalia (Balslev & Henderson) Barfod is a multipurpose palm that is exploited both commercially and for subsistence purposes. Its fibers are important in Peruvian and Ecuadorean broom industries and supportmany people economically. In Brazil, it is found in the western part of Acre, where it is the main source for a local broom market. Data from fieldwork in Peru (2007) suggests that the variation in gross profit per kilogram of fiber is considerable among the different segments in the broom industry. Harvesters and distributors earn negligible amounts of money whereas manufacturers reap of the major part of the earnings. Fiber extraction appears to be sustainable in Ecuador and in some parts of Peru, whereas in other parts of Peru unsustainable harvest occurs, involving felling of entire palm trees for the harvest of fibers. The same destructive extraction method is used in Brazil, where the palm is becoming rare in its natural distribution area.

La palmera de piasaba (piassava, piassaba) —Aphandra natalia (Balslev& Henderson) Barfod es una palma que se utiliza para muchos propósitos, tanto comerciales como para la subsistencia de pueblos rurales. Sus fibras son de importancia económica en industrias de escobas en Perú y Ecuador, las cuales sostienen económicamente a muchas personas. En Brasil, esta palma se encuentra en la parte oeste del estado de Acre, donde sus fibras constituyen el recurso principal para el mercado local de escobas. Información de campo originada en Perú en el año 2007, muestra que existe una importante variación en las ganancias económicas por kilo de fibra entre los diferentes sectores de la industria de escobas. Los que cosechan y distribuyen los productos obtienen ganancias muy reducidas, mientras que los productores de escobas son los que más ganan. La extracción de fibras parece ser sostenible en Ecuador y en algunas partes de Perú, mientras que en otras partes de Perú se tumban palmeras enteras para sacar la fibra, lo cual representa un método no sostenible. La misma forma destructiva de cosecha de las fibras existe en Brasil, lo cual ha traído como consecuencia que las poblaciones de la palma se encuentran muy disminuidas en su hábitat natural.

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Se presenta información etnobotánica sobre usos de 64 especies de palmas encontradas en 28 comunidades en el Departamento de Loreto, Perú. Las palmas tienen gran importancia como fuente de alimento (Bactris gasipaes, Mauritia flexuosa, Euterpe precatoria, Oenocarpus bataua), para la obtención de fibras (Astrocaryum chambira, Aphandra natalia), en la construcción de viviendas (Euterpe precatoria, Iriartea deltoidea, Socratea exorrhiza), para su techado (muchas especies de Attalea, Lepidocaryum tenue) y para usos medicinales (Euterpe precatoria, Oenocarpus bataua).

This paper describes the uses of 64 species of palms in 28 villages in Departamento de Loreto, Peru. There, the palms are of great use as food (Bactris gasipaes, Mauritia flexuosa, Euterpe precatoria, Oenocarpus bataua), for fiber production (Astrocaryum chambira, Aphandra natalia), for construction of houses (Euterpe precatoria, Iriartea deltoidea, Socratea exorrhiza), thatching (many species of Attalea, Lepidocaryum tenue) and for many medicinal purposes (Euterpe precatoria, Oenocarpus bataua).

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The center of diversity of palms (Arecaceae) in tropical America is found in the Amazon basin and along the Panamanian isthmus. The greatest palm species richness has been reported for the Iquitos and Choco areas. Many species of palms are used mainly for construction and due to their edible fruits. In addition, there are 104 palms species that are used for medicinal purposes in many regions of the Americas. Cocos nucifera and Oenocarpus bataua are the most commonly used species for medicinal purposes. The fruit is the most commonly used part of palms for medicinal purposes (57 species). The traditional and medicinal use of plants has deep roots in the indigenous communities of Latin America. The significance of ethnomedicine for health care of local populations can not be ignored anymore because it plays a significant role in basic health care in developing countries. Interdisciplinary research in anthropology, ethnobotany and ethnopharmacology helps gather information on ethnomedicine and desing new drugs for modern medicine. American palms are sources of useful bioactive compounds against diabetes, prostate hyperplasia and leishmaniasis.

El centro de la diversidad de palmeras (Arecaceae) en América tropical se encuentra en la cuenca del Amazonas y a lo largo del istmo de Panamá. La mayor riqueza de especies de palmeras ha sido registrada para las áreas de Iquitos y de Chocó. Numerosas especies de palmeras son útiles, principalmente en la construcción y por sus frutos comestibles. Adicionalmente, 104 especies de palmeras neotropicales han sido reportadas con aplicaciones medicinales en muchas regiones de América. Cocos nucifera y Oenocarpus bataua, son las especies más utilizadas como medicinales. Los frutos, son la parte de la palmera de mayor uso con fines medicinales (57 especies). El uso tradicional y medicinal de plantas, tiene raíces profundas no sólo en comunidades indígenas de Latinoamérica, sino que es practicado en gran parte de la sociedad. El significado de la etnomedicina para la asistencia médica de las poblaciones locales no puede seguir siendo ignorado, porque la etnomedicina juega un papel significativo en la asistencia médica básica en los países en desarrollo. Investigaciones interdisciplinarias, antropológicas, etnobotánicas y etnofarmacológicas ayudan a brindar información sobre etnomedicina y diseñar nuevas drogas para la medicina moderna. Las palmeras americanas son fuentes de compuestos bioactivos útiles que pueden ser usados contra la diabetes, la hiperplasia de la próstata y la leishmaniasis entre otros.

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RESUMO

BACKGROUND: Tobler's first law of geography, 'Everything is related to everything else, but near things are more related than distant things' also applies to biological systems as illustrated by a general and strong occurrence of geographic distance decay in ecological community similarity. Using American palms (Arecaceae) as an example, we assess the extent to which Tobler's first law applies to species richness and species composition, two fundamental aspects of ecological community structure. To shed light on the mechanisms driving distance decays in community structure, we also quantify the relative contribution of geographic distance per se and environmental changes as drivers of spatial turnover in species richness and composition. RESULTS: Across the Americas, similarity in species composition followed a negative exponential decay curve, while similarity in species richness exhibited a parabolic relationship with geographic distance. Within the four subregions geographic distance decays were observed in both species composition and richness, though the decays were less regular for species richness than for species composition. Similarity in species composition showed a faster, more consistent decay with distance than similarity in species richness, both across the Americas and within the subregions. At both spatial extents, geographic distance decay in species richness depended more on environmental distance than on geographic distance, while the opposite was true for species composition. The environmentally complex or geographically fragmented subregions exhibited stronger distance decays than the more homogenous subregions. CONCLUSION: Similarity in species composition exhibited a strong geographic distance decay, in agreement with Tobler's first law of geography. In contrast, similarity in species richness did not exhibit a consistent distance decay, especially not at distances >4000 kilometers. Therefore, the degree to which Tobler's first law of geography applies to community structure depends on which aspect hereof is considered - species composition or species richness. Environmentally complex or geographically fragmented regions exhibited the strongest distance decays. We conclude that Tobler's law may be most applicable when dispersal is a strong determinant of spatial turnover and less so when environmental control predominates.

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