268 research outputs found

    Light converts endosymbiotic fungus to pathogen, influencing seedling survival and host tree recruitment

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    Endophytic fungi that asymptomatically colonize plants^1^ are diverse and abundant in tropical ecosystems^2^. These organisms can be weakly pathogenic^3^ and/or mutualistic, frequently enabling plants to adapt to extreme environments, alter competitive abilities of host individuals and improve host fitness under abiotic or biotic stresses^4,5,6^. _Diplodia mutila_ is a symbiotic endophyte/plant pathogenic fungus infecting the palm _Iriartea deltoidea_^7^, which dominates many wet lowland Neotropical forests. The fungus is an asymptomatic endophyte in mature plants, and disease and mortality are expressed in some seedlings, while others remain disease free. Here we show that seedlings bearing the endophyte show enhanced resistance to insect herbivory. However, high light availability triggers pathogenicity of the fungus, while low light favors endosymbiotic development, constraining recruitment of endophyte-infested seedlings to the shaded understory by limiting survival of seedlings in direct light. These results provide evidence that patterns of plant abundance and the mechanisms maintaining tropical forest biodiversity are the result of a more complex interplay between abiotic and biotic environments than previously thought

    Management of Astrocaryum standleyanum (Arecaceae) for Handicraft Production in Colombia

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    We studied use and management of Astrocaryum standleyanum among the Wounaan people at the Pacific Coast of Colombia between 2009 and 2011, with the intention of generating recommendations for a sustainable management of the palm. We used ethnobotanical techniques and established plots to monitor palm populations. A. standleyanum grows in forest and cultivated fields near the Wounaan villages, where leaves are harvested non-destructively by using a medialuna mounted on a pole. Fiber is then extracted from the epidermis and mesophyll of the leaflets, processed, dyed, and used to produce baskets woven with the coiled technique. The handicrafts are marketed through middlemen or in handicraft fairs, and they are the major source of cash income for the Wounaan. As a result of the now abandoned malpractice of cutting down palms to obtain the fiber, there is a low number of adult palms, but the population structure shows signs of recovery. Integration of traditional practices with non-destructive harvest techniques suggests that in this region it is possible to conserve both the palm and the artisanal activity, which represents a major line for the socioeconomic development for the Wounaan

    Comunidades de palmas en los bosques tropicales de Madre de Dios de la Amazonía Peruana

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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

    Ritual uses of palms in traditional medicine in sub-Saharan Africa: a review

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    Phytoregionalisation of the Andean páramo

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    Background: The pa´ramo 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 pa´ramo. Specifically, (1) clustering analyses were conducted to identify the main phytogeographical units in the three altitudinal belts: sub-pa´ramo, mid-pa´ramo and super-pa´ramo, 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 pa´ramo range in northern Peru, Ecuador, Colombia and Venezuela. The analyses were based on 1,647 phytosociological plots from the VegPa´ramo database. The K-means nonhierarchical 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-pa´ramo, nine the mid-pa´ramo and four the super-pa´ramo. Even though data representativeness was a potential limitation to segregate certain subpa ´ramo and super-pa´ramo units, the overall bioregionalisation was robust and represented important latitudinal, altitudinal and climatic gradients. Discussion: This study is the first to bioregionalise the pa´ramo 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 pa´ramo 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

    Aphandra natalia(Arecaceae) – un recurso poco conocido de piassaba en el oeste de la Amazonía

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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 support many 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

    Fine-scale plant richness mapping of the Andean Páramo according to macroclimate

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    Understanding the main relationships between the current macroclimate and broad spatial patterns of plant diversity is a priority in biogeography, and although there is an important body of studies on the topic worldwide, tropical mountains remain underrepresented. Because understanding primary drivers of diversity patterns in the Andean páramo is still in its infancy, we focused on evaluating the role of the current macroclimate in form of three complementary hypotheses, energy, seasonality and harshness, in explaining local variation of plant species richness. We relied on 1,559 vegetation plots that offered a fine-scale outlook on real species assemblages due to community rules and species' interactions with their surrounding environment, including climate. Generalized Least Squares (GLS) regression models provided insight on the significance of the different hypotheses in explaining local plant richness, but only the energy and seasonality hypotheses received partial support. The best model was then combined with spatial interpolation Kriging modeling techniques to project species richness for a standardized 25 m2 plot throughout the entire páramo biogeographical province. We highlighted a North-South increase in richness with several species-rich areas, potential local biodiversity hotspots, independent of the general gradient: the Amotape-Huancabamba zone, Sangay and Cotacachi areas, and eastern Venezuelan Andes. Our endeavor to finely map local richness is the first effort predicting macroecological patterns in the emblematic Andean páramo and contributes novel biogeographical knowledge useful to further support in-depth research and conservation focus in the northern Andes

    Balancing plant conservation and agricultural production in the Ecuadorian Dry Inter-Andean Valleys

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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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