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Insights into variations of seasonal and daily soil temperatures under the effect of biocrusts in central-western Argentina

Background and Aims: Biocrusts play an essential role on the earth’s surface and have a direct influence on soil parameters. Their effects on soil temperature are considered one of the most important because they affect ecological and hydrological processes, as well as the diversity of natural ecosystems. Although there are several studies concerning biocrust effects on the soil surface, investigations about the effect of the biocrust on soil temperature are still scarce. Our objective was to evaluate the influence of biocrusts on soil temperature conditions in drylands of central-western Argentina. Methods: Temperature values were recorded in the Monte phytogeographic region in the central-western part of Argentina, in three sites, during the dry and wet seasons in 2017-2018. We collected samples from a total of 30 randomly selected plots. We recorded daily temperatures values in two paired plots with crusted and uncrusted zones using a calibrated data logger Ibutton. The sampling took 18 days in total, three days on each site.Key results: Our results indicate that biocrusts produce a change in micro-soil temperatures. Areas in which biocrusts are present show a temperature reduction both in the wet and dry seasons. This effect is observed in the three studied sites. Temperature reduction varies according to the time of the day, study site and season. The morning, noon, and afternoon recorded the highest mean temperatures.Conclusions: The presence of biocrusts reduces soil temperatures in drylands of central-western Argentina. Large differences in mean temperature values between crusted and uncrusted zones were observed. The thermal reduction was more notorious in the hyper-arid site. How they affect their surrounding environment can be related to multiple factors, such as the composition of the microphytic community, the local climate and environmental conditions.

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Notes on the marine algae of the International Biosphere Reserve Seaflower, Caribbean Colombia IX: new records of Lobophora declerckii, Taonia abbottiana and Verosphacela ebrachia for Colombia

Background and Aims: During the Seaflower Scientific Expedition in 2019, extensive seaweed collection was carried out around Old Providence and Santa Catalina islands. Despite the intensive phycological studies realized during the past decade, new reports of macroalgae are still recorded for the Seaflower Biosphere Reserve. The objective of this work is to present three new records of brown algae for Colombia.Methods: The algal sampling was carried out in September 2019 during the Seaflower Scientific Expedition. The samples were collected around the Providencia and Santa Catalina islands in coral patches ecosystems, by SCUBA diving at depths between 3 and 16 m. The algae collected were preserved in a 4% formalin/seawater solution. The identification was carried out using optical and stereoscopic microscopes. All specimens were deposited in the herbarium JIW of the Biology Department of the Universidad Nacional de Colombia, Bogotá, Colombia. Key results: Three species of brown algae are newly reported for Colombia: Lobophora declerckii, Taonia abbottiana and Verosphacela ebrachia. Verosphacela has been reported, to date, only from the type locality in Florida and from Isla Mujeres, in Mexico. Due to its cryptic and small habit, it may be much more common than actually reported. Lobophora declerckii is apparently the most common species of Lobophora in the Archipelago. Taonia abbottiana may be much more common than reported to date, but it is easily confused with Stypopodium zonale. Conclusions: Despite the intense phycological research carried out in the past decade in the Archipelago of San Andrés, Old Providence and Santa Catalina, there is still much to be discovered.

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Formulation and phytochemical analysis of a potentially functional beverage from combining a leaf extract and pulp of Annona muricata (Annonaceae)

Background and Aims: Annona muricata beverages are widely used in traditional medicine to treat different ailments; however, they have been little characterized phytochemically and are consumed as sugary beverages, and may contribute to non-communicable diseases, including obesity. The objective of this work was to obtain and characterize a sensorially acceptable beverage from an extract of A. muricata leaves and pulp. Methods: A mixture design was used to formulate nine beverages by combining different ratios of the aqueous extract of A. muricata leaves and pulp. These beverages were subjected to physicochemical and sensory evaluation. Based on these results, one beverage was selected to be characterized by spectrophotometry and compared with an infused and commercial beverage. In addition, the selected beverage was further analyzed for its phytochemical composition by ultra-high-performance chromatography coupled to mass spectrometry and high-performance liquid chromatography coupled to a photodiode array detector. Key results: The selected beverage was formulated with 25% pulp, 50% leaf extract, and 25% water; it also displayed a 7.63 °Brix, pH 3.42, and 0.40% acidity. This beverage was up to three times higher in bioactive compounds than infused and commercial beverages. Fourteen phenolic compounds and two acetogenins were quantified, while two alkaloids (coclaurine and reticuline) and fifteen acetogenins were tentatively identified. Conclusions: The combination of A. muricata leaf extract and pulp is a vital alternative to obtain a sensorially acceptable beverage that contains bioactive compounds with a potential medicinal action since the phenolic compounds, alkaloids, and acetogenins present in the beverage could have efficient biological activities in the prevention of chronic degenerative diseases.

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Inclusions of flowers of Podopterus (Polygonaceae) in the Miocene amber of Simojovel de Allende, Chiapas, Mexico

Background and Aims: The Miocene amber from Chiapas, Mexico, shows high diversity of biological inclusions such as plants, fungi, arthropods, and vertebrates, being one of the most important amber-bearing areas worldwide. The aim of this work is to describe a new record based on four bisexual flowers belonging to the fossil species Podopterus mijangosae, that has been described recently based on its winged fruits only.Methods: The morphological and anatomical characteristics of the four fossil flowers were observed using a binocular stereoscopic microscope. The taxonomic affinity was decided by consulting specialized literature, as well as the review of herbarium material of the genera Podopterus, Fallopia, and Neomillspaughia of Polygonaceae.Key results: The four fossil specimens are bisexual, small, and have actinomorphic flowers, with differentiated perianth, three petals and three sepals per series, stamens are free and with thread-like filaments, anthers are dithecal and basifixed, the ovary is superior, syncarpous, 3-angular, with three free styles, and capitate stigmas. Conclusions: This new report of flowers of Podopterus adds more evidence that the family Polygonaceae was an important component of the tropical forest of Simojovel de Allende, Chiapas, Mexico, during the Miocene.

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Nutritional and nutraceutical components of four Cantharellus species (Cantharellaceae, Cantharellales) from the Mountain Region, Veracruz, Mexico

Background and Aims: Cantharellus species are traded in agricultural markets of the Mountain Region, Veracruz, Mexico, as an appreciated mushroom. The objective of this study was to analyze nutrients and nutraceutical properties in four Cantharellus species from Veracruz: antioxidant activity, total phenols, flavonoids, ascorbic acid, lycopene, and β-carotene; as well as the nutritional properties: dry matter, total ashes, crude protein, crude fat, crude fiber, moisture, carbohydrates and energy value of four wild edible mushrooms (Cantharellus violaceovinosus, C. veraecrucis, C. roseocanus y Cantharellus sp.). Methods: Basidiomas of Cantharellus spp. were collected in the Mountain Region, Veracruz, Mexico. The ITS and tef-1α regions were amplified and sequenced. Species were identified molecularly based on the BLAST results. Samples were lyophilized and stored at 4 °C in vacuum bags for the preservation of nutraceutical and nutritional compounds. A methanol-water mixture (80:20 v/v) was used to extract the nutraceutical compounds and to analyze them by spectrophotometric techniques. Key results: In general, outstanding values ​​were found in C. violaceovinosus both in crude protein content (8.04 g/100 g-1) and in antioxidant capacity 2.28 mg TE/g extract. For flavonoids, C. roseocanus showed 2.98 mg QE/g extract and 6.23±0.68 mg/g of carotene. In addition, a high energy value was found in C. violaceovinosus (266.53 Kcal/100g) and C. roseocanus (222.73±15.43 Kcal/100 g). The nutritional and nutraceutical content of C. violaceovinosus, C. veraecrucis and C. roseocanus is presented for the first time. Conclusions: The results show these species from nutritional and nutraceutical perspectives. Cantharellus violaceovinosus showed the highest values of the parameters evaluated. The consumption of these species constitutes an alternative source of protein and nutraceutical components that contribute to food security.

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Flora y vegetación de los trópicos estacionalmente secos en México: origen e implicaciones biogeográficas

Entre las diversas ideas que se han propuesto para explicar la gran diversidad biológica de México está la que afirma que ésta es el resultado del contacto de las biotas neotropical y neártica; sin embargo, esta explicación relacionada con el gran contacto biótico de las Américas no es completamente satisfactoria y necesita ser revisada a la luz de la biogeografía histórica. En este artículo ofrecemos nuevas perspectivas sobre este asunto por medio de una revisión de la historia de la flora y la heterogeneidad vegetacional del trópico estacionalmente seco de este país. Se han usado varios criterios ambientales para definir las regiones tropicales estacionalmente secas, pero ubicar con precisión sus límites geográficos no es siempre fácil. Esto se debe en gran medida a la gran heterogeneidad de la vegetación presente en esta región, entre la que predomina el bosque tropical caducifolio (BTC). El origen de la flora del BTC se remonta, por lo menos, unos 20 millones de años antes del presente y parece estar asociada con la flora del Terciario de Norteamérica. La evidencia disponible no apoya un origen sudamericano para el BTC. Asimismo, no hay razones que justifiquen de forma convincente la separación de la flora del BTC y la de los desiertos calientes de Norteamérica en dos reinos biogeográficos diferentes. La historia de la flora del trópico estacionalmente seco de México sugiere fuertemente que esta dicotomía biogeográfica debería ser reemplazada por el reconocimiento de la existencia de un Reino Panamericano.

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Siembra directa de Brosimum alicastrum Sw. (Moraceae) y Enterolobium cyclocarpum (Jacq.) Griseb. (Mimosaceae) en diferentes habitats en el trópico seco del centro de Veracruz

Los acahuales (i.e. selvas secundarias) de zonas tropicales secas o estacionales, suelen ser pobres en especies arbóreas y dominados por unas cuantas especies de arbustos y árboles pioneros, usualmente dispersados por viento, siendo notable la ausencia de plantas arbóreas del dosel cuyas semillas relativamente grandes dependen de vectores animales para su dispersión. Varios estudios han encontrado que la siembra directa de especies arbóreas zoócoras con semillas grandes, en pastizales abandonados puede ser una práctica exitosa para enriquecer y acelerar la sucesión secundaria. Sin embargo, todavía no se conocen cabalmente las condiciones de hábitat o etapa sucesional óptima para realizar la siembra directa de semillas de árboles de fases sucesionales tardías. En este estudio seleccionamos dos especies arbóreas con semillas zoócoras relativamente grandes, que suelen formar parte del dosel de las selvas sub-caducifolias del centro de Veracruz: Brosimum alicastrum y Enterolobium cyclocarpum. Las sembramos en siete hábitats; seis de ellos representando un gradiente de menor a mayor complejidad estructural o desarrollo sucesional, desde pastizal activo hasta acahual de 10 años y el hábitat restante fue selva mediana sub-caducifolia bien conservada. Evaluamos experimentalmente la importancia de la depredación de semillas, protegiendo la mitad de ellas sembradas dentro de jaulas diseñadas para excluir a vertebrados granívoros. Durante un año monitoreamos la emergencia, supervivencia y crecimiento de plántulas, marcando a las que sobrevivieron su primer año, para ser registradas cuatro años y medio después. Un porcentaje relativamente alto de plántulas emergió de las semillas sembradas (75% en Brosimum, 60% Enterolobium). No detectamos diferencias significativas en la emergencia de plántulas entre los siete hábitats, ni entre los dos tratamientos de exposición a granívoros (dentro vs. fuera de exclusorios). Ninguna de las semillas sembradas fue removida por granívoros. La supervivencia y crecimiento deEnterolobium durante el primer año fue mayor en hábitats abiertos sin cobertura de plantas leñosas (ca. 60%) que en los sombreados por arbustos y árboles (<10%). En contraste, las plántulas de Brosimum sobrevivieron y crecieron mucho mejor bajo la sombra de plantas leñosas (>80%) que en hábitats abiertos (0%). Nuestros resultados muestran que los pastizales abandonados y los acahuales pobres en especies arbóreas, pueden ser enriquecidos mediante la siembra directa de árboles de fases sucesionales tardías con baja capacidad de dispersión, siempre y cuando se elija cuidadosamente el hábitat (o etapa sucesional) óptimo para la siembra de semillas, con base en la ecología del establecimiento de plántulas de las especies involucradas. En el centro de Veracruz se puede acelerar la recuperación de la selva, sembrando semillas de Enterolobium desde el momento del abandono del pastizal, siempre y cuando se controle el crecimiento de los pastos durante los primeros dos a tres años de crecimiento de las plántulas. A su vez las semillas de Brosimum deberán sembrarse hasta que los arbustos o árboles pioneros hayan colonizado el sitio y sombreado a los pastos.

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Yerba del coyote, veneno del perro: la evidencia léxica para identificar plantas en el Códice de la Cruz Badiano

La terminología botánica registrada en el Códice de la Cruz Badiano no ha sido estudiada desde el trabajo precursor de Garibay en 1964. Un análisis etimológico de los nombres de las plantas, sustentado en las investigaciones recientes sobre la fonología, gramática y la composición léxica del náhuatl clásico, nos permite proponer nuevas identificaciones para algunas especies ilustradas en el manuscrito, cotejándolas con las designaciones que reciben en las variantes nahuas contemporáneas mejor documentadas. La lista de plantas que podemos determinar de manera confiable, con base en la evidencia léxica, iconográfica y etnobotánica, deja entrever un patrón biogeográfico inesperado: el número de géneros con afinidad meridional supera con mucho a los taxa de distribución boreal. Inferimos por ello que buena parte del conocimiento farmacológico de las élites precolombinas se originó en las tierras bajas tropicales, como lo indican en forma análoga las materias primas vegetales y animales empleadas en las artes suntuarias. Esta línea de investigación, que relaciona la historia natural de México con la medicina tradicional y la cultura material de los pueblos indígenas, puede aportar nuevas pistas para esclarecer la historia temprana de la civilización mesoamericana. Para concluir, examinamos el papel que jugó el Códice, como primer texto botánico que se conservó del Nuevo Mundo, en los proyectos de la Academia de los Linceos y el curso de la ciencia occidental en el siglo XVII.

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