The pseudaril of Bursera and Commiphora, a foretold homology?

AbstractRecent molecular studies on the Burseraceae phylogeny point out that the Bursera - Commiphora complex is monophyletic. Both genera develop a brightly colored paseudaril, and it is possible to presume which tissue is a homologous character. This work analyzes the development of this tissue in 14 species of Bursera, with the aim to determine the existence of a single type of ontogenetic origin. The overall development of the pseudaril in Bursera is described from a histological point of view and it is compared with the development of this tissue in Commiphora, as reported in the literature. Results indicate that the exocarp and endocarp sensu stricto derive from the external and internal epidermis, respectively, whereas the pseudaril differentiates from mesocarp in both genera. The primary difference in fruit development between the 2 sections of Bursera consists in the pseudaril differentiation, which initiates in earlier developmental stages in species of section Bullockia compared to those of section Bursera. To conclude, ontogeny and function of the pseudaril of Bursera agree with that described for Commiphora; thus, it is strongly suggested that the aforesaid tissue is homologous in both genera

Hummingbird migration and flowering synchrony in the temperate forests of northwestern Mexico

Background Many species of birds are morphologically and physiologically adapted for migration. Migratory movements of birds can range from thousands of kilometers, such as when birds migrate from wintering to breeding sites in summer, to several kilometers, such as when birds migrate among habitats in a single mountain system. The main factor that influences bird migration is the seasonal fluctuation of food resources; climate, predation, competition for resources and endogenous programming are also important factors. Hummingbirds are highly dependent on nectar, so their migration is likely correlated with the blooming of plant species. The ecological implications of altitudinal migration in the mountains of North America as well as the latitudinal migration of Selasphorus rufus through Mexico are still poorly understood. To explore these issues, over three non-consecutive years, we evaluated interannual variation in the phenologies of a latitudinal migrant (S. rufus) and an altitudinal migrant (Amazilia beryllina) and their visited plants. Methods We assessed the relationship between two migratory hummingbirds and flower abundance in 20 fixed-radius plots (25 m radius). All available flowers were counted along transects (40 × 5 m) inside each fixed-radius plot. Sampling was performed every 10 days from November 12 through February 20 of 2010–2011, 2013–2014 and 2015–2016, resulting in a total of 11 samples of each plot per period. Phenological variation and the relationships among hummingbird abundance, flower abundance and vegetation type were evaluated using a generalized additive mixed model. Results S. rufus abundance was related to sampling time in the first and third periods; this relationship was not significant in the second period. A. beryllina abundance was related with the sampling time over all three periods. The abundance of S. rufus hummingbirds was significantly related to the number of Salvia iodantha flowers. The abundance of A. beryllina hummingbirds was related to the number of S. iodantha and Cestrum thyrsoideum flowers and the total number of flowers. We found a non-significant correlation between S. rufus and A. beryllina abundance and vegetation types. Conclusion Contrary to expectations, the long-distance migration of S. rufus was not consistent over the sampling periods. The migration of S. rufus through the study region may be altered by changes in climate, as has occurred with other species of migratory birds. In the present study, the migration of S. rufus was correlated with the blooming of S. iodantha. In comparison, the altitudinal migrant A. beryllina responded to the availability of floral resources but was not associated with a particular plant. The migration of this latter species in the area probably depends on multiple factors, including climatic and demographic factors, but is particularly dependent on the supply of floral resources and competition for these resources

Extracción y morfología del embrión de Bursera bipinnata (Burseraceae)

Background and Aims: The understanding of the reproductive biology of plants, from the formation of the seed to its establishment, allows the development of different conservation strategies. In the genus Bursera, whose main center of diversification is Mexico, the diaspore is a pyrene formed by a strongly lignified endocarp enclosing the seed. The anatomical characteristics of the pyrene and the parthenocarpy are the main factors that have hindered the study of embryogenesis and the development of propagation techniques. In this paper we describe the morphology of the Bursera bipinnata embryo, extracted by a technique that does not alter the structure or the chemical composition of tissues.Methods: During the beginning of the dispersal stage 2014, we collected unripe fruits and pyrenes with exposed pseudaril. Unripe fruits were fixed in FAA. A low speed micromotor with handpiece was used. A conical burr was used in unripe fruits to scabble the fruit valves. To open the pyrenes a diamond disc was used. After opening the endocarp, embryos were removed and fixed.Key results: The pattern of development coincides with other model species of angiosperms. In immature fruits globular, heart-shaped, torpedo and cotyledonary stages were observed, the latter in early stages. During the torpedo stage, cotyledons branch into three lobes and are spliced, as they grow, they are folded upon themselves, and cover the embryonic axis; however, the radicular meristem is always exposed.Conclusions: The extraction technique is rapid, inexpensive and non-destructive to tissues, having a potential use in the detailed analysis of embryogenesis in the genus Bursera, tissue culture and ex situ conservation.Antecedentes y Objetivos: El entendimiento de la biología reproductiva de las plantas, desde la formación de la semilla hasta su establecimiento, permite el desarrollo de diferentes estrategias de conservación. En el género Bursera, cuyo principal centro de diversificación es México, la diáspora es un pireno formado por un endocarpo fuertemente lignificado que encierra a la semilla. Las características anatómicas del pireno y la partenocarpia son los principales factores que han obstaculizado el estudio de la embriogénesis y el desarrollo de técnicas de propagación. En este trabajo se describe la morfología del embrión de Bursera bipinnata extraído mediante una técnica que no altera la estructura o la composición química de los tejidos.Métodos: Durante el inicio de la etapa de dispersión 2014, se colectaron frutos inmaduros y pirenos con pseudoarilo expuesto, los frutos inmaduros se fijaron en FAA. Se utilizó un micromotor con pieza de mano de baja velocidad. En los frutos inmaduros se utilizó un fresón cónico para desgastar las valvas del fruto. Para abrir los pirenos se utilizó un disco de diamante. Una vez abierto el endocarpo, los embriones se extrajeron y se fijaron.Resultados clave: El patrón de desarrollo coincide con otras especies modelo de angiospermas. En los frutos inmaduros se encontraron las fases globular, acorazonada, torpedo y cotiledonar, ésta última en etapas iniciales. En la fase de torpedo los cotiledones se ramifican en tres lóbulos y se empalman, a medida que crecen se pliegan sobre si mismos encerrando el eje embrionario; sin embargo, el meristemo radicular siempre queda expuesto. El embrión se clasificó como embrión axial foliado contortuplicado.Conclusiones: La técnica de extracción es rápida, de bajo costo y no invasiva para los tejidos, teniendo un uso potencial en el análisis detallado de la embriogénesis del género Bursera, el cultivo de tejidos y la conservación ex situ

Responses to risks and opportunities associated with pollinators and pollination

The overall aim of the thematic assessment of Pollinators, Pollination and Food Production is to assess animal pollination as a regulating ecosystem service under pinning food production in the context of its contribution to nature'sgifts to people and supporting a good quality of life. Toachieve this, the focus is on the role of native and exoticpollinators, the status of, and trends in pollinators andpollinator-plant networks and pollination, drivers of change,impacts on human well-being, food production in responseto pollination declines and deficits and the effectiveness ofresponses from various governance systems to pollinationdeclines and deficits. The scope is global, covering allcontinents except Antarctica, where no pollinators areknown. The assessment brings together contributions notonly from natural, social and economic science perspectives but also from knowledge of indigenous and local community stake holders and practitioners.The assessment strives to critically review the broadest range of evidence and make its findings readily availableto support policy and management responses to declinesand deficits in pollination. The report represents the firstIPBES thematic assessment deliverable that aims toidentify policy-relevant findings for decision-making ingovernment, the private sector and civil society, as wellas helping to demonstrate how an essential ecosystem service could potentially contribute to the post-2015 development agendaFil: Dicks, Lynn. University of Cambridge; Reino UnidoFil: Viana, Blandina Felipe. Universidad federal de Bahia; BrasilFil: del Coro Arizmendi, Maria. Universidad Nacional Autónoma de México; MéxicoFil: Bommarco, Riccardo. Mid Sweden University.; SueciaFil: Brosi, Berry. University of Washington; Estados UnidosFil: Cunningham, Saul. Australian National University; AustraliaFil: Galetto, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Lopes, Ariadna. Universidade Federal de Pernambuco; BrasilFil: Taki, Hisatomo. University of Florida; Estados Unido

Avifauna de la selva baja caducifolia en la cañada del río Sabino, Oaxaca, México Avifauna of the tropical dry forest in the Sabino Canyon, Oaxaca, Mexico

Se describe la avifauna de la selva baja caducifolia del cañón del río Sabino, Oaxaca, al sureste de la Reserva de la Biosfera Tehuacán-Cuicatlán y compara la similitud de la avifauna de la Reserva con la de otras regiones con selvas bajas en México. El trabajo se realizó entre junio de 2005 y octubre de 2006, registrando 113 especies pertenecientes a 13 órdenes y 34 familias; 6 especies son muy abundantes, 10 abundantes, 20 comunes, 32 poco comunes y 37 raras; 79 de las especies registradas fueron residentes, 28 visitantes invernales, 2 visitantes de verano, 3 transitorias y 5 residentes con movimientos estacionales; 15 especies son endémicas a México y 23 están dentro de alguna categoría de riesgo. La avifauna estudiada representa una mezcla de especies características de la cuenca del Balsas, las vertientes pacífica y atlántica y los ambientes montanos y áridos del centro de México. Por su composición específica la avifauna estudiada se relacionó con las avifaunas de la cuenca del Balsas. La selva baja del cañón del Sabino es prioritaria para la conservación debido a su riqueza en especies endémicas y a la presencia una colonia reproductora de la guacamaya verde, Ara militaris, especie globalmente amenazada.<br>This study describes the birds of the tropical dry forest in Sabino Canyon, Oaxaca, in the southeastern part of the Tehuacán-Cuicatlán biosphere reserve. Field work was conducted between June 2005 and October 2006. A total of 113 species belonging to 13 orders and 34 families were recorded. Six species were classified as very abundant, 10 as abundant, 20 as common, 32 as uncommon, and 37 as rare; 79 species were permanent residents, 28 were winter visitors, 2 summer visitors, 3 transients, and 5 were local migrants; 15 species were classified as endemic to Mexico, and 23 are threatened. The bird composition of Sabino Canyon mainly resembles the avifauna the Balsas river basin. The avifauna of the tropical dry forest in Sabino Canyon is important for bird conservation due its richness in endemic birds and to the presence of an important reproductive colony of the Military Macaw, Ara militaris, a globally threatened bird species

When a forest becomes a city, are hummingbirds enjoying gardens good enough?

Presence data for some hummingbird species demonstrates that cities are good living spaces across the Americas. Monitoring hummingbird populations in big cities shows that some species could be very abundant in highly transformed environments. Individuals are managing to face interaction with human activities. On the other hand, forest specialists or species less tolerant to habitat disturbance have become rare or completely absent from cities or other environments modified by humans, such as peri urban suburbia or agricultural landscapes. Hummingbirds are particularly challenging animals to monitor with marking methods, their metabolic requirements and small bodies can not hold heavy targets or electronic devices for telemetry. Even ring marking could be considered not completely adequate. Xalapa is a medium size city located in central east Mexico where cloud montane forest used to extend. Two hummingbird species (Pampa curvipennis and Saucerottia cyanocephala) associated with cloud forest are becoming abundant city species and have been observed feeding from several exotic plants and nesting in highly perturbed environments such as human houses. The third aim of my PhD project is to gain a better understanding on how hummingbirds are coping with human environments when forests are highly transformed and cities become attractive providers of nectar. Some research questions to address are: How cloud forest hummingbirds respond to human presence: exotic plants and artificial feeders? Arecities becoming ecological traps? Can we identify if urban populations are behaving differently towards humans than forest ones? (Tolerant to noise, cars or people when feeding). At what point of environmental transformation will species disappear from their habitat forests? Are native individuals from cities also able to return to forest or an ecological segregation could be going on among our backyard gardens? I present preliminary ideas to discuss these topics in order to set a monitoring method to explain why forest hummingbirds are now living in cities

AVIFAUNA DE LOS BOSQUES DE CACTACEAS COLUMNARES DEL VALLE DE TEHUACAN, PUEBLA

We present a list of the avifauna of the columnar cacti forests of central México in the Tehuacán Valley. We found 90 species grouped into 13 orders and 27 families. Residents (56 species) are mostiy species of insectivorous and frugivorous-granivorous birds. Migrant birds are aiso pnmarily insectivorous. Another group of species moves locally between habitats during time of resource abundance. These species are common to the surrounding tropical deciduous forests that move constantly between habitats. The avifauna of the Tehuacan Valley share about 30% of the species with North American deserts (Sonoran, Chihuahuan, Mohave and Great Basin) and 33% with tropical deciduous forests in México. This asseiritjiage of species from different habitats is probably the cause of the high bird diversity found in the Valley.Se presenta una lista de la avifauna de los bosques de cactáceas columnares y hábitats adyacentes en una zona árida del centro de México, en el Valle de Tehuacán, Puebla. Se encontraron 90 especies de aves pertenecientes a 1 3 órdenes y 27 familias. De éstas, 56 son residentes en la zona siendo en su mayoría insectívoras y frugívoro-granívoras. las migratorias son también predominantemente insectívoras. Otro grupo de especies, está formado por aquellas que se mueven localmente y están en el valle durante las temporadas de abundancia de recursos. Son especies típicas de las selvas bajas caducifolias que probablemente se mueven constantemente entre hábitats. la avifauna del Valle de Tehuacán, Puebla, comparte con los desiertos de Norte América (Sonorense, Chihuahuense, Mohave y Gran Cañón) alrededor del 30% de sus especies. De igual forma, comparte el 33% de las especies con la selva baja caducifolia. Esta es probablemente la causa de su alta diversidad avifaunística presentándose un mosaico de especies características de otros sistemas