Distribución espacial, estructura de tamaños y reproducción de Astrophytum ornatum (Cactaceae)

Background and Aims: The family Cactaceae possesses the largest number of species listed as endangered, but biological information as well as ecological studies are needed to assess the conservation status of cacti and apply guidelines to include or exclude species from red lists. Astrophytum ornatum has a status of vulnerable, but its ecological situation has not been evaluated, so its local and regional status is unknown. The aim of this study was to determine factors influencing the maintenance of their populations to provide information to establish their conservation status.Methods: We analyzed the population structure, spatial distribution pattern and reproduction of A. ornatum in one remnant population in Cadereyta de Montes, Querétaro, Mexico.Key results: The species has an aggregated spatial distribution pattern, which suggests an interaction with nurse species or cracks and rocks that provide shade. Individuals are concentrated in the first size categories, 34% were reproductive, large plants have a greater number of reproductive structures but with less seeds per fruit in comparison to medium-sized plants.Conclusions: The studied population has a potential to grow because its population structure displays the typical form of species with common recruitment. This population structure, high density and the presence of small plants suggest that the remaining population of A. ornatum is in good condition; however, no recruitment of seedlings was observed, there is a high mortality in all size classes and the risks posed to the locality are its proximity to human settlements and sand banks. Global assessment suggests that A. ornatum should be considered a threatened species.Antecedentes y Objetivos: La familia Cactaceae tiene el mayor número de especies listadas en riesgo de extinción, pero la información biológica y poblacional de estas especies, necesaria para determinar su riesgo poblacional y su estatus de conservación en las listas rojas, es escasa o insuficiente. El estatus de Astrophytum ornatum es vulnerable, pero su situación ecológica no ha sido evaluada, por lo que no se conoce exactamente cuál es su condición local y regional. El objetivo de este estudio fue estimar algunos de los factores que influyen en el mantenimiento de sus poblaciones y aportar información que permita establecer su estatus de conservación.Métodos: En este trabajo se analizó la estructura poblacional, el patrón de distribución espacial y la reproducción de A. ornatum en una población remanente localizada en Cadereyta de Montes, Querétaro, México.Resultados clave: Astrophytum ornatum tiene un patrón de distribución espacial agregado, similar a otras especies que requieren nodrizas o grietas y rocas que les proporcionan sombra. La mayoría de sus individuos se concentran en las primeras categorías de tamaño, 34% son reproductivos, las plantas grandes presentan un mayor número de estructuras reproductivas (botones, flores, frutos) y un menor número promedio de semillas por fruto.Conclusiones: La población estudiada presenta un potencial de crecimiento ya que su estructura poblacional tiene la forma típica de especies con reclutamiento frecuente. Dicha estructura poblacional, la alta densidad y la presencia de plantas pequeñas sugieren que la población está en buenas condiciones; sin embargo, no se observó reclutamiento de plántulas y hay una alta mortalidad en todas las clases de tamaño, además los riesgos para esta población son la cercanía a núcleos de población humana y a bancos de materiales. La evaluación global sugiere que se considere la especie como amenazada

Una nueva especie de Mammillaria (Cactaceae) para Tamaulipas, México

Mammillaria cielensis (Cactaceae), a new species of Cactaceae from “El Cielo” Biosphere Reserve (RBC) in Tamaulipas, Mexico, is described and illustrated. The new species is similar to M. zublerae Repp., differing from this species in the size of the stem, the rounded form of the apex, the smaller tubercles, the areoles with white wool, the more numerous and somewhat shorter radial and central spines, the colour and size of the fruits, the shinier and larger seeds, with heavily pitted and slightly reticulate testa, and larger hilum. Its known distribution is restricted to pine oak forest in the RBC, in the southern part of the state of Tamaulipas, Mexico. A comparison with related species is presented.Se propone a Mammillaria cielensis (Cactaceae), como una especie nueva de la Reserva de la Biosfera “El Cielo” (RBC) en Tamaulipas, México. Es morfológicamente muy similar a M. zublerae Repp., de la cual difiere en el tamaño del tallo, la forma redondeada del ápice, los tubérculos de menor tamaño y glabros, aréolas con lana blanca, las espinas radiales y centrales más numerosas y ligeramente más cortas, frutos de diferente color y tamaño, la semilla de mayor tamaño, con testa porosa y el hilo de mayores dimensiones. Su distribución conocida se restringe al bosque de pino encino en el área de la RBC, al sur del estado de Tamaulipas, México. Se presenta una comparación con las especies afines

The University Endoscopy Unit: The Standard of Care?

In an attempt to investigate practice patterns of the modern gastrointestinal endoscopy unit, a survey was undertaken in 10 university-affiliated endoscopy units in three Ontario cities. The results showed that there was a wide range of premedications used, a nd that there was variation tn the extent of patient monitoring, the method of endoscope sterilization and the degree of safety precautions. This survey provides information on the 'standard of care' in the university endoscopy unit and provides a framework for discussion for the establishment of guidelines for the modern gastrointestinal endoscopy unit

Distribución espacial, estructura de tamaños y reproducción de Astrophytum ornatum (Cactaceae)

Background and Aims: The family Cactaceae possesses the largest number of species listed as endangered, but biological information as well as ecological studies are needed to assess the conser-vation status of cacti and apply guidelines to include or exclude species from red lists. Astrophytum ornatum has a status of vulnerable, but its ecological situation has not been evaluated, so its local and regional status is unknown. The aim of this study was to determine factors influencing the mainte-nance of their populations to provide information to establish their conservation status. Methods: We analyzed the population structure, spatial distribution pattern and reproduction of A. ornatum in one remnant population in Cadereyta de Montes, Querétaro, Mexico. Key results: The species has an aggregated spatial distribution pattern, which suggests an interac-tion with nurse species or cracks and rocks that provide shade. Individuals are concentrated in the first size categories, 34% were reproductive, large plants have a greater number of reproductive structures but with less seeds per fruit in comparison to medium-sized plants. Conclusions: The studied population has a potential to grow because its population structure displays the typical form of species with common recruitment. This population structure, high density and the presence of small plants suggest that the remaining population of A. ornatum is in good condition; however, no recruitment of seedlings was observed, there is a high mortality in all size classes and the risks posed to the locality are its proximity to human settlements and sand banks. Global assessment suggests that A. ornatum should be considered a threatened species.Antecedentes y Objetivos: La familia Cactaceae tiene el mayor número de especies listadas en riesgo de extinción, pero la información biológica y poblacional de estas especies, necesaria para determinar su riesgo poblacional y su estatus de conservación en las listas rojas, es escasa o insuficiente. El estatus de Astrophytum ornatum es vulnerable, pero su situación ecológica no ha sido evaluada, por lo que no se conoce exactamente cuál es su condición local y regional. El objetivo de este estudio fue estimar algunos de los factores que influyen en el mantenimiento de sus poblaciones y aportar información que permita establecer su estatus de conservación. Métodos: En este trabajo se analizó la estructura poblacional, el patrón de distribución espacial y la reproducción de A. ornatum en una población remanente localizada en Cadereyta de Montes, Querétaro, México. Resultados clave: Astrophytum ornatum tiene un patrón de distribución espacial agregado, similar a otras especies que requieren nodrizas o grietas y rocas que les proporcionan sombra. La mayoría de sus individuos se concentran en las primeras categorías de tamaño, 34% son reproductivos, las plantas grandes presentan un mayor número de estructuras reproductivas (botones, flores, frutos) y un menor número promedio de semillas por fruto. Conclusiones: La población estudiada presenta un potencial de crecimiento ya que su estructura poblacional tiene la forma típica de especies con reclutamiento frecuente. Dicha estructura poblacional, la alta densidad y la presencia de plantas pequeñas sugieren que la población está en buenas condiciones; sin embargo, no se observó reclutamiento de plántulas y hay una alta mortalidad en todas las clases de tamaño, además los riesgos para esta población son la cercanía a núcleos de población humana y a bancos de materiales. La evaluación global sugiere que se considere la especie como amenazada

Bee Assemblage in the Southern Chihuahuan Desert: The Role of Season, Year, and Trap Color in Abundance

Recognizing how populations fluctuate over time is a crucial factor in determining the environmental elements affecting population persistence. However, the limited information on wild bee populations complicates the estimation of the impact of anthropogenic threats leading to changes in population size. To address this, we conducted a study capturing and monitoring nine species of wild bees through monthly samplings over four years. Tray traps were placed in permanent plots, and capture records were used to determine population size (N) and density (D). A generalized linear model (GLM) was employed to determine how the use of traps affected bee species captures. The families Apidae and Halictidae represented the most captures. Apis mellifera, the Lasioglossum (Dialictus spp.) complex, and Macrotera sinaloana exhibited the largest number of captures and highest population density. Most species (77.7%) showed a tendency to remain constant over the years and to have a higher number of captures in the spring months. Moreover, yellow traps were the most effective in capturing bee individuals. We suggest that the availability of essential resources and the reduction in environmental stressors positively affected the capture of wild bee populations

Difference in Germination Traits between Congeneric Native and Exotic Species May Affect Invasion

Germination traits are components of invasion potential, and comparing seed traits in sympatric native and invasive species can offer insights into the invasion process. We characterized seed germination traits and how they influenced the success of Eragrostis mexicana, a native species, and Eragrostis tenuifolia, an exotic species (Poaceae) in Mexico, in the context of their potential for biological invasion. Seeds from both species were collected from four sites in a natural protected area in Mexico City, and the germination of seeds of different ages was conducted in experiments at different temperatures. E. tenuifolia exhibited higher germination percentages than the native E. mexicana across all treatments. Seed age had differential effects, with older seeds of the native E. mexicana germinating better, while E. tenuifolia performed better with younger seeds. Temperature positively impacted germination for both species, although E. mexicana was limited at lower temperatures. Exotic E. tenuifolia can germinate over a wider temperature range with earlier germination rates, and generate a seed bank lasting several years, which may contribute to naturalization. The importance of germination traits in the context of invasive species establishment underscores the potential role of seed banks in facilitating biological invasions

The reproductive traits that contribute to the invasive success of Mediterranean onionweed (Asphodelus fistulosus)

Background and aims – Understanding the traits that lead to the invasion potential of invasive alien species (IAS) provides insight for their management. The reproductive traits of IAS help us understand the mechanisms that allow for their invasive potential, and colonization into new ranges. Asphodelus fistulosus is a native Mediterranean species commonly found invading Australia, South-East Asia, South Africa, and North America. Materials and methods – Two populations of A. fistulosus in the Chihuahuan Desert were monitored for reproductive phenology. Floral visitors and their behaviour were described, and we assessed the breeding system through floral morphological characters and the mating system in controlled pollination experiments. Key results – Reproductive phenology showed continuous reproduction throughout the year. Floral morphology suggested a facultative autogamous breeding system, but the mating system was mixed with autonomous selfing. Flowers lasted one day, with anthesis lasting 11 h. Floral visitors of A. fistulosus consisted of a variety of taxa including species of Coleoptera, Hymenoptera, and Lepidoptera, the exotic Apis mellifera being the most frequent visitor. Conclusions – The reproductive traits of A. fistulosus in the invaded range provide the biological potential for further invasion. The continuous production of reproductive structures attracts many diverse pollinators, and the autonomous self-pollination implies that a single plant has the potential to develop a new population, which makes the control of this IAS a global challenge