Antecedentes y Objetivos: Thunbergia alata es una de las diez especies de plantas invasoras más problemáticas de Colombia. Su rápida colonización y adaptación a los bosques andinos ha afectado la composición y estructura de las comunidades vegetales nativas. En esta investigación se realizó un análisis de rasgos funcionales, generando nueva información que podría explicar la rápida colonización, adaptación y potencial invasor de T. alata en este tipo de ambientes andinos. Métodos: Para obtener esta información se realizó una serie de observaciones sobre la morfología y anatomía de raíces, tallos, hojas, flores, frutos y semillas. Asimismo, se realizó una caracterización de sus visitantes florales y de las relaciones simbióticas con los microorganismos del suelo. Resultados clave: Se determinó que tanto los rasgos morfológicos como los fenómenos de interacción favorecen la adaptabilidad de T. alata en los bosques andinos y podrían contribuir en mayor medida a su colonización activa en este tipo de ambientes. Se encontró una asociación activa de T. alata con diferentes especies de visitantes florales nativos e introducidos, con un total de 2266 visitas florales realizadas durante nuestro estudio por siete especies de insectos pertenecientes a los órdenes Coleoptera e Hymenoptera. En todos los sitios de muestreo se encontraron esporas de hongos micorrizógenos asociadas a las poblaciones de T. alata. El número de esporas por 100 g de suelo variaba entre 300 y 424. Todas las raíces de T. alata, sin excepción, presentaban una alta colonización por hongos micorrizógenos arbusculares. Conclusiones: Creemos que la información obtenida en esta investigación contribuirá a la generación de estrategias integrales y efectivas para el control de esta especie en los bosques andinos.

Seed dormancy is a key trait used around the world to help understand the ecological dynamics of plant species, however, in some ecosystems such as the Andean forests of Colombia, the identification of dormancy class remains poorly known. To address this, we described the morphology, anatomy and dormancy class of the seeds and fruits of 14 species using microtome sections, light microscopy and scanning electron microscopy. Five native pioneer species showed Morphophysiological Dormancy, three Physical Dormancy + Physiological Dormancy and two Physical Dormancy, whereas two invasive species showed Physiological Dormancy. Only the species of the genus Cecropia had seeds with PY + PD that was promoted by the anatomical structure of the achenes. Of the analysed species, 85% showed dormancy and followed a pattern like other tropical montane ecosystems in the world. The anatomy of achenes and development of seed dormancy play important roles in the capacity of Cecropia species to contribute to the natural regeneration of Andean ecosystems. Additionally, seed dormancy may promote the high invasiveness of Thunbergia alata and Ulex europaeus in the Andean forests of the Central Cordillera of Colombia.

Weeds can have both positive and negative effects on agricultural environments. However, despite the growing interest in the ecology of weed communities in agricultural areas, a few studies have been carried out in the northern region of the Andes of Colombia, where urban and agricultural expansion have generated highly disturbed scenarios. The aim of this study was to analyze the diversity of vegetation and weed seed banks in three agricultural production systems and a forest ecosystem in the northern Andes of Colombia. Hill numbers were used to compare diversity, Beta diversity to assess changes in composition, and range—abundance–dominance curves at different sites. Likewise, indicator species were analyzed to find species associations to each system. The results revealed differences in the composition of weeds between the forest ecosystem and the agricultural production systems, with higher equitability in the forest ecosystem and higher dominance in agricultural systems. Significant differentiation was observed among the dominant species within each agricultural system, particularly highlighting those species considered pests due to their unique life history traits. These traits confer them with a greater advantage in the face of various anthropogenic selection pressures. These findings highlight the impact of anthropogenic disturbances on the ecological dynamics of weed communities in different ecosystems, which should be considered when planning integrated weed management techniques.

Plants of the subfamily Amaryllidoideae are a source of unique and bioactive alkaloids called Amaryllidaceae alkaloids. The study of their anticancer potential has intensified in recent years. This work aims to locate and characterize the profile of cytotoxic alkaloids biosynthesized and stored in different tissues of Phaedranassa lehmannii Regel using different histochemical methods and chromatographic analysis. The histochemical analysis in the bulbs revealed the presence of alkaloids at the basal edge of the scale-like leaves and bud apical zone. The GC-MS analysis indicated that the bulbs biosynthesize crinane- (9.80 µg/g DW), galanthamine- (8.04 µg/g DW), lycorine- (7.38 µg/g DW), and narciclasine-type (3.75 µg/g DW) alkaloids. The root biosynthesizes alkaloids that are mainly distributed mostly in lycorine- (225.29 µg/g DW) and galanthamine-type (72.35 µg/g DW) alkaloids. The total alkaloids biosynthesized by the root (324.93 µg/g DW) exceeded eleven times the abundance of the alkaloids identified in the bulbs (28.97 µg/g DW). In addition, the total alkaloid fractions exhibited a dose-dependent cytotoxic effect in the evaluated concentrations, with IC₅₀ values of 11.76 ± 0.99 µg/mL and 2.59 ± 0.56 µg/mL against human lung (A549) cancer cells and 8.00 ± 1.35 µg/mL and 18.74 ± 1.99 µg/mL against gastric (AGS) cancer cells. The present study provided evidence to locate and characterize the alkaloids of P. lehmannii grown under nursery conditions as a species producing potential antiproliferative alkaloids.