Los insectos acuáticos son indicadores ecológicos de perturbación antrópica y actualmente existe una tendencia a explorar el enfoque funcional como herramienta para la evaluación de la calidad del agua. Los insectos pueden cambiar el modo y tipo de adquisición de alimento de acuerdo con las condiciones del medio. Se evaluó la influencia del impacto agrícola y minero sobre la diversidad, los grupos funcionales alimentarios y gremios tróficos de insectos acuáticos en la cuenca alta del río Chinchiná (Caldas, Colombia). Se eligieron dos localidades una minera y otra agrícola, y en cada una se evaluaron dos quebradas, una de referencia y otra impactada. Mediante red Surber se recolectaron 8239 individuos agrupados en ocho ordenes, 36 familias y 71 taxones (Ĉn=100%). Se analizó el contenido intestinal de los individuos de los nueve géneros más abundantes y según el porcentaje de material ingerido se clasificaron como: fragmentadores, recolectores, depredadores, raspadores y filtradores. El tipo de alimento no cambió entre zonas de referencia e impactadas, los recolectores fueron dominantes en el área de estudio, seguidos por los fragmentadores. La mayor diversidad estuvo asociada a las quebradas no impactadas. No se evidenciaron cambios en la dieta de los insectos acuáticos, posiblemente debido a la disponibilidad de recursos. La actividad agrícola presentó el efecto negativo más fuerte sobre la diversidad del grupo, lo que puede estar asociado tanto con la extensión de los cultivos hasta las quebradas, con la consecuente pérdida de la vegetación ribereña y con el uso de agroquímicos.
We undertook a molecular phylogenetic revision of hayscented ferns (Dennstaedtiaceae: Dennstaedtioideae) using four plastid markers. Our sampling represents ca. 40% of the extant diversity and includes the type species for each of the relevant segregate genera. We coded 18 discrete morphological characters which we used to find diagnosable clades. We show that Dennstaedtia is polyphyletic, with the majority of species forming three morphologically distinct clades, but its type (D. flaccida) is nested within Microlepia. As such, we support the conservation of Dennstaedtia with a new type, D. dissecta. Following our results, we develop a classification of four genera: Dennstaedtia, Microlepia, Mucura (gen. nov.) and Sitobolium. Beyond the inclusion of D. flaccida, we propose to maintain Microlepia with its current circumscription. Except for a single adventive species in the Neotropics, Microlepia is a Paleotropical genus of about 60 species diagnosed by their distinctive perispore ornamentation of rodlets, and by petioles that lack epipetiolar buds. Mucura is a Neotropical genus of two species that differ from all other Dennstaedtiaceae by the combination of dichotomously branching rhizomes, petioles that lack epipetiolar buds, marginal sori with both abaxial and adaxial indusia, and trilete spores with a unique perispore ornamentation. As defined here, Dennstaedtia is a pantropical genus of about 55 species recognized by having unbranched rhizomes, petioles bearing epipetiolar buds, and by often bearing proliferous buds upon the leaves. Sitobolium is a small clade of ca. five species distinguished by their relatively small leaves that have elongate catenate hairs. These hairs often bear a capitate non‐glandular terminal cell. In support of our classification, we provide a key to the eleven genera of Dennstaedtiaceae, and for the four genera of Dennstaedtioideae we provide morphological and geographic synopses, a list of constituent species, and necessary new combinations.
Parablechnum prostratum, a new species with dimorphic leaves from southern Colombia, is described and illustrated. The new species is characterized by featuring prostrate sterile leaves, a unique character within the genus. Morphological similarities and resemblances to other species of Parablechnum are discussed.
A new hybrid distributed to the south of the Colombian Andes is described in the genus Parablechnum. Morphological relationship with the parents and with other similar species is discussed. This is the first Parablechnum hybrid recorded in the Neotropical region. Se describe un nuevo híbrido en el género Parablechnum distribuido al sur de los Andes de Colombia. Se discute su relación morfológica con los parentales y con otras especies parecidas. Este es el primer híbrido de Parablechnum registrado en la región neotropical.
Austroblechnum bullatum, a new species from Colombia, is described and illustrated. This fern is characterized by having pendulous laminae, rachis abundantly covered with hairs up to 2.5 mm long, and pinnae bullate on both surfaces. In addition, the distribution range is extended for A. aequatoriense, a species previously known from northern Ecuador, and now also recorded for Colombia. Lastly, an identification key for the nine Colombian species of Austroblechnum is presented.