Search

Abstract: Several High Andes Rivers are characterized by inorganic water pollution known as acid mine drainage (AMD). The aim of this study was to assess the relationship between metal concentrations in the sediments and the macroinvertebrate communities in two river basins affected by AMD. In general, the taxon diversity of the macroinvertebrate community at the family level was low. The concentrations of Cd, Cu, Zn, Pb and Ni at mining sites were higher than at unpolluted sites. The pH of the water was alkaline (7.0–8.5) in unpolluted sites, whereas it dropped to very low values (<3) at mining sites. Redundancy Analysis (RDA) showed that pH was the best predictor of macroinvertebrate community richness. The number of macroinvertebrate families decreased gradually with increasing acidity, both in pools and riffles, though it is suggested that riffle communities were more affected because they are in closer contact with the acid water. [Copyright &y& Elsevier]

Copyright of Arnaldoa is the property of Universidad Privada Antenor Orrego, Museo de Historia Natural and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of the Botanical Research Institute of Texas is the property of Journal of the Botanical Research Institute of Texas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A new species from the Northern Peruvian Andes (Cajamarca department), Drymaria veliziae sp. nov., is proposed in the present paper. It grows in the high-elevation montane grasslands and it is morphologically similar to D. auriculipetala from which it differs in having elliptic-ovate leaves, blade margin bases glandular, large number of stipules arranged in a pedicel form at the leaf axis and by the short and glandular pedicels. A detailed description, original photographs and a location map are provided, as well as an updated diagnostic key of Drymaria Ser. Frutescens. The IUCN status of the new species is assessed as Endangered (EN). [ABSTRACT FROM AUTHOR]

Aim Partners in co-evolutionary interactions must be ecologically interdependent and at least at some stage have matching traits and more or less overlapping ranges. As co-evolution is a process, neither the mutual dependence nor the trait and range matching are expected to be static or perfect. Here we investigate the extent of evolutionary flexibility in tight pollination mutualisms between hummingbirds and plants, ranging from straight-billed species to sicklebills. Location The Americas. Methods The five considered pollination mutualisms are between the following hummingbird and plant species: Calypte anna and Ribes speciosum (Grossulariaceae); Basilinna xantusii and Arbutus peninsularis (Ericaceae); two species of Sephanoides and Tristerix aphyllus/corymbosus (Loranthaceae); two species of Eutoxeres and 34 species of curved-corolla Centropogon (Campanulaceae); and six species of Oreotrochilus and seven species of Chuquiraga (Asteraceae). While ecological interdependence and trait matching in these mutualisms are well established, geographic occurrence data and molecular clock-based ages for the 10 clades were newly compiled. Results We found matching bird and plant stem ages in two of the five systems and (much) older bird than plant ages in the other three. The implied adaptation of plant populations to already existing hummingbird species fits with the modelled distributions. In three of the systems, the ranges of the plants overlap those of their pollinators by > 90%; conversely, the range overlap between the bird species and the plant species they pollinate is much less than that. Surprisingly, the age mismatch was greatest in the Eutoxeres/ Centropogon system, in spite of the perfect morphological fit among bills and corollas, illustrating the evolutionary flexibility of these mutualisms and the apparently rapid 'addition' of further plant species. Main conclusions These findings illuminate the macroevolutionary assembly of hummingbird/plant mutualisms, which has been highly dynamic, even in specialized systems with perfect morphological trait fitting. [ABSTRACT FROM AUTHOR]

In view of the amount of adaptive radiation among ovenbirds, Furnariinae, the traditional taxonomy needs scrutiny. We used nuclear DNA data to study relationships of the genus Upucerthia. Five species belong in the Furnariini, as traditionally assumed. The other species represent two independent cases of specialisation for terrestrial life, in response to formation of arid habitats in the southern Andes, within the paraphyletic assemblage of arboreal species referred to as Philydorini. [ABSTRACT FROM AUTHOR]