Browsing by Author "Pinto, Raquel"

Now showing 1 - 4 of 4
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    A New Distinctive Species of Schizanthus (Solanaceae) and the Reinstatement of Schizanthus fallax
    (2021) Lavandero, Nicolas; Chinga, Javiera; Pinto, Raquel; Fernanda Perez, Maria
    A new Schizanthus species from northern Chile is described and illustrated. Schizanthus nutantiflorus was discovered based on recent collections made during unusual rain events in the Atacama Desert in 2015. The new species is distinguished morphologically from other Schizanthus species from northern Chile by its short corolla tube, with a distinct upper lip arrangement and colour, having the longest lower lip, and downward-facing flowers. Additionally, the reinstatement of Schizanthus fallax is proposed. By using both nDNA and cpDNA, phylogenetic relationships among all species of Schizanthus were investigated. Molecular and field observations, as well as an exhaustive morphological revision of fresh material and herbarium specimens, supports the segregation of Schizanthus with short corolla tubes from northern Chile into three species. We propose that, in order to fully understand both the taxonomy and evolution of Schizanthus, an integrative framework encompassing molecular, ecological, and morphological data should be carried out. Information on distribution, habitat, informal conservation status, as well as taxonomic notes and illustrations are provided. In addition, an updated key for the species of Schizanthus from northern Chile is given.
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    Bromeliad growth and stoichiometry: responses to atmospheric nutrient supply in fog-dependent ecosystems of the hyper-arid Atacama Desert, Chile
    (2011) Gonzalez, Angelica L.; Miguel Farina, Jose; Pinto, Raquel; Perez, Cecilia; Weathers, Kathleen C.; Armesto, Juan J.; Marquet, Pablo A.
    Carbon, nitrogen, and phosphorus (C, N, P) stoichiometry influences the growth of plants and nutrient cycling within ecosystems. Indeed, elemental ratios are used as an index for functional differences between plants and their responses to natural or anthropogenic variations in nutrient supply. We investigated the variation in growth and elemental content of the rootless terrestrial bromeliad Tillandsia landbeckii, which obtains its moisture, and likely its nutrients, from coastal fogs in the Atacama Desert. We assessed (1) how fog nutrient supply influences plant growth and stoichiometry and (2) the response of plant growth and stoichiometry to variations in nutrient supply by using reciprocal transplants. We hypothesized that T. landbeckii should exhibit physiological and biochemical plastic responses commensurate with nutrient supply from atmospheric deposition. In the case of the Atacama Desert, nutrient supply from fog is variable over space and time, which suggests a relatively high variation in the growth and elemental content of atmospheric bromeliads. We found that the nutrient content of T. landbeckii showed high spatio-temporal variability, driven partially by fog nutrient deposition but also by plant growth rates. Reciprocal transplant experiments showed that transplanted individuals converged to similar nutrient content, growth rates, and leaf production of resident plants at each site, reflecting local nutrient availability. Although plant nutrient content did not exactly match the relative supply of N and P, our results suggest that atmospheric nutrient supply is a dominant driver of plant growth and stoichiometry. In fact, our results indicate that N uptake by T. landbeckii plants depends more on N supplied by fog, whereas P uptake is mainly regulated by within-plant nutrient demand for growth. Overall, these findings indicate that variation in fog nutrient supply exerts a strong control over growth and nutrient dynamics of atmospheric plants, which are ubiquitous across fog-dominated ecosystems.
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    Establishment and formation of fog-dependent Tillandsia landbeckii dunes in the Atacama Desert: Evidence from radiocarbon and stable isotopes
    (2011) Latorre, Claudio; Gonzalez, Angelica L.; Quade, Jay; Farina, Jose M.; Pinto, Raquel; Marquet, Pablo A.
    Extensive dune fields made up exclusively of the bromeliad Tillandsia landbeckii thrive in the Atacama Desert, one of the most extreme landscapes on earth. These plants survive by adapting exclusively to take in abundant advective fog and dew as moisture sources. Although some information has been gathered regarding their modern distribution and adaptations, very little is known about how these dune systems actually form and accumulate over time. We present evidence based on 20 radiocarbon dates for the establishment age and development of five different such dune systems located along a similar to 215 km transect in northern Chile. Using stratigraphy, geochronology and stable C and N isotopes, we (1) develop an establishment chronology of these ecosystems, (2) explain how the unique T. landbeckii dunes form, and (3) link changes in foliar delta N-15 values to moisture availability in buried fossil T. landbeckii layers. We conclude by pointing out the potential that these systems have for reconstructing past climate change along coastal northern Chile during the late Holocene.
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    Experimental transplants of the large kelp Lessonia nigrescens (Phaeophyceae) in high-energy wave exposed rocky intertidal habitats of northern Chile
    (2006) Correa, Juan A.; Lagos, Nelson A.; Medina, Matias H.; Castilla, Juan C.; Cerda, Mauricio; Ramirez, Marco; Martinez, Enrique; Faugeron, Sylvain; Andrade, Santiago; Pinto, Raquel; Contreras, Loretto
    Potential for addressing ecological and physiological issues becomes severely limited when the organisms required to experimentally test specific hypotheses are absent from the study areas. This report describes a simple and inexpensive device for re-planting kelps into the lower intertidal zone of wave-swept rocky habitats, using Lessonia nigrescens Bory as a model organism. The device allows a wide range of plant sizes to be anchored by the holdfast. Transplanted kelps regenerated, re-attached to the substratum and overgrew the transplanting device. These results confirm the feasibility of using this technique to tackle a variety of highly relevant questions involving ecological, physiological, conservation, restoration and management issues. (c) 2006 Elsevier B.V. All rights reserved.