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GROWTH AND TOTAL CAROTENOID CONTENT IN FOUR CHILEAN STRAINS OF HAEMATOCOCCUS PLUVIALIS FLOTOW, UNDER LABORATORY CONDITIONS
No full textHaematococcus pluvialis is a unicellular green microalga cultivated on a large scale as a natural source of astaxanthin, a ketocarotenoid of high commercial value due to its colorant and antioxidant properties. The aim of this study was to compare growth and total carotenoids among four strains of H. pluvialis isolated from different microhabitats in two geographical locations in Chile. Growth was carried out under autotrophic and mixotrophic conditions and under two photon flux densities (PFD) (20 and 85 umol nrV¹). Total carotenoid content was estimated on day 45. Most of the strains grew better under the autotrophic conditions; the highest exponential growth rates were exhibited at the high PFD in all the strains (ranging from 0.73 to 1.20 div day"¹) with the exception of CCM-UDEC 023 which showed the same exponential growth rate with either PFD (0.73 div day"¹). However, the cell density estimated on day 14 was higher at the low PFD in CCM-UDEC 022 and CCM-UDEC 023 (4.4 x 10(5) and 8.9 x 10(4) cells ml"¹, respectively). The mixotrophic condition slightly improved the growth rate of the strain CCM-UDEC 021 at the high PFD (from 1.04 div day"¹ at autotrophic condition to 1.25 and 1.14 div day"¹ at 2mM and 1 OmM sodium acetate, respectively). The algal dry weight estimated on day 14 was not significantly correlated with the cell density, but it was, to a certain extent, related to the proportion and size of the different cell types quantified on that day. The strain with the highest dry weight at the end of the experimental period and under all the assayed conditions was CCM-UDEC 023. It was also the strain that produced the highest total carotenoid content under both autotrophic (5.6 mg l"¹ and 95.6 pg cell"¹ at the high PFD) and mixotrophic (with 2mM acetate) conditions (10.8 mg l"¹ and 297 pg cell"¹ at the high PFD). Ahigh intraspecific variability in the physiological attributes analyzed existed among the strains under study. Even though the mixotrophic condition assayed did not substantially improve the growth rate of any strain, it did improve the total carotenoid yield in the strain CCM-UDEC 023
ALGAL STUDIES IN BOLIVIA: A COMPILATION AND PRELIMINARY ANALYSIS OF EXISTING PHYCOLOGICAL LITERATURE
No full textA compilation of phycological literature published on Bolivian algae is presented together with an analysis of strengths, weaknesses, and needs in this field of investigation. An analysis of the nationality of authors, type, content, and geographic focus of the references shows that literature is largely produced by foreign scientist, concentrated on just a few areas of the country, or are biased toward particular algal groups, leaving ample room for more exploration. The Altiplano (high mountain plateau) and Amazon concentrate most of the publications, the phytoplankton and algae found in sediment cores, being the communities that have received more attention from scientists. Taxonomic references focus more on phytoplankton and tychoplankton communities and are largely restricted to the mere presentation of taxa lists, but using old and geographically unsuitable floras as the source for taxa names. The present work does not incorporate an account of the number and identity of taxa at the genus, species or infraspecific levels. That work will be presented later after appropriate taxonomic review. The purpose of this compilation is to provide an overview for what is known about Bolivian algae up to this point and to provide the bases for further investigations in this field, including a catalog of Bolivian algae
NOTA SOBRE LA PRESENCIA DE HELIOTROPIUM KRAUSEANUM FEDDE (HELIOTROPIACEAE) EN CHILE
No full textThe presence of Heliotropium krauseanum Fedde is reported near Iquique in northern Chile (19°37'S, 70°11'O). The species had been previously collected only in Perú. This report represents an important southward geographic range extension for the species, and a northward extension of the range of the section Cochranea of this genus in Chil
Native or exotic plantations: Thoughts about the environmental impacts in Chile Plantaciones nativas o exóticas: Reflexiones sobre los impactos ambientales en Chile
No full textPlan de ordenamiento territorial participativo para la reconstrucción productiva y restauración ecológica post incendios experiencia en San Antonio de Cuda comuna de Florida Región del Bio Bio
Get PDF31 páginasEn el presente documento, se entrega el plan de ordenamiento territorial desarrollado para la localidad de San Antonio de Cuda, centrado en las características del territorio, físicas, productivas y ecológicas, a través del cual se recomiendan y sugieren áreas potenciales para su uso mediante diferentes opciones productivas y de manejo de los recursos naturales, zonas de protección o utilización con determinadas restricciones que permitan asegurar y mantener la provisión de servicios ecosistémicos claves y la conservación de la biodiversidad en el marco de la restauración ecológica.
El propósito de este plan es que se lo consigne como una pauta para la reconstrucción productiva y de restauración ecológica no solo para la comunidad de San Antonio de Cuda, sino también para otras localidades de la región y del país
Long-term effect of fertilization on stone pine growth and cone production
No full textFertilization is a feasible management technique for Pinus pinea L. cropping, with increased cone production up to 9 years after the application and superior trunk diameter growth every year. Fertilization effects on cone size-weight indicate the value of re-fertilizing
El paisaje rural antropogénico de Aisén, Chile: Estructura y dinámica de la vegetación
No full textSe estudió la dinámica de degradación de la vegetación en un mosaico vegetal antropogénico del paisaje rural de la Región de Aisén para establecer las posibles relaciones de origen tanto espacial como temporal entre las comunidades y proponer series de degradación. Se trabajó con metodología fitosociológica levantando 50 censos de vegetación. La tabla inicial fue ordenada usando especies diferenciales en 7 comunidades: matorral de ñire (Anemone multifida-Nothofagus antarctica), silvopastoreo con ñire, silvopastoreo con chacay, pradera de trébol-ballica (Bromus catharticus-Trifolium repens), pradera de chépica-cadillo (Acaena ovalifolia-Agrostis capillaris), pradera de cadillo-Aira y estepa de cadillo, las que se compararon en sus espectros sistemáticos, biológicos y de origen. Posteriormente, se realizaron análisis estadísticos multivariados de clasificación (conglomerados) y de ordenación (componentes principales) a la tabla inicial transformada previamente en una matriz de datos. Finalmente, utilizando el índice de Ellenberg se compararon las comunidades encontradas, las que se distribuyeron en una constelación de comunidades. La flora de la tabla inicial estuvo conformada por 78 especies con un predominio de plantas herbáceas perennes y anuales alóctonas que indican un alto grado de antropización. Se estableció la siguiente dinámica vegetacional de degradación: el matorral de ñire se degrada por pastoreo a un silvopastoreo con ñire, el cual se transforma en una pradera antropogénica, con sobrepastoreo ésta da origen a una pradera de cadillo-Aira, la que por abandono desemboca en una estepa de cadillo. Se discuten los resultados obtenidos y la aplicabilidad del método